| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Completely Fair Scheduling (CFS) Class (SCHED_NORMAL/SCHED_BATCH) |
| * |
| * Copyright (C) 2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
| * |
| * Interactivity improvements by Mike Galbraith |
| * (C) 2007 Mike Galbraith <efault@gmx.de> |
| * |
| * Various enhancements by Dmitry Adamushko. |
| * (C) 2007 Dmitry Adamushko <dmitry.adamushko@gmail.com> |
| * |
| * Group scheduling enhancements by Srivatsa Vaddagiri |
| * Copyright IBM Corporation, 2007 |
| * Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> |
| * |
| * Scaled math optimizations by Thomas Gleixner |
| * Copyright (C) 2007, Thomas Gleixner <tglx@linutronix.de> |
| * |
| * Adaptive scheduling granularity, math enhancements by Peter Zijlstra |
| * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra |
| */ |
| |
| #include <linux/sched/mm.h> |
| #include <linux/sched/topology.h> |
| |
| #include <linux/latencytop.h> |
| #include <linux/cpumask.h> |
| #include <linux/cpuidle.h> |
| #include <linux/slab.h> |
| #include <linux/profile.h> |
| #include <linux/interrupt.h> |
| #include <linux/mempolicy.h> |
| #include <linux/migrate.h> |
| #include <linux/task_work.h> |
| |
| #include <trace/events/sched.h> |
| #if defined(OPLUS_FEATURE_IOMONITOR) && defined(CONFIG_IOMONITOR) |
| #include <linux/iomonitor/iomonitor.h> |
| #endif /*OPLUS_FEATURE_IOMONITOR*/ |
| |
| #include "sched.h" |
| #include "tune.h" |
| #include "walt.h" |
| #include "eas_plus.h" |
| #include "hmp.h" |
| #ifdef OPLUS_FEATURE_UIFIRST |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/05/25, Add for UIFirst |
| #include <linux/uifirst/uifirst_sched_common.h> |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // wenbin.liu@PSW.BSP.MM, 2018/05/02 |
| // Add for get cpu load |
| #ifdef CONFIG_OPPO_HEALTHINFO |
| #include <soc/oplus/oppo_healthinfo.h> |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| #if defined (CONFIG_SCHED_WALT) && defined (OPLUS_FEATURE_UIFIRST) |
| #include <linux/sched.h> |
| extern u64 ux_task_load[]; |
| extern u64 ux_load_ts[]; |
| extern unsigned int walt_ravg_window; |
| #define walt_scale_demand_divisor (walt_ravg_window >> SCHED_CAPACITY_SHIFT) |
| #define scale_demand(d) ((d)/walt_scale_demand_divisor) |
| #define UX_LOAD_WINDOW 8000000 |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| |
| #ifdef OPLUS_FEATURE_SPECIALOPT |
| // Liujie.Xie@TECH.Kernel.Sched, 2020/02/26, add for heavy load task |
| #include <linux/special_opt/special_opt.h> |
| #endif |
| |
| /* |
| * Targeted preemption latency for CPU-bound tasks: |
| * |
| * NOTE: this latency value is not the same as the concept of |
| * 'timeslice length' - timeslices in CFS are of variable length |
| * and have no persistent notion like in traditional, time-slice |
| * based scheduling concepts. |
| * |
| * (to see the precise effective timeslice length of your workload, |
| * run vmstat and monitor the context-switches (cs) field) |
| * |
| * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds) |
| */ |
| unsigned int sysctl_sched_latency = 6000000ULL; |
| unsigned int normalized_sysctl_sched_latency = 6000000ULL; |
| |
| /* |
| * Enable/disable honoring sync flag in energy-aware wakeups. |
| */ |
| unsigned int sysctl_sched_sync_hint_enable = 1; |
| |
| #ifdef CONFIG_MTK_SCHED_BOOST |
| unsigned int sysctl_sched_isolation_hint_enable; |
| #endif |
| |
| /* |
| * Enable/disable using cstate knowledge in idle sibling selection |
| */ |
| |
| unsigned int sysctl_sched_cstate_aware = 1; |
| |
| /* |
| * The initial- and re-scaling of tunables is configurable |
| * |
| * Options are: |
| * |
| * SCHED_TUNABLESCALING_NONE - unscaled, always *1 |
| * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus) |
| * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus |
| * |
| * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) |
| */ |
| enum sched_tunable_scaling sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LINEAR; |
| |
| /* |
| * Minimal preemption granularity for CPU-bound tasks: |
| * |
| * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds) |
| */ |
| unsigned int sysctl_sched_min_granularity = 750000ULL; |
| unsigned int normalized_sysctl_sched_min_granularity = 750000ULL; |
| |
| /* |
| * This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity |
| */ |
| static unsigned int sched_nr_latency = 8; |
| |
| /* |
| * After fork, child runs first. If set to 0 (default) then |
| * parent will (try to) run first. |
| */ |
| unsigned int sysctl_sched_child_runs_first __read_mostly; |
| |
| /* |
| * SCHED_OTHER wake-up granularity. |
| * |
| * This option delays the preemption effects of decoupled workloads |
| * and reduces their over-scheduling. Synchronous workloads will still |
| * have immediate wakeup/sleep latencies. |
| * |
| * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) |
| */ |
| unsigned int sysctl_sched_wakeup_granularity = 1000000UL; |
| unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL; |
| |
| const_debug unsigned int sysctl_sched_migration_cost = 33000UL; |
| |
| #ifdef CONFIG_SCHED_WALT |
| #ifdef OPLUS_FEATURE_UIFIRST |
| unsigned int sysctl_sched_use_walt_cpu_util = 0; |
| unsigned int sysctl_sched_use_walt_task_util = 0; |
| #else |
| unsigned int sysctl_sched_use_walt_cpu_util = 1; |
| unsigned int sysctl_sched_use_walt_task_util = 1; |
| #endif |
| __read_mostly unsigned int sysctl_sched_walt_cpu_high_irqload = |
| (10 * NSEC_PER_MSEC); |
| #endif |
| |
| #ifdef CONFIG_SMP |
| /* |
| * For asym packing, by default the lower numbered cpu has higher priority. |
| */ |
| int __weak arch_asym_cpu_priority(int cpu) |
| { |
| return -cpu; |
| } |
| #endif |
| |
| #ifdef CONFIG_CFS_BANDWIDTH |
| /* |
| * Amount of runtime to allocate from global (tg) to local (per-cfs_rq) pool |
| * each time a cfs_rq requests quota. |
| * |
| * Note: in the case that the slice exceeds the runtime remaining (either due |
| * to consumption or the quota being specified to be smaller than the slice) |
| * we will always only issue the remaining available time. |
| * |
| * (default: 5 msec, units: microseconds) |
| */ |
| unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL; |
| #endif |
| |
| /* |
| * The margin used when comparing utilization with CPU capacity: |
| * util * margin < capacity * 1024 |
| * |
| * (default: ~20%) |
| */ |
| unsigned int capacity_margin = 1280; |
| |
| #if defined(OPLUS_FEATURE_SCHEDUTIL_USE_TL) && defined(CONFIG_SCHEDUTIL_USE_TL) |
| #define DEFAULT_CAP_MARGIN_DVFS 1280 /* ~20% margin */ |
| unsigned int capacity_margin_dvfs = DEFAULT_CAP_MARGIN_DVFS; |
| #endif |
| |
| |
| static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
| { |
| lw->weight += inc; |
| lw->inv_weight = 0; |
| } |
| |
| static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
| { |
| lw->weight -= dec; |
| lw->inv_weight = 0; |
| } |
| |
| static inline void update_load_set(struct load_weight *lw, unsigned long w) |
| { |
| lw->weight = w; |
| lw->inv_weight = 0; |
| } |
| |
| /* |
| * Increase the granularity value when there are more CPUs, |
| * because with more CPUs the 'effective latency' as visible |
| * to users decreases. But the relationship is not linear, |
| * so pick a second-best guess by going with the log2 of the |
| * number of CPUs. |
| * |
| * This idea comes from the SD scheduler of Con Kolivas: |
| */ |
| static unsigned int get_update_sysctl_factor(void) |
| { |
| unsigned int cpus = min_t(unsigned int, num_online_cpus(), 8); |
| unsigned int factor; |
| |
| switch (sysctl_sched_tunable_scaling) { |
| case SCHED_TUNABLESCALING_NONE: |
| factor = 1; |
| break; |
| case SCHED_TUNABLESCALING_LINEAR: |
| factor = cpus; |
| break; |
| case SCHED_TUNABLESCALING_LOG: |
| default: |
| factor = 1 + ilog2(cpus); |
| break; |
| } |
| |
| return factor; |
| } |
| |
| static void update_sysctl(void) |
| { |
| unsigned int factor = get_update_sysctl_factor(); |
| |
| #define SET_SYSCTL(name) \ |
| (sysctl_##name = (factor) * normalized_sysctl_##name) |
| SET_SYSCTL(sched_min_granularity); |
| SET_SYSCTL(sched_latency); |
| SET_SYSCTL(sched_wakeup_granularity); |
| #undef SET_SYSCTL |
| } |
| |
| void sched_init_granularity(void) |
| { |
| update_sysctl(); |
| } |
| |
| #define WMULT_CONST (~0U) |
| #define WMULT_SHIFT 32 |
| |
| static void __update_inv_weight(struct load_weight *lw) |
| { |
| unsigned long w; |
| |
| if (likely(lw->inv_weight)) |
| return; |
| |
| w = scale_load_down(lw->weight); |
| |
| if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST)) |
| lw->inv_weight = 1; |
| else if (unlikely(!w)) |
| lw->inv_weight = WMULT_CONST; |
| else |
| lw->inv_weight = WMULT_CONST / w; |
| } |
| |
| /* |
| * delta_exec * weight / lw.weight |
| * OR |
| * (delta_exec * (weight * lw->inv_weight)) >> WMULT_SHIFT |
| * |
| * Either weight := NICE_0_LOAD and lw \e sched_prio_to_wmult[], in which case |
| * we're guaranteed shift stays positive because inv_weight is guaranteed to |
| * fit 32 bits, and NICE_0_LOAD gives another 10 bits; therefore shift >= 22. |
| * |
| * Or, weight =< lw.weight (because lw.weight is the runqueue weight), thus |
| * weight/lw.weight <= 1, and therefore our shift will also be positive. |
| */ |
| static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight *lw) |
| { |
| u64 fact = scale_load_down(weight); |
| int shift = WMULT_SHIFT; |
| |
| __update_inv_weight(lw); |
| |
| if (unlikely(fact >> 32)) { |
| while (fact >> 32) { |
| fact >>= 1; |
| shift--; |
| } |
| } |
| |
| /* hint to use a 32x32->64 mul */ |
| fact = (u64)(u32)fact * lw->inv_weight; |
| |
| while (fact >> 32) { |
| fact >>= 1; |
| shift--; |
| } |
| |
| return mul_u64_u32_shr(delta_exec, fact, shift); |
| } |
| |
| |
| const struct sched_class fair_sched_class; |
| |
| /************************************************************** |
| * CFS operations on generic schedulable entities: |
| */ |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| |
| /* cpu runqueue to which this cfs_rq is attached */ |
| static inline struct rq *rq_of(struct cfs_rq *cfs_rq) |
| { |
| return cfs_rq->rq; |
| } |
| |
| /* An entity is a task if it doesn't "own" a runqueue */ |
| #define entity_is_task(se) (!se->my_q) |
| |
| static inline struct task_struct *task_of(struct sched_entity *se) |
| { |
| SCHED_WARN_ON(!entity_is_task(se)); |
| return container_of(se, struct task_struct, se); |
| } |
| |
| /* Walk up scheduling entities hierarchy */ |
| #define for_each_sched_entity(se) \ |
| for (; se; se = se->parent) |
| |
| static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) |
| { |
| return p->se.cfs_rq; |
| } |
| |
| /* runqueue on which this entity is (to be) queued */ |
| static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) |
| { |
| return se->cfs_rq; |
| } |
| |
| /* runqueue "owned" by this group */ |
| static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) |
| { |
| return grp->my_q; |
| } |
| |
| static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) |
| { |
| if (!cfs_rq->on_list) { |
| struct rq *rq = rq_of(cfs_rq); |
| int cpu = cpu_of(rq); |
| /* |
| * Ensure we either appear before our parent (if already |
| * enqueued) or force our parent to appear after us when it is |
| * enqueued. The fact that we always enqueue bottom-up |
| * reduces this to two cases and a special case for the root |
| * cfs_rq. Furthermore, it also means that we will always reset |
| * tmp_alone_branch either when the branch is connected |
| * to a tree or when we reach the beg of the tree |
| */ |
| if (cfs_rq->tg->parent && |
| cfs_rq->tg->parent->cfs_rq[cpu]->on_list) { |
| /* |
| * If parent is already on the list, we add the child |
| * just before. Thanks to circular linked property of |
| * the list, this means to put the child at the tail |
| * of the list that starts by parent. |
| */ |
| list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list, |
| &(cfs_rq->tg->parent->cfs_rq[cpu]->leaf_cfs_rq_list)); |
| /* |
| * The branch is now connected to its tree so we can |
| * reset tmp_alone_branch to the beginning of the |
| * list. |
| */ |
| rq->tmp_alone_branch = &rq->leaf_cfs_rq_list; |
| } else if (!cfs_rq->tg->parent) { |
| /* |
| * cfs rq without parent should be put |
| * at the tail of the list. |
| */ |
| list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list, |
| &rq->leaf_cfs_rq_list); |
| /* |
| * We have reach the beg of a tree so we can reset |
| * tmp_alone_branch to the beginning of the list. |
| */ |
| rq->tmp_alone_branch = &rq->leaf_cfs_rq_list; |
| } else { |
| /* |
| * The parent has not already been added so we want to |
| * make sure that it will be put after us. |
| * tmp_alone_branch points to the beg of the branch |
| * where we will add parent. |
| */ |
| list_add_rcu(&cfs_rq->leaf_cfs_rq_list, |
| rq->tmp_alone_branch); |
| /* |
| * update tmp_alone_branch to points to the new beg |
| * of the branch |
| */ |
| rq->tmp_alone_branch = &cfs_rq->leaf_cfs_rq_list; |
| } |
| |
| cfs_rq->on_list = 1; |
| } |
| } |
| |
| static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq) |
| { |
| if (cfs_rq->on_list) { |
| list_del_rcu(&cfs_rq->leaf_cfs_rq_list); |
| cfs_rq->on_list = 0; |
| } |
| } |
| |
| /* Iterate through all leaf cfs_rq's on a runqueue: */ |
| #define for_each_leaf_cfs_rq(rq, cfs_rq) \ |
| list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list) |
| |
| /* Do the two (enqueued) entities belong to the same group ? */ |
| static inline struct cfs_rq * |
| is_same_group(struct sched_entity *se, struct sched_entity *pse) |
| { |
| if (se->cfs_rq == pse->cfs_rq) |
| return se->cfs_rq; |
| |
| return NULL; |
| } |
| |
| static inline struct sched_entity *parent_entity(struct sched_entity *se) |
| { |
| return se->parent; |
| } |
| |
| static void |
| find_matching_se(struct sched_entity **se, struct sched_entity **pse) |
| { |
| int se_depth, pse_depth; |
| |
| /* |
| * preemption test can be made between sibling entities who are in the |
| * same cfs_rq i.e who have a common parent. Walk up the hierarchy of |
| * both tasks until we find their ancestors who are siblings of common |
| * parent. |
| */ |
| |
| /* First walk up until both entities are at same depth */ |
| se_depth = (*se)->depth; |
| pse_depth = (*pse)->depth; |
| |
| while (se_depth > pse_depth) { |
| se_depth--; |
| *se = parent_entity(*se); |
| } |
| |
| while (pse_depth > se_depth) { |
| pse_depth--; |
| *pse = parent_entity(*pse); |
| } |
| |
| while (!is_same_group(*se, *pse)) { |
| *se = parent_entity(*se); |
| *pse = parent_entity(*pse); |
| } |
| } |
| |
| #else /* !CONFIG_FAIR_GROUP_SCHED */ |
| |
| static inline struct task_struct *task_of(struct sched_entity *se) |
| { |
| return container_of(se, struct task_struct, se); |
| } |
| |
| static inline struct rq *rq_of(struct cfs_rq *cfs_rq) |
| { |
| return container_of(cfs_rq, struct rq, cfs); |
| } |
| |
| #define entity_is_task(se) 1 |
| |
| #define for_each_sched_entity(se) \ |
| for (; se; se = NULL) |
| |
| static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) |
| { |
| return &task_rq(p)->cfs; |
| } |
| |
| static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) |
| { |
| struct task_struct *p = task_of(se); |
| struct rq *rq = task_rq(p); |
| |
| return &rq->cfs; |
| } |
| |
| /* runqueue "owned" by this group */ |
| static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) |
| { |
| return NULL; |
| } |
| |
| static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) |
| { |
| } |
| |
| static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq) |
| { |
| } |
| |
| #define for_each_leaf_cfs_rq(rq, cfs_rq) \ |
| for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL) |
| |
| static inline struct sched_entity *parent_entity(struct sched_entity *se) |
| { |
| return NULL; |
| } |
| |
| static inline void |
| find_matching_se(struct sched_entity **se, struct sched_entity **pse) |
| { |
| } |
| |
| #endif /* CONFIG_FAIR_GROUP_SCHED */ |
| |
| static __always_inline |
| void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec); |
| |
| /************************************************************** |
| * Scheduling class tree data structure manipulation methods: |
| */ |
| |
| static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime) |
| { |
| s64 delta = (s64)(vruntime - max_vruntime); |
| if (delta > 0) |
| max_vruntime = vruntime; |
| |
| return max_vruntime; |
| } |
| |
| static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime) |
| { |
| s64 delta = (s64)(vruntime - min_vruntime); |
| if (delta < 0) |
| min_vruntime = vruntime; |
| |
| return min_vruntime; |
| } |
| |
| static inline int entity_before(struct sched_entity *a, |
| struct sched_entity *b) |
| { |
| return (s64)(a->vruntime - b->vruntime) < 0; |
| } |
| |
| static void update_min_vruntime(struct cfs_rq *cfs_rq) |
| { |
| struct sched_entity *curr = cfs_rq->curr; |
| struct rb_node *leftmost = rb_first_cached(&cfs_rq->tasks_timeline); |
| |
| u64 vruntime = cfs_rq->min_vruntime; |
| |
| if (curr) { |
| if (curr->on_rq) |
| vruntime = curr->vruntime; |
| else |
| curr = NULL; |
| } |
| |
| if (leftmost) { /* non-empty tree */ |
| struct sched_entity *se; |
| se = rb_entry(leftmost, struct sched_entity, run_node); |
| |
| if (!curr) |
| vruntime = se->vruntime; |
| else |
| vruntime = min_vruntime(vruntime, se->vruntime); |
| } |
| |
| /* ensure we never gain time by being placed backwards. */ |
| cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime); |
| #ifndef CONFIG_64BIT |
| smp_wmb(); |
| cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; |
| #endif |
| } |
| |
| /* |
| * Enqueue an entity into the rb-tree: |
| */ |
| static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| struct rb_node **link = &cfs_rq->tasks_timeline.rb_root.rb_node; |
| struct rb_node *parent = NULL; |
| struct sched_entity *entry; |
| bool leftmost = true; |
| |
| /* |
| * Find the right place in the rbtree: |
| */ |
| while (*link) { |
| parent = *link; |
| entry = rb_entry(parent, struct sched_entity, run_node); |
| /* |
| * We dont care about collisions. Nodes with |
| * the same key stay together. |
| */ |
| if (entity_before(se, entry)) { |
| link = &parent->rb_left; |
| } else { |
| link = &parent->rb_right; |
| leftmost = false; |
| } |
| } |
| |
| rb_link_node(&se->run_node, parent, link); |
| rb_insert_color_cached(&se->run_node, |
| &cfs_rq->tasks_timeline, leftmost); |
| } |
| |
| static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| rb_erase_cached(&se->run_node, &cfs_rq->tasks_timeline); |
| } |
| |
| struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq) |
| { |
| struct rb_node *left = rb_first_cached(&cfs_rq->tasks_timeline); |
| |
| if (!left) |
| return NULL; |
| |
| return rb_entry(left, struct sched_entity, run_node); |
| } |
| |
| static struct sched_entity *__pick_next_entity(struct sched_entity *se) |
| { |
| struct rb_node *next = rb_next(&se->run_node); |
| |
| if (!next) |
| return NULL; |
| |
| return rb_entry(next, struct sched_entity, run_node); |
| } |
| |
| #ifdef CONFIG_SCHED_DEBUG |
| struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) |
| { |
| struct rb_node *last = rb_last(&cfs_rq->tasks_timeline.rb_root); |
| |
| if (!last) |
| return NULL; |
| |
| return rb_entry(last, struct sched_entity, run_node); |
| } |
| |
| /************************************************************** |
| * Scheduling class statistics methods: |
| */ |
| |
| int sched_proc_update_handler(struct ctl_table *table, int write, |
| void __user *buffer, size_t *lenp, |
| loff_t *ppos) |
| { |
| int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
| unsigned int factor = get_update_sysctl_factor(); |
| |
| if (ret || !write) |
| return ret; |
| |
| sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency, |
| sysctl_sched_min_granularity); |
| |
| #define WRT_SYSCTL(name) \ |
| (normalized_sysctl_##name = sysctl_##name / (factor)) |
| WRT_SYSCTL(sched_min_granularity); |
| WRT_SYSCTL(sched_latency); |
| WRT_SYSCTL(sched_wakeup_granularity); |
| #undef WRT_SYSCTL |
| |
| return 0; |
| } |
| #endif |
| |
| /* |
| * delta /= w |
| */ |
| static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se) |
| { |
| if (unlikely(se->load.weight != NICE_0_LOAD)) |
| delta = __calc_delta(delta, NICE_0_LOAD, &se->load); |
| |
| return delta; |
| } |
| |
| /* |
| * The idea is to set a period in which each task runs once. |
| * |
| * When there are too many tasks (sched_nr_latency) we have to stretch |
| * this period because otherwise the slices get too small. |
| * |
| * p = (nr <= nl) ? l : l*nr/nl |
| */ |
| static u64 __sched_period(unsigned long nr_running) |
| { |
| if (unlikely(nr_running > sched_nr_latency)) |
| return nr_running * sysctl_sched_min_granularity; |
| else |
| return sysctl_sched_latency; |
| } |
| |
| /* |
| * We calculate the wall-time slice from the period by taking a part |
| * proportional to the weight. |
| * |
| * s = p*P[w/rw] |
| */ |
| static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq); |
| |
| for_each_sched_entity(se) { |
| struct load_weight *load; |
| struct load_weight lw; |
| |
| cfs_rq = cfs_rq_of(se); |
| load = &cfs_rq->load; |
| |
| if (unlikely(!se->on_rq)) { |
| lw = cfs_rq->load; |
| |
| update_load_add(&lw, se->load.weight); |
| load = &lw; |
| } |
| slice = __calc_delta(slice, se->load.weight, load); |
| } |
| return slice; |
| } |
| |
| /* |
| * We calculate the vruntime slice of a to-be-inserted task. |
| * |
| * vs = s/w |
| */ |
| static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| return calc_delta_fair(sched_slice(cfs_rq, se), se); |
| } |
| |
| #ifdef CONFIG_SMP |
| |
| #include "sched-pelt.h" |
| |
| static int select_idle_sibling(struct task_struct *p, int prev_cpu, int cpu); |
| static unsigned long task_h_load(struct task_struct *p); |
| static unsigned long capacity_of(int cpu); |
| |
| /* Give new sched_entity start runnable values to heavy its load in infant time */ |
| void init_entity_runnable_average(struct sched_entity *se) |
| { |
| struct sched_avg *sa = &se->avg; |
| |
| memset(sa, 0, sizeof(*sa)); |
| /* |
| * util_avg is initialized in post_init_entity_util_avg. |
| * util_est should start from zero. |
| * sched_avg's period_contrib should be strictly less then 1024, so |
| * we give it 1023 to make sure it is almost a period (1024us), and |
| * will definitely be update (after enqueue). |
| */ |
| sa->period_contrib = 1023; |
| /* |
| * Tasks are intialized with full load to be seen as heavy tasks until |
| * they get a chance to stabilize to their real load level. |
| * Group entities are intialized with zero load to reflect the fact that |
| * nothing has been attached to the task group yet. |
| */ |
| if (entity_is_task(se)) |
| sa->load_avg = scale_load_down(se->load.weight); |
| sa->load_sum = sa->load_avg * LOAD_AVG_MAX; |
| #ifdef CONFIG_SCHED_HMP |
| if (entity_is_task(se)) |
| sa->loadwop_avg = scale_load_down(NICE_0_LOAD); |
| sa->loadwop_sum = sa->loadwop_avg * LOAD_AVG_MAX; |
| #endif |
| /* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */ |
| } |
| |
| static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq); |
| static void attach_entity_cfs_rq(struct sched_entity *se); |
| |
| /* |
| * With new tasks being created, their initial util_avgs are extrapolated |
| * based on the cfs_rq's current util_avg: |
| * |
| * util_avg = cfs_rq->util_avg / (cfs_rq->load_avg + 1) * se.load.weight |
| * |
| * However, in many cases, the above util_avg does not give a desired |
| * value. Moreover, the sum of the util_avgs may be divergent, such |
| * as when the series is a harmonic series. |
| * |
| * To solve this problem, we also cap the util_avg of successive tasks to |
| * only 1/2 of the left utilization budget: |
| * |
| * util_avg_cap = (cpu_scale - cfs_rq->avg.util_avg) / 2^n |
| * |
| * where n denotes the nth task and cpu_scale the CPU capacity. |
| * |
| * For example, for a CPU with 1024 of capacity, a simplest series from |
| * the beginning would be like: |
| * |
| * task util_avg: 512, 256, 128, 64, 32, 16, 8, ... |
| * cfs_rq util_avg: 512, 768, 896, 960, 992, 1008, 1016, ... |
| * |
| * Finally, that extrapolated util_avg is clamped to the cap (util_avg_cap) |
| * if util_avg > util_avg_cap. |
| */ |
| void post_init_entity_util_avg(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| struct sched_avg *sa = &se->avg; |
| long cpu_scale = arch_scale_cpu_capacity(NULL, cpu_of(rq_of(cfs_rq))); |
| long cap = (long)(cpu_scale - cfs_rq->avg.util_avg) / 2; |
| |
| if (cap > 0) { |
| if (cfs_rq->avg.util_avg != 0) { |
| sa->util_avg = cfs_rq->avg.util_avg * se->load.weight; |
| sa->util_avg /= (cfs_rq->avg.load_avg + 1); |
| |
| if (sa->util_avg > cap) |
| sa->util_avg = cap; |
| } else { |
| sa->util_avg = cap; |
| } |
| sa->util_sum = sa->util_avg * LOAD_AVG_MAX; |
| } |
| |
| if (entity_is_task(se)) { |
| struct task_struct *p = task_of(se); |
| if (p->sched_class != &fair_sched_class) { |
| /* |
| * For !fair tasks do: |
| * |
| update_cfs_rq_load_avg(now, cfs_rq); |
| attach_entity_load_avg(cfs_rq, se); |
| switched_from_fair(rq, p); |
| * |
| * such that the next switched_to_fair() has the |
| * expected state. |
| */ |
| se->avg.last_update_time = cfs_rq_clock_task(cfs_rq); |
| return; |
| } |
| } |
| |
| attach_entity_cfs_rq(se); |
| } |
| |
| #else /* !CONFIG_SMP */ |
| void init_entity_runnable_average(struct sched_entity *se) |
| { |
| } |
| void post_init_entity_util_avg(struct sched_entity *se) |
| { |
| } |
| static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) |
| { |
| } |
| #endif /* CONFIG_SMP */ |
| |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // Liujie.Xie@TECH.Kernel.Sched, 2019/08/29, add for jank monitor |
| #ifdef CONFIG_OPPO_JANK_INFO |
| extern void update_jank_trace_info(struct task_struct *tsk, int trace_type, unsigned int cpu, u64 delta); |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| /* |
| * Update the current task's runtime statistics. |
| */ |
| static void update_curr(struct cfs_rq *cfs_rq) |
| { |
| struct sched_entity *curr = cfs_rq->curr; |
| u64 now = rq_clock_task(rq_of(cfs_rq)); |
| u64 delta_exec; |
| |
| if (unlikely(!curr)) |
| return; |
| |
| delta_exec = now - curr->exec_start; |
| if (unlikely((s64)delta_exec <= 0)) |
| return; |
| |
| curr->exec_start = now; |
| |
| schedstat_set(curr->statistics.exec_max, |
| max(delta_exec, curr->statistics.exec_max)); |
| |
| curr->sum_exec_runtime += delta_exec; |
| schedstat_add(cfs_rq->exec_clock, delta_exec); |
| |
| curr->vruntime += calc_delta_fair(delta_exec, curr); |
| update_min_vruntime(cfs_rq); |
| |
| if (entity_is_task(curr)) { |
| struct task_struct *curtask = task_of(curr); |
| |
| trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime); |
| cpuacct_charge(curtask, delta_exec); |
| account_group_exec_runtime(curtask, delta_exec); |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // Liujie.Xie@TECH.Kernel.Sched, 2019/08/29, add for jank monitor |
| #ifdef CONFIG_OPPO_JANK_INFO |
| update_jank_trace_info(curtask, JANK_TRACE_RUNNING, cpu_of(rq_of(cfs_rq)), delta_exec); |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| } |
| |
| account_cfs_rq_runtime(cfs_rq, delta_exec); |
| } |
| |
| static void update_curr_fair(struct rq *rq) |
| { |
| update_curr(cfs_rq_of(&rq->curr->se)); |
| } |
| |
| static inline void |
| update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| u64 wait_start, prev_wait_start; |
| |
| if (!schedstat_enabled()) |
| return; |
| |
| wait_start = rq_clock(rq_of(cfs_rq)); |
| prev_wait_start = schedstat_val(se->statistics.wait_start); |
| |
| if (entity_is_task(se) && task_on_rq_migrating(task_of(se)) && |
| likely(wait_start > prev_wait_start)) |
| wait_start -= prev_wait_start; |
| |
| schedstat_set(se->statistics.wait_start, wait_start); |
| } |
| |
| static inline void |
| update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| struct task_struct *p; |
| u64 delta; |
| |
| if (!schedstat_enabled()) |
| return; |
| |
| delta = rq_clock(rq_of(cfs_rq)) - schedstat_val(se->statistics.wait_start); |
| |
| if (entity_is_task(se)) { |
| p = task_of(se); |
| if (task_on_rq_migrating(p)) { |
| /* |
| * Preserve migrating task's wait time so wait_start |
| * time stamp can be adjusted to accumulate wait time |
| * prior to migration. |
| */ |
| schedstat_set(se->statistics.wait_start, delta); |
| return; |
| } |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // wenbin.liu@PSW.BSP.MM, 2018/05/26 |
| // Add for get sched latency stat |
| #ifdef CONFIG_OPPO_HEALTHINFO |
| ohm_schedstats_record(OHM_SCHED_SCHEDLATENCY, p, (delta >> 20)); |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // Liujie.Xie@TECH.Kernel.Sched, 2019/08/29, add for jank monitor |
| #ifdef CONFIG_OPPO_JANK_INFO |
| update_jank_trace_info(p, JANK_TRACE_RUNNABLE, 0, delta); |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| trace_sched_stat_wait(p, delta); |
| } |
| |
| schedstat_set(se->statistics.wait_max, |
| max(schedstat_val(se->statistics.wait_max), delta)); |
| schedstat_inc(se->statistics.wait_count); |
| schedstat_add(se->statistics.wait_sum, delta); |
| schedstat_set(se->statistics.wait_start, 0); |
| } |
| |
| static inline void |
| update_stats_enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| struct task_struct *tsk = NULL; |
| u64 sleep_start, block_start; |
| |
| if (!schedstat_enabled()) |
| return; |
| |
| sleep_start = schedstat_val(se->statistics.sleep_start); |
| block_start = schedstat_val(se->statistics.block_start); |
| |
| if (entity_is_task(se)) |
| tsk = task_of(se); |
| |
| if (sleep_start) { |
| u64 delta = rq_clock(rq_of(cfs_rq)) - sleep_start; |
| |
| if ((s64)delta < 0) |
| delta = 0; |
| |
| if (unlikely(delta > schedstat_val(se->statistics.sleep_max))) |
| schedstat_set(se->statistics.sleep_max, delta); |
| |
| schedstat_set(se->statistics.sleep_start, 0); |
| schedstat_add(se->statistics.sum_sleep_runtime, delta); |
| |
| if (tsk) { |
| account_scheduler_latency(tsk, delta >> 10, 1); |
| trace_sched_stat_sleep(tsk, delta); |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // Liujie.Xie@TECH.Kernel.Sched, 2019/08/29, add for jank monitor |
| #ifdef CONFIG_OPPO_JANK_INFO |
| update_jank_trace_info(tsk, JANK_TRACE_SSTATE, 0, delta); |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| } |
| } |
| if (block_start) { |
| u64 delta = rq_clock(rq_of(cfs_rq)) - block_start; |
| |
| if ((s64)delta < 0) |
| delta = 0; |
| |
| if (unlikely(delta > schedstat_val(se->statistics.block_max))) |
| schedstat_set(se->statistics.block_max, delta); |
| |
| schedstat_set(se->statistics.block_start, 0); |
| schedstat_add(se->statistics.sum_sleep_runtime, delta); |
| |
| if (tsk) { |
| if (tsk->in_iowait) { |
| schedstat_add(se->statistics.iowait_sum, delta); |
| schedstat_inc(se->statistics.iowait_count); |
| trace_sched_stat_iowait(tsk, delta); |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // wenbin.liu@PSW.BSP.MM, 2018/05/09 |
| // Add for get iowait |
| #ifdef CONFIG_OPPO_HEALTHINFO |
| ohm_schedstats_record(OHM_SCHED_IOWAIT, tsk, (delta >> 20)); |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| #if defined(OPLUS_FEATURE_IOMONITOR) && defined(CONFIG_IOMONITOR) |
| iomonitor_record_iowait(tsk, (delta >> 20)); |
| #endif /*OPLUS_FEATURE_IOMONITOR*/ |
| } |
| trace_sched_stat_blocked(tsk, delta); |
| trace_sched_blocked_reason(tsk); |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // Jiheng,Xie@TECH.BSP.Performance, 2019/05/18,add for get dstate statictics |
| #ifdef CONFIG_OPPO_HEALTHINFO |
| if(!tsk->in_iowait) { |
| ohm_schedstats_record(OHM_SCHED_DSTATE, tsk, (delta >> 20)); |
| } |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| #ifdef OPLUS_FEATURE_HEALTHINFO |
| // Liujie.Xie@TECH.Kernel.Sched, 2019/08/29, add for jank monitor |
| #ifdef CONFIG_OPPO_JANK_INFO |
| update_jank_trace_info(tsk, JANK_TRACE_DSTATE, 0, delta); |
| #endif |
| #endif /* OPLUS_FEATURE_HEALTHINFO */ |
| /* |
| * Blocking time is in units of nanosecs, so shift by |
| * 20 to get a milliseconds-range estimation of the |
| * amount of time that the task spent sleeping: |
| */ |
| if (unlikely(prof_on == SLEEP_PROFILING)) { |
| profile_hits(SLEEP_PROFILING, |
| (void *)get_wchan(tsk), |
| delta >> 20); |
| } |
| account_scheduler_latency(tsk, delta >> 10, 0); |
| } |
| } |
| } |
| |
| /* |
| * Task is being enqueued - update stats: |
| */ |
| static inline void |
| update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) |
| { |
| if (!schedstat_enabled()) |
| return; |
| |
| /* |
| * Are we enqueueing a waiting task? (for current tasks |
| * a dequeue/enqueue event is a NOP) |
| */ |
| if (se != cfs_rq->curr) |
| update_stats_wait_start(cfs_rq, se); |
| |
| if (flags & ENQUEUE_WAKEUP) |
| update_stats_enqueue_sleeper(cfs_rq, se); |
| } |
| |
| static inline void |
| update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) |
| { |
| |
| if (!schedstat_enabled()) |
| return; |
| |
| /* |
| * Mark the end of the wait period if dequeueing a |
| * waiting task: |
| */ |
| if (se != cfs_rq->curr) |
| update_stats_wait_end(cfs_rq, se); |
| |
| if ((flags & DEQUEUE_SLEEP) && entity_is_task(se)) { |
| struct task_struct *tsk = task_of(se); |
| |
| if (tsk->state & TASK_INTERRUPTIBLE) |
| schedstat_set(se->statistics.sleep_start, |
| rq_clock(rq_of(cfs_rq))); |
| if (tsk->state & TASK_UNINTERRUPTIBLE) |
| schedstat_set(se->statistics.block_start, |
| rq_clock(rq_of(cfs_rq))); |
| } |
| } |
| |
| /* |
| * We are picking a new current task - update its stats: |
| */ |
| static inline void |
| update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| /* |
| * We are starting a new run period: |
| */ |
| se->exec_start = rq_clock_task(rq_of(cfs_rq)); |
| } |
| |
| /************************************************** |
| * Scheduling class queueing methods: |
| */ |
| |
| #ifdef CONFIG_NUMA_BALANCING |
| /* |
| * Approximate time to scan a full NUMA task in ms. The task scan period is |
| * calculated based on the tasks virtual memory size and |
| * numa_balancing_scan_size. |
| */ |
| unsigned int sysctl_numa_balancing_scan_period_min = 1000; |
| unsigned int sysctl_numa_balancing_scan_period_max = 60000; |
| |
| /* Portion of address space to scan in MB */ |
| unsigned int sysctl_numa_balancing_scan_size = 256; |
| |
| /* Scan @scan_size MB every @scan_period after an initial @scan_delay in ms */ |
| unsigned int sysctl_numa_balancing_scan_delay = 1000; |
| |
| struct numa_group { |
| atomic_t refcount; |
| |
| spinlock_t lock; /* nr_tasks, tasks */ |
| int nr_tasks; |
| pid_t gid; |
| int active_nodes; |
| |
| struct rcu_head rcu; |
| unsigned long total_faults; |
| unsigned long max_faults_cpu; |
| /* |
| * Faults_cpu is used to decide whether memory should move |
| * towards the CPU. As a consequence, these stats are weighted |
| * more by CPU use than by memory faults. |
| */ |
| unsigned long *faults_cpu; |
| unsigned long faults[0]; |
| }; |
| |
| static inline unsigned long group_faults_priv(struct numa_group *ng); |
| static inline unsigned long group_faults_shared(struct numa_group *ng); |
| |
| static unsigned int task_nr_scan_windows(struct task_struct *p) |
| { |
| unsigned long rss = 0; |
| unsigned long nr_scan_pages; |
| |
| /* |
| * Calculations based on RSS as non-present and empty pages are skipped |
| * by the PTE scanner and NUMA hinting faults should be trapped based |
| * on resident pages |
| */ |
| nr_scan_pages = sysctl_numa_balancing_scan_size << (20 - PAGE_SHIFT); |
| rss = get_mm_rss(p->mm); |
| if (!rss) |
| rss = nr_scan_pages; |
| |
| rss = round_up(rss, nr_scan_pages); |
| return rss / nr_scan_pages; |
| } |
| |
| /* For sanitys sake, never scan more PTEs than MAX_SCAN_WINDOW MB/sec. */ |
| #define MAX_SCAN_WINDOW 2560 |
| |
| static unsigned int task_scan_min(struct task_struct *p) |
| { |
| unsigned int scan_size = READ_ONCE(sysctl_numa_balancing_scan_size); |
| unsigned int scan, floor; |
| unsigned int windows = 1; |
| |
| if (scan_size < MAX_SCAN_WINDOW) |
| windows = MAX_SCAN_WINDOW / scan_size; |
| floor = 1000 / windows; |
| |
| scan = sysctl_numa_balancing_scan_period_min / task_nr_scan_windows(p); |
| return max_t(unsigned int, floor, scan); |
| } |
| |
| static unsigned int task_scan_start(struct task_struct *p) |
| { |
| unsigned long smin = task_scan_min(p); |
| unsigned long period = smin; |
| |
| /* Scale the maximum scan period with the amount of shared memory. */ |
| if (p->numa_group) { |
| struct numa_group *ng = p->numa_group; |
| unsigned long shared = group_faults_shared(ng); |
| unsigned long private = group_faults_priv(ng); |
| |
| period *= atomic_read(&ng->refcount); |
| period *= shared + 1; |
| period /= private + shared + 1; |
| } |
| |
| return max(smin, period); |
| } |
| |
| static unsigned int task_scan_max(struct task_struct *p) |
| { |
| unsigned long smin = task_scan_min(p); |
| unsigned long smax; |
| |
| /* Watch for min being lower than max due to floor calculations */ |
| smax = sysctl_numa_balancing_scan_period_max / task_nr_scan_windows(p); |
| |
| /* Scale the maximum scan period with the amount of shared memory. */ |
| if (p->numa_group) { |
| struct numa_group *ng = p->numa_group; |
| unsigned long shared = group_faults_shared(ng); |
| unsigned long private = group_faults_priv(ng); |
| unsigned long period = smax; |
| |
| period *= atomic_read(&ng->refcount); |
| period *= shared + 1; |
| period /= private + shared + 1; |
| |
| smax = max(smax, period); |
| } |
| |
| return max(smin, smax); |
| } |
| |
| static void account_numa_enqueue(struct rq *rq, struct task_struct *p) |
| { |
| rq->nr_numa_running += (p->numa_preferred_nid != -1); |
| rq->nr_preferred_running += (p->numa_preferred_nid == task_node(p)); |
| } |
| |
| static void account_numa_dequeue(struct rq *rq, struct task_struct *p) |
| { |
| rq->nr_numa_running -= (p->numa_preferred_nid != -1); |
| rq->nr_preferred_running -= (p->numa_preferred_nid == task_node(p)); |
| } |
| |
| /* Shared or private faults. */ |
| #define NR_NUMA_HINT_FAULT_TYPES 2 |
| |
| /* Memory and CPU locality */ |
| #define NR_NUMA_HINT_FAULT_STATS (NR_NUMA_HINT_FAULT_TYPES * 2) |
| |
| /* Averaged statistics, and temporary buffers. */ |
| #define NR_NUMA_HINT_FAULT_BUCKETS (NR_NUMA_HINT_FAULT_STATS * 2) |
| |
| pid_t task_numa_group_id(struct task_struct *p) |
| { |
| return p->numa_group ? p->numa_group->gid : 0; |
| } |
| |
| /* |
| * The averaged statistics, shared & private, memory & cpu, |
| * occupy the first half of the array. The second half of the |
| * array is for current counters, which are averaged into the |
| * first set by task_numa_placement. |
| */ |
| static inline int task_faults_idx(enum numa_faults_stats s, int nid, int priv) |
| { |
| return NR_NUMA_HINT_FAULT_TYPES * (s * nr_node_ids + nid) + priv; |
| } |
| |
| static inline unsigned long task_faults(struct task_struct *p, int nid) |
| { |
| if (!p->numa_faults) |
| return 0; |
| |
| return p->numa_faults[task_faults_idx(NUMA_MEM, nid, 0)] + |
| p->numa_faults[task_faults_idx(NUMA_MEM, nid, 1)]; |
| } |
| |
| static inline unsigned long group_faults(struct task_struct *p, int nid) |
| { |
| if (!p->numa_group) |
| return 0; |
| |
| return p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 0)] + |
| p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 1)]; |
| } |
| |
| static inline unsigned long group_faults_cpu(struct numa_group *group, int nid) |
| { |
| return group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 0)] + |
| group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 1)]; |
| } |
| |
| static inline unsigned long group_faults_priv(struct numa_group *ng) |
| { |
| unsigned long faults = 0; |
| int node; |
| |
| for_each_online_node(node) { |
| faults += ng->faults[task_faults_idx(NUMA_MEM, node, 1)]; |
| } |
| |
| return faults; |
| } |
| |
| static inline unsigned long group_faults_shared(struct numa_group *ng) |
| { |
| unsigned long faults = 0; |
| int node; |
| |
| for_each_online_node(node) { |
| faults += ng->faults[task_faults_idx(NUMA_MEM, node, 0)]; |
| } |
| |
| return faults; |
| } |
| |
| /* |
| * A node triggering more than 1/3 as many NUMA faults as the maximum is |
| * considered part of a numa group's pseudo-interleaving set. Migrations |
| * between these nodes are slowed down, to allow things to settle down. |
| */ |
| #define ACTIVE_NODE_FRACTION 3 |
| |
| static bool numa_is_active_node(int nid, struct numa_group *ng) |
| { |
| return group_faults_cpu(ng, nid) * ACTIVE_NODE_FRACTION > ng->max_faults_cpu; |
| } |
| |
| /* Handle placement on systems where not all nodes are directly connected. */ |
| static unsigned long score_nearby_nodes(struct task_struct *p, int nid, |
| int maxdist, bool task) |
| { |
| unsigned long score = 0; |
| int node; |
| |
| /* |
| * All nodes are directly connected, and the same distance |
| * from each other. No need for fancy placement algorithms. |
| */ |
| if (sched_numa_topology_type == NUMA_DIRECT) |
| return 0; |
| |
| /* |
| * This code is called for each node, introducing N^2 complexity, |
| * which should be ok given the number of nodes rarely exceeds 8. |
| */ |
| for_each_online_node(node) { |
| unsigned long faults; |
| int dist = node_distance(nid, node); |
| |
| /* |
| * The furthest away nodes in the system are not interesting |
| * for placement; nid was already counted. |
| */ |
| if (dist == sched_max_numa_distance || node == nid) |
| continue; |
| |
| /* |
| * On systems with a backplane NUMA topology, compare groups |
| * of nodes, and move tasks towards the group with the most |
| * memory accesses. When comparing two nodes at distance |
| * "hoplimit", only nodes closer by than "hoplimit" are part |
| * of each group. Skip other nodes. |
| */ |
| if (sched_numa_topology_type == NUMA_BACKPLANE && |
| dist > maxdist) |
| continue; |
| |
| /* Add up the faults from nearby nodes. */ |
| if (task) |
| faults = task_faults(p, node); |
| else |
| faults = group_faults(p, node); |
| |
| /* |
| * On systems with a glueless mesh NUMA topology, there are |
| * no fixed "groups of nodes". Instead, nodes that are not |
| * directly connected bounce traffic through intermediate |
| * nodes; a numa_group can occupy any set of nodes. |
| * The further away a node is, the less the faults count. |
| * This seems to result in good task placement. |
| */ |
| if (sched_numa_topology_type == NUMA_GLUELESS_MESH) { |
| faults *= (sched_max_numa_distance - dist); |
| faults /= (sched_max_numa_distance - LOCAL_DISTANCE); |
| } |
| |
| score += faults; |
| } |
| |
| return score; |
| } |
| |
| /* |
| * These return the fraction of accesses done by a particular task, or |
| * task group, on a particular numa node. The group weight is given a |
| * larger multiplier, in order to group tasks together that are almost |
| * evenly spread out between numa nodes. |
| */ |
| static inline unsigned long task_weight(struct task_struct *p, int nid, |
| int dist) |
| { |
| unsigned long faults, total_faults; |
| |
| if (!p->numa_faults) |
| return 0; |
| |
| total_faults = p->total_numa_faults; |
| |
| if (!total_faults) |
| return 0; |
| |
| faults = task_faults(p, nid); |
| faults += score_nearby_nodes(p, nid, dist, true); |
| |
| return 1000 * faults / total_faults; |
| } |
| |
| static inline unsigned long group_weight(struct task_struct *p, int nid, |
| int dist) |
| { |
| unsigned long faults, total_faults; |
| |
| if (!p->numa_group) |
| return 0; |
| |
| total_faults = p->numa_group->total_faults; |
| |
| if (!total_faults) |
| return 0; |
| |
| faults = group_faults(p, nid); |
| faults += score_nearby_nodes(p, nid, dist, false); |
| |
| return 1000 * faults / total_faults; |
| } |
| |
| bool should_numa_migrate_memory(struct task_struct *p, struct page * page, |
| int src_nid, int dst_cpu) |
| { |
| struct numa_group *ng = p->numa_group; |
| int dst_nid = cpu_to_node(dst_cpu); |
| int last_cpupid, this_cpupid; |
| |
| this_cpupid = cpu_pid_to_cpupid(dst_cpu, current->pid); |
| |
| /* |
| * Multi-stage node selection is used in conjunction with a periodic |
| * migration fault to build a temporal task<->page relation. By using |
| * a two-stage filter we remove short/unlikely relations. |
| * |
| * Using P(p) ~ n_p / n_t as per frequentist probability, we can equate |
| * a task's usage of a particular page (n_p) per total usage of this |
| * page (n_t) (in a given time-span) to a probability. |
| * |
| * Our periodic faults will sample this probability and getting the |
| * same result twice in a row, given these samples are fully |
| * independent, is then given by P(n)^2, provided our sample period |
| * is sufficiently short compared to the usage pattern. |
| * |
| * This quadric squishes small probabilities, making it less likely we |
| * act on an unlikely task<->page relation. |
| */ |
| last_cpupid = page_cpupid_xchg_last(page, this_cpupid); |
| if (!cpupid_pid_unset(last_cpupid) && |
| cpupid_to_nid(last_cpupid) != dst_nid) |
| return false; |
| |
| /* Always allow migrate on private faults */ |
| if (cpupid_match_pid(p, last_cpupid)) |
| return true; |
| |
| /* A shared fault, but p->numa_group has not been set up yet. */ |
| if (!ng) |
| return true; |
| |
| /* |
| * Destination node is much more heavily used than the source |
| * node? Allow migration. |
| */ |
| if (group_faults_cpu(ng, dst_nid) > group_faults_cpu(ng, src_nid) * |
| ACTIVE_NODE_FRACTION) |
| return true; |
| |
| /* |
| * Distribute memory according to CPU & memory use on each node, |
| * with 3/4 hysteresis to avoid unnecessary memory migrations: |
| * |
| * faults_cpu(dst) 3 faults_cpu(src) |
| * --------------- * - > --------------- |
| * faults_mem(dst) 4 faults_mem(src) |
| */ |
| return group_faults_cpu(ng, dst_nid) * group_faults(p, src_nid) * 3 > |
| group_faults_cpu(ng, src_nid) * group_faults(p, dst_nid) * 4; |
| } |
| |
| static unsigned long weighted_cpuload(struct rq *rq); |
| static unsigned long source_load(int cpu, int type); |
| static unsigned long target_load(int cpu, int type); |
| |
| /* Cached statistics for all CPUs within a node */ |
| struct numa_stats { |
| unsigned long nr_running; |
| unsigned long load; |
| |
| /* Total compute capacity of CPUs on a node */ |
| unsigned long compute_capacity; |
| |
| /* Approximate capacity in terms of runnable tasks on a node */ |
| unsigned long task_capacity; |
| int has_free_capacity; |
| }; |
| |
| /* |
| * XXX borrowed from update_sg_lb_stats |
| */ |
| static void update_numa_stats(struct numa_stats *ns, int nid) |
| { |
| int smt, cpu, cpus = 0; |
| unsigned long capacity; |
| |
| memset(ns, 0, sizeof(*ns)); |
| for_each_cpu(cpu, cpumask_of_node(nid)) { |
| struct rq *rq = cpu_rq(cpu); |
| |
| ns->nr_running += rq->nr_running; |
| ns->load += weighted_cpuload(rq); |
| ns->compute_capacity += capacity_of(cpu); |
| |
| cpus++; |
| } |
| |
| /* |
| * If we raced with hotplug and there are no CPUs left in our mask |
| * the @ns structure is NULL'ed and task_numa_compare() will |
| * not find this node attractive. |
| * |
| * We'll either bail at !has_free_capacity, or we'll detect a huge |
| * imbalance and bail there. |
| */ |
| if (!cpus) |
| return; |
| |
| /* smt := ceil(cpus / capacity), assumes: 1 < smt_power < 2 */ |
| smt = DIV_ROUND_UP(SCHED_CAPACITY_SCALE * cpus, ns->compute_capacity); |
| capacity = cpus / smt; /* cores */ |
| |
| ns->task_capacity = min_t(unsigned, capacity, |
| DIV_ROUND_CLOSEST(ns->compute_capacity, SCHED_CAPACITY_SCALE)); |
| ns->has_free_capacity = (ns->nr_running < ns->task_capacity); |
| } |
| |
| struct task_numa_env { |
| struct task_struct *p; |
| |
| int src_cpu, src_nid; |
| int dst_cpu, dst_nid; |
| |
| struct numa_stats src_stats, dst_stats; |
| |
| int imbalance_pct; |
| int dist; |
| |
| struct task_struct *best_task; |
| long best_imp; |
| int best_cpu; |
| }; |
| |
| static void task_numa_assign(struct task_numa_env *env, |
| struct task_struct *p, long imp) |
| { |
| if (env->best_task) |
| put_task_struct(env->best_task); |
| if (p) |
| get_task_struct(p); |
| |
| env->best_task = p; |
| env->best_imp = imp; |
| env->best_cpu = env->dst_cpu; |
| } |
| |
| static bool load_too_imbalanced(long src_load, long dst_load, |
| struct task_numa_env *env) |
| { |
| long imb, old_imb; |
| long orig_src_load, orig_dst_load; |
| long src_capacity, dst_capacity; |
| |
| /* |
| * The load is corrected for the CPU capacity available on each node. |
| * |
| * src_load dst_load |
| * ------------ vs --------- |
| * src_capacity dst_capacity |
| */ |
| src_capacity = env->src_stats.compute_capacity; |
| dst_capacity = env->dst_stats.compute_capacity; |
| |
| /* We care about the slope of the imbalance, not the direction. */ |
| if (dst_load < src_load) |
| swap(dst_load, src_load); |
| |
| /* Is the difference below the threshold? */ |
| imb = dst_load * src_capacity * 100 - |
| src_load * dst_capacity * env->imbalance_pct; |
| if (imb <= 0) |
| return false; |
| |
| /* |
| * The imbalance is above the allowed threshold. |
| * Compare it with the old imbalance. |
| */ |
| orig_src_load = env->src_stats.load; |
| orig_dst_load = env->dst_stats.load; |
| |
| if (orig_dst_load < orig_src_load) |
| swap(orig_dst_load, orig_src_load); |
| |
| old_imb = orig_dst_load * src_capacity * 100 - |
| orig_src_load * dst_capacity * env->imbalance_pct; |
| |
| /* Would this change make things worse? */ |
| return (imb > old_imb); |
| } |
| |
| /* |
| * This checks if the overall compute and NUMA accesses of the system would |
| * be improved if the source tasks was migrated to the target dst_cpu taking |
| * into account that it might be best if task running on the dst_cpu should |
| * be exchanged with the source task |
| */ |
| static void task_numa_compare(struct task_numa_env *env, |
| long taskimp, long groupimp) |
| { |
| struct rq *src_rq = cpu_rq(env->src_cpu); |
| struct rq *dst_rq = cpu_rq(env->dst_cpu); |
| struct task_struct *cur; |
| long src_load, dst_load; |
| long load; |
| long imp = env->p->numa_group ? groupimp : taskimp; |
| long moveimp = imp; |
| int dist = env->dist; |
| |
| rcu_read_lock(); |
| cur = task_rcu_dereference(&dst_rq->curr); |
| if (cur && ((cur->flags & PF_EXITING) || is_idle_task(cur))) |
| cur = NULL; |
| |
| /* |
| * Because we have preemption enabled we can get migrated around and |
| * end try selecting ourselves (current == env->p) as a swap candidate. |
| */ |
| if (cur == env->p) |
| goto unlock; |
| |
| /* |
| * "imp" is the fault differential for the source task between the |
| * source and destination node. Calculate the total differential for |
| * the source task and potential destination task. The more negative |
| * the value is, the more rmeote accesses that would be expected to |
| * be incurred if the tasks were swapped. |
| */ |
| if (cur) { |
| /* Skip this swap candidate if cannot move to the source cpu */ |
| if (!cpumask_test_cpu(env->src_cpu, &cur->cpus_allowed)) |
| goto unlock; |
| |
| /* |
| * If dst and source tasks are in the same NUMA group, or not |
| * in any group then look only at task weights. |
| */ |
| if (cur->numa_group == env->p->numa_group) { |
| imp = taskimp + task_weight(cur, env->src_nid, dist) - |
| task_weight(cur, env->dst_nid, dist); |
| /* |
| * Add some hysteresis to prevent swapping the |
| * tasks within a group over tiny differences. |
| */ |
| if (cur->numa_group) |
| imp -= imp/16; |
| } else { |
| /* |
| * Compare the group weights. If a task is all by |
| * itself (not part of a group), use the task weight |
| * instead. |
| */ |
| if (cur->numa_group) |
| imp += group_weight(cur, env->src_nid, dist) - |
| group_weight(cur, env->dst_nid, dist); |
| else |
| imp += task_weight(cur, env->src_nid, dist) - |
| task_weight(cur, env->dst_nid, dist); |
| } |
| } |
| |
| if (imp <= env->best_imp && moveimp <= env->best_imp) |
| goto unlock; |
| |
| if (!cur) { |
| /* Is there capacity at our destination? */ |
| if (env->src_stats.nr_running <= env->src_stats.task_capacity && |
| !env->dst_stats.has_free_capacity) |
| goto unlock; |
| |
| goto balance; |
| } |
| |
| /* Balance doesn't matter much if we're running a task per cpu */ |
| if (imp > env->best_imp && src_rq->nr_running == 1 && |
| dst_rq->nr_running == 1) |
| goto assign; |
| |
| /* |
| * In the overloaded case, try and keep the load balanced. |
| */ |
| balance: |
| load = task_h_load(env->p); |
| dst_load = env->dst_stats.load + load; |
| src_load = env->src_stats.load - load; |
| |
| if (moveimp > imp && moveimp > env->best_imp) { |
| /* |
| * If the improvement from just moving env->p direction is |
| * better than swapping tasks around, check if a move is |
| * possible. Store a slightly smaller score than moveimp, |
| * so an actually idle CPU will win. |
| */ |
| if (!load_too_imbalanced(src_load, dst_load, env)) { |
| imp = moveimp - 1; |
| cur = NULL; |
| goto assign; |
| } |
| } |
| |
| if (imp <= env->best_imp) |
| goto unlock; |
| |
| if (cur) { |
| load = task_h_load(cur); |
| dst_load -= load; |
| src_load += load; |
| } |
| |
| if (load_too_imbalanced(src_load, dst_load, env)) |
| goto unlock; |
| |
| /* |
| * One idle CPU per node is evaluated for a task numa move. |
| * Call select_idle_sibling to maybe find a better one. |
| */ |
| if (!cur) { |
| /* |
| * select_idle_siblings() uses an per-cpu cpumask that |
| * can be used from IRQ context. |
| */ |
| local_irq_disable(); |
| env->dst_cpu = select_idle_sibling(env->p, env->src_cpu, |
| env->dst_cpu); |
| local_irq_enable(); |
| } |
| |
| assign: |
| task_numa_assign(env, cur, imp); |
| unlock: |
| rcu_read_unlock(); |
| } |
| |
| static void task_numa_find_cpu(struct task_numa_env *env, |
| long taskimp, long groupimp) |
| { |
| int cpu; |
| |
| for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) { |
| /* Skip this CPU if the source task cannot migrate */ |
| if (!cpumask_test_cpu(cpu, &env->p->cpus_allowed)) |
| continue; |
| |
| env->dst_cpu = cpu; |
| task_numa_compare(env, taskimp, groupimp); |
| } |
| } |
| |
| /* Only move tasks to a NUMA node less busy than the current node. */ |
| static bool numa_has_capacity(struct task_numa_env *env) |
| { |
| struct numa_stats *src = &env->src_stats; |
| struct numa_stats *dst = &env->dst_stats; |
| |
| if (src->has_free_capacity && !dst->has_free_capacity) |
| return false; |
| |
| /* |
| * Only consider a task move if the source has a higher load |
| * than the destination, corrected for CPU capacity on each node. |
| * |
| * src->load dst->load |
| * --------------------- vs --------------------- |
| * src->compute_capacity dst->compute_capacity |
| */ |
| if (src->load * dst->compute_capacity * env->imbalance_pct > |
| |
| dst->load * src->compute_capacity * 100) |
| return true; |
| |
| return false; |
| } |
| |
| static int task_numa_migrate(struct task_struct *p) |
| { |
| struct task_numa_env env = { |
| .p = p, |
| |
| .src_cpu = task_cpu(p), |
| .src_nid = task_node(p), |
| |
| .imbalance_pct = 112, |
| |
| .best_task = NULL, |
| .best_imp = 0, |
| .best_cpu = -1, |
| }; |
| struct sched_domain *sd; |
| unsigned long taskweight, groupweight; |
| int nid, ret, dist; |
| long taskimp, groupimp; |
| |
| /* |
| * Pick the lowest SD_NUMA domain, as that would have the smallest |
| * imbalance and would be the first to start moving tasks about. |
| * |
| * And we want to avoid any moving of tasks about, as that would create |
| * random movement of tasks -- counter the numa conditions we're trying |
| * to satisfy here. |
| */ |
| rcu_read_lock(); |
| sd = rcu_dereference(per_cpu(sd_numa, env.src_cpu)); |
| if (sd) |
| env.imbalance_pct = 100 + (sd->imbalance_pct - 100) / 2; |
| rcu_read_unlock(); |
| |
| /* |
| * Cpusets can break the scheduler domain tree into smaller |
| * balance domains, some of which do not cross NUMA boundaries. |
| * Tasks that are "trapped" in such domains cannot be migrated |
| * elsewhere, so there is no point in (re)trying. |
| */ |
| if (unlikely(!sd)) { |
| p->numa_preferred_nid = task_node(p); |
| return -EINVAL; |
| } |
| |
| env.dst_nid = p->numa_preferred_nid; |
| dist = env.dist = node_distance(env.src_nid, env.dst_nid); |
| taskweight = task_weight(p, env.src_nid, dist); |
| groupweight = group_weight(p, env.src_nid, dist); |
| update_numa_stats(&env.src_stats, env.src_nid); |
| taskimp = task_weight(p, env.dst_nid, dist) - taskweight; |
| groupimp = group_weight(p, env.dst_nid, dist) - groupweight; |
| update_numa_stats(&env.dst_stats, env.dst_nid); |
| |
| /* Try to find a spot on the preferred nid. */ |
| if (numa_has_capacity(&env)) |
| task_numa_find_cpu(&env, taskimp, groupimp); |
| |
| /* |
| * Look at other nodes in these cases: |
| * - there is no space available on the preferred_nid |
| * - the task is part of a numa_group that is interleaved across |
| * multiple NUMA nodes; in order to better consolidate the group, |
| * we need to check other locations. |
| */ |
| if (env.best_cpu == -1 || (p->numa_group && p->numa_group->active_nodes > 1)) { |
| for_each_online_node(nid) { |
| if (nid == env.src_nid || nid == p->numa_preferred_nid) |
| continue; |
| |
| dist = node_distance(env.src_nid, env.dst_nid); |
| if (sched_numa_topology_type == NUMA_BACKPLANE && |
| dist != env.dist) { |
| taskweight = task_weight(p, env.src_nid, dist); |
| groupweight = group_weight(p, env.src_nid, dist); |
| } |
| |
| /* Only consider nodes where both task and groups benefit */ |
| taskimp = task_weight(p, nid, dist) - taskweight; |
| groupimp = group_weight(p, nid, dist) - groupweight; |
| if (taskimp < 0 && groupimp < 0) |
| continue; |
| |
| env.dist = dist; |
| env.dst_nid = nid; |
| update_numa_stats(&env.dst_stats, env.dst_nid); |
| if (numa_has_capacity(&env)) |
| task_numa_find_cpu(&env, taskimp, groupimp); |
| } |
| } |
| |
| /* |
| * If the task is part of a workload that spans multiple NUMA nodes, |
| * and is migrating into one of the workload's active nodes, remember |
| * this node as the task's preferred numa node, so the workload can |
| * settle down. |
| * A task that migrated to a second choice node will be better off |
| * trying for a better one later. Do not set the preferred node here. |
| */ |
| if (p->numa_group) { |
| struct numa_group *ng = p->numa_group; |
| |
| if (env.best_cpu == -1) |
| nid = env.src_nid; |
| else |
| nid = env.dst_nid; |
| |
| if (ng->active_nodes > 1 && numa_is_active_node(env.dst_nid, ng)) |
| sched_setnuma(p, env.dst_nid); |
| } |
| |
| /* No better CPU than the current one was found. */ |
| if (env.best_cpu == -1) |
| return -EAGAIN; |
| |
| /* |
| * Reset the scan period if the task is being rescheduled on an |
| * alternative node to recheck if the tasks is now properly placed. |
| */ |
| p->numa_scan_period = task_scan_start(p); |
| |
| if (env.best_task == NULL) { |
| ret = migrate_task_to(p, env.best_cpu); |
| if (ret != 0) |
| trace_sched_stick_numa(p, env.src_cpu, env.best_cpu); |
| return ret; |
| } |
| |
| ret = migrate_swap(p, env.best_task); |
| if (ret != 0) |
| trace_sched_stick_numa(p, env.src_cpu, task_cpu(env.best_task)); |
| put_task_struct(env.best_task); |
| return ret; |
| } |
| |
| /* Attempt to migrate a task to a CPU on the preferred node. */ |
| static void numa_migrate_preferred(struct task_struct *p) |
| { |
| unsigned long interval = HZ; |
| |
| /* This task has no NUMA fault statistics yet */ |
| if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults)) |
| return; |
| |
| /* Periodically retry migrating the task to the preferred node */ |
| interval = min(interval, msecs_to_jiffies(p->numa_scan_period) / 16); |
| p->numa_migrate_retry = jiffies + interval; |
| |
| /* Success if task is already running on preferred CPU */ |
| if (task_node(p) == p->numa_preferred_nid) |
| return; |
| |
| /* Otherwise, try migrate to a CPU on the preferred node */ |
| task_numa_migrate(p); |
| } |
| |
| /* |
| * Find out how many nodes on the workload is actively running on. Do this by |
| * tracking the nodes from which NUMA hinting faults are triggered. This can |
| * be different from the set of nodes where the workload's memory is currently |
| * located. |
| */ |
| static void numa_group_count_active_nodes(struct numa_group *numa_group) |
| { |
| unsigned long faults, max_faults = 0; |
| int nid, active_nodes = 0; |
| |
| for_each_online_node(nid) { |
| faults = group_faults_cpu(numa_group, nid); |
| if (faults > max_faults) |
| max_faults = faults; |
| } |
| |
| for_each_online_node(nid) { |
| faults = group_faults_cpu(numa_group, nid); |
| if (faults * ACTIVE_NODE_FRACTION > max_faults) |
| active_nodes++; |
| } |
| |
| numa_group->max_faults_cpu = max_faults; |
| numa_group->active_nodes = active_nodes; |
| } |
| |
| /* |
| * When adapting the scan rate, the period is divided into NUMA_PERIOD_SLOTS |
| * increments. The more local the fault statistics are, the higher the scan |
| * period will be for the next scan window. If local/(local+remote) ratio is |
| * below NUMA_PERIOD_THRESHOLD (where range of ratio is 1..NUMA_PERIOD_SLOTS) |
| * the scan period will decrease. Aim for 70% local accesses. |
| */ |
| #define NUMA_PERIOD_SLOTS 10 |
| #define NUMA_PERIOD_THRESHOLD 7 |
| |
| /* |
| * Increase the scan period (slow down scanning) if the majority of |
| * our memory is already on our local node, or if the majority of |
| * the page accesses are shared with other processes. |
| * Otherwise, decrease the scan period. |
| */ |
| static void update_task_scan_period(struct task_struct *p, |
| unsigned long shared, unsigned long private) |
| { |
| unsigned int period_slot; |
| int lr_ratio, ps_ratio; |
| int diff; |
| |
| unsigned long remote = p->numa_faults_locality[0]; |
| unsigned long local = p->numa_faults_locality[1]; |
| |
| /* |
| * If there were no record hinting faults then either the task is |
| * completely idle or all activity is areas that are not of interest |
| * to automatic numa balancing. Related to that, if there were failed |
| * migration then it implies we are migrating too quickly or the local |
| * node is overloaded. In either case, scan slower |
| */ |
| if (local + shared == 0 || p->numa_faults_locality[2]) { |
| p->numa_scan_period = min(p->numa_scan_period_max, |
| p->numa_scan_period << 1); |
| |
| p->mm->numa_next_scan = jiffies + |
| msecs_to_jiffies(p->numa_scan_period); |
| |
| return; |
| } |
| |
| /* |
| * Prepare to scale scan period relative to the current period. |
| * == NUMA_PERIOD_THRESHOLD scan period stays the same |
| * < NUMA_PERIOD_THRESHOLD scan period decreases (scan faster) |
| * >= NUMA_PERIOD_THRESHOLD scan period increases (scan slower) |
| */ |
| period_slot = DIV_ROUND_UP(p->numa_scan_period, NUMA_PERIOD_SLOTS); |
| lr_ratio = (local * NUMA_PERIOD_SLOTS) / (local + remote); |
| ps_ratio = (private * NUMA_PERIOD_SLOTS) / (private + shared); |
| |
| if (ps_ratio >= NUMA_PERIOD_THRESHOLD) { |
| /* |
| * Most memory accesses are local. There is no need to |
| * do fast NUMA scanning, since memory is already local. |
| */ |
| int slot = ps_ratio - NUMA_PERIOD_THRESHOLD; |
| if (!slot) |
| slot = 1; |
| diff = slot * period_slot; |
| } else if (lr_ratio >= NUMA_PERIOD_THRESHOLD) { |
| /* |
| * Most memory accesses are shared with other tasks. |
| * There is no point in continuing fast NUMA scanning, |
| * since other tasks may just move the memory elsewhere. |
| */ |
| int slot = lr_ratio - NUMA_PERIOD_THRESHOLD; |
| if (!slot) |
| slot = 1; |
| diff = slot * period_slot; |
| } else { |
| /* |
| * Private memory faults exceed (SLOTS-THRESHOLD)/SLOTS, |
| * yet they are not on the local NUMA node. Speed up |
| * NUMA scanning to get the memory moved over. |
| */ |
| int ratio = max(lr_ratio, ps_ratio); |
| diff = -(NUMA_PERIOD_THRESHOLD - ratio) * period_slot; |
| } |
| |
| p->numa_scan_period = clamp(p->numa_scan_period + diff, |
| task_scan_min(p), task_scan_max(p)); |
| memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality)); |
| } |
| |
| /* |
| * Get the fraction of time the task has been running since the last |
| * NUMA placement cycle. The scheduler keeps similar statistics, but |
| * decays those on a 32ms period, which is orders of magnitude off |
| * from the dozens-of-seconds NUMA balancing period. Use the scheduler |
| * stats only if the task is so new there are no NUMA statistics yet. |
| */ |
| static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period) |
| { |
| u64 runtime, delta, now; |
| /* Use the start of this time slice to avoid calculations. */ |
| now = p->se.exec_start; |
| runtime = p->se.sum_exec_runtime; |
| |
| if (p->last_task_numa_placement) { |
| delta = runtime - p->last_sum_exec_runtime; |
| *period = now - p->last_task_numa_placement; |
| |
| /* Avoid time going backwards, prevent potential divide error: */ |
| if (unlikely((s64)*period < 0)) |
| *period = 0; |
| } else { |
| delta = p->se.avg.load_sum / p->se.load.weight; |
| *period = LOAD_AVG_MAX; |
| } |
| |
| p->last_sum_exec_runtime = runtime; |
| p->last_task_numa_placement = now; |
| |
| return delta; |
| } |
| |
| /* |
| * Determine the preferred nid for a task in a numa_group. This needs to |
| * be done in a way that produces consistent results with group_weight, |
| * otherwise workloads might not converge. |
| */ |
| static int preferred_group_nid(struct task_struct *p, int nid) |
| { |
| nodemask_t nodes; |
| int dist; |
| |
| /* Direct connections between all NUMA nodes. */ |
| if (sched_numa_topology_type == NUMA_DIRECT) |
| return nid; |
| |
| /* |
| * On a system with glueless mesh NUMA topology, group_weight |
| * scores nodes according to the number of NUMA hinting faults on |
| * both the node itself, and on nearby nodes. |
| */ |
| if (sched_numa_topology_type == NUMA_GLUELESS_MESH) { |
| unsigned long score, max_score = 0; |
| int node, max_node = nid; |
| |
| dist = sched_max_numa_distance; |
| |
| for_each_online_node(node) { |
| score = group_weight(p, node, dist); |
| if (score > max_score) { |
| max_score = score; |
| max_node = node; |
| } |
| } |
| return max_node; |
| } |
| |
| /* |
| * Finding the preferred nid in a system with NUMA backplane |
| * interconnect topology is more involved. The goal is to locate |
| * tasks from numa_groups near each other in the system, and |
| * untangle workloads from different sides of the system. This requires |
| * searching down the hierarchy of node groups, recursively searching |
| * inside the highest scoring group of nodes. The nodemask tricks |
| * keep the complexity of the search down. |
| */ |
| nodes = node_online_map; |
| for (dist = sched_max_numa_distance; dist > LOCAL_DISTANCE; dist--) { |
| unsigned long max_faults = 0; |
| nodemask_t max_group = NODE_MASK_NONE; |
| int a, b; |
| |
| /* Are there nodes at this distance from each other? */ |
| if (!find_numa_distance(dist)) |
| continue; |
| |
| for_each_node_mask(a, nodes) { |
| unsigned long faults = 0; |
| nodemask_t this_group; |
| nodes_clear(this_group); |
| |
| /* Sum group's NUMA faults; includes a==b case. */ |
| for_each_node_mask(b, nodes) { |
| if (node_distance(a, b) < dist) { |
| faults += group_faults(p, b); |
| node_set(b, this_group); |
| node_clear(b, nodes); |
| } |
| } |
| |
| /* Remember the top group. */ |
| if (faults > max_faults) { |
| max_faults = faults; |
| max_group = this_group; |
| /* |
| * subtle: at the smallest distance there is |
| * just one node left in each "group", the |
| * winner is the preferred nid. |
| */ |
| nid = a; |
| } |
| } |
| /* Next round, evaluate the nodes within max_group. */ |
| if (!max_faults) |
| break; |
| nodes = max_group; |
| } |
| return nid; |
| } |
| |
| static void task_numa_placement(struct task_struct *p) |
| { |
| int seq, nid, max_nid = -1, max_group_nid = -1; |
| unsigned long max_faults = 0, max_group_faults = 0; |
| unsigned long fault_types[2] = { 0, 0 }; |
| unsigned long total_faults; |
| u64 runtime, period; |
| spinlock_t *group_lock = NULL; |
| |
| /* |
| * The p->mm->numa_scan_seq field gets updated without |
| * exclusive access. Use READ_ONCE() here to ensure |
| * that the field is read in a single access: |
| */ |
| seq = READ_ONCE(p->mm->numa_scan_seq); |
| if (p->numa_scan_seq == seq) |
| return; |
| p->numa_scan_seq = seq; |
| p->numa_scan_period_max = task_scan_max(p); |
| |
| total_faults = p->numa_faults_locality[0] + |
| p->numa_faults_locality[1]; |
| runtime = numa_get_avg_runtime(p, &period); |
| |
| /* If the task is part of a group prevent parallel updates to group stats */ |
| if (p->numa_group) { |
| group_lock = &p->numa_group->lock; |
| spin_lock_irq(group_lock); |
| } |
| |
| /* Find the node with the highest number of faults */ |
| for_each_online_node(nid) { |
| /* Keep track of the offsets in numa_faults array */ |
| int mem_idx, membuf_idx, cpu_idx, cpubuf_idx; |
| unsigned long faults = 0, group_faults = 0; |
| int priv; |
| |
| for (priv = 0; priv < NR_NUMA_HINT_FAULT_TYPES; priv++) { |
| long diff, f_diff, f_weight; |
| |
| mem_idx = task_faults_idx(NUMA_MEM, nid, priv); |
| membuf_idx = task_faults_idx(NUMA_MEMBUF, nid, priv); |
| cpu_idx = task_faults_idx(NUMA_CPU, nid, priv); |
| cpubuf_idx = task_faults_idx(NUMA_CPUBUF, nid, priv); |
| |
| /* Decay existing window, copy faults since last scan */ |
| diff = p->numa_faults[membuf_idx] - p->numa_faults[mem_idx] / 2; |
| fault_types[priv] += p->numa_faults[membuf_idx]; |
| p->numa_faults[membuf_idx] = 0; |
| |
| /* |
| * Normalize the faults_from, so all tasks in a group |
| * count according to CPU use, instead of by the raw |
| * number of faults. Tasks with little runtime have |
| * little over-all impact on throughput, and thus their |
| * faults are less important. |
| */ |
| f_weight = div64_u64(runtime << 16, period + 1); |
| f_weight = (f_weight * p->numa_faults[cpubuf_idx]) / |
| (total_faults + 1); |
| f_diff = f_weight - p->numa_faults[cpu_idx] / 2; |
| p->numa_faults[cpubuf_idx] = 0; |
| |
| p->numa_faults[mem_idx] += diff; |
| p->numa_faults[cpu_idx] += f_diff; |
| faults += p->numa_faults[mem_idx]; |
| p->total_numa_faults += diff; |
| if (p->numa_group) { |
| /* |
| * safe because we can only change our own group |
| * |
| * mem_idx represents the offset for a given |
| * nid and priv in a specific region because it |
| * is at the beginning of the numa_faults array. |
| */ |
| p->numa_group->faults[mem_idx] += diff; |
| p->numa_group->faults_cpu[mem_idx] += f_diff; |
| p->numa_group->total_faults += diff; |
| group_faults += p->numa_group->faults[mem_idx]; |
| } |
| } |
| |
| if (faults > max_faults) { |
| max_faults = faults; |
| max_nid = nid; |
| } |
| |
| if (group_faults > max_group_faults) { |
| max_group_faults = group_faults; |
| max_group_nid = nid; |
| } |
| } |
| |
| update_task_scan_period(p, fault_types[0], fault_types[1]); |
| |
| if (p->numa_group) { |
| numa_group_count_active_nodes(p->numa_group); |
| spin_unlock_irq(group_lock); |
| max_nid = preferred_group_nid(p, max_group_nid); |
| } |
| |
| if (max_faults) { |
| /* Set the new preferred node */ |
| if (max_nid != p->numa_preferred_nid) |
| sched_setnuma(p, max_nid); |
| |
| if (task_node(p) != p->numa_preferred_nid) |
| numa_migrate_preferred(p); |
| } |
| } |
| |
| static inline int get_numa_group(struct numa_group *grp) |
| { |
| return atomic_inc_not_zero(&grp->refcount); |
| } |
| |
| static inline void put_numa_group(struct numa_group *grp) |
| { |
| if (atomic_dec_and_test(&grp->refcount)) |
| kfree_rcu(grp, rcu); |
| } |
| |
| static void task_numa_group(struct task_struct *p, int cpupid, int flags, |
| int *priv) |
| { |
| struct numa_group *grp, *my_grp; |
| struct task_struct *tsk; |
| bool join = false; |
| int cpu = cpupid_to_cpu(cpupid); |
| int i; |
| |
| if (unlikely(!p->numa_group)) { |
| unsigned int size = sizeof(struct numa_group) + |
| 4*nr_node_ids*sizeof(unsigned long); |
| |
| grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); |
| if (!grp) |
| return; |
| |
| atomic_set(&grp->refcount, 1); |
| grp->active_nodes = 1; |
| grp->max_faults_cpu = 0; |
| spin_lock_init(&grp->lock); |
| grp->gid = p->pid; |
| /* Second half of the array tracks nids where faults happen */ |
| grp->faults_cpu = grp->faults + NR_NUMA_HINT_FAULT_TYPES * |
| nr_node_ids; |
| |
| for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) |
| grp->faults[i] = p->numa_faults[i]; |
| |
| grp->total_faults = p->total_numa_faults; |
| |
| grp->nr_tasks++; |
| rcu_assign_pointer(p->numa_group, grp); |
| } |
| |
| rcu_read_lock(); |
| tsk = READ_ONCE(cpu_rq(cpu)->curr); |
| |
| if (!cpupid_match_pid(tsk, cpupid)) |
| goto no_join; |
| |
| grp = rcu_dereference(tsk->numa_group); |
| if (!grp) |
| goto no_join; |
| |
| my_grp = p->numa_group; |
| if (grp == my_grp) |
| goto no_join; |
| |
| /* |
| * Only join the other group if its bigger; if we're the bigger group, |
| * the other task will join us. |
| */ |
| if (my_grp->nr_tasks > grp->nr_tasks) |
| goto no_join; |
| |
| /* |
| * Tie-break on the grp address. |
| */ |
| if (my_grp->nr_tasks == grp->nr_tasks && my_grp > grp) |
| goto no_join; |
| |
| /* Always join threads in the same process. */ |
| if (tsk->mm == current->mm) |
| join = true; |
| |
| /* Simple filter to avoid false positives due to PID collisions */ |
| if (flags & TNF_SHARED) |
| join = true; |
| |
| /* Update priv based on whether false sharing was detected */ |
| *priv = !join; |
| |
| if (join && !get_numa_group(grp)) |
| goto no_join; |
| |
| rcu_read_unlock(); |
| |
| if (!join) |
| return; |
| |
| BUG_ON(irqs_disabled()); |
| double_lock_irq(&my_grp->lock, &grp->lock); |
| |
| for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) { |
| my_grp->faults[i] -= p->numa_faults[i]; |
| grp->faults[i] += p->numa_faults[i]; |
| } |
| my_grp->total_faults -= p->total_numa_faults; |
| grp->total_faults += p->total_numa_faults; |
| |
| my_grp->nr_tasks--; |
| grp->nr_tasks++; |
| |
| spin_unlock(&my_grp->lock); |
| spin_unlock_irq(&grp->lock); |
| |
| rcu_assign_pointer(p->numa_group, grp); |
| |
| put_numa_group(my_grp); |
| return; |
| |
| no_join: |
| rcu_read_unlock(); |
| return; |
| } |
| |
| /* |
| * Get rid of NUMA staticstics associated with a task (either current or dead). |
| * If @final is set, the task is dead and has reached refcount zero, so we can |
| * safely free all relevant data structures. Otherwise, there might be |
| * concurrent reads from places like load balancing and procfs, and we should |
| * reset the data back to default state without freeing ->numa_faults. |
| */ |
| void task_numa_free(struct task_struct *p, bool final) |
| { |
| struct numa_group *grp = p->numa_group; |
| unsigned long *numa_faults = p->numa_faults; |
| unsigned long flags; |
| int i; |
| |
| if (!numa_faults) |
| return; |
| |
| if (grp) { |
| spin_lock_irqsave(&grp->lock, flags); |
| for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) |
| grp->faults[i] -= p->numa_faults[i]; |
| grp->total_faults -= p->total_numa_faults; |
| |
| grp->nr_tasks--; |
| spin_unlock_irqrestore(&grp->lock, flags); |
| RCU_INIT_POINTER(p->numa_group, NULL); |
| put_numa_group(grp); |
| } |
| |
| if (final) { |
| p->numa_faults = NULL; |
| kfree(numa_faults); |
| } else { |
| p->total_numa_faults = 0; |
| for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) |
| numa_faults[i] = 0; |
| } |
| } |
| |
| /* |
| * Got a PROT_NONE fault for a page on @node. |
| */ |
| void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags) |
| { |
| struct task_struct *p = current; |
| bool migrated = flags & TNF_MIGRATED; |
| int cpu_node = task_node(current); |
| int local = !!(flags & TNF_FAULT_LOCAL); |
| struct numa_group *ng; |
| int priv; |
| |
| if (!static_branch_likely(&sched_numa_balancing)) |
| return; |
| |
| /* for example, ksmd faulting in a user's mm */ |
| if (!p->mm) |
| return; |
| |
| /* Allocate buffer to track faults on a per-node basis */ |
| if (unlikely(!p->numa_faults)) { |
| int size = sizeof(*p->numa_faults) * |
| NR_NUMA_HINT_FAULT_BUCKETS * nr_node_ids; |
| |
| p->numa_faults = kzalloc(size, GFP_KERNEL|__GFP_NOWARN); |
| if (!p->numa_faults) |
| return; |
| |
| p->total_numa_faults = 0; |
| memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality)); |
| } |
| |
| /* |
| * First accesses are treated as private, otherwise consider accesses |
| * to be private if the accessing pid has not changed |
| */ |
| if (unlikely(last_cpupid == (-1 & LAST_CPUPID_MASK))) { |
| priv = 1; |
| } else { |
| priv = cpupid_match_pid(p, last_cpupid); |
| if (!priv && !(flags & TNF_NO_GROUP)) |
| task_numa_group(p, last_cpupid, flags, &priv); |
| } |
| |
| /* |
| * If a workload spans multiple NUMA nodes, a shared fault that |
| * occurs wholly within the set of nodes that the workload is |
| * actively using should be counted as local. This allows the |
| * scan rate to slow down when a workload has settled down. |
| */ |
| ng = p->numa_group; |
| if (!priv && !local && ng && ng->active_nodes > 1 && |
| numa_is_active_node(cpu_node, ng) && |
| numa_is_active_node(mem_node, ng)) |
| local = 1; |
| |
| task_numa_placement(p); |
| |
| /* |
| * Retry task to preferred node migration periodically, in case it |
| * case it previously failed, or the scheduler moved us. |
| */ |
| if (time_after(jiffies, p->numa_migrate_retry)) |
| numa_migrate_preferred(p); |
| |
| if (migrated) |
| p->numa_pages_migrated += pages; |
| if (flags & TNF_MIGRATE_FAIL) |
| p->numa_faults_locality[2] += pages; |
| |
| p->numa_faults[task_faults_idx(NUMA_MEMBUF, mem_node, priv)] += pages; |
| p->numa_faults[task_faults_idx(NUMA_CPUBUF, cpu_node, priv)] += pages; |
| p->numa_faults_locality[local] += pages; |
| } |
| |
| static void reset_ptenuma_scan(struct task_struct *p) |
| { |
| /* |
| * We only did a read acquisition of the mmap sem, so |
| * p->mm->numa_scan_seq is written to without exclusive access |
| * and the update is not guaranteed to be atomic. That's not |
| * much of an issue though, since this is just used for |
| * statistical sampling. Use READ_ONCE/WRITE_ONCE, which are not |
| * expensive, to avoid any form of compiler optimizations: |
| */ |
| WRITE_ONCE(p->mm->numa_scan_seq, READ_ONCE(p->mm->numa_scan_seq) + 1); |
| p->mm->numa_scan_offset = 0; |
| } |
| |
| /* |
| * The expensive part of numa migration is done from task_work context. |
| * Triggered from task_tick_numa(). |
| */ |
| void task_numa_work(struct callback_head *work) |
| { |
| unsigned long migrate, next_scan, now = jiffies; |
| struct task_struct *p = current; |
| struct mm_struct *mm = p->mm; |
| u64 runtime = p->se.sum_exec_runtime; |
| struct vm_area_struct *vma; |
| unsigned long start, end; |
| unsigned long nr_pte_updates = 0; |
| long pages, virtpages; |
| |
| SCHED_WARN_ON(p != container_of(work, struct task_struct, numa_work)); |
| |
| work->next = work; /* protect against double add */ |
| /* |
| * Who cares about NUMA placement when they're dying. |
| * |
| * NOTE: make sure not to dereference p->mm before this check, |
| * exit_task_work() happens _after_ exit_mm() so we could be called |
| * without p->mm even though we still had it when we enqueued this |
| * work. |
| */ |
| if (p->flags & PF_EXITING) |
| return; |
| |
| if (!mm->numa_next_scan) { |
| mm->numa_next_scan = now + |
| msecs_to_jiffies(sysctl_numa_balancing_scan_delay); |
| } |
| |
| /* |
| * Enforce maximal scan/migration frequency.. |
| */ |
| migrate = mm->numa_next_scan; |
| if (time_before(now, migrate)) |
| return; |
| |
| if (p->numa_scan_period == 0) { |
| p->numa_scan_period_max = task_scan_max(p); |
| p->numa_scan_period = task_scan_start(p); |
| } |
| |
| next_scan = now + msecs_to_jiffies(p->numa_scan_period); |
| if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate) |
| return; |
| |
| /* |
| * Delay this task enough that another task of this mm will likely win |
| * the next time around. |
| */ |
| p->node_stamp += 2 * TICK_NSEC; |
| |
| start = mm->numa_scan_offset; |
| pages = sysctl_numa_balancing_scan_size; |
| pages <<= 20 - PAGE_SHIFT; /* MB in pages */ |
| virtpages = pages * 8; /* Scan up to this much virtual space */ |
| if (!pages) |
| return; |
| |
| |
| if (!down_read_trylock(&mm->mmap_sem)) |
| return; |
| vma = find_vma(mm, start); |
| if (!vma) { |
| reset_ptenuma_scan(p); |
| start = 0; |
| vma = mm->mmap; |
| } |
| for (; vma; vma = vma->vm_next) { |
| if (!vma_migratable(vma) || !vma_policy_mof(vma) || |
| is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) { |
| continue; |
| } |
| |
| /* |
| * Shared library pages mapped by multiple processes are not |
| * migrated as it is expected they are cache replicated. Avoid |
| * hinting faults in read-only file-backed mappings or the vdso |
| * as migrating the pages will be of marginal benefit. |
| */ |
| if (!vma->vm_mm || |
| (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ))) |
| continue; |
| |
| /* |
| * Skip inaccessible VMAs to avoid any confusion between |
| * PROT_NONE and NUMA hinting ptes |
| */ |
| if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) |
| continue; |
| |
| do { |
| start = max(start, vma->vm_start); |
| end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE); |
| end = min(end, vma->vm_end); |
| nr_pte_updates = change_prot_numa(vma, start, end); |
| |
| /* |
| * Try to scan sysctl_numa_balancing_size worth of |
| * hpages that have at least one present PTE that |
| * is not already pte-numa. If the VMA contains |
| * areas that are unused or already full of prot_numa |
| * PTEs, scan up to virtpages, to skip through those |
| * areas faster. |
| */ |
| if (nr_pte_updates) |
| pages -= (end - start) >> PAGE_SHIFT; |
| virtpages -= (end - start) >> PAGE_SHIFT; |
| |
| start = end; |
| if (pages <= 0 || virtpages <= 0) |
| goto out; |
| |
| cond_resched(); |
| } while (end != vma->vm_end); |
| } |
| |
| out: |
| /* |
| * It is possible to reach the end of the VMA list but the last few |
| * VMAs are not guaranteed to the vma_migratable. If they are not, we |
| * would find the !migratable VMA on the next scan but not reset the |
| * scanner to the start so check it now. |
| */ |
| if (vma) |
| mm->numa_scan_offset = start; |
| else |
| reset_ptenuma_scan(p); |
| up_read(&mm->mmap_sem); |
| |
| /* |
| * Make sure tasks use at least 32x as much time to run other code |
| * than they used here, to limit NUMA PTE scanning overhead to 3% max. |
| * Usually update_task_scan_period slows down scanning enough; on an |
| * overloaded system we need to limit overhead on a per task basis. |
| */ |
| if (unlikely(p->se.sum_exec_runtime != runtime)) { |
| u64 diff = p->se.sum_exec_runtime - runtime; |
| p->node_stamp += 32 * diff; |
| } |
| } |
| |
| /* |
| * Drive the periodic memory faults.. |
| */ |
| void task_tick_numa(struct rq *rq, struct task_struct *curr) |
| { |
| struct callback_head *work = &curr->numa_work; |
| u64 period, now; |
| |
| /* |
| * We don't care about NUMA placement if we don't have memory. |
| */ |
| if ((curr->flags & (PF_EXITING | PF_KTHREAD)) || work->next != work) |
| return; |
| |
| /* |
| * Using runtime rather than walltime has the dual advantage that |
| * we (mostly) drive the selection from busy threads and that the |
| * task needs to have done some actual work before we bother with |
| * NUMA placement. |
| */ |
| now = curr->se.sum_exec_runtime; |
| period = (u64)curr->numa_scan_period * NSEC_PER_MSEC; |
| |
| if (now > curr->node_stamp + period) { |
| if (!curr->node_stamp) |
| curr->numa_scan_period = task_scan_start(curr); |
| curr->node_stamp += period; |
| |
| if (!time_before(jiffies, curr->mm->numa_next_scan)) { |
| init_task_work(work, task_numa_work); /* TODO: move this into sched_fork() */ |
| task_work_add(curr, work, true); |
| } |
| } |
| } |
| |
| #else |
| static void task_tick_numa(struct rq *rq, struct task_struct *curr) |
| { |
| } |
| |
| static inline void account_numa_enqueue(struct rq *rq, struct task_struct *p) |
| { |
| } |
| |
| static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p) |
| { |
| } |
| |
| #endif /* CONFIG_NUMA_BALANCING */ |
| |
| static void |
| account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| update_load_add(&cfs_rq->load, se->load.weight); |
| if (!parent_entity(se)) |
| update_load_add(&rq_of(cfs_rq)->load, se->load.weight); |
| #ifdef CONFIG_SMP |
| if (entity_is_task(se)) { |
| struct rq *rq = rq_of(cfs_rq); |
| |
| account_numa_enqueue(rq, task_of(se)); |
| list_add(&se->group_node, &rq->cfs_tasks); |
| } |
| #endif |
| cfs_rq->nr_running++; |
| } |
| |
| static void |
| account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| update_load_sub(&cfs_rq->load, se->load.weight); |
| if (!parent_entity(se)) |
| update_load_sub(&rq_of(cfs_rq)->load, se->load.weight); |
| #ifdef CONFIG_SMP |
| if (entity_is_task(se)) { |
| account_numa_dequeue(rq_of(cfs_rq), task_of(se)); |
| list_del_init(&se->group_node); |
| } |
| #endif |
| cfs_rq->nr_running--; |
| } |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| # ifdef CONFIG_SMP |
| static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) |
| { |
| long tg_weight, load, shares; |
| |
| /* |
| * This really should be: cfs_rq->avg.load_avg, but instead we use |
| * cfs_rq->load.weight, which is its upper bound. This helps ramp up |
| * the shares for small weight interactive tasks. |
| */ |
| load = scale_load_down(cfs_rq->load.weight); |
| |
| tg_weight = atomic_long_read(&tg->load_avg); |
| |
| /* Ensure tg_weight >= load */ |
| tg_weight -= cfs_rq->tg_load_avg_contrib; |
| tg_weight += load; |
| |
| shares = (tg->shares * load); |
| if (tg_weight) |
| shares /= tg_weight; |
| |
| /* |
| * MIN_SHARES has to be unscaled here to support per-CPU partitioning |
| * of a group with small tg->shares value. It is a floor value which is |
| * assigned as a minimum load.weight to the sched_entity representing |
| * the group on a CPU. |
| * |
| * E.g. on 64-bit for a group with tg->shares of scale_load(15)=15*1024 |
| * on an 8-core system with 8 tasks each runnable on one CPU shares has |
| * to be 15*1024*1/8=1920 instead of scale_load(MIN_SHARES)=2*1024. In |
| * case no task is runnable on a CPU MIN_SHARES=2 should be returned |
| * instead of 0. |
| */ |
| if (shares < MIN_SHARES) |
| shares = MIN_SHARES; |
| if (shares > tg->shares) |
| shares = tg->shares; |
| |
| return shares; |
| } |
| # else /* CONFIG_SMP */ |
| static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) |
| { |
| return tg->shares; |
| } |
| # endif /* CONFIG_SMP */ |
| |
| static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, |
| unsigned long weight) |
| { |
| if (se->on_rq) { |
| /* commit outstanding execution time */ |
| if (cfs_rq->curr == se) |
| update_curr(cfs_rq); |
| account_entity_dequeue(cfs_rq, se); |
| } |
| |
| update_load_set(&se->load, weight); |
| |
| if (se->on_rq) |
| account_entity_enqueue(cfs_rq, se); |
| } |
| |
| static inline int throttled_hierarchy(struct cfs_rq *cfs_rq); |
| |
| static void update_cfs_shares(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq = group_cfs_rq(se); |
| struct task_group *tg; |
| long shares; |
| |
| if (!cfs_rq) |
| return; |
| |
| if (throttled_hierarchy(cfs_rq)) |
| return; |
| |
| tg = cfs_rq->tg; |
| |
| #ifndef CONFIG_SMP |
| if (likely(se->load.weight == tg->shares)) |
| return; |
| #endif |
| shares = calc_cfs_shares(cfs_rq, tg); |
| |
| reweight_entity(cfs_rq_of(se), se, shares); |
| } |
| |
| #else /* CONFIG_FAIR_GROUP_SCHED */ |
| static inline void update_cfs_shares(struct sched_entity *se) |
| { |
| } |
| #endif /* CONFIG_FAIR_GROUP_SCHED */ |
| |
| static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq) |
| { |
| struct rq *rq = rq_of(cfs_rq); |
| |
| if (&rq->cfs == cfs_rq) { |
| /* |
| * There are a few boundary cases this might miss but it should |
| * get called often enough that that should (hopefully) not be |
| * a real problem -- added to that it only calls on the local |
| * CPU, so if we enqueue remotely we'll miss an update, but |
| * the next tick/schedule should update. |
| * |
| * It will not get called when we go idle, because the idle |
| * thread is a different class (!fair), nor will the utilization |
| * number include things like RT tasks. |
| * |
| * As is, the util number is not freq-invariant (we'd have to |
| * implement arch_scale_freq_capacity() for that). |
| * |
| * See cpu_util(). |
| */ |
| cpufreq_update_util(rq, 0); |
| } |
| } |
| |
| #ifdef CONFIG_SMP |
| /* |
| * Approximate: |
| * val * y^n, where y^32 ~= 0.5 (~1 scheduling period) |
| */ |
| static u64 decay_load(u64 val, u64 n) |
| { |
| unsigned int local_n; |
| |
| if (unlikely(n > LOAD_AVG_PERIOD * 63)) |
| return 0; |
| |
| /* after bounds checking we can collapse to 32-bit */ |
| local_n = n; |
| |
| /* |
| * As y^PERIOD = 1/2, we can combine |
| * y^n = 1/2^(n/PERIOD) * y^(n%PERIOD) |
| * With a look-up table which covers y^n (n<PERIOD) |
| * |
| * To achieve constant time decay_load. |
| */ |
| if (unlikely(local_n >= LOAD_AVG_PERIOD)) { |
| val >>= local_n / LOAD_AVG_PERIOD; |
| local_n %= LOAD_AVG_PERIOD; |
| } |
| |
| val = mul_u64_u32_shr(val, runnable_avg_yN_inv[local_n], 32); |
| return val; |
| } |
| |
| static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3) |
| { |
| u32 c1, c2, c3 = d3; /* y^0 == 1 */ |
| |
| /* |
| * c1 = d1 y^p |
| */ |
| c1 = decay_load((u64)d1, periods); |
| |
| /* |
| * p-1 |
| * c2 = 1024 \Sum y^n |
| * n=1 |
| * |
| * inf inf |
| * = 1024 ( \Sum y^n - \Sum y^n - y^0 ) |
| * n=0 n=p |
| */ |
| c2 = LOAD_AVG_MAX - decay_load(LOAD_AVG_MAX, periods) - 1024; |
| |
| return c1 + c2 + c3; |
| } |
| |
| #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) |
| |
| /* |
| * Accumulate the three separate parts of the sum; d1 the remainder |
| * of the last (incomplete) period, d2 the span of full periods and d3 |
| * the remainder of the (incomplete) current period. |
| * |
| * d1 d2 d3 |
| * ^ ^ ^ |
| * | | | |
| * |<->|<----------------->|<--->| |
| * ... |---x---|------| ... |------|-----x (now) |
| * |
| * p-1 |
| * u' = (u + d1) y^p + 1024 \Sum y^n + d3 y^0 |
| * n=1 |
| * |
| * = u y^p + (Step 1) |
| * |
| * p-1 |
| * d1 y^p + 1024 \Sum y^n + d3 y^0 (Step 2) |
| * n=1 |
| */ |
| static __always_inline u32 |
| accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, |
| unsigned long weight, int running, struct cfs_rq *cfs_rq) |
| { |
| unsigned long scale_freq, scale_cpu; |
| u32 contrib = (u32)delta; /* p == 0 -> delta < 1024 */ |
| u64 periods; |
| |
| scale_freq = arch_scale_freq_capacity(NULL, cpu); |
| scale_cpu = arch_scale_cpu_capacity(NULL, cpu); |
| |
| delta += sa->period_contrib; |
| periods = delta / 1024; /* A period is 1024us (~1ms) */ |
| |
| /* |
| * Step 1: decay old *_sum if we crossed period boundaries. |
| */ |
| if (periods) { |
| sa->load_sum = decay_load(sa->load_sum, periods); |
| sa->loadwop_sum = decay_load(sa->loadwop_sum, periods); |
| if (cfs_rq) { |
| cfs_rq->runnable_load_sum = |
| decay_load(cfs_rq->runnable_load_sum, periods); |
| } |
| sa->util_sum = decay_load((u64)(sa->util_sum), periods); |
| |
| /* |
| * Step 2 |
| */ |
| delta %= 1024; |
| contrib = __accumulate_pelt_segments(periods, |
| 1024 - sa->period_contrib, delta); |
| } |
| sa->period_contrib = delta; |
| |
| contrib = cap_scale(contrib, scale_freq); |
| if (weight) { |
| unsigned long weightwop; |
| |
| weightwop = scale_load_down(NICE_0_LOAD); |
| if (cfs_rq) |
| weightwop *= cfs_rq->h_nr_running; |
| |
| sa->load_sum += weight * contrib; |
| sa->loadwop_sum += weightwop * contrib; |
| if (cfs_rq) |
| cfs_rq->runnable_load_sum += weight * contrib; |
| } |
| if (running) |
| sa->util_sum += contrib * scale_cpu; |
| |
| return periods; |
| } |
| |
| /* |
| * We can represent the historical contribution to runnable average as the |
| * coefficients of a geometric series. To do this we sub-divide our runnable |
| * history into segments of approximately 1ms (1024us); label the segment that |
| * occurred N-ms ago p_N, with p_0 corresponding to the current period, e.g. |
| * |
| * [<- 1024us ->|<- 1024us ->|<- 1024us ->| ... |
| * p0 p1 p2 |
| * (now) (~1ms ago) (~2ms ago) |
| * |
| * Let u_i denote the fraction of p_i that the entity was runnable. |
| * |
| * We then designate the fractions u_i as our co-efficients, yielding the |
| * following representation of historical load: |
| * u_0 + u_1*y + u_2*y^2 + u_3*y^3 + ... |
| * |
| * We choose y based on the with of a reasonably scheduling period, fixing: |
| * y^32 = 0.5 |
| * |
| * This means that the contribution to load ~32ms ago (u_32) will be weighted |
| * approximately half as much as the contribution to load within the last ms |
| * (u_0). |
| * |
| * When a period "rolls over" and we have new u_0`, multiplying the previous |
| * sum again by y is sufficient to update: |
| * load_avg = u_0` + y*(u_0 + u_1*y + u_2*y^2 + ... ) |
| * = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}] |
| */ |
| static __always_inline int |
| ___update_load_avg(u64 now, int cpu, struct sched_avg *sa, |
| unsigned long weight, int running, struct cfs_rq *cfs_rq, |
| struct rt_rq *rt_rq) |
| { |
| u64 delta; |
| |
| delta = now - sa->last_update_time; |
| /* |
| * This should only happen when time goes backwards, which it |
| * unfortunately does during sched clock init when we swap over to TSC. |
| */ |
| if ((s64)delta < 0) { |
| sa->last_update_time = now; |
| return 0; |
| } |
| |
| /* |
| * Use 1024ns as the unit of measurement since it's a reasonable |
| * approximation of 1us and fast to compute. |
| */ |
| delta >>= 10; |
| if (!delta) |
| return 0; |
| |
| sa->last_update_time += delta << 10; |
| |
| /* |
| * running is a subset of runnable (weight) so running can't be set if |
| * runnable is clear. But there are some corner cases where the current |
| * se has been already dequeued but cfs_rq->curr still points to it. |
| * This means that weight will be 0 but not running for a sched_entity |
| * but also for a cfs_rq if the latter becomes idle. As an example, |
| * this happens during idle_balance() which calls |
| * update_blocked_averages() |
| */ |
| if (!weight) |
| running = 0; |
| |
| /* |
| * Now we know we crossed measurement unit boundaries. The *_avg |
| * accrues by two steps: |
| * |
| * Step 1: accumulate *_sum since last_update_time. If we haven't |
| * crossed period boundaries, finish. |
| */ |
| if (!accumulate_sum(delta, cpu, sa, weight, running, cfs_rq)) |
| return 0; |
| |
| /* |
| * Step 2: update *_avg. |
| */ |
| sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib); |
| sa->loadwop_avg = div_u64(sa->loadwop_sum, |
| LOAD_AVG_MAX - 1024 + sa->period_contrib); |
| if (cfs_rq) { |
| cfs_rq->runnable_load_avg = |
| div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib); |
| } |
| sa->util_avg = sa->util_sum / (LOAD_AVG_MAX - 1024 + sa->period_contrib); |
| |
| if (cfs_rq) { |
| trace_sched_load_cfs_rq(cfs_rq); |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| trace_sched_cfs_runnable_load(cpu_of(cfs_rq->rq), |
| cfs_rq->avg.loadwop_avg, cfs_rq->h_nr_running); |
| #endif |
| } |
| else { |
| if (likely(!rt_rq)) |
| trace_sched_load_se(container_of(sa, struct sched_entity, avg)); |
| else |
| trace_sched_load_rt_rq(cpu, rt_rq); |
| } |
| |
| return 1; |
| } |
| |
| /* |
| * When a task is dequeued, its estimated utilization should not be update if |
| * its util_avg has not been updated at least once. |
| * This flag is used to synchronize util_avg updates with util_est updates. |
| * We map this information into the LSB bit of the utilization saved at |
| * dequeue time (i.e. util_est.dequeued). |
| */ |
| #define UTIL_AVG_UNCHANGED 0x1 |
| |
| static inline void cfs_se_util_change(struct sched_avg *avg) |
| { |
| unsigned int enqueued; |
| |
| if (!sched_feat(UTIL_EST)) |
| return; |
| |
| /* Avoid store if the flag has been already set */ |
| enqueued = avg->util_est.enqueued; |
| if (!(enqueued & UTIL_AVG_UNCHANGED)) |
| return; |
| |
| /* Reset flag to report util_avg has been updated */ |
| enqueued &= ~UTIL_AVG_UNCHANGED; |
| WRITE_ONCE(avg->util_est.enqueued, enqueued); |
| } |
| |
| static int |
| __update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se) |
| { |
| return ___update_load_avg(now, cpu, &se->avg, 0, 0, NULL, NULL); |
| } |
| |
| static int |
| __update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| if (___update_load_avg(now, cpu, &se->avg, |
| se->on_rq * scale_load_down(se->load.weight), |
| cfs_rq->curr == se, NULL, NULL)) { |
| cfs_se_util_change(&se->avg); |
| trace_uclamp_util_se(entity_is_task(se), |
| container_of(se, struct task_struct, se), |
| cpu_rq(cpu)); |
| |
| #ifdef UTIL_EST_DEBUG |
| /* |
| * Trace utilization only for actual tasks. |
| * |
| * These trace events are mostly useful to get easier to |
| * read plots for the estimated utilization, where we can |
| * compare it with the actual grow/decrease of the original |
| * PELT signal. |
| * Let's keep them disabled by default in "production kernels". |
| */ |
| if (entity_is_task(se)) { |
| struct task_struct *tsk = task_of(se); |
| |
| trace_sched_util_est_task(tsk, &se->avg); |
| |
| /* Trace utilization only for top level CFS RQ */ |
| cfs_rq = &(task_rq(tsk)->cfs); |
| trace_sched_util_est_cpu(cpu, cfs_rq); |
| } |
| #endif /* UTIL_EST_DEBUG */ |
| |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| static int |
| __update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq) |
| { |
| int ret; |
| bool __maybe_unused is_root_rq = (&cpu_rq(cpu)->cfs == cfs_rq); |
| |
| ret = ___update_load_avg(now, cpu, &cfs_rq->avg, |
| scale_load_down(cfs_rq->load.weight), |
| cfs_rq->curr != NULL, cfs_rq, NULL); |
| |
| trace_uclamp_util_cfs(is_root_rq, cpu, cfs_rq); |
| return ret; |
| } |
| |
| /* |
| * Signed add and clamp on underflow. |
| * |
| * Explicitly do a load-store to ensure the intermediate value never hits |
| * memory. This allows lockless observations without ever seeing the negative |
| * values. |
| */ |
| #define add_positive(_ptr, _val) do { \ |
| typeof(_ptr) ptr = (_ptr); \ |
| typeof(_val) val = (_val); \ |
| typeof(*ptr) res, var = READ_ONCE(*ptr); \ |
| \ |
| res = var + val; \ |
| \ |
| if (val < 0 && res > var) \ |
| res = 0; \ |
| \ |
| WRITE_ONCE(*ptr, res); \ |
| } while (0) |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| /** |
| * update_tg_load_avg - update the tg's load avg |
| * @cfs_rq: the cfs_rq whose avg changed |
| * @force: update regardless of how small the difference |
| * |
| * This function 'ensures': tg->load_avg := \Sum tg->cfs_rq[]->avg.load. |
| * However, because tg->load_avg is a global value there are performance |
| * considerations. |
| * |
| * In order to avoid having to look at the other cfs_rq's, we use a |
| * differential update where we store the last value we propagated. This in |
| * turn allows skipping updates if the differential is 'small'. |
| * |
| * Updating tg's load_avg is necessary before update_cfs_share(). |
| */ |
| static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) |
| { |
| long delta = cfs_rq->avg.load_avg - cfs_rq->tg_load_avg_contrib; |
| |
| /* |
| * No need to update load_avg for root_task_group as it is not used. |
| */ |
| if (cfs_rq->tg == &root_task_group) |
| return; |
| |
| if (force || abs(delta) > cfs_rq->tg_load_avg_contrib / 64) { |
| atomic_long_add(delta, &cfs_rq->tg->load_avg); |
| cfs_rq->tg_load_avg_contrib = cfs_rq->avg.load_avg; |
| } |
| |
| trace_sched_load_tg(cfs_rq); |
| } |
| |
| /* |
| * Called within set_task_rq() right before setting a task's cpu. The |
| * caller only guarantees p->pi_lock is held; no other assumptions, |
| * including the state of rq->lock, should be made. |
| */ |
| void set_task_rq_fair(struct sched_entity *se, |
| struct cfs_rq *prev, struct cfs_rq *next) |
| { |
| u64 p_last_update_time; |
| u64 n_last_update_time; |
| |
| if (!sched_feat(ATTACH_AGE_LOAD)) |
| return; |
| |
| /* |
| * We are supposed to update the task to "current" time, then its up to |
| * date and ready to go to new CPU/cfs_rq. But we have difficulty in |
| * getting what current time is, so simply throw away the out-of-date |
| * time. This will result in the wakee task is less decayed, but giving |
| * the wakee more load sounds not bad. |
| */ |
| if (!(se->avg.last_update_time && prev)) |
| return; |
| |
| #ifndef CONFIG_64BIT |
| { |
| u64 p_last_update_time_copy; |
| u64 n_last_update_time_copy; |
| |
| do { |
| p_last_update_time_copy = prev->load_last_update_time_copy; |
| n_last_update_time_copy = next->load_last_update_time_copy; |
| |
| smp_rmb(); |
| |
| p_last_update_time = prev->avg.last_update_time; |
| n_last_update_time = next->avg.last_update_time; |
| |
| } while (p_last_update_time != p_last_update_time_copy || |
| n_last_update_time != n_last_update_time_copy); |
| } |
| #else |
| p_last_update_time = prev->avg.last_update_time; |
| n_last_update_time = next->avg.last_update_time; |
| #endif |
| __update_load_avg_blocked_se(p_last_update_time, cpu_of(rq_of(prev)), se); |
| se->avg.last_update_time = n_last_update_time; |
| } |
| |
| /* Take into account change of utilization of a child task group */ |
| static inline void |
| update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| struct cfs_rq *gcfs_rq = group_cfs_rq(se); |
| long delta = gcfs_rq->avg.util_avg - se->avg.util_avg; |
| |
| /* Nothing to update */ |
| if (!delta) |
| return; |
| |
| /* Set new sched_entity's utilization */ |
| se->avg.util_avg = gcfs_rq->avg.util_avg; |
| se->avg.util_sum = se->avg.util_avg * LOAD_AVG_MAX; |
| |
| /* Update parent cfs_rq utilization */ |
| add_positive(&cfs_rq->avg.util_avg, delta); |
| cfs_rq->avg.util_sum = cfs_rq->avg.util_avg * LOAD_AVG_MAX; |
| } |
| |
| /* Take into account change of load of a child task group */ |
| static inline void |
| update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| struct cfs_rq *gcfs_rq = group_cfs_rq(se); |
| long delta, load = gcfs_rq->avg.load_avg; |
| |
| /* |
| * If the load of group cfs_rq is null, the load of the |
| * sched_entity will also be null so we can skip the formula |
| */ |
| if (load) { |
| long tg_load; |
| |
| /* Get tg's load and ensure tg_load > 0 */ |
| tg_load = atomic_long_read(&gcfs_rq->tg->load_avg) + 1; |
| |
| /* Ensure tg_load >= load and updated with current load*/ |
| tg_load -= gcfs_rq->tg_load_avg_contrib; |
| tg_load += load; |
| |
| /* |
| * We need to compute a correction term in the case that the |
| * task group is consuming more CPU than a task of equal |
| * weight. A task with a weight equals to tg->shares will have |
| * a load less or equal to scale_load_down(tg->shares). |
| * Similarly, the sched_entities that represent the task group |
| * at parent level, can't have a load higher than |
| * scale_load_down(tg->shares). And the Sum of sched_entities' |
| * load must be <= scale_load_down(tg->shares). |
| */ |
| if (tg_load > scale_load_down(gcfs_rq->tg->shares)) { |
| /* scale gcfs_rq's load into tg's shares*/ |
| load *= scale_load_down(gcfs_rq->tg->shares); |
| load /= tg_load; |
| } |
| } |
| |
| delta = load - se->avg.load_avg; |
| |
| /* Nothing to update */ |
| if (!delta) |
| return; |
| |
| /* Set new sched_entity's load */ |
| se->avg.load_avg = load; |
| se->avg.load_sum = se->avg.load_avg * LOAD_AVG_MAX; |
| |
| /* Update parent cfs_rq load */ |
| add_positive(&cfs_rq->avg.load_avg, delta); |
| cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * LOAD_AVG_MAX; |
| |
| /* |
| * If the sched_entity is already enqueued, we also have to update the |
| * runnable load avg. |
| */ |
| if (se->on_rq) { |
| /* Update parent cfs_rq runnable_load_avg */ |
| add_positive(&cfs_rq->runnable_load_avg, delta); |
| cfs_rq->runnable_load_sum = cfs_rq->runnable_load_avg * LOAD_AVG_MAX; |
| } |
| } |
| |
| static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq) |
| { |
| cfs_rq->propagate_avg = 1; |
| } |
| |
| static inline int test_and_clear_tg_cfs_propagate(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq = group_cfs_rq(se); |
| |
| if (!cfs_rq->propagate_avg) |
| return 0; |
| |
| cfs_rq->propagate_avg = 0; |
| return 1; |
| } |
| |
| /* Update task and its cfs_rq load average */ |
| static inline int propagate_entity_load_avg(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq; |
| |
| if (entity_is_task(se)) |
| return 0; |
| |
| if (!test_and_clear_tg_cfs_propagate(se)) |
| return 0; |
| |
| cfs_rq = cfs_rq_of(se); |
| |
| set_tg_cfs_propagate(cfs_rq); |
| |
| update_tg_cfs_util(cfs_rq, se); |
| update_tg_cfs_load(cfs_rq, se); |
| |
| trace_sched_load_cfs_rq(cfs_rq); |
| trace_sched_load_se(se); |
| |
| return 1; |
| } |
| |
| /* |
| * Check if we need to update the load and the utilization of a blocked |
| * group_entity: |
| */ |
| static inline bool skip_blocked_update(struct sched_entity *se) |
| { |
| struct cfs_rq *gcfs_rq = group_cfs_rq(se); |
| |
| /* |
| * If sched_entity still have not zero load or utilization, we have to |
| * decay it: |
| */ |
| if (se->avg.load_avg || se->avg.util_avg) |
| return false; |
| |
| /* |
| * If there is a pending propagation, we have to update the load and |
| * the utilization of the sched_entity: |
| */ |
| if (gcfs_rq->propagate_avg) |
| return false; |
| |
| /* |
| * Otherwise, the load and the utilization of the sched_entity is |
| * already zero and there is no pending propagation, so it will be a |
| * waste of time to try to decay it: |
| */ |
| return true; |
| } |
| |
| #else /* CONFIG_FAIR_GROUP_SCHED */ |
| |
| static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) {} |
| |
| static inline int propagate_entity_load_avg(struct sched_entity *se) |
| { |
| return 0; |
| } |
| |
| static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq) {} |
| |
| #endif /* CONFIG_FAIR_GROUP_SCHED */ |
| |
| /* |
| * Unsigned subtract and clamp on underflow. |
| * |
| * Explicitly do a load-store to ensure the intermediate value never hits |
| * memory. This allows lockless observations without ever seeing the negative |
| * values. |
| */ |
| #define sub_positive(_ptr, _val) do { \ |
| typeof(_ptr) ptr = (_ptr); \ |
| typeof(*ptr) val = (_val); \ |
| typeof(*ptr) res, var = READ_ONCE(*ptr); \ |
| res = var - val; \ |
| if (res > var) \ |
| res = 0; \ |
| WRITE_ONCE(*ptr, res); \ |
| } while (0) |
| |
| /** |
| * update_cfs_rq_load_avg - update the cfs_rq's load/util averages |
| * @now: current time, as per cfs_rq_clock_task() |
| * @cfs_rq: cfs_rq to update |
| * |
| * The cfs_rq avg is the direct sum of all its entities (blocked and runnable) |
| * avg. The immediate corollary is that all (fair) tasks must be attached, see |
| * post_init_entity_util_avg(). |
| * |
| * cfs_rq->avg is used for task_h_load() and update_cfs_share() for example. |
| * |
| * Returns true if the load decayed or we removed load. |
| * |
| * Since both these conditions indicate a changed cfs_rq->avg.load we should |
| * call update_tg_load_avg() when this function returns true. |
| */ |
| static inline int |
| update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) |
| { |
| struct sched_avg *sa = &cfs_rq->avg; |
| int decayed, removed_load = 0, removed_util = 0; |
| |
| if (atomic_long_read(&cfs_rq->removed_load_avg)) { |
| s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0); |
| sub_positive(&sa->load_avg, r); |
| sub_positive(&sa->load_sum, r * LOAD_AVG_MAX); |
| removed_load = 1; |
| set_tg_cfs_propagate(cfs_rq); |
| } |
| |
| if (atomic_long_read(&cfs_rq->removed_util_avg)) { |
| long r = atomic_long_xchg(&cfs_rq->removed_util_avg, 0); |
| sub_positive(&sa->util_avg, r); |
| sub_positive(&sa->util_sum, r * LOAD_AVG_MAX); |
| removed_util = 1; |
| set_tg_cfs_propagate(cfs_rq); |
| } |
| |
| decayed = __update_load_avg_cfs_rq(now, cpu_of(rq_of(cfs_rq)), cfs_rq); |
| |
| #ifndef CONFIG_64BIT |
| smp_wmb(); |
| cfs_rq->load_last_update_time_copy = sa->last_update_time; |
| #endif |
| |
| if (decayed || removed_util) |
| cfs_rq_util_change(cfs_rq); |
| |
| return decayed || removed_load; |
| } |
| |
| int update_rt_rq_load_avg(u64 now, int cpu, struct rt_rq *rt_rq, int running) |
| { |
| int ret; |
| |
| ret = ___update_load_avg(now, cpu, &rt_rq->avg, running, running, NULL, rt_rq); |
| |
| return ret; |
| } |
| |
| /* |
| * Optional action to be done while updating the load average |
| */ |
| #define UPDATE_TG 0x1 |
| #define SKIP_AGE_LOAD 0x2 |
| |
| /* Update task and its cfs_rq load average */ |
| static inline void update_load_avg(struct sched_entity *se, int flags) |
| { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| u64 now = cfs_rq_clock_task(cfs_rq); |
| struct rq *rq = rq_of(cfs_rq); |
| int cpu = cpu_of(rq); |
| int decayed; |
| |
| /* |
| * Track task load average for carrying it to new CPU after migrated, and |
| * track group sched_entity load average for task_h_load calc in migration |
| */ |
| if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) { |
| #ifdef CONFIG_MTK_SCHED_RQAVG_US |
| if (entity_is_task(se) && se->on_rq) |
| inc_nr_heavy_running(0, task_of(se), -1, false); |
| #endif |
| __update_load_avg_se(now, cpu, cfs_rq, se); |
| #ifdef CONFIG_MTK_SCHED_RQAVG_US |
| if (entity_is_task(se) && se->on_rq) |
| inc_nr_heavy_running(1, task_of(se), 1, false); |
| #endif |
| } |
| |
| decayed = update_cfs_rq_load_avg(now, cfs_rq); |
| decayed |= propagate_entity_load_avg(se); |
| |
| if (decayed && (flags & UPDATE_TG)) |
| update_tg_load_avg(cfs_rq, 0); |
| } |
| |
| /** |
| * attach_entity_load_avg - attach this entity to its cfs_rq load avg |
| * @cfs_rq: cfs_rq to attach to |
| * @se: sched_entity to attach |
| * |
| * Must call update_cfs_rq_load_avg() before this, since we rely on |
| * cfs_rq->avg.last_update_time being current. |
| */ |
| static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| se->avg.last_update_time = cfs_rq->avg.last_update_time; |
| cfs_rq->avg.load_avg += se->avg.load_avg; |
| cfs_rq->avg.load_sum += se->avg.load_sum; |
| cfs_rq->avg.util_avg += se->avg.util_avg; |
| cfs_rq->avg.util_sum += se->avg.util_sum; |
| set_tg_cfs_propagate(cfs_rq); |
| |
| cfs_rq_util_change(cfs_rq); |
| |
| trace_sched_load_cfs_rq(cfs_rq); |
| } |
| |
| /** |
| * detach_entity_load_avg - detach this entity from its cfs_rq load avg |
| * @cfs_rq: cfs_rq to detach from |
| * @se: sched_entity to detach |
| * |
| * Must call update_cfs_rq_load_avg() before this, since we rely on |
| * cfs_rq->avg.last_update_time being current. |
| */ |
| static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| |
| sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg); |
| sub_positive(&cfs_rq->avg.load_sum, se->avg.load_sum); |
| sub_positive(&cfs_rq->avg.util_avg, se->avg.util_avg); |
| sub_positive(&cfs_rq->avg.util_sum, se->avg.util_sum); |
| set_tg_cfs_propagate(cfs_rq); |
| |
| cfs_rq_util_change(cfs_rq); |
| |
| trace_sched_load_cfs_rq(cfs_rq); |
| } |
| |
| /* Add the load generated by se into cfs_rq's load average */ |
| static inline void |
| enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| struct sched_avg *sa = &se->avg; |
| |
| cfs_rq->runnable_load_avg += sa->load_avg; |
| cfs_rq->runnable_load_sum += sa->load_sum; |
| |
| if (!sa->last_update_time) { |
| attach_entity_load_avg(cfs_rq, se); |
| update_tg_load_avg(cfs_rq, 0); |
| } |
| |
| #ifdef CONFIG_SCHED_HMP |
| if (sched_feat(SCHED_HMP) && entity_is_task(se)) |
| hmp_enqueue_entity_load_avg(cfs_rq, se); |
| #endif |
| } |
| |
| /* Remove the runnable load generated by se from cfs_rq's runnable load average */ |
| static inline void |
| dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| cfs_rq->runnable_load_avg = |
| max_t(long, cfs_rq->runnable_load_avg - se->avg.load_avg, 0); |
| cfs_rq->runnable_load_sum = |
| max_t(s64, cfs_rq->runnable_load_sum - se->avg.load_sum, 0); |
| |
| #ifdef CONFIG_SCHED_HMP |
| if (sched_feat(SCHED_HMP) && entity_is_task(se)) |
| hmp_dequeue_entity_load_avg(cfs_rq, se); |
| #endif |
| } |
| |
| #ifndef CONFIG_64BIT |
| static inline u64 cfs_rq_last_update_time(struct cfs_rq *cfs_rq) |
| { |
| u64 last_update_time_copy; |
| u64 last_update_time; |
| |
| do { |
| last_update_time_copy = cfs_rq->load_last_update_time_copy; |
| smp_rmb(); |
| last_update_time = cfs_rq->avg.last_update_time; |
| } while (last_update_time != last_update_time_copy); |
| |
| return last_update_time; |
| } |
| #else |
| static inline u64 cfs_rq_last_update_time(struct cfs_rq *cfs_rq) |
| { |
| return cfs_rq->avg.last_update_time; |
| } |
| #endif |
| |
| /* |
| * Synchronize entity load avg of dequeued entity without locking |
| * the previous rq. |
| */ |
| void sync_entity_load_avg(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| u64 last_update_time; |
| |
| last_update_time = cfs_rq_last_update_time(cfs_rq); |
| __update_load_avg_blocked_se(last_update_time, cpu_of(rq_of(cfs_rq)), se); |
| } |
| |
| /* |
| * Task first catches up with cfs_rq, and then subtract |
| * itself from the cfs_rq (task must be off the queue now). |
| */ |
| void remove_entity_load_avg(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| |
| /* |
| * tasks cannot exit without having gone through wake_up_new_task() -> |
| * post_init_entity_util_avg() which will have added things to the |
| * cfs_rq, so we can remove unconditionally. |
| * |
| * Similarly for groups, they will have passed through |
| * post_init_entity_util_avg() before unregister_sched_fair_group() |
| * calls this. |
| */ |
| |
| sync_entity_load_avg(se); |
| atomic_long_add(se->avg.load_avg, &cfs_rq->removed_load_avg); |
| atomic_long_add(se->avg.util_avg, &cfs_rq->removed_util_avg); |
| } |
| |
| static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq) |
| { |
| return cfs_rq->runnable_load_avg; |
| } |
| |
| static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq) |
| { |
| return cfs_rq->avg.load_avg; |
| } |
| |
| static int idle_balance(struct rq *this_rq, struct rq_flags *rf); |
| |
| static inline int task_fits_capacity(struct task_struct *p, long capacity); |
| |
| static inline void update_misfit_status(struct task_struct *p, struct rq *rq) |
| { |
| if (!static_branch_unlikely(&sched_asym_cpucapacity)) |
| return; |
| |
| if (!p) { |
| rq->misfit_task_load = 0; |
| return; |
| } |
| |
| if (task_fits_capacity(p, capacity_of(cpu_of(rq)))) { |
| rq->misfit_task_load = 0; |
| return; |
| } |
| |
| rq->misfit_task_load = task_h_load(p); |
| } |
| |
| #ifdef OPLUS_FEATURE_SPECIALOPT |
| // Liujie.Xie@TECH.Kernel.Sched, 2020/02/26, add for heavy load task |
| inline unsigned long task_util(struct task_struct *p) |
| #else |
| static inline unsigned long task_util(struct task_struct *p) |
| #endif |
| { |
| #ifdef CONFIG_SCHED_WALT |
| if (likely(!walt_disabled && sysctl_sched_use_walt_task_util)) |
| return (p->ravg.demand / |
| (walt_ravg_window >> SCHED_CAPACITY_SHIFT)); |
| #endif |
| return READ_ONCE(p->se.avg.util_avg); |
| } |
| |
| static inline unsigned long _task_util_est(struct task_struct *p) |
| { |
| struct util_est ue = READ_ONCE(p->se.avg.util_est); |
| |
| return max(ue.ewma, ue.enqueued); |
| } |
| |
| unsigned long task_util_est(struct task_struct *p) |
| { |
| #ifdef CONFIG_SCHED_WALT |
| if (likely(!walt_disabled && sysctl_sched_use_walt_task_util)) |
| return (p->ravg.demand / |
| (walt_ravg_window >> SCHED_CAPACITY_SHIFT)); |
| #endif |
| return max(task_util(p), _task_util_est(p)); |
| } |
| |
| static inline void util_est_enqueue(struct cfs_rq *cfs_rq, |
| struct task_struct *p) |
| { |
| unsigned int enqueued; |
| |
| if (!sched_feat(UTIL_EST)) |
| return; |
| |
| /* Update root cfs_rq's estimated utilization */ |
| enqueued = cfs_rq->avg.util_est.enqueued; |
| enqueued += (_task_util_est(p) | UTIL_AVG_UNCHANGED); |
| WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued); |
| |
| trace_sched_util_est_task(p, &p->se.avg); |
| trace_sched_util_est_cpu(cpu_of(rq_of(cfs_rq)), cfs_rq); |
| } |
| |
| /* |
| * Check if a (signed) value is within a specified (unsigned) margin, |
| * based on the observation that: |
| * |
| * abs(x) < y := (unsigned)(x + y - 1) < (2 * y - 1) |
| * |
| * NOTE: this only works when value + maring < INT_MAX. |
| */ |
| static inline bool within_margin(int value, int margin) |
| { |
| return ((unsigned int)(value + margin - 1) < (2 * margin - 1)); |
| } |
| |
| static void |
| util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep) |
| { |
| long last_ewma_diff; |
| struct util_est ue; |
| |
| if (!sched_feat(UTIL_EST)) |
| return; |
| |
| /* |
| * Update root cfs_rq's estimated utilization |
| * |
| * If *p is the last task then the root cfs_rq's estimated utilization |
| * of a CPU is 0 by definition. |
| */ |
| ue.enqueued = 0; |
| if (cfs_rq->nr_running) { |
| ue.enqueued = cfs_rq->avg.util_est.enqueued; |
| ue.enqueued -= min_t(unsigned int, ue.enqueued, |
| (_task_util_est(p) | UTIL_AVG_UNCHANGED)); |
| } |
| WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued); |
| |
| trace_sched_util_est_cpu(cpu_of(rq_of(cfs_rq)), cfs_rq); |
| |
| /* |
| * Skip update of task's estimated utilization when the task has not |
| * yet completed an activation, e.g. being migrated. |
| */ |
| if (!task_sleep) |
| return; |
| |
| /* |
| * If the PELT values haven't changed since enqueue time, |
| * skip the util_est update. |
| */ |
| ue = p->se.avg.util_est; |
| if (ue.enqueued & UTIL_AVG_UNCHANGED) |
| return; |
| |
| /* |
| * Skip update of task's estimated utilization when its EWMA is |
| * already ~1% close to its last activation value. |
| */ |
| ue.enqueued = (task_util(p) | UTIL_AVG_UNCHANGED); |
| last_ewma_diff = ue.enqueued - ue.ewma; |
| if (within_margin(last_ewma_diff, (SCHED_CAPACITY_SCALE / 100))) |
| return; |
| |
| /* |
| * Update Task's estimated utilization |
| * |
| * When *p completes an activation we can consolidate another sample |
| * of the task size. This is done by storing the current PELT value |
| * as ue.enqueued and by using this value to update the Exponential |
| * Weighted Moving Average (EWMA): |
| * |
| * ewma(t) = w * task_util(p) + (1-w) * ewma(t-1) |
| * = w * task_util(p) + ewma(t-1) - w * ewma(t-1) |
| * = w * (task_util(p) - ewma(t-1)) + ewma(t-1) |
| * = w * ( last_ewma_diff ) + ewma(t-1) |
| * = w * (last_ewma_diff + ewma(t-1) / w) |
| * |
| * Where 'w' is the weight of new samples, which is configured to be |
| * 0.25, thus making w=1/4 ( >>= UTIL_EST_WEIGHT_SHIFT) |
| */ |
| ue.ewma <<= UTIL_EST_WEIGHT_SHIFT; |
| ue.ewma += last_ewma_diff; |
| ue.ewma >>= UTIL_EST_WEIGHT_SHIFT; |
| WRITE_ONCE(p->se.avg.util_est, ue); |
| |
| trace_sched_util_est_task(p, &p->se.avg); |
| } |
| |
| #else /* CONFIG_SMP */ |
| |
| static inline int |
| update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) |
| { |
| return 0; |
| } |
| |
| int update_rt_rq_load_avg(u64 now, int cpu, struct rt_rq *rt_rq, int running) |
| { |
| return 0; |
| } |
| |
| #define UPDATE_TG 0x0 |
| #define SKIP_AGE_LOAD 0x0 |
| |
| static inline void update_load_avg(struct sched_entity *se, int not_used1) |
| { |
| cfs_rq_util_change(cfs_rq_of(se)); |
| } |
| |
| static inline void |
| enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} |
| static inline void |
| dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} |
| static inline void remove_entity_load_avg(struct sched_entity *se) {} |
| |
| static inline void |
| attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} |
| static inline void |
| detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} |
| |
| static inline int idle_balance(struct rq *rq, struct rq_flags *rf) |
| { |
| return 0; |
| } |
| |
| static inline void update_misfit_status(struct task_struct *p, struct rq *rq) {} |
| |
| static inline void |
| util_est_enqueue(struct cfs_rq *cfs_rq, struct task_struct *p) {} |
| |
| static inline void |
| util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, |
| bool task_sleep) {} |
| |
| #endif /* CONFIG_SMP */ |
| |
| static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| #ifdef CONFIG_SCHED_DEBUG |
| s64 d = se->vruntime - cfs_rq->min_vruntime; |
| |
| if (d < 0) |
| d = -d; |
| |
| if (d > 3*sysctl_sched_latency) |
| schedstat_inc(cfs_rq->nr_spread_over); |
| #endif |
| } |
| |
| static inline bool entity_is_long_sleeper(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq; |
| u64 sleep_time; |
| |
| if (se->exec_start == 0) |
| return false; |
| |
| cfs_rq = cfs_rq_of(se); |
| |
| sleep_time = rq_clock_task(rq_of(cfs_rq)); |
| |
| /* Happen while migrating because of clock task divergence */ |
| if (sleep_time <= se->exec_start) |
| return false; |
| |
| sleep_time -= se->exec_start; |
| if (sleep_time > ((1ULL << 63) / scale_load_down(NICE_0_LOAD))) |
| return true; |
| |
| return false; |
| } |
| |
| static void |
| place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) |
| { |
| u64 vruntime = cfs_rq->min_vruntime; |
| |
| /* |
| * The 'current' period is already promised to the current tasks, |
| * however the extra weight of the new task will slow them down a |
| * little, place the new task so that it fits in the slot that |
| * stays open at the end. |
| */ |
| if (initial && sched_feat(START_DEBIT)) |
| vruntime += sched_vslice(cfs_rq, se); |
| |
| /* sleeps up to a single latency don't count. */ |
| if (!initial) { |
| unsigned long thresh = sysctl_sched_latency; |
| |
| /* |
| * Halve their sleep time's effect, to allow |
| * for a gentler effect of sleepers: |
| */ |
| if (sched_feat(GENTLE_FAIR_SLEEPERS)) |
| thresh >>= 1; |
| |
| vruntime -= thresh; |
| } |
| |
| #ifdef OPLUS_FEATURE_UIFIRST |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/08/18, Add for UIFirst |
| place_entity_adjust_ux_task(cfs_rq, se, initial); |
| #endif |
| |
| /* |
| * Pull vruntime of the entity being placed to the base level of |
| * cfs_rq, to prevent boosting it if placed backwards. |
| * However, min_vruntime can advance much faster than real time, with |
| * the extreme being when an entity with the minimal weight always runs |
| * on the cfs_rq. If the waking entity slept for a long time, its |
| * vruntime difference from min_vruntime may overflow s64 and their |
| * comparison may get inversed, so ignore the entity's original |
| * vruntime in that case. |
| * The maximal vruntime speedup is given by the ratio of normal to |
| * minimal weight: scale_load_down(NICE_0_LOAD) / MIN_SHARES. |
| * When placing a migrated waking entity, its exec_start has been set |
| * from a different rq. In order to take into account a possible |
| * divergence between new and prev rq's clocks task because of irq and |
| * stolen time, we take an additional margin. |
| * So, cutting off on the sleep time of |
| * 2^63 / scale_load_down(NICE_0_LOAD) ~ 104 days |
| * should be safe. |
| */ |
| if (entity_is_long_sleeper(se)) |
| se->vruntime = vruntime; |
| else |
| se->vruntime = max_vruntime(se->vruntime, vruntime); |
| } |
| |
| static void check_enqueue_throttle(struct cfs_rq *cfs_rq); |
| |
| static inline void check_schedstat_required(void) |
| { |
| #ifdef CONFIG_SCHEDSTATS |
| if (schedstat_enabled()) |
| return; |
| |
| /* Force schedstat enabled if a dependent tracepoint is active */ |
| if (trace_sched_stat_wait_enabled() || |
| trace_sched_stat_sleep_enabled() || |
| trace_sched_stat_iowait_enabled() || |
| trace_sched_stat_blocked_enabled() || |
| trace_sched_stat_runtime_enabled()) { |
| printk_deferred_once("Scheduler tracepoints stat_sleep, stat_iowait, " |
| "stat_blocked and stat_runtime require the " |
| "kernel parameter schedstats=enable or " |
| "kernel.sched_schedstats=1\n"); |
| } |
| #endif |
| } |
| |
| |
| /* |
| * MIGRATION |
| * |
| * dequeue |
| * update_curr() |
| * update_min_vruntime() |
| * vruntime -= min_vruntime |
| * |
| * enqueue |
| * update_curr() |
| * update_min_vruntime() |
| * vruntime += min_vruntime |
| * |
| * this way the vruntime transition between RQs is done when both |
| * min_vruntime are up-to-date. |
| * |
| * WAKEUP (remote) |
| * |
| * ->migrate_task_rq_fair() (p->state == TASK_WAKING) |
| * vruntime -= min_vruntime |
| * |
| * enqueue |
| * update_curr() |
| * update_min_vruntime() |
| * vruntime += min_vruntime |
| * |
| * this way we don't have the most up-to-date min_vruntime on the originating |
| * CPU and an up-to-date min_vruntime on the destination CPU. |
| */ |
| |
| static void |
| enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) |
| { |
| bool renorm = !(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_MIGRATED); |
| bool curr = cfs_rq->curr == se; |
| |
| /* |
| * If we're the current task, we must renormalise before calling |
| * update_curr(). |
| */ |
| if (renorm && curr) |
| se->vruntime += cfs_rq->min_vruntime; |
| |
| update_curr(cfs_rq); |
| |
| /* |
| * Otherwise, renormalise after, such that we're placed at the current |
| * moment in time, instead of some random moment in the past. Being |
| * placed in the past could significantly boost this task to the |
| * fairness detriment of existing tasks. |
| */ |
| if (renorm && !curr) |
| se->vruntime += cfs_rq->min_vruntime; |
| |
| /* |
| * When enqueuing a sched_entity, we must: |
| * - Update loads to have both entity and cfs_rq synced with now. |
| * - Add its load to cfs_rq->runnable_avg |
| * - For group_entity, update its weight to reflect the new share of |
| * its group cfs_rq |
| * - Add its new weight to cfs_rq->load.weight |
| */ |
| update_load_avg(se, UPDATE_TG); |
| enqueue_entity_load_avg(cfs_rq, se); |
| update_cfs_shares(se); |
| account_entity_enqueue(cfs_rq, se); |
| |
| if (flags & ENQUEUE_WAKEUP) |
| place_entity(cfs_rq, se, 0); |
| /* Entity has migrated, no longer consider this task hot */ |
| if (flags & ENQUEUE_MIGRATED) |
| se->exec_start = 0; |
| |
| check_schedstat_required(); |
| update_stats_enqueue(cfs_rq, se, flags); |
| check_spread(cfs_rq, se); |
| if (!curr) |
| __enqueue_entity(cfs_rq, se); |
| se->on_rq = 1; |
| |
| if (cfs_rq->nr_running == 1) { |
| list_add_leaf_cfs_rq(cfs_rq); |
| check_enqueue_throttle(cfs_rq); |
| } |
| } |
| |
| static void __clear_buddies_last(struct sched_entity *se) |
| { |
| for_each_sched_entity(se) { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| if (cfs_rq->last != se) |
| break; |
| |
| cfs_rq->last = NULL; |
| } |
| } |
| |
| static void __clear_buddies_next(struct sched_entity *se) |
| { |
| for_each_sched_entity(se) { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| if (cfs_rq->next != se) |
| break; |
| |
| cfs_rq->next = NULL; |
| } |
| } |
| |
| static void __clear_buddies_skip(struct sched_entity *se) |
| { |
| for_each_sched_entity(se) { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| if (cfs_rq->skip != se) |
| break; |
| |
| cfs_rq->skip = NULL; |
| } |
| } |
| |
| static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| if (cfs_rq->last == se) |
| __clear_buddies_last(se); |
| |
| if (cfs_rq->next == se) |
| __clear_buddies_next(se); |
| |
| if (cfs_rq->skip == se) |
| __clear_buddies_skip(se); |
| } |
| |
| static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq); |
| |
| static void |
| dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) |
| { |
| /* |
| * Update run-time statistics of the 'current'. |
| */ |
| update_curr(cfs_rq); |
| |
| /* |
| * When dequeuing a sched_entity, we must: |
| * - Update loads to have both entity and cfs_rq synced with now. |
| * - Substract its load from the cfs_rq->runnable_avg. |
| * - Substract its previous weight from cfs_rq->load.weight. |
| * - For group entity, update its weight to reflect the new share |
| * of its group cfs_rq. |
| */ |
| update_load_avg(se, UPDATE_TG); |
| dequeue_entity_load_avg(cfs_rq, se); |
| |
| update_stats_dequeue(cfs_rq, se, flags); |
| |
| clear_buddies(cfs_rq, se); |
| |
| if (se != cfs_rq->curr) |
| __dequeue_entity(cfs_rq, se); |
| se->on_rq = 0; |
| account_entity_dequeue(cfs_rq, se); |
| |
| /* |
| * Normalize after update_curr(); which will also have moved |
| * min_vruntime if @se is the one holding it back. But before doing |
| * update_min_vruntime() again, which will discount @se's position and |
| * can move min_vruntime forward still more. |
| */ |
| if (!(flags & DEQUEUE_SLEEP)) |
| se->vruntime -= cfs_rq->min_vruntime; |
| |
| /* return excess runtime on last dequeue */ |
| return_cfs_rq_runtime(cfs_rq); |
| |
| update_cfs_shares(se); |
| |
| /* |
| * Now advance min_vruntime if @se was the entity holding it back, |
| * except when: DEQUEUE_SAVE && !DEQUEUE_MOVE, in this case we'll be |
| * put back on, and if we advance min_vruntime, we'll be placed back |
| * further than we started -- ie. we'll be penalized. |
| */ |
| if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) != DEQUEUE_SAVE) |
| update_min_vruntime(cfs_rq); |
| } |
| |
| /* |
| * Preempt the current task with a newly woken task if needed: |
| */ |
| static void |
| check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) |
| { |
| unsigned long ideal_runtime, delta_exec; |
| struct sched_entity *se; |
| s64 delta; |
| |
| ideal_runtime = sched_slice(cfs_rq, curr); |
| delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; |
| #ifdef OPLUS_FEATURE_SPECIALOPT |
| // Liujie.Xie@TECH.Kernel.Sched, 2020/02/26, add for heavy load task |
| if (is_heavy_load_task(current)) |
| ideal_runtime = 1024000000; |
| #endif |
| |
| if (delta_exec > ideal_runtime) { |
| resched_curr(rq_of(cfs_rq)); |
| /* |
| * The current task ran long enough, ensure it doesn't get |
| * re-elected due to buddy favours. |
| */ |
| clear_buddies(cfs_rq, curr); |
| return; |
| } |
| |
| #ifdef OPLUS_FEATURE_SPECIALOPT |
| // Liujie.Xie@TECH.Kernel.Sched, 2020/02/26, add for heavy load task |
| if (is_heavy_load_task(current)) |
| return; |
| #endif |
| |
| /* |
| * Ensure that a task that missed wakeup preemption by a |
| * narrow margin doesn't have to wait for a full slice. |
| * This also mitigates buddy induced latencies under load. |
| */ |
| if (delta_exec < sysctl_sched_min_granularity) |
| return; |
| |
| se = __pick_first_entity(cfs_rq); |
| delta = curr->vruntime - se->vruntime; |
| |
| if (delta < 0) |
| return; |
| |
| if (delta > ideal_runtime) |
| resched_curr(rq_of(cfs_rq)); |
| } |
| |
| static void |
| set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) |
| { |
| /* 'current' is not kept within the tree. */ |
| if (se->on_rq) { |
| /* |
| * Any task has to be enqueued before it get to execute on |
| * a CPU. So account for the time it spent waiting on the |
| * runqueue. |
| */ |
| update_stats_wait_end(cfs_rq, se); |
| __dequeue_entity(cfs_rq, se); |
| update_load_avg(se, UPDATE_TG); |
| } |
| |
| update_stats_curr_start(cfs_rq, se); |
| cfs_rq->curr = se; |
| |
| /* |
| * Track our maximum slice length, if the CPU's load is at |
| * least twice that of our own weight (i.e. dont track it |
| * when there are only lesser-weight tasks around): |
| */ |
| if (schedstat_enabled() && rq_of(cfs_rq)->load.weight >= 2*se->load.weight) { |
| schedstat_set(se->statistics.slice_max, |
| max((u64)schedstat_val(se->statistics.slice_max), |
| se->sum_exec_runtime - se->prev_sum_exec_runtime)); |
| } |
| |
| se->prev_sum_exec_runtime = se->sum_exec_runtime; |
| } |
| |
| static int |
| wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se); |
| |
| /* |
| * Pick the next process, keeping these things in mind, in this order: |
| * 1) keep things fair between processes/task groups |
| * 2) pick the "next" process, since someone really wants that to run |
| * 3) pick the "last" process, for cache locality |
| * 4) do not run the "skip" process, if something else is available |
| */ |
| static struct sched_entity * |
| pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr) |
| { |
| struct sched_entity *left = __pick_first_entity(cfs_rq); |
| struct sched_entity *se; |
| |
| /* |
| * If curr is set we have to see if its left of the leftmost entity |
| * still in the tree, provided there was anything in the tree at all. |
| */ |
| if (!left || (curr && entity_before(curr, left))) |
| left = curr; |
| |
| se = left; /* ideally we run the leftmost entity */ |
| |
| /* |
| * Avoid running the skip buddy, if running something else can |
| * be done without getting too unfair. |
| */ |
| if (cfs_rq->skip == se) { |
| struct sched_entity *second; |
| |
| if (se == curr) { |
| second = __pick_first_entity(cfs_rq); |
| } else { |
| second = __pick_next_entity(se); |
| if (!second || (curr && entity_before(curr, second))) |
| second = curr; |
| } |
| |
| if (second && wakeup_preempt_entity(second, left) < 1) |
| se = second; |
| } |
| |
| /* |
| * Prefer last buddy, try to return the CPU to a preempted task. |
| */ |
| if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1) |
| se = cfs_rq->last; |
| |
| /* |
| * Someone really wants this to run. If it's not unfair, run it. |
| */ |
| if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1) |
| se = cfs_rq->next; |
| |
| clear_buddies(cfs_rq, se); |
| |
| return se; |
| } |
| |
| static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq); |
| |
| static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) |
| { |
| /* |
| * If still on the runqueue then deactivate_task() |
| * was not called and update_curr() has to be done: |
| */ |
| if (prev->on_rq) |
| update_curr(cfs_rq); |
| |
| /* throttle cfs_rqs exceeding runtime */ |
| check_cfs_rq_runtime(cfs_rq); |
| |
| check_spread(cfs_rq, prev); |
| |
| if (prev->on_rq) { |
| update_stats_wait_start(cfs_rq, prev); |
| /* Put 'current' back into the tree. */ |
| __enqueue_entity(cfs_rq, prev); |
| /* in !on_rq case, update occurred at dequeue */ |
| update_load_avg(prev, 0); |
| } |
| cfs_rq->curr = NULL; |
| } |
| |
| static void |
| entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) |
| { |
| /* |
| * Update run-time statistics of the 'current'. |
| */ |
| update_curr(cfs_rq); |
| |
| /* |
| * Ensure that runnable average is periodically updated. |
| */ |
| update_load_avg(curr, UPDATE_TG); |
| update_cfs_shares(curr); |
| |
| #ifdef CONFIG_SCHED_HRTICK |
| /* |
| * queued ticks are scheduled to match the slice, so don't bother |
| * validating it and just reschedule. |
| */ |
| if (queued) { |
| resched_curr(rq_of(cfs_rq)); |
| return; |
| } |
| /* |
| * don't let the period tick interfere with the hrtick preemption |
| */ |
| if (!sched_feat(DOUBLE_TICK) && |
| hrtimer_active(&rq_of(cfs_rq)->hrtick_timer)) |
| return; |
| #endif |
| |
| if (cfs_rq->nr_running > 1) |
| check_preempt_tick(cfs_rq, curr); |
| } |
| |
| |
| /************************************************** |
| * CFS bandwidth control machinery |
| */ |
| |
| #ifdef CONFIG_CFS_BANDWIDTH |
| |
| #ifdef HAVE_JUMP_LABEL |
| static struct static_key __cfs_bandwidth_used; |
| |
| static inline bool cfs_bandwidth_used(void) |
| { |
| return static_key_false(&__cfs_bandwidth_used); |
| } |
| |
| void cfs_bandwidth_usage_inc(void) |
| { |
| static_key_slow_inc_cpuslocked(&__cfs_bandwidth_used); |
| } |
| |
| void cfs_bandwidth_usage_dec(void) |
| { |
| static_key_slow_dec_cpuslocked(&__cfs_bandwidth_used); |
| } |
| #else /* HAVE_JUMP_LABEL */ |
| static bool cfs_bandwidth_used(void) |
| { |
| return true; |
| } |
| |
| void cfs_bandwidth_usage_inc(void) {} |
| void cfs_bandwidth_usage_dec(void) {} |
| #endif /* HAVE_JUMP_LABEL */ |
| |
| /* |
| * default period for cfs group bandwidth. |
| * default: 0.1s, units: nanoseconds |
| */ |
| static inline u64 default_cfs_period(void) |
| { |
| return 100000000ULL; |
| } |
| |
| static inline u64 sched_cfs_bandwidth_slice(void) |
| { |
| return (u64)sysctl_sched_cfs_bandwidth_slice * NSEC_PER_USEC; |
| } |
| |
| /* |
| * Replenish runtime according to assigned quota. We use sched_clock_cpu |
| * directly instead of rq->clock to avoid adding additional synchronization |
| * around rq->lock. |
| * |
| * requires cfs_b->lock |
| */ |
| void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b) |
| { |
| if (cfs_b->quota != RUNTIME_INF) |
| cfs_b->runtime = cfs_b->quota; |
| } |
| |
| static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) |
| { |
| return &tg->cfs_bandwidth; |
| } |
| |
| /* rq->task_clock normalized against any time this cfs_rq has spent throttled */ |
| static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq) |
| { |
| if (unlikely(cfs_rq->throttle_count)) |
| return cfs_rq->throttled_clock_task - cfs_rq->throttled_clock_task_time; |
| |
| return rq_clock_task(rq_of(cfs_rq)) - cfs_rq->throttled_clock_task_time; |
| } |
| |
| /* returns 0 on failure to allocate runtime */ |
| static int assign_cfs_rq_runtime(struct cfs_rq *cfs_rq) |
| { |
| struct task_group *tg = cfs_rq->tg; |
| struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg); |
| u64 amount = 0, min_amount; |
| |
| /* note: this is a positive sum as runtime_remaining <= 0 */ |
| min_amount = sched_cfs_bandwidth_slice() - cfs_rq->runtime_remaining; |
| |
| raw_spin_lock(&cfs_b->lock); |
| if (cfs_b->quota == RUNTIME_INF) |
| amount = min_amount; |
| else { |
| start_cfs_bandwidth(cfs_b); |
| |
| if (cfs_b->runtime > 0) { |
| amount = min(cfs_b->runtime, min_amount); |
| cfs_b->runtime -= amount; |
| cfs_b->idle = 0; |
| } |
| } |
| raw_spin_unlock(&cfs_b->lock); |
| |
| cfs_rq->runtime_remaining += amount; |
| |
| return cfs_rq->runtime_remaining > 0; |
| } |
| |
| static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec) |
| { |
| /* dock delta_exec before expiring quota (as it could span periods) */ |
| cfs_rq->runtime_remaining -= delta_exec; |
| |
| if (likely(cfs_rq->runtime_remaining > 0)) |
| return; |
| |
| if (cfs_rq->throttled) |
| return; |
| /* |
| * if we're unable to extend our runtime we resched so that the active |
| * hierarchy can be throttled |
| */ |
| if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr)) |
| resched_curr(rq_of(cfs_rq)); |
| } |
| |
| static __always_inline |
| void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec) |
| { |
| if (!cfs_bandwidth_used() || !cfs_rq->runtime_enabled) |
| return; |
| |
| __account_cfs_rq_runtime(cfs_rq, delta_exec); |
| } |
| |
| static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq) |
| { |
| return cfs_bandwidth_used() && cfs_rq->throttled; |
| } |
| |
| /* check whether cfs_rq, or any parent, is throttled */ |
| static inline int throttled_hierarchy(struct cfs_rq *cfs_rq) |
| { |
| return cfs_bandwidth_used() && cfs_rq->throttle_count; |
| } |
| |
| /* |
| * Ensure that neither of the group entities corresponding to src_cpu or |
| * dest_cpu are members of a throttled hierarchy when performing group |
| * load-balance operations. |
| */ |
| static inline int throttled_lb_pair(struct task_group *tg, |
| int src_cpu, int dest_cpu) |
| { |
| struct cfs_rq *src_cfs_rq, *dest_cfs_rq; |
| |
| src_cfs_rq = tg->cfs_rq[src_cpu]; |
| dest_cfs_rq = tg->cfs_rq[dest_cpu]; |
| |
| return throttled_hierarchy(src_cfs_rq) || |
| throttled_hierarchy(dest_cfs_rq); |
| } |
| |
| /* updated child weight may affect parent so we have to do this bottom up */ |
| static int tg_unthrottle_up(struct task_group *tg, void *data) |
| { |
| struct rq *rq = data; |
| struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; |
| |
| cfs_rq->throttle_count--; |
| if (!cfs_rq->throttle_count) { |
| /* adjust cfs_rq_clock_task() */ |
| cfs_rq->throttled_clock_task_time += rq_clock_task(rq) - |
| cfs_rq->throttled_clock_task; |
| } |
| |
| return 0; |
| } |
| |
| static int tg_throttle_down(struct task_group *tg, void *data) |
| { |
| struct rq *rq = data; |
| struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; |
| |
| /* group is entering throttled state, stop time */ |
| if (!cfs_rq->throttle_count) |
| cfs_rq->throttled_clock_task = rq_clock_task(rq); |
| cfs_rq->throttle_count++; |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_SCHED_WALT |
| static inline void walt_propagate_cumulative_runnable_avg(u64 *accumulated, |
| u64 value, bool add) |
| { |
| if (add) |
| *accumulated += value; |
| else |
| *accumulated -= value; |
| } |
| #else |
| /* |
| * Provide a nop definition since cumulative_runnable_avg is not |
| * available in rq or cfs_rq when WALT is not enabled. |
| */ |
| #define walt_propagate_cumulative_runnable_avg(...) |
| #endif |
| |
| static void throttle_cfs_rq(struct cfs_rq *cfs_rq) |
| { |
| struct rq *rq = rq_of(cfs_rq); |
| struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); |
| struct sched_entity *se; |
| long task_delta, dequeue = 1; |
| bool empty; |
| |
| se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))]; |
| |
| /* freeze hierarchy runnable averages while throttled */ |
| rcu_read_lock(); |
| walk_tg_tree_from(cfs_rq->tg, tg_throttle_down, tg_nop, (void *)rq); |
| rcu_read_unlock(); |
| |
| task_delta = cfs_rq->h_nr_running; |
| for_each_sched_entity(se) { |
| struct cfs_rq *qcfs_rq = cfs_rq_of(se); |
| /* throttled entity or throttle-on-deactivate */ |
| if (!se->on_rq) |
| break; |
| |
| if (dequeue) |
| dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP); |
| qcfs_rq->h_nr_running -= task_delta; |
| walt_propagate_cumulative_runnable_avg( |
| &qcfs_rq->cumulative_runnable_avg, |
| cfs_rq->cumulative_runnable_avg, false); |
| |
| |
| if (qcfs_rq->load.weight) |
| dequeue = 0; |
| } |
| |
| if (!se) { |
| sub_nr_running(rq, task_delta); |
| walt_propagate_cumulative_runnable_avg( |
| &rq->cumulative_runnable_avg, |
| cfs_rq->cumulative_runnable_avg, false); |
| } |
| |
| cfs_rq->throttled = 1; |
| cfs_rq->throttled_clock = rq_clock(rq); |
| raw_spin_lock(&cfs_b->lock); |
| empty = list_empty(&cfs_b->throttled_cfs_rq); |
| |
| /* |
| * Add to the _head_ of the list, so that an already-started |
| * distribute_cfs_runtime will not see us. If disribute_cfs_runtime is |
| * not running add to the tail so that later runqueues don't get starved. |
| */ |
| if (cfs_b->distribute_running) |
| list_add_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq); |
| else |
| list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq); |
| |
| /* |
| * If we're the first throttled task, make sure the bandwidth |
| * timer is running. |
| */ |
| if (empty) |
| start_cfs_bandwidth(cfs_b); |
| |
| raw_spin_unlock(&cfs_b->lock); |
| } |
| |
| void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) |
| { |
| struct rq *rq = rq_of(cfs_rq); |
| struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); |
| struct sched_entity *se; |
| int enqueue = 1; |
| long task_delta; |
| struct cfs_rq *tcfs_rq __maybe_unused = cfs_rq; |
| |
| se = cfs_rq->tg->se[cpu_of(rq)]; |
| |
| cfs_rq->throttled = 0; |
| |
| update_rq_clock(rq); |
| |
| raw_spin_lock(&cfs_b->lock); |
| cfs_b->throttled_time += rq_clock(rq) - cfs_rq->throttled_clock; |
| list_del_rcu(&cfs_rq->throttled_list); |
| raw_spin_unlock(&cfs_b->lock); |
| |
| /* update hierarchical throttle state */ |
| walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq); |
| |
| if (!cfs_rq->load.weight) |
| return; |
| |
| task_delta = cfs_rq->h_nr_running; |
| for_each_sched_entity(se) { |
| if (se->on_rq) |
| enqueue = 0; |
| |
| cfs_rq = cfs_rq_of(se); |
| if (enqueue) |
| enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP); |
| cfs_rq->h_nr_running += task_delta; |
| walt_propagate_cumulative_runnable_avg( |
| &cfs_rq->cumulative_runnable_avg, |
| tcfs_rq->cumulative_runnable_avg, true); |
| |
| if (cfs_rq_throttled(cfs_rq)) |
| break; |
| } |
| |
| if (!se) { |
| add_nr_running(rq, task_delta); |
| walt_propagate_cumulative_runnable_avg( |
| &rq->cumulative_runnable_avg, |
| tcfs_rq->cumulative_runnable_avg, true); |
| } |
| |
| /* determine whether we need to wake up potentially idle cpu */ |
| if (rq->curr == rq->idle && rq->cfs.nr_running) |
| resched_curr(rq); |
| } |
| |
| static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b, u64 remaining) |
| { |
| struct cfs_rq *cfs_rq; |
| u64 runtime; |
| u64 starting_runtime = remaining; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(cfs_rq, &cfs_b->throttled_cfs_rq, |
| throttled_list) { |
| struct rq *rq = rq_of(cfs_rq); |
| struct rq_flags rf; |
| |
| rq_lock(rq, &rf); |
| if (!cfs_rq_throttled(cfs_rq)) |
| goto next; |
| |
| /* By the above check, this should never be true */ |
| SCHED_WARN_ON(cfs_rq->runtime_remaining > 0); |
| |
| runtime = -cfs_rq->runtime_remaining + 1; |
| if (runtime > remaining) |
| runtime = remaining; |
| remaining -= runtime; |
| |
| cfs_rq->runtime_remaining += runtime; |
| |
| /* we check whether we're throttled above */ |
| if (cfs_rq->runtime_remaining > 0) |
| unthrottle_cfs_rq(cfs_rq); |
| |
| next: |
| rq_unlock(rq, &rf); |
| |
| if (!remaining) |
| break; |
| } |
| rcu_read_unlock(); |
| |
| return starting_runtime - remaining; |
| } |
| |
| /* |
| * Responsible for refilling a task_group's bandwidth and unthrottling its |
| * cfs_rqs as appropriate. If there has been no activity within the last |
| * period the timer is deactivated until scheduling resumes; cfs_b->idle is |
| * used to track this state. |
| */ |
| static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) |
| { |
| u64 runtime; |
| int throttled; |
| |
| /* no need to continue the timer with no bandwidth constraint */ |
| if (cfs_b->quota == RUNTIME_INF) |
| goto out_deactivate; |
| |
| throttled = !list_empty(&cfs_b->throttled_cfs_rq); |
| cfs_b->nr_periods += overrun; |
| |
| /* |
| * idle depends on !throttled (for the case of a large deficit), and if |
| * we're going inactive then everything else can be deferred |
| */ |
| if (cfs_b->idle && !throttled) |
| goto out_deactivate; |
| |
| __refill_cfs_bandwidth_runtime(cfs_b); |
| |
| if (!throttled) { |
| /* mark as potentially idle for the upcoming period */ |
| cfs_b->idle = 1; |
| return 0; |
| } |
| |
| /* account preceding periods in which throttling occurred */ |
| cfs_b->nr_throttled += overrun; |
| |
| /* |
| * This check is repeated as we are holding onto the new bandwidth while |
| * we unthrottle. This can potentially race with an unthrottled group |
| * trying to acquire new bandwidth from the global pool. This can result |
| * in us over-using our runtime if it is all used during this loop, but |
| * only by limited amounts in that extreme case. |
| */ |
| while (throttled && cfs_b->runtime > 0 && !cfs_b->distribute_running) { |
| runtime = cfs_b->runtime; |
| cfs_b->distribute_running = 1; |
| raw_spin_unlock(&cfs_b->lock); |
| /* we can't nest cfs_b->lock while distributing bandwidth */ |
| runtime = distribute_cfs_runtime(cfs_b, runtime); |
| raw_spin_lock(&cfs_b->lock); |
| |
| cfs_b->distribute_running = 0; |
| throttled = !list_empty(&cfs_b->throttled_cfs_rq); |
| |
| cfs_b->runtime -= min(runtime, cfs_b->runtime); |
| } |
| |
| /* |
| * While we are ensured activity in the period following an |
| * unthrottle, this also covers the case in which the new bandwidth is |
| * insufficient to cover the existing bandwidth deficit. (Forcing the |
| * timer to remain active while there are any throttled entities.) |
| */ |
| cfs_b->idle = 0; |
| |
| return 0; |
| |
| out_deactivate: |
| return 1; |
| } |
| |
| /* a cfs_rq won't donate quota below this amount */ |
| static const u64 min_cfs_rq_runtime = 1 * NSEC_PER_MSEC; |
| /* minimum remaining period time to redistribute slack quota */ |
| static const u64 min_bandwidth_expiration = 2 * NSEC_PER_MSEC; |
| /* how long we wait to gather additional slack before distributing */ |
| static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC; |
| |
| /* |
| * Are we near the end of the current quota period? |
| * |
| * Requires cfs_b->lock for hrtimer_expires_remaining to be safe against the |
| * hrtimer base being cleared by hrtimer_start. In the case of |
| * migrate_hrtimers, base is never cleared, so we are fine. |
| */ |
| static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire) |
| { |
| struct hrtimer *refresh_timer = &cfs_b->period_timer; |
| s64 remaining; |
| |
| /* if the call-back is running a quota refresh is already occurring */ |
| if (hrtimer_callback_running(refresh_timer)) |
| return 1; |
| |
| /* is a quota refresh about to occur? */ |
| remaining = ktime_to_ns(hrtimer_expires_remaining(refresh_timer)); |
| if (remaining < (s64)min_expire) |
| return 1; |
| |
| return 0; |
| } |
| |
| static void start_cfs_slack_bandwidth(struct cfs_bandwidth *cfs_b) |
| { |
| u64 min_left = cfs_bandwidth_slack_period + min_bandwidth_expiration; |
| |
| /* if there's a quota refresh soon don't bother with slack */ |
| if (runtime_refresh_within(cfs_b, min_left)) |
| return; |
| |
| hrtimer_start(&cfs_b->slack_timer, |
| ns_to_ktime(cfs_bandwidth_slack_period), |
| HRTIMER_MODE_REL); |
| } |
| |
| /* we know any runtime found here is valid as update_curr() precedes return */ |
| static void __return_cfs_rq_runtime(struct cfs_rq *cfs_rq) |
| { |
| struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); |
| s64 slack_runtime = cfs_rq->runtime_remaining - min_cfs_rq_runtime; |
| |
| if (slack_runtime <= 0) |
| return; |
| |
| raw_spin_lock(&cfs_b->lock); |
| if (cfs_b->quota != RUNTIME_INF) { |
| cfs_b->runtime += slack_runtime; |
| |
| /* we are under rq->lock, defer unthrottling using a timer */ |
| if (cfs_b->runtime > sched_cfs_bandwidth_slice() && |
| !list_empty(&cfs_b->throttled_cfs_rq)) |
| start_cfs_slack_bandwidth(cfs_b); |
| } |
| raw_spin_unlock(&cfs_b->lock); |
| |
| /* even if it's not valid for return we don't want to try again */ |
| cfs_rq->runtime_remaining -= slack_runtime; |
| } |
| |
| static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) |
| { |
| if (!cfs_bandwidth_used()) |
| return; |
| |
| if (!cfs_rq->runtime_enabled || cfs_rq->nr_running) |
| return; |
| |
| __return_cfs_rq_runtime(cfs_rq); |
| } |
| |
| /* |
| * This is done with a timer (instead of inline with bandwidth return) since |
| * it's necessary to juggle rq->locks to unthrottle their respective cfs_rqs. |
| */ |
| static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b) |
| { |
| u64 runtime = 0, slice = sched_cfs_bandwidth_slice(); |
| |
| /* confirm we're still not at a refresh boundary */ |
| raw_spin_lock(&cfs_b->lock); |
| if (cfs_b->distribute_running) { |
| raw_spin_unlock(&cfs_b->lock); |
| return; |
| } |
| |
| if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) { |
| raw_spin_unlock(&cfs_b->lock); |
| return; |
| } |
| |
| if (cfs_b->quota != RUNTIME_INF && cfs_b->runtime > slice) |
| runtime = cfs_b->runtime; |
| |
| if (runtime) |
| cfs_b->distribute_running = 1; |
| |
| raw_spin_unlock(&cfs_b->lock); |
| |
| if (!runtime) |
| return; |
| |
| runtime = distribute_cfs_runtime(cfs_b, runtime); |
| |
| raw_spin_lock(&cfs_b->lock); |
| cfs_b->runtime -= min(runtime, cfs_b->runtime); |
| cfs_b->distribute_running = 0; |
| raw_spin_unlock(&cfs_b->lock); |
| } |
| |
| /* |
| * When a group wakes up we want to make sure that its quota is not already |
| * expired/exceeded, otherwise it may be allowed to steal additional ticks of |
| * runtime as update_curr() throttling can not not trigger until it's on-rq. |
| */ |
| static void check_enqueue_throttle(struct cfs_rq *cfs_rq) |
| { |
| if (!cfs_bandwidth_used()) |
| return; |
| |
| /* an active group must be handled by the update_curr()->put() path */ |
| if (!cfs_rq->runtime_enabled || cfs_rq->curr) |
| return; |
| |
| /* ensure the group is not already throttled */ |
| if (cfs_rq_throttled(cfs_rq)) |
| return; |
| |
| /* update runtime allocation */ |
| account_cfs_rq_runtime(cfs_rq, 0); |
| if (cfs_rq->runtime_remaining <= 0) |
| throttle_cfs_rq(cfs_rq); |
| } |
| |
| static void sync_throttle(struct task_group *tg, int cpu) |
| { |
| struct cfs_rq *pcfs_rq, *cfs_rq; |
| |
| if (!cfs_bandwidth_used()) |
| return; |
| |
| if (!tg->parent) |
| return; |
| |
| cfs_rq = tg->cfs_rq[cpu]; |
| pcfs_rq = tg->parent->cfs_rq[cpu]; |
| |
| cfs_rq->throttle_count = pcfs_rq->throttle_count; |
| cfs_rq->throttled_clock_task = rq_clock_task(cpu_rq(cpu)); |
| } |
| |
| /* conditionally throttle active cfs_rq's from put_prev_entity() */ |
| static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq) |
| { |
| if (!cfs_bandwidth_used()) |
| return false; |
| |
| if (likely(!cfs_rq->runtime_enabled || cfs_rq->runtime_remaining > 0)) |
| return false; |
| |
| /* |
| * it's possible for a throttled entity to be forced into a running |
| * state (e.g. set_curr_task), in this case we're finished. |
| */ |
| if (cfs_rq_throttled(cfs_rq)) |
| return true; |
| |
| throttle_cfs_rq(cfs_rq); |
| return true; |
| } |
| |
| static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer) |
| { |
| struct cfs_bandwidth *cfs_b = |
| container_of(timer, struct cfs_bandwidth, slack_timer); |
| |
| do_sched_cfs_slack_timer(cfs_b); |
| |
| return HRTIMER_NORESTART; |
| } |
| |
| extern const u64 max_cfs_quota_period; |
| |
| static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) |
| { |
| struct cfs_bandwidth *cfs_b = |
| container_of(timer, struct cfs_bandwidth, period_timer); |
| int overrun; |
| int idle = 0; |
| int count = 0; |
| |
| raw_spin_lock(&cfs_b->lock); |
| for (;;) { |
| overrun = hrtimer_forward_now(timer, cfs_b->period); |
| if (!overrun) |
| break; |
| |
| if (++count > 3) { |
| u64 new, old = ktime_to_ns(cfs_b->period); |
| |
| /* |
| * Grow period by a factor of 2 to avoid losing precision. |
| * Precision loss in the quota/period ratio can cause __cfs_schedulable |
| * to fail. |
| */ |
| new = old * 2; |
| if (new < max_cfs_quota_period) { |
| cfs_b->period = ns_to_ktime(new); |
| cfs_b->quota *= 2; |
| |
| pr_warn_ratelimited( |
| "cfs_period_timer[cpu%d]: period too short, scaling up (new cfs_period_us = %lld, cfs_quota_us = %lld)\n", |
| smp_processor_id(), |
| div_u64(new, NSEC_PER_USEC), |
| div_u64(cfs_b->quota, NSEC_PER_USEC)); |
| } else { |
| pr_warn_ratelimited( |
| "cfs_period_timer[cpu%d]: period too short, but cannot scale up without losing precision (cfs_period_us = %lld, cfs_quota_us = %lld)\n", |
| smp_processor_id(), |
| div_u64(old, NSEC_PER_USEC), |
| div_u64(cfs_b->quota, NSEC_PER_USEC)); |
| } |
| |
| /* reset count so we don't come right back in here */ |
| count = 0; |
| } |
| |
| idle = do_sched_cfs_period_timer(cfs_b, overrun); |
| } |
| if (idle) |
| cfs_b->period_active = 0; |
| raw_spin_unlock(&cfs_b->lock); |
| |
| return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; |
| } |
| |
| void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) |
| { |
| raw_spin_lock_init(&cfs_b->lock); |
| cfs_b->runtime = 0; |
| cfs_b->quota = RUNTIME_INF; |
| cfs_b->period = ns_to_ktime(default_cfs_period()); |
| |
| INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq); |
| hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); |
| cfs_b->period_timer.function = sched_cfs_period_timer; |
| hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
| cfs_b->slack_timer.function = sched_cfs_slack_timer; |
| cfs_b->distribute_running = 0; |
| } |
| |
| static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) |
| { |
| cfs_rq->runtime_enabled = 0; |
| INIT_LIST_HEAD(&cfs_rq->throttled_list); |
| } |
| |
| void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) |
| { |
| lockdep_assert_held(&cfs_b->lock); |
| |
| if (!cfs_b->period_active) { |
| cfs_b->period_active = 1; |
| hrtimer_forward_now(&cfs_b->period_timer, cfs_b->period); |
| hrtimer_start_expires(&cfs_b->period_timer, HRTIMER_MODE_ABS_PINNED); |
| } |
| } |
| |
| static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) |
| { |
| /* init_cfs_bandwidth() was not called */ |
| if (!cfs_b->throttled_cfs_rq.next) |
| return; |
| |
| hrtimer_cancel(&cfs_b->period_timer); |
| hrtimer_cancel(&cfs_b->slack_timer); |
| } |
| |
| /* |
| * Both these cpu hotplug callbacks race against unregister_fair_sched_group() |
| * |
| * The race is harmless, since modifying bandwidth settings of unhooked group |
| * bits doesn't do much. |
| */ |
| |
| /* cpu online calback */ |
| static void __maybe_unused update_runtime_enabled(struct rq *rq) |
| { |
| struct task_group *tg; |
| |
| lockdep_assert_held(&rq->lock); |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(tg, &task_groups, list) { |
| struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
| struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; |
| |
| raw_spin_lock(&cfs_b->lock); |
| cfs_rq->runtime_enabled = cfs_b->quota != RUNTIME_INF; |
| raw_spin_unlock(&cfs_b->lock); |
| } |
| rcu_read_unlock(); |
| } |
| |
| /* cpu offline callback */ |
| static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq) |
| { |
| struct task_group *tg; |
| |
| lockdep_assert_held(&rq->lock); |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(tg, &task_groups, list) { |
| struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; |
| |
| if (!cfs_rq->runtime_enabled) |
| continue; |
| |
| /* |
| * clock_task is not advancing so we just need to make sure |
| * there's some valid quota amount |
| */ |
| cfs_rq->runtime_remaining = 1; |
| /* |
| * Offline rq is schedulable till cpu is completely disabled |
| * in take_cpu_down(), so we prevent new cfs throttling here. |
| */ |
| cfs_rq->runtime_enabled = 0; |
| |
| if (cfs_rq_throttled(cfs_rq)) |
| unthrottle_cfs_rq(cfs_rq); |
| } |
| rcu_read_unlock(); |
| } |
| |
| #ifdef CONFIG_SCHED_WALT |
| static void walt_fixup_cumulative_runnable_avg_fair(struct rq *rq, |
| struct task_struct *p, |
| u64 new_task_load) |
| { |
| struct cfs_rq *cfs_rq; |
| struct sched_entity *se = &p->se; |
| s64 task_load_delta = (s64)new_task_load - p->ravg.demand; |
| |
| for_each_sched_entity(se) { |
| cfs_rq = cfs_rq_of(se); |
| |
| cfs_rq->cumulative_runnable_avg += task_load_delta; |
| if (cfs_rq_throttled(cfs_rq)) |
| break; |
| } |
| |
| /* Fix up rq only if we didn't find any throttled cfs_rq */ |
| if (!se) |
| walt_fixup_cumulative_runnable_avg(rq, p, new_task_load); |
| } |
| |
| #endif /* CONFIG_SCHED_WALT */ |
| |
| #else /* CONFIG_CFS_BANDWIDTH */ |
| static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq) |
| { |
| return rq_clock_task(rq_of(cfs_rq)); |
| } |
| |
| static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec) {} |
| static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq) { return false; } |
| static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {} |
| static inline void sync_throttle(struct task_group *tg, int cpu) {} |
| static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {} |
| |
| static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq) |
| { |
| return 0; |
| } |
| |
| static inline int throttled_hierarchy(struct cfs_rq *cfs_rq) |
| { |
| return 0; |
| } |
| |
| static inline int throttled_lb_pair(struct task_group *tg, |
| int src_cpu, int dest_cpu) |
| { |
| return 0; |
| } |
| |
| void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {} |
| #endif |
| |
| static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) |
| { |
| return NULL; |
| } |
| static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} |
| static inline void update_runtime_enabled(struct rq *rq) {} |
| static inline void unthrottle_offline_cfs_rqs(struct rq *rq) {} |
| |
| #define walt_fixup_cumulative_runnable_avg_fair \ |
| walt_fixup_cumulative_runnable_avg |
| |
| #endif /* CONFIG_CFS_BANDWIDTH */ |
| |
| /************************************************** |
| * CFS operations on tasks: |
| */ |
| |
| #ifdef CONFIG_SCHED_HRTICK |
| static void hrtick_start_fair(struct rq *rq, struct task_struct *p) |
| { |
| struct sched_entity *se = &p->se; |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| |
| SCHED_WARN_ON(task_rq(p) != rq); |
| |
| if (rq->cfs.h_nr_running > 1) { |
| u64 slice = sched_slice(cfs_rq, se); |
| u64 ran = se->sum_exec_runtime - se->prev_sum_exec_runtime; |
| s64 delta = slice - ran; |
| |
| if (delta < 0) { |
| if (rq->curr == p) |
| resched_curr(rq); |
| return; |
| } |
| hrtick_start(rq, delta); |
| } |
| } |
| |
| /* |
| * called from enqueue/dequeue and updates the hrtick when the |
| * current task is from our class and nr_running is low enough |
| * to matter. |
| */ |
| static void hrtick_update(struct rq *rq) |
| { |
| struct task_struct *curr = rq->curr; |
| |
| if (!hrtick_enabled(rq) || curr->sched_class != &fair_sched_class) |
| return; |
| |
| if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency) |
| hrtick_start_fair(rq, curr); |
| } |
| #else /* !CONFIG_SCHED_HRTICK */ |
| static inline void |
| hrtick_start_fair(struct rq *rq, struct task_struct *p) |
| { |
| } |
| |
| static inline void hrtick_update(struct rq *rq) |
| { |
| } |
| #endif |
| |
| #ifdef CONFIG_SMP |
| static bool cpu_overutilized(int cpu); |
| |
| static bool sd_overutilized(struct sched_domain *sd) |
| { |
| return sd->shared->overutilized; |
| } |
| |
| static void set_sd_overutilized(struct sched_domain *sd) |
| { |
| trace_sched_overutilized(sd, sd->shared->overutilized, true); |
| sd->shared->overutilized = true; |
| } |
| |
| static void clear_sd_overutilized(struct sched_domain *sd) |
| { |
| trace_sched_overutilized(sd, sd->shared->overutilized, false); |
| sd->shared->overutilized = false; |
| } |
| |
| static inline void update_overutilized_status(struct rq *rq) |
| { |
| struct sched_domain *sd; |
| |
| rcu_read_lock(); |
| sd = rcu_dereference(rq->sd); |
| if (sd && !sd_overutilized(sd) && |
| cpu_overutilized(rq->cpu)) { |
| int min_cap_orig_cpu; |
| unsigned long min_capacity = -1; |
| |
| min_cap_orig_cpu = rq->rd->min_cap_orig_cpu; |
| if (min_cap_orig_cpu > -1) |
| min_capacity = capacity_orig_of(min_cap_orig_cpu); |
| if (!sched_feat(SCHED_MTK_EAS) || (sched_feat(SCHED_MTK_EAS) |
| && capacity_orig_of(cpu_of(rq)) == min_capacity)) { |
| set_sd_overutilized(sd); |
| } |
| } |
| |
| rcu_read_unlock(); |
| } |
| |
| unsigned long boosted_cpu_util(int cpu); |
| #else |
| |
| #define update_overutilized_status(rq) do {} while (0) |
| #define boosted_cpu_util(cpu) cpu_util_freq(cpu) |
| |
| #endif /* CONFIG_SMP */ |
| |
| /* |
| * The enqueue_task method is called before nr_running is |
| * increased. Here we update the fair scheduling stats and |
| * then put the task into the rbtree: |
| */ |
| static void |
| enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) |
| { |
| struct cfs_rq *cfs_rq; |
| struct sched_entity *se = &p->se; |
| int task_new = !(flags & ENQUEUE_WAKEUP); |
| |
| /* |
| * The code below (indirectly) updates schedutil which looks at |
| * the cfs_rq utilization to select a frequency. |
| * Let's add the task's estimated utilization to the cfs_rq's |
| * estimated utilization, before we update schedutil. |
| */ |
| util_est_enqueue(&rq->cfs, p); |
| |
| /* |
| * The code below (indirectly) updates schedutil which looks at |
| * the cfs_rq utilization to select a frequency. |
| * Let's update schedtune here to ensure the boost value of the |
| * current task is accounted for in the selection of the OPP. |
| * |
| * We do it also in the case where we enqueue a throttled task; |
| * we could argue that a throttled task should not boost a CPU, |
| * however: |
| * a) properly implementing CPU boosting considering throttled |
| * tasks will increase a lot the complexity of the solution |
| * b) it's not easy to quantify the benefits introduced by |
| * such a more complex solution. |
| * Thus, for the time being we go for the simple solution and boost |
| * also for throttled RQs. |
| */ |
| schedtune_enqueue_task(p, cpu_of(rq)); |
| |
| /* |
| * If in_iowait is set, the code below may not trigger any cpufreq |
| * utilization updates, so do it here explicitly with the IOWAIT flag |
| * passed. |
| */ |
| if (p->in_iowait) { |
| #ifdef VENDOR_EDIT |
| /* Gaowei.Pu@BSP.Power.Basic, 2020/9/15, add to fix iowait boost issue*/ |
| trace_iowait_task(p); |
| cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT); |
| #endif |
| } |
| |
| for_each_sched_entity(se) { |
| if (se->on_rq) |
| break; |
| cfs_rq = cfs_rq_of(se); |
| enqueue_entity(cfs_rq, se, flags); |
| |
| /* |
| * end evaluation on encountering a throttled cfs_rq |
| * |
| * note: in the case of encountering a throttled cfs_rq we will |
| * post the final h_nr_running increment below. |
| */ |
| if (cfs_rq_throttled(cfs_rq)) |
| break; |
| cfs_rq->h_nr_running++; |
| walt_inc_cfs_cumulative_runnable_avg(cfs_rq, p); |
| |
| flags = ENQUEUE_WAKEUP; |
| } |
| #ifdef OPLUS_FEATURE_UIFIRST |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/05/25, Add for UIFirst |
| if (sysctl_uifirst_enabled) { |
| enqueue_ux_thread(rq, p); |
| } |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| |
| for_each_sched_entity(se) { |
| cfs_rq = cfs_rq_of(se); |
| cfs_rq->h_nr_running++; |
| walt_inc_cfs_cumulative_runnable_avg(cfs_rq, p); |
| |
| if (cfs_rq_throttled(cfs_rq)) |
| break; |
| |
| update_load_avg(se, UPDATE_TG); |
| update_cfs_shares(se); |
| } |
| |
| if (!se) { |
| add_nr_running(rq, 1); |
| #ifdef CONFIG_MTK_SCHED_RQAVG_US |
| inc_nr_heavy_running(2, p, 1, false); |
| #endif |
| if (!task_new) |
| update_overutilized_status(rq); |
| walt_inc_cumulative_runnable_avg(rq, p); |
| } |
| |
| hrtick_update(rq); |
| } |
| |
| static void set_next_buddy(struct sched_entity *se); |
| |
| /* |
| * The dequeue_task method is called before nr_running is |
| * decreased. We remove the task from the rbtree and |
| * update the fair scheduling stats: |
| */ |
| static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) |
| { |
| struct cfs_rq *cfs_rq; |
| struct sched_entity *se = &p->se; |
| int task_sleep = flags & DEQUEUE_SLEEP; |
| |
| /* |
| * The code below (indirectly) updates schedutil which looks at |
| * the cfs_rq utilization to select a frequency. |
| * Let's update schedtune here to ensure the boost value of the |
| * current task is not more accounted for in the selection of the OPP. |
| */ |
| schedtune_dequeue_task(p, cpu_of(rq)); |
| |
| for_each_sched_entity(se) { |
| cfs_rq = cfs_rq_of(se); |
| dequeue_entity(cfs_rq, se, flags); |
| |
| /* |
| * end evaluation on encountering a throttled cfs_rq |
| * |
| * note: in the case of encountering a throttled cfs_rq we will |
| * post the final h_nr_running decrement below. |
| */ |
| if (cfs_rq_throttled(cfs_rq)) |
| break; |
| cfs_rq->h_nr_running--; |
| walt_dec_cfs_cumulative_runnable_avg(cfs_rq, p); |
| |
| /* Don't dequeue parent if it has other entities besides us */ |
| if (cfs_rq->load.weight) { |
| /* Avoid re-evaluating load for this entity: */ |
| se = parent_entity(se); |
| /* |
| * Bias pick_next to pick a task from this cfs_rq, as |
| * p is sleeping when it is within its sched_slice. |
| */ |
| if (task_sleep && se && !throttled_hierarchy(cfs_rq)) |
| set_next_buddy(se); |
| break; |
| } |
| flags |= DEQUEUE_SLEEP; |
| } |
| #ifdef OPLUS_FEATURE_UIFIRST |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/05/25, Add for UIFirst |
| if (sysctl_uifirst_enabled) { |
| dequeue_ux_thread(rq, p); |
| } |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| |
| for_each_sched_entity(se) { |
| cfs_rq = cfs_rq_of(se); |
| cfs_rq->h_nr_running--; |
| walt_dec_cfs_cumulative_runnable_avg(cfs_rq, p); |
| |
| if (cfs_rq_throttled(cfs_rq)) |
| break; |
| |
| update_load_avg(se, UPDATE_TG); |
| update_cfs_shares(se); |
| } |
| |
| if (!se) { |
| sub_nr_running(rq, 1); |
| #ifdef CONFIG_MTK_SCHED_RQAVG_US |
| inc_nr_heavy_running(3, p, -1, false); |
| #endif |
| walt_dec_cumulative_runnable_avg(rq, p); |
| } |
| |
| util_est_dequeue(&rq->cfs, p, task_sleep); |
| hrtick_update(rq); |
| } |
| |
| #ifdef CONFIG_SMP |
| |
| /* Working cpumask for: load_balance, load_balance_newidle. */ |
| DEFINE_PER_CPU(cpumask_var_t, load_balance_mask); |
| DEFINE_PER_CPU(cpumask_var_t, select_idle_mask); |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| /* |
| * per rq 'load' arrray crap; XXX kill this. |
| */ |
| |
| /* |
| * The exact cpuload calculated at every tick would be: |
| * |
| * load' = (1 - 1/2^i) * load + (1/2^i) * cur_load |
| * |
| * If a cpu misses updates for n ticks (as it was idle) and update gets |
| * called on the n+1-th tick when cpu may be busy, then we have: |
| * |
| * load_n = (1 - 1/2^i)^n * load_0 |
| * load_n+1 = (1 - 1/2^i) * load_n + (1/2^i) * cur_load |
| * |
| * decay_load_missed() below does efficient calculation of |
| * |
| * load' = (1 - 1/2^i)^n * load |
| * |
| * Because x^(n+m) := x^n * x^m we can decompose any x^n in power-of-2 factors. |
| * This allows us to precompute the above in said factors, thereby allowing the |
| * reduction of an arbitrary n in O(log_2 n) steps. (See also |
| * fixed_power_int()) |
| * |
| * The calculation is approximated on a 128 point scale. |
| */ |
| #define DEGRADE_SHIFT 7 |
| |
| static const u8 degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128}; |
| static const u8 degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = { |
| { 0, 0, 0, 0, 0, 0, 0, 0 }, |
| { 64, 32, 8, 0, 0, 0, 0, 0 }, |
| { 96, 72, 40, 12, 1, 0, 0, 0 }, |
| { 112, 98, 75, 43, 15, 1, 0, 0 }, |
| { 120, 112, 98, 76, 45, 16, 2, 0 } |
| }; |
| |
| /* |
| * Update cpu_load for any missed ticks, due to tickless idle. The backlog |
| * would be when CPU is idle and so we just decay the old load without |
| * adding any new load. |
| */ |
| static unsigned long |
| decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) |
| { |
| int j = 0; |
| |
| if (!missed_updates) |
| return load; |
| |
| if (missed_updates >= degrade_zero_ticks[idx]) |
| return 0; |
| |
| if (idx == 1) |
| return load >> missed_updates; |
| |
| while (missed_updates) { |
| if (missed_updates % 2) |
| load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT; |
| |
| missed_updates >>= 1; |
| j++; |
| } |
| return load; |
| } |
| #endif /* CONFIG_NO_HZ_COMMON */ |
| |
| /** |
| * __cpu_load_update - update the rq->cpu_load[] statistics |
| * @this_rq: The rq to update statistics for |
| * @this_load: The current load |
| * @pending_updates: The number of missed updates |
| * |
| * Update rq->cpu_load[] statistics. This function is usually called every |
| * scheduler tick (TICK_NSEC). |
| * |
| * This function computes a decaying average: |
| * |
| * load[i]' = (1 - 1/2^i) * load[i] + (1/2^i) * load |
| * |
| * Because of NOHZ it might not get called on every tick which gives need for |
| * the @pending_updates argument. |
| * |
| * load[i]_n = (1 - 1/2^i) * load[i]_n-1 + (1/2^i) * load_n-1 |
| * = A * load[i]_n-1 + B ; A := (1 - 1/2^i), B := (1/2^i) * load |
| * = A * (A * load[i]_n-2 + B) + B |
| * = A * (A * (A * load[i]_n-3 + B) + B) + B |
| * = A^3 * load[i]_n-3 + (A^2 + A + 1) * B |
| * = A^n * load[i]_0 + (A^(n-1) + A^(n-2) + ... + 1) * B |
| * = A^n * load[i]_0 + ((1 - A^n) / (1 - A)) * B |
| * = (1 - 1/2^i)^n * (load[i]_0 - load) + load |
| * |
| * In the above we've assumed load_n := load, which is true for NOHZ_FULL as |
| * any change in load would have resulted in the tick being turned back on. |
| * |
| * For regular NOHZ, this reduces to: |
| * |
| * load[i]_n = (1 - 1/2^i)^n * load[i]_0 |
| * |
| * see decay_load_misses(). For NOHZ_FULL we get to subtract and add the extra |
| * term. |
| */ |
| static void cpu_load_update(struct rq *this_rq, unsigned long this_load, |
| unsigned long pending_updates) |
| { |
| unsigned long __maybe_unused tickless_load = this_rq->cpu_load[0]; |
| int i, scale; |
| |
| this_rq->nr_load_updates++; |
| |
| /* Update our load: */ |
| this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ |
| for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { |
| unsigned long old_load, new_load; |
| |
| /* scale is effectively 1 << i now, and >> i divides by scale */ |
| |
| old_load = this_rq->cpu_load[i]; |
| #ifdef CONFIG_NO_HZ_COMMON |
| old_load = decay_load_missed(old_load, pending_updates - 1, i); |
| if (tickless_load) { |
| old_load -= decay_load_missed(tickless_load, pending_updates - 1, i); |
| /* |
| * old_load can never be a negative value because a |
| * decayed tickless_load cannot be greater than the |
| * original tickless_load. |
| */ |
| old_load += tickless_load; |
| } |
| #endif |
| new_load = this_load; |
| /* |
| * Round up the averaging division if load is increasing. This |
| * prevents us from getting stuck on 9 if the load is 10, for |
| * example. |
| */ |
| if (new_load > old_load) |
| new_load += scale - 1; |
| |
| this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; |
| } |
| |
| sched_avg_update(this_rq); |
| } |
| |
| /* Used instead of source_load when we know the type == 0 */ |
| static unsigned long weighted_cpuload(struct rq *rq) |
| { |
| return cfs_rq_runnable_load_avg(&rq->cfs); |
| } |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| /* |
| * There is no sane way to deal with nohz on smp when using jiffies because the |
| * cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading |
| * causing off-by-one errors in observed deltas; {0,2} instead of {1,1}. |
| * |
| * Therefore we need to avoid the delta approach from the regular tick when |
| * possible since that would seriously skew the load calculation. This is why we |
| * use cpu_load_update_periodic() for CPUs out of nohz. However we'll rely on |
| * jiffies deltas for updates happening while in nohz mode (idle ticks, idle |
| * loop exit, nohz_idle_balance, nohz full exit...) |
| * |
| * This means we might still be one tick off for nohz periods. |
| */ |
| |
| static void cpu_load_update_nohz(struct rq *this_rq, |
| unsigned long curr_jiffies, |
| unsigned long load) |
| { |
| unsigned long pending_updates; |
| |
| pending_updates = curr_jiffies - this_rq->last_load_update_tick; |
| if (pending_updates) { |
| this_rq->last_load_update_tick = curr_jiffies; |
| /* |
| * In the regular NOHZ case, we were idle, this means load 0. |
| * In the NOHZ_FULL case, we were non-idle, we should consider |
| * its weighted load. |
| */ |
| cpu_load_update(this_rq, load, pending_updates); |
| } |
| } |
| |
| /* |
| * Called from nohz_idle_balance() to update the load ratings before doing the |
| * idle balance. |
| */ |
| static void cpu_load_update_idle(struct rq *this_rq) |
| { |
| /* |
| * bail if there's load or we're actually up-to-date. |
| */ |
| if (weighted_cpuload(this_rq)) |
| return; |
| |
| cpu_load_update_nohz(this_rq, READ_ONCE(jiffies), 0); |
| } |
| |
| /* |
| * Record CPU load on nohz entry so we know the tickless load to account |
| * on nohz exit. cpu_load[0] happens then to be updated more frequently |
| * than other cpu_load[idx] but it should be fine as cpu_load readers |
| * shouldn't rely into synchronized cpu_load[*] updates. |
| */ |
| void cpu_load_update_nohz_start(void) |
| { |
| struct rq *this_rq = this_rq(); |
| |
| /* |
| * This is all lockless but should be fine. If weighted_cpuload changes |
| * concurrently we'll exit nohz. And cpu_load write can race with |
| * cpu_load_update_idle() but both updater would be writing the same. |
| */ |
| this_rq->cpu_load[0] = weighted_cpuload(this_rq); |
| } |
| |
| /* |
| * Account the tickless load in the end of a nohz frame. |
| */ |
| void cpu_load_update_nohz_stop(void) |
| { |
| unsigned long curr_jiffies = READ_ONCE(jiffies); |
| struct rq *this_rq = this_rq(); |
| unsigned long load; |
| struct rq_flags rf; |
| |
| if (curr_jiffies == this_rq->last_load_update_tick) |
| return; |
| |
| load = weighted_cpuload(this_rq); |
| rq_lock(this_rq, &rf); |
| update_rq_clock(this_rq); |
| cpu_load_update_nohz(this_rq, curr_jiffies, load); |
| rq_unlock(this_rq, &rf); |
| } |
| #else /* !CONFIG_NO_HZ_COMMON */ |
| static inline void cpu_load_update_nohz(struct rq *this_rq, |
| unsigned long curr_jiffies, |
| unsigned long load) { } |
| #endif /* CONFIG_NO_HZ_COMMON */ |
| |
| static void cpu_load_update_periodic(struct rq *this_rq, unsigned long load) |
| { |
| #ifdef CONFIG_NO_HZ_COMMON |
| /* See the mess around cpu_load_update_nohz(). */ |
| this_rq->last_load_update_tick = READ_ONCE(jiffies); |
| #endif |
| cpu_load_update(this_rq, load, 1); |
| } |
| |
| /* |
| * Called from scheduler_tick() |
| */ |
| void cpu_load_update_active(struct rq *this_rq) |
| { |
| unsigned long load = weighted_cpuload(this_rq); |
| |
| if (tick_nohz_tick_stopped()) |
| cpu_load_update_nohz(this_rq, READ_ONCE(jiffies), load); |
| else |
| cpu_load_update_periodic(this_rq, load); |
| } |
| |
| /* |
| * Return a low guess at the load of a migration-source cpu weighted |
| * according to the scheduling class and "nice" value. |
| * |
| * We want to under-estimate the load of migration sources, to |
| * balance conservatively. |
| */ |
| static unsigned long source_load(int cpu, int type) |
| { |
| struct rq *rq = cpu_rq(cpu); |
| unsigned long total = weighted_cpuload(rq); |
| |
| if (type == 0 || !sched_feat(LB_BIAS)) |
| return total; |
| |
| return min(rq->cpu_load[type-1], total); |
| } |
| |
| /* |
| * Return a high guess at the load of a migration-target cpu weighted |
| * according to the scheduling class and "nice" value. |
| */ |
| static unsigned long target_load(int cpu, int type) |
| { |
| struct rq *rq = cpu_rq(cpu); |
| unsigned long total = weighted_cpuload(rq); |
| |
| if (type == 0 || !sched_feat(LB_BIAS)) |
| return total; |
| |
| return max(rq->cpu_load[type-1], total); |
| } |
| |
| static unsigned long cpu_avg_load_per_task(int cpu) |
| { |
| struct rq *rq = cpu_rq(cpu); |
| unsigned long nr_running = READ_ONCE(rq->cfs.h_nr_running); |
| unsigned long load_avg = weighted_cpuload(rq); |
| |
| if (nr_running) |
| return load_avg / nr_running; |
| |
| return 0; |
| } |
| |
| static void record_wakee(struct task_struct *p) |
| { |
| /* |
| * Only decay a single time; tasks that have less then 1 wakeup per |
| * jiffy will not have built up many flips. |
| */ |
| if (time_after(jiffies, current->wakee_flip_decay_ts + HZ)) { |
| current->wakee_flips >>= 1; |
| current->wakee_flip_decay_ts = jiffies; |
| } |
| |
| if (current->last_wakee != p) { |
| current->last_wakee = p; |
| current->wakee_flips++; |
| } |
| } |
| |
| /* |
| * Returns the current capacity of cpu after applying both |
| * cpu and freq scaling. |
| */ |
| unsigned long capacity_curr_of(int cpu) |
| { |
| unsigned long max_cap = cpu_rq(cpu)->cpu_capacity_orig; |
| unsigned long scale_freq = arch_scale_freq_capacity(NULL, cpu); |
| |
| return cap_scale(max_cap, scale_freq); |
| } |
| |
| inline bool energy_aware(void) |
| { |
| return sched_feat(ENERGY_AWARE); |
| } |
| |
| /* |
| * __cpu_norm_util() returns the cpu util relative to a specific capacity, |
| * i.e. it's busy ratio, in the range [0..SCHED_CAPACITY_SCALE] which is useful |
| * for energy calculations. Using the scale-invariant util returned by |
| * cpu_util() and approximating scale-invariant util by: |
| * |
| * util ~ (curr_freq/max_freq)*1024 * capacity_orig/1024 * running_time/time |
| * |
| * the normalized util can be found using the specific capacity. |
| * |
| * capacity = capacity_orig * curr_freq/max_freq |
| * |
| * norm_util = running_time/time ~ util/capacity |
| */ |
| static unsigned long __cpu_norm_util(unsigned long util, unsigned long capacity) |
| { |
| if (util >= capacity) |
| return SCHED_CAPACITY_SCALE; |
| |
| return (util << SCHED_CAPACITY_SHIFT)/capacity; |
| } |
| |
| /* |
| * CPU candidates. |
| * |
| * These are labels to reference CPU candidates for an energy_diff. |
| * Currently we support only two possible candidates: the task's previous CPU |
| * and another candiate CPU. |
| * More advanced/aggressive EAS selection policies can consider more |
| * candidates. |
| */ |
| #define EAS_CPU_PRV 0 |
| #define EAS_CPU_NXT 1 |
| #define EAS_CPU_BKP 2 |
| |
| /* |
| * energy_diff - supports the computation of the estimated energy impact in |
| * moving a "task"'s "util_delta" between different CPU candidates. |
| */ |
| /* |
| * NOTE: When using or examining WALT task signals, all wakeup |
| * latency is included as busy time for task util. |
| * |
| * This is relevant here because: |
| * When debugging is enabled, it can take as much as 1ms to |
| * write the output to the trace buffer for each eenv |
| * scenario. For periodic tasks where the sleep time is of |
| * a similar order, the WALT task util can be inflated. |
| * |
| * Further, and even without debugging enabled, |
| * task wakeup latency changes depending upon the EAS |
| * wakeup algorithm selected - FIND_BEST_TARGET only does |
| * energy calculations for up to 2 candidate CPUs. When |
| * NO_FIND_BEST_TARGET is configured, we can potentially |
| * do an energy calculation across all CPUS in the system. |
| * |
| * The impact to WALT task util on a Juno board |
| * running a periodic task which only sleeps for 200usec |
| * between 1ms activations has been measured. |
| * (i.e. the wakeup latency induced by energy calculation |
| * and debug output is double the desired sleep time and |
| * almost equivalent to the runtime which is more-or-less |
| * the worst case possible for this test) |
| * |
| * In this scenario, a task which has a PELT util of around |
| * 220 is inflated under WALT to have util around 400. |
| * |
| * This is simply a property of the way WALT includes |
| * wakeup latency in busy time while PELT does not. |
| * |
| * Hence - be careful when enabling DEBUG_EENV_DECISIONS |
| * expecially if WALT is the task signal. |
| */ |
| |
| /** |
| * Amount of capacity of a CPU that is (estimated to be) used by CFS tasks |
| * @cpu: the CPU to get the utilization of |
| * |
| * The unit of the return value must be the one of capacity so we can compare |
| * the utilization with the capacity of the CPU that is available for CFS task |
| * (ie cpu_capacity). |
| * |
| * cfs_rq.avg.util_avg is the sum of running time of runnable tasks plus the |
| * recent utilization of currently non-runnable tasks on a CPU. It represents |
| * the amount of utilization of a CPU in the range [0..capacity_orig] where |
| * capacity_orig is the cpu_capacity available at the highest frequency, |
| * i.e. arch_scale_cpu_capacity(). |
| * The utilization of a CPU converges towards a sum equal to or less than the |
| * current capacity (capacity_curr <= capacity_orig) of the CPU because it is |
| * the running time on this CPU scaled by capacity_curr. |
| * |
| * The estimated utilization of a CPU is defined to be the maximum between its |
| * cfs_rq.avg.util_avg and the sum of the estimated utilization of the tasks |
| * currently RUNNABLE on that CPU. |
| * This allows to properly represent the expected utilization of a CPU which |
| * has just got a big task running since a long sleep period. At the same time |
| * however it preserves the benefits of the "blocked utilization" in |
| * describing the potential for other tasks waking up on the same CPU. |
| * |
| * Nevertheless, cfs_rq.avg.util_avg can be higher than capacity_curr or even |
| * higher than capacity_orig because of unfortunate rounding in |
| * cfs.avg.util_avg or just after migrating tasks and new task wakeups until |
| * the average stabilizes with the new running time. We need to check that the |
| * utilization stays within the range of [0..capacity_orig] and cap it if |
| * necessary. Without utilization capping, a group could be seen as overloaded |
| * (CPU0 utilization at 121% + CPU1 utilization at 80%) whereas CPU1 has 20% of |
| * available capacity. We allow utilization to overshoot capacity_curr (but not |
| * capacity_orig) as it useful for predicting the capacity required after task |
| * migrations (scheduler-driven DVFS). |
| * |
| * Return: the (estimated) utilization for the specified CPU |
| */ |
| static inline unsigned long cpu_util(int cpu) |
| { |
| struct cfs_rq *cfs_rq; |
| unsigned int util; |
| |
| #ifdef CONFIG_SCHED_WALT |
| if (likely(!walt_disabled && sysctl_sched_use_walt_cpu_util)) { |
| u64 walt_cpu_util = cpu_rq(cpu)->cumulative_runnable_avg; |
| |
| walt_cpu_util <<= SCHED_CAPACITY_SHIFT; |
| do_div(walt_cpu_util, walt_ravg_window); |
| |
| return min_t(unsigned long, walt_cpu_util, |
| capacity_orig_of(cpu)); |
| } |
| #endif |
| |
| cfs_rq = &cpu_rq(cpu)->cfs; |
| util = READ_ONCE(cfs_rq->avg.util_avg); |
| |
| if (sched_feat(UTIL_EST)) |
| util = max(util, READ_ONCE(cfs_rq->avg.util_est.enqueued)); |
| |
| return min_t(unsigned long, util, capacity_orig_of(cpu)); |
| } |
| |
| static inline unsigned long cpu_util_rt(int cpu) |
| { |
| struct rt_rq *rt_rq = &(cpu_rq(cpu)->rt); |
| |
| return rt_rq->avg.util_avg; |
| } |
| |
| static inline unsigned long cpu_util_freq(int cpu) |
| { |
| #ifdef CONFIG_SCHED_WALT |
| u64 walt_cpu_util; |
| |
| #ifdef OPLUS_FEATURE_UIFIRST |
| u64 wallclock = walt_ktime_clock(); |
| u64 timeline = 0; |
| |
| if (sysctl_uifirst_enabled && sysctl_slide_boost_enabled && ux_task_load[cpu]) { |
| walt_cpu_util = cpu_rq(cpu)->prev_runnable_sum; |
| |
| timeline = wallclock - ux_load_ts[cpu]; |
| if (timeline >= UX_LOAD_WINDOW) |
| ux_task_load[cpu] = 0; |
| |
| walt_cpu_util = max_t(u64, walt_cpu_util, ux_task_load[cpu]); |
| walt_cpu_util <<= SCHED_CAPACITY_SHIFT; |
| do_div(walt_cpu_util, walt_ravg_window); |
| |
| return min_t(unsigned long, walt_cpu_util, capacity_orig_of(cpu)); |
| } else { |
| return min(cpu_util(cpu) + cpu_util_rt(cpu), capacity_orig_of(cpu)); |
| } |
| #else |
| if (unlikely(walt_disabled || !sysctl_sched_use_walt_cpu_util)) { |
| return min(cpu_util(cpu) + cpu_util_rt(cpu), |
| capacity_orig_of(cpu)); |
| } |
| |
| walt_cpu_util = cpu_rq(cpu)->prev_runnable_sum; |
| walt_cpu_util <<= SCHED_CAPACITY_SHIFT; |
| do_div(walt_cpu_util, walt_ravg_window); |
| |
| return min_t(unsigned long, walt_cpu_util, capacity_orig_of(cpu)); |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| |
| #else |
| return min(cpu_util(cpu) + cpu_util_rt(cpu), capacity_orig_of(cpu)); |
| #endif |
| } |
| |
| |
| /* |
| * cpu_util_without: compute cpu utilization without any contributions from *p |
| * @cpu: the CPU which utilization is requested |
| * @p: the task which utilization should be discounted |
| * |
| * The utilization of a CPU is defined by the utilization of tasks currently |
| * enqueued on that CPU as well as tasks which are currently sleeping after an |
| * execution on that CPU. |
| * |
| * This method returns the utilization of the specified CPU by discounting the |
| * utilization of the specified task, whenever the task is currently |
| * contributing to the CPU utilization. |
| */ |
| unsigned long cpu_util_without(int cpu, struct task_struct *p) |
| { |
| struct cfs_rq *cfs_rq; |
| unsigned int util; |
| |
| #ifdef CONFIG_SCHED_WALT |
| /* |
| * WALT does not decay idle tasks in the same manner |
| * as PELT, so it makes little sense to subtract task |
| * utilization from cpu utilization. Instead just use |
| * cpu_util for this case. |
| */ |
| if (likely(!walt_disabled && sysctl_sched_use_walt_cpu_util)) |
| return cpu_util(cpu); |
| #endif |
| |
| /* Task has no contribution or is new */ |
| if (cpu != task_cpu(p) || !READ_ONCE(p->se.avg.last_update_time)) |
| return cpu_util(cpu); |
| |
| cfs_rq = &cpu_rq(cpu)->cfs; |
| util = READ_ONCE(cfs_rq->avg.util_avg); |
| |
| /* Discount task's util from CPU's util */ |
| util -= min_t(unsigned int, util, task_util(p)); |
| |
| /* |
| * Covered cases: |
| * |
| * a) if *p is the only task sleeping on this CPU, then: |
| * cpu_util (== task_util) > util_est (== 0) |
| * and thus we return: |
| * cpu_util_without = (cpu_util - task_util) = 0 |
| * |
| * b) if other tasks are SLEEPING on this CPU, which is now exiting |
| * IDLE, then: |
| * cpu_util >= task_util |
| * cpu_util > util_est (== 0) |
| * and thus we discount *p's blocked utilization to return: |
| * cpu_util_without = (cpu_util - task_util) >= 0 |
| * |
| * c) if other tasks are RUNNABLE on that CPU and |
| * util_est > cpu_util |
| * then we use util_est since it returns a more restrictive |
| * estimation of the spare capacity on that CPU, by just |
| * considering the expected utilization of tasks already |
| * runnable on that CPU. |
| * |
| * Cases a) and b) are covered by the above code, while case c) is |
| * covered by the following code when estimated utilization is |
| * enabled. |
| */ |
| if (sched_feat(UTIL_EST)) { |
| unsigned int estimated = |
| READ_ONCE(cfs_rq->avg.util_est.enqueued); |
| |
| /* |
| * Despite the following checks we still have a small window |
| * for a possible race, when an execl's select_task_rq_fair() |
| * races with LB's detach_task(): |
| * |
| * detach_task() |
| * p->on_rq = TASK_ON_RQ_MIGRATING; |
| * ---------------------------------- A |
| * deactivate_task() \ |
| * dequeue_task() + RaceTime |
| * util_est_dequeue() / |
| * ---------------------------------- B |
| * |
| * The additional check on "current == p" it's required to |
| * properly fix the execl regression and it helps in further |
| * reducing the chances for the above race. |
| */ |
| if (unlikely(task_on_rq_queued(p) || current == p)) { |
| estimated -= min_t(unsigned int, estimated, |
| (_task_util_est(p) | UTIL_AVG_UNCHANGED)); |
| } |
| util = max(util, estimated); |
| } |
| |
| /* |
| * Utilization (estimated) can exceed the CPU capacity, thus let's |
| * clamp to the maximum CPU capacity to ensure consistency with |
| * the cpu_util call. |
| */ |
| return min_t(unsigned long, util, capacity_orig_of(cpu)); |
| } |
| |
| unsigned long get_cpu_util(int cpu) |
| { |
| return cpu_util_freq(cpu); |
| } |
| |
| #ifndef CONFIG_MTK_SCHED_EAS_POWER_SUPPORT |
| static unsigned long group_max_util(struct energy_env *eenv, int cpu_idx) |
| { |
| unsigned long max_util = 0; |
| unsigned long util; |
| int cpu; |
| |
| for_each_cpu(cpu, sched_group_span(eenv->sg_cap)) { |
| util = cpu_util_without(cpu, eenv->p); |
| |
| /* |
| * If we are looking at the target CPU specified by the eenv, |
| * then we should add the (estimated) utilization of the task |
| * assuming we will wake it up on that CPU. |
| */ |
| if (unlikely(cpu == eenv->cpu[cpu_idx].cpu_id)) |
| util += eenv->util_delta_boosted; |
| |
| max_util = max(max_util, util); |
| } |
| |
| return max_util; |
| } |
| |
| /* |
| * group_norm_util() returns the approximated group util relative to it's |
| * current capacity (busy ratio) in the range [0..SCHED_CAPACITY_SCALE] for use |
| * in energy calculations. Since task executions may or may not overlap in time |
| * in the group the true normalized util is between max(cpu_norm_util(i)) and |
| * sum(cpu_norm_util(i)) when iterating over all cpus in the group, i. The |
| * latter is used as the estimate as it leads to a more pessimistic energy |
| * estimate (more busy). |
| */ |
| static unsigned |
| long group_norm_util(struct energy_env *eenv, int cpu_idx) |
| { |
| unsigned long capacity = eenv->cpu[cpu_idx].cap; |
| unsigned long util, util_sum = 0; |
| int cpu; |
| |
| for_each_cpu(cpu, sched_group_span(eenv->sg)) { |
| util = cpu_util_without(cpu, eenv->p); |
| |
| /* |
| * If we are looking at the target CPU specified by the eenv, |
| * then we should add the (estimated) utilization of the task |
| * assuming we will wake it up on that CPU. |
| */ |
| if (unlikely(cpu == eenv->cpu[cpu_idx].cpu_id)) |
| util += eenv->util_delta; |
| |
| util_sum += __cpu_norm_util(util, capacity); |
| } |
| |
| if (util_sum > SCHED_CAPACITY_SCALE) |
| return SCHED_CAPACITY_SCALE; |
| return util_sum; |
| } |
| |
| static int find_new_capacity(struct energy_env *eenv, int cpu_idx) |
| { |
| const struct sched_group_energy *sge = eenv->sg_cap->sge; |
| unsigned long util = group_max_util(eenv, cpu_idx); |
| int idx, cap_idx; |
| |
| cap_idx = sge->nr_cap_states - 1; |
| |
| for (idx = 0; idx < sge->nr_cap_states; idx++) { |
| if (sge->cap_states[idx].cap >= util) { |
| cap_idx = idx; |
| break; |
| } |
| } |
| /* Keep track of SG's capacity */ |
| eenv->cpu[cpu_idx].cap = sge->cap_states[cap_idx].cap; |
| eenv->cpu[cpu_idx].cap_idx = cap_idx; |
| |
| return cap_idx; |
| } |
| #else |
| static unsigned long group_norm_util(struct energy_env *eenv, int cpu_idx); |
| #endif |
| |
| static int group_idle_state(struct energy_env *eenv, int cpu_idx) |
| { |
| struct sched_group *sg = eenv->sg; |
| int src_in_grp, dst_in_grp; |
| int i, state = INT_MAX; |
| int max_idle_state_idx; |
| long grp_util = 0; |
| int new_state; |
| |
| /* Find the shallowest idle state in the sched group. */ |
| for_each_cpu(i, sched_group_span(sg)) |
| state = min(state, idle_get_state_idx(cpu_rq(i))); |
| |
| /* Take non-cpuidle idling into account (active idle/arch_cpu_idle()) */ |
| state++; |
| /* |
| * Try to estimate if a deeper idle state is |
| * achievable when we move the task. |
| */ |
| for_each_cpu(i, sched_group_span(sg)) |
| grp_util += cpu_util(i); |
| |
| src_in_grp = cpumask_test_cpu(eenv->cpu[EAS_CPU_PRV].cpu_id, |
| sched_group_span(sg)); |
| dst_in_grp = cpumask_test_cpu(eenv->cpu[cpu_idx].cpu_id, |
| sched_group_span(sg)); |
| if (src_in_grp == dst_in_grp) { |
| /* |
| * both CPUs under consideration are in the same group or not in |
| * either group, migration should leave idle state the same. |
| */ |
| return state; |
| } |
| /* |
| * add or remove util as appropriate to indicate what group util |
| * will be (worst case - no concurrent execution) after moving the task |
| */ |
| grp_util += src_in_grp ? -eenv->util_delta : eenv->util_delta; |
| |
| if (grp_util > |
| ((long)sg->sgc->max_capacity * (int)sg->group_weight)) { |
| /* |
| * After moving, the group will be fully occupied |
| * so assume it will not be idle at all. |
| */ |
| return 0; |
| } |
| |
| /* |
| * after moving, this group is at most partly |
| * occupied, so it should have some idle time. |
| */ |
| max_idle_state_idx = sg->sge->nr_idle_states - 2; |
| new_state = grp_util * max_idle_state_idx; |
| if (grp_util <= 0) { |
| /* group will have no util, use lowest state */ |
| new_state = max_idle_state_idx + 1; |
| } else { |
| /* |
| * for partially idle, linearly map util to idle |
| * states, excluding the lowest one. This does not |
| * correspond to the state we expect to enter in |
| * reality, but an indication of what might happen. |
| */ |
| new_state = min_t(int, max_idle_state_idx, |
| new_state / sg->sgc->max_capacity); |
| new_state = max_idle_state_idx - new_state; |
| } |
| return new_state; |
| } |
| |
| #ifdef DEBUG_EENV_DECISIONS |
| static struct _eenv_debug *eenv_debug_entry_ptr(struct _eenv_debug *base, int idx); |
| |
| static void store_energy_calc_debug_info(struct energy_env *eenv, int cpu_idx, int cap_idx, int idle_idx) |
| { |
| int debug_idx = eenv->cpu[cpu_idx].debug_idx; |
| unsigned long sg_util, busy_energy, idle_energy; |
| const struct sched_group_energy *sge; |
| struct _eenv_debug *dbg; |
| int cpu; |
| |
| if (debug_idx < EAS_EENV_DEBUG_LEVELS) { |
| sge = eenv->sg->sge; |
| sg_util = group_norm_util(eenv, cpu_idx); |
| busy_energy = sge->cap_states[cap_idx].power; |
| busy_energy *= sg_util; |
| idle_energy = SCHED_CAPACITY_SCALE - sg_util; |
| idle_energy *= sge->idle_states[idle_idx].power; |
| /* should we use sg_cap or sg? */ |
| dbg = eenv_debug_entry_ptr(eenv->cpu[cpu_idx].debug, debug_idx); |
| dbg->cap = sge->cap_states[cap_idx].cap; |
| dbg->norm_util = sg_util; |
| dbg->cap_energy = sge->cap_states[cap_idx].power; |
| dbg->idle_energy = sge->idle_states[idle_idx].power; |
| dbg->this_energy = busy_energy + idle_energy; |
| dbg->this_busy_energy = busy_energy; |
| dbg->this_idle_energy = idle_energy; |
| |
| cpumask_copy(&dbg->group_cpumask, |
| sched_group_span(eenv->sg)); |
| |
| for_each_cpu(cpu, &dbg->group_cpumask) |
| dbg->cpu_util[cpu] = cpu_util(cpu); |
| |
| eenv->cpu[cpu_idx].debug_idx = debug_idx+1; |
| } |
| } |
| #else |
| #define store_energy_calc_debug_info(a,b,c,d) {} |
| #endif /* DEBUG_EENV_DECISIONS */ |
| |
| /* |
| * calc_sg_energy: compute energy for the eenv's SG (i.e. eenv->sg). |
| * |
| * This works in iterations to compute the SG's energy for each CPU |
| * candidate defined by the energy_env's cpu array. |
| */ |
| static void calc_sg_energy(struct energy_env *eenv, struct sched_domain *sd) |
| { |
| struct sched_group *sg = eenv->sg; |
| unsigned long busy_energy, idle_energy; |
| unsigned int busy_power, idle_power; |
| unsigned long total_energy = 0; |
| unsigned long sg_util; |
| int idle_idx; |
| #ifndef CONFIG_MTK_SCHED_EAS_POWER_SUPPORT |
| int cap_idx; |
| #endif |
| int cpu_idx; |
| |
| for (cpu_idx = EAS_CPU_PRV; cpu_idx < eenv->max_cpu_count; ++cpu_idx) { |
| if (eenv->cpu[cpu_idx].cpu_id == -1) |
| continue; |
| |
| mt_sched_printf(sched_eas_energy_calc, |
| "%s cpu_idx=%d src_cpu=%d dst_cpu=%d cpu=%d", |
| __func__, cpu_idx, eenv->cpu[EAS_CPU_PRV].cpu_id, |
| eenv->cpu[cpu_idx].cpu_id, group_first_cpu(sg)); |
| |
| #ifdef CONFIG_MTK_UNIFY_POWER |
| #ifdef CONFIG_MTK_SCHED_EAS_POWER_SUPPORT |
| busy_power = sg->sge->busy_power(cpu_idx, group_first_cpu(sg), |
| eenv, (sd->child) ? 1 : 0); |
| /* |
| * in order to calculate cpu_norm_util, we need to know which |
| * capacity level the group will be at, so calculate that first |
| */ |
| sg_util = group_norm_util(eenv, cpu_idx); |
| |
| busy_energy = sg_util * busy_power; |
| |
| /* Compute IDLE energy */ |
| idle_idx = group_idle_state(eenv, cpu_idx); |
| idle_power = sg->sge->idle_power(cpu_idx, idle_idx, |
| group_first_cpu(sg), eenv, |
| (sd->child) ? 1 : 0); |
| |
| idle_energy = SCHED_CAPACITY_SCALE - sg_util; |
| idle_energy *= idle_power; |
| #else |
| /* Compute ACTIVE energy */ |
| cap_idx = find_new_capacity(eenv, cpu_idx); |
| |
| busy_power = sg->sge->cap_states[cap_idx].dyn_pwr; |
| /* |
| * in order to calculate cpu_norm_util, we need to know which |
| * capacity level the group will be at, so calculate that first |
| */ |
| sg_util = group_norm_util(eenv, cpu_idx); |
| |
| busy_energy = sg_util * busy_power; |
| |
| /* Compute IDLE energy */ |
| idle_idx = group_idle_state(eenv, cpu_idx); |
| idle_power = sg->sge->idle_states[idle_idx].power; |
| |
| idle_energy = SCHED_CAPACITY_SCALE - sg_util; |
| idle_energy *= idle_power; |
| #endif |
| #else |
| /* Compute ACTIVE energy */ |
| cap_idx = find_new_capacity(eenv, cpu_idx); |
| busy_power = sg->sge->cap_states[cap_idx].power; |
| sg_util = group_norm_util(eenv, cpu_idx); |
| busy_energy = sg_util * busy_power; |
| |
| /* Compute IDLE energy */ |
| idle_idx = group_idle_state(eenv, cpu_idx); |
| idle_power = sg->sge->idle_states[idle_idx].power; |
| idle_energy = SCHED_CAPACITY_SCALE - sg_util; |
| idle_energy *= idle_power; |
| #endif |
| |
| total_energy = busy_energy + idle_energy; |
| eenv->cpu[cpu_idx].energy += total_energy; |
| |
| store_energy_calc_debug_info(eenv, cpu_idx, cap_idx, idle_idx); |
| |
| mt_sched_printf(sched_eas_energy_calc, |
| "sg_util=%lu busy_egy=%d idle_egy=%d (cost=%d total_egy=%d) mask=0x%lx child=%d", |
| sg_util, |
| (int)busy_energy, (int)idle_energy, (int)total_energy, |
| (int)eenv->cpu[cpu_idx].energy, |
| sched_group_span(sg)->bits[0], |
| (sd->child) ? 1 : 0); |
| |
| } |
| } |
| |
| /* |
| * compute_energy() computes the absolute variation in energy consumption by |
| * moving eenv.util_delta from EAS_CPU_PRV to EAS_CPU_NXT. |
| * |
| * NOTE: compute_energy() may fail when racing with sched_domain updates, in |
| * which case we abort by returning -EINVAL. |
| */ |
| static int compute_energy(struct energy_env *eenv) |
| { |
| struct sched_domain *sd; |
| int cpu; |
| struct cpumask visit_cpus; |
| struct sched_group *sg; |
| int cpu_count; |
| #ifdef CONFIG_MTK_SCHED_EAS_POWER_SUPPORT |
| int only_lv1_sd = 0; |
| #endif |
| |
| WARN_ON(!eenv->sg_top->sge); |
| |
| cpumask_copy(&visit_cpus, sched_group_span(eenv->sg_top)); |
| /* If a cpu is hotplugged in while we are in this function, it does |
| * not appear in the existing visit_cpus mask which came from the |
| * sched_group pointer of the sched_domain pointed at by sd_ea for |
| * either the prev or next cpu and was dereferenced in |
| * select_energy_cpu_idx. |
| * Since we will dereference sd_scs later as we iterate through the |
| * CPUs we expect to visit, new CPUs can be present which are not in |
| * the visit_cpus mask. Guard this with cpu_count. |
| */ |
| cpu_count = cpumask_weight(&visit_cpus); |
| while (!cpumask_empty(&visit_cpus)) { |
| struct sched_group *sg_shared_cap = NULL; |
| |
| cpu = cpumask_first(&visit_cpus); |
| |
| sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); |
| if (!sd) { |
| /* a corner racing with hotplug? |
| * sd doesn't exist in this cpu. |
| */ |
| |
| return -EINVAL; |
| } |
| |
| /* |
| * Is the group utilization affected by cpus outside this |
| * sched_group? |
| * This sd may have groups with cpus which were not present |
| * when we took visit_cpus. |
| */ |
| sd = rcu_dereference(per_cpu(sd_scs, cpu)); |
| #ifdef CONFIG_MTK_SCHED_EAS_POWER_SUPPORT |
| /* Try to handle one CPU in this cluster by hotplug. |
| * In it there is only lv-1 sched_domain exist which having |
| * no share_cap_states. |
| */ |
| if (!sd) { |
| sd = rcu_dereference(per_cpu(sd_ea, cpu)); |
| only_lv1_sd = 1; |
| } |
| #endif |
| if (!sd) { |
| /* |
| * We most probably raced with hotplug; returning a |
| * wrong energy estimation is better than entering an |
| * infinite loop. |
| */ |
| return -EINVAL; |
| } |
| |
| if (sd && sd->parent) |
| sg_shared_cap = sd->parent->groups; |
| |
| for_each_domain(cpu, sd) { |
| sg = sd->groups; |
| |
| /* Has this sched_domain already been visited? */ |
| if (sd->child && group_first_cpu(sg) != cpu) |
| break; |
| |
| do { |
| eenv->sg_cap = sg; |
| if (sg_shared_cap && sg_shared_cap->group_weight >= sg->group_weight) |
| eenv->sg_cap = sg_shared_cap; |
| |
| /* |
| * Compute the energy for all the candidate |
| * CPUs in the current visited SG. |
| */ |
| eenv->sg = sg; |
| calc_sg_energy(eenv, sd); |
| |
| /* remove CPUs we have just visited */ |
| if (!sd->child) { |
| /* |
| * cpu_count here is the number of |
| * cpus we expect to visit in this |
| * calculation. If we race against |
| * hotplug, we can have extra cpus |
| * added to the groups we are |
| * iterating which do not appear in |
| * the visit_cpus mask. In that case |
| * we are not able to calculate energy |
| * without restarting so we will bail |
| * out and use prev_cpu this time. |
| */ |
| if (!cpu_count) |
| return -EINVAL; |
| cpumask_xor(&visit_cpus, &visit_cpus, sched_group_span(sg)); |
| cpu_count--; |
| } |
| |
| #ifdef CONFIG_MTK_SCHED_EAS_POWER_SUPPORT |
| /* |
| * We try to get correct energy estimation |
| * while racing with hotplug and |
| * avoid entering a infinite loop. |
| */ |
| if (only_lv1_sd) |
| return 0; |
| #endif |
| |
| if (cpumask_equal(sched_group_span(sg), sched_group_span(eenv->sg_top)) && |
| sd->child) |
| goto next_cpu; |
| |
| } while (sg = sg->next, sg != sd->groups); |
| } |
| next_cpu: |
| cpumask_clear_cpu(cpu, &visit_cpus); |
| continue; |
| } |
| |
| return 0; |
| } |
| |
| static inline bool cpu_in_sg(struct sched_group *sg, int cpu) |
| { |
| return cpu != -1 && cpumask_test_cpu(cpu, sched_group_span(sg)); |
| } |
| |
| #ifdef DEBUG_EENV_DECISIONS |
| static void dump_eenv_debug(struct energy_env *eenv) |
| { |
| int cpu_idx, grp_idx; |
| char cpu_utils[(NR_CPUS*12)+10]="cpu_util: "; |
| char cpulist[64]; |
| |
| trace_printk("eenv scenario: task=%p %s task_util=%lu prev_cpu=%d", |
| eenv->p, eenv->p->comm, eenv->util_delta, eenv->cpu[EAS_CPU_PRV].cpu_id); |
| |
| for (cpu_idx=EAS_CPU_PRV; cpu_idx < eenv->max_cpu_count; cpu_idx++) { |
| if (eenv->cpu[cpu_idx].cpu_id == -1) |
| continue; |
| trace_printk("---Scenario %d: Place task on cpu %d energy=%lu (%d debug logs at %p)", |
| cpu_idx+1, eenv->cpu[cpu_idx].cpu_id, |
| eenv->cpu[cpu_idx].energy >> SCHED_CAPACITY_SHIFT, |
| eenv->cpu[cpu_idx].debug_idx, |
| eenv->cpu[cpu_idx].debug); |
| for (grp_idx = 0; grp_idx < eenv->cpu[cpu_idx].debug_idx; grp_idx++) { |
| struct _eenv_debug *debug; |
| int cpu, written=0; |
| |
| debug = eenv_debug_entry_ptr(eenv->cpu[cpu_idx].debug, grp_idx); |
| cpu = scnprintf(cpulist, sizeof(cpulist), "%*pbl", cpumask_pr_args(&debug->group_cpumask)); |
| |
| cpu_utils[0] = 0; |
| /* print out the relevant cpu_util */ |
| for_each_cpu(cpu, &(debug->group_cpumask)) { |
| char tmp[64]; |
| if (written > sizeof(cpu_utils)-10) { |
| cpu_utils[written]=0; |
| break; |
| } |
| written += snprintf(tmp, sizeof(tmp), "cpu%d(%lu) ", cpu, debug->cpu_util[cpu]); |
| strcat(cpu_utils, tmp); |
| } |
| /* trace the data */ |
| trace_printk(" | %s : cap=%lu nutil=%lu, cap_nrg=%lu, idle_nrg=%lu energy=%lu busy_energy=%lu idle_energy=%lu %s", |
| cpulist, debug->cap, debug->norm_util, |
| debug->cap_energy, debug->idle_energy, |
| debug->this_energy >> SCHED_CAPACITY_SHIFT, |
| debug->this_busy_energy >> SCHED_CAPACITY_SHIFT, |
| debug->this_idle_energy >> SCHED_CAPACITY_SHIFT, |
| cpu_utils); |
| |
| } |
| trace_printk("---"); |
| } |
| trace_printk("----- done"); |
| return; |
| } |
| #else |
| #define dump_eenv_debug(a) {} |
| #endif /* DEBUG_EENV_DECISIONS */ |
| /* |
| * select_energy_cpu_idx(): estimate the energy impact of changing the |
| * utilization distribution. |
| * |
| * The eenv parameter specifies the changes: utilization amount and a |
| * collection of possible CPU candidates. The number of candidates |
| * depends upon the selection algorithm used. |
| * |
| * If find_best_target was used to select candidate CPUs, there will |
| * be at most 3 including prev_cpu. If not, we used a brute force |
| * selection which will provide the union of: |
| * * CPUs belonging to the highest sd which is not overutilized |
| * * CPUs the task is allowed to run on |
| * * online CPUs |
| * |
| * This function returns the index of a CPU candidate specified by the |
| * energy_env which corresponds to the most energy efficient CPU. |
| * Thus, 0 (EAS_CPU_PRV) means that non of the CPU candidate is more energy |
| * efficient than running on prev_cpu. This is also the value returned in case |
| * of abort due to error conditions during the computations. The only |
| * exception to this if we fail to access the energy model via sd_ea, where |
| * we return -1 with the intent of asking the system to use a different |
| * wakeup placement algorithm. |
| * |
| * A value greater than zero means that the most energy efficient CPU is the |
| * one represented by eenv->cpu[eenv->next_idx].cpu_id. |
| */ |
| static inline int select_energy_cpu_idx(struct energy_env *eenv) |
| { |
| int last_cpu_idx = eenv->max_cpu_count - 1; |
| struct sched_domain *sd; |
| struct sched_group *sg; |
| int sd_cpu = -1; |
| int cpu_idx; |
| int margin; |
| |
| sd_cpu = eenv->cpu[EAS_CPU_PRV].cpu_id; |
| sd = rcu_dereference(per_cpu(sd_ea, sd_cpu)); |
| if (!sd) |
| return -1; |
| |
| cpumask_clear(&eenv->cpus_mask); |
| for (cpu_idx = EAS_CPU_PRV; cpu_idx < eenv->max_cpu_count; ++cpu_idx) { |
| int cpu = eenv->cpu[cpu_idx].cpu_id; |
| |
| if (cpu < 0 && cpu_isolated(cpu)) |
| continue; |
| cpumask_set_cpu(cpu, &eenv->cpus_mask); |
| } |
| |
| mtk_update_new_capacity(eenv); |
| |
| sg = sd->groups; |
| do { |
| /* Skip SGs which do not contains a candidate CPU */ |
| if (!cpumask_intersects(&eenv->cpus_mask, sched_group_span(sg))) |
| continue; |
| |
| eenv->sg_top = sg; |
| if (compute_energy(eenv) == -EINVAL) |
| return EAS_CPU_PRV; |
| } while (sg = sg->next, sg != sd->groups); |
| /* remember - eenv energy values are unscaled */ |
| |
| /* |
| * Compute the dead-zone margin used to prevent too many task |
| * migrations with negligible energy savings. |
| * An energy saving is considered meaningful if it reduces the energy |
| * consumption of EAS_CPU_PRV CPU candidate by at least ~1.56% |
| */ |
| /* margin = eenv->cpu[EAS_CPU_PRV].energy >> 6; */ |
| margin = 0; |
| |
| /* |
| * By default the EAS_CPU_PRV CPU is considered the most energy |
| * efficient, with a 0 energy variation. |
| */ |
| eenv->next_idx = EAS_CPU_PRV; |
| eenv->cpu[EAS_CPU_PRV].nrg_delta = 0; |
| |
| dump_eenv_debug(eenv); |
| |
| /* |
| * Compare the other CPU candidates to find a CPU which can be |
| * more energy efficient then EAS_CPU_PRV |
| */ |
| if (sched_feat(FBT_STRICT_ORDER)) |
| last_cpu_idx = EAS_CPU_BKP; |
| |
| for(cpu_idx = EAS_CPU_NXT; cpu_idx <= last_cpu_idx; cpu_idx++) { |
| if (eenv->cpu[cpu_idx].cpu_id < 0) |
| continue; |
| eenv->cpu[cpu_idx].nrg_delta = |
| eenv->cpu[cpu_idx].energy - |
| eenv->cpu[EAS_CPU_PRV].energy; |
| |
| /* filter energy variations within the dead-zone margin */ |
| if (abs(eenv->cpu[cpu_idx].nrg_delta) < margin) |
| eenv->cpu[cpu_idx].nrg_delta = 0; |
| |
| trace_sched_energy_diff(eenv->p, |
| eenv->cpu[EAS_CPU_PRV].cpu_id, |
| eenv->cpu[cpu_idx].cpu_id, |
| eenv->util_delta, |
| eenv->cpu[EAS_CPU_PRV].energy, |
| eenv->cpu[cpu_idx].energy, |
| eenv->cpu[cpu_idx].nrg_delta); |
| |
| /* update the schedule candidate with min(nrg_delta) */ |
| if (eenv->cpu[cpu_idx].nrg_delta < |
| eenv->cpu[eenv->next_idx].nrg_delta) { |
| eenv->next_idx = cpu_idx; |
| /* break out if we want to stop on first saving candidate */ |
| if (sched_feat(FBT_STRICT_ORDER)) |
| break; |
| } |
| } |
| |
| mt_sched_printf(sched_eas_energy_calc, "%s next_idx=%d ", |
| __func__, eenv->next_idx); |
| |
| return eenv->next_idx; |
| } |
| |
| /* |
| * Detect M:N waker/wakee relationships via a switching-frequency heuristic. |
| * |
| * A waker of many should wake a different task than the one last awakened |
| * at a frequency roughly N times higher than one of its wakees. |
| * |
| * In order to determine whether we should let the load spread vs consolidating |
| * to shared cache, we look for a minimum 'flip' frequency of llc_size in one |
| * partner, and a factor of lls_size higher frequency in the other. |
| * |
| * With both conditions met, we can be relatively sure that the relationship is |
| * non-monogamous, with partner count exceeding socket size. |
| * |
| * Waker/wakee being client/server, worker/dispatcher, interrupt source or |
| * whatever is irrelevant, spread criteria is apparent partner count exceeds |
| * socket size. |
| */ |
| static int wake_wide(struct task_struct *p, int sibling_count_hint) |
| { |
| unsigned int master = current->wakee_flips; |
| unsigned int slave = p->wakee_flips; |
| int llc_size = this_cpu_read(sd_llc_size); |
| |
| if (sibling_count_hint >= llc_size) |
| return 1; |
| |
| if (master < slave) |
| swap(master, slave); |
| if (slave < llc_size || master < slave * llc_size) |
| return 0; |
| return 1; |
| } |
| |
| /* |
| * The purpose of wake_affine() is to quickly determine on which CPU we can run |
| * soonest. For the purpose of speed we only consider the waking and previous |
| * CPU. |
| * |
| * wake_affine_idle() - only considers 'now', it check if the waking CPU is (or |
| * will be) idle. |
| * |
| * wake_affine_weight() - considers the weight to reflect the average |
| * scheduling latency of the CPUs. This seems to work |
| * for the overloaded case. |
| */ |
| |
| static bool |
| wake_affine_idle(struct sched_domain *sd, struct task_struct *p, |
| int this_cpu, int prev_cpu, int sync) |
| { |
| if (idle_cpu(this_cpu)) |
| return true; |
| |
| if (sync && cpu_rq(this_cpu)->nr_running == 1) |
| return true; |
| |
| return false; |
| } |
| |
| static bool |
| wake_affine_weight(struct sched_domain *sd, struct task_struct *p, |
| int this_cpu, int prev_cpu, int sync) |
| { |
| s64 this_eff_load, prev_eff_load; |
| unsigned long task_load; |
| |
| this_eff_load = target_load(this_cpu, sd->wake_idx); |
| prev_eff_load = source_load(prev_cpu, sd->wake_idx); |
| |
| if (sync) { |
| unsigned long current_load = task_h_load(current); |
| |
| if (current_load > this_eff_load) |
| return true; |
| |
| this_eff_load -= current_load; |
| } |
| |
| task_load = task_h_load(p); |
| |
| this_eff_load += task_load; |
| if (sched_feat(WA_BIAS)) |
| this_eff_load *= 100; |
| this_eff_load *= capacity_of(prev_cpu); |
| |
| prev_eff_load -= task_load; |
| if (sched_feat(WA_BIAS)) |
| prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2; |
| prev_eff_load *= capacity_of(this_cpu); |
| |
| return this_eff_load <= prev_eff_load; |
| } |
| |
| static int wake_affine(struct sched_domain *sd, struct task_struct *p, |
| int prev_cpu, int sync) |
| { |
| int this_cpu = smp_processor_id(); |
| bool affine = false; |
| |
| if (sched_feat(WA_IDLE) && !affine) |
| affine = wake_affine_idle(sd, p, this_cpu, prev_cpu, sync); |
| |
| if (sched_feat(WA_WEIGHT) && !affine) |
| affine = wake_affine_weight(sd, p, this_cpu, prev_cpu, sync); |
| |
| schedstat_inc(p->se.statistics.nr_wakeups_affine_attempts); |
| if (affine) { |
| schedstat_inc(sd->ttwu_move_affine); |
| schedstat_inc(p->se.statistics.nr_wakeups_affine); |
| } |
| |
| return affine; |
| } |
| |
| #ifdef CONFIG_SCHED_TUNE |
| struct reciprocal_value schedtune_spc_rdiv; |
| |
| static long |
| schedtune_margin(int cpu, unsigned long signal, long boost) |
| { |
| long long margin = 0; |
| |
| /* |
| * Signal proportional compensation (SPC) |
| * |
| * The Boost (B) value is used to compute a Margin (M) which is |
| * proportional to the complement of the original Signal (S): |
| * M = B * (SCHED_CAPACITY_SCALE - S) |
| * The obtained M could be used by the caller to "boost" S. |
| */ |
| if (cpu == -1) { /* task margin */ |
| if (boost >= 0) { |
| margin = SCHED_CAPACITY_SCALE - signal; |
| margin *= boost; |
| } else |
| margin = -signal * boost; |
| } else { /* cpu margin */ |
| if (boost >= 0) { |
| margin = capacity_orig_of(cpu) - signal; |
| margin *= boost; |
| } else |
| margin = -signal * boost; |
| } |
| |
| margin = reciprocal_divide(margin, schedtune_spc_rdiv); |
| |
| if (boost < 0) |
| margin *= -1; |
| return margin; |
| } |
| |
| static inline int |
| schedtune_cpu_margin(unsigned long util, int cpu) |
| { |
| int boost = schedtune_cpu_boost(cpu); |
| |
| if (boost == 0) |
| return 0; |
| |
| return schedtune_margin(cpu, util, boost); |
| } |
| |
| static inline long |
| schedtune_task_margin(struct task_struct *task) |
| { |
| int boost = schedtune_task_boost(task); |
| unsigned long util; |
| long margin; |
| |
| if (boost == 0) |
| return 0; |
| |
| util = task_util_est(task); |
| margin = schedtune_margin(-1, util, boost); |
| |
| return margin; |
| } |
| |
| #else /* CONFIG_SCHED_TUNE */ |
| |
| static inline int |
| schedtune_cpu_margin(unsigned long util, int cpu) |
| { |
| return 0; |
| } |
| |
| static inline int |
| schedtune_task_margin(struct task_struct *task) |
| { |
| return 0; |
| } |
| |
| #endif /* CONFIG_SCHED_TUNE */ |
| |
| unsigned long |
| boosted_cpu_util(int cpu) |
| { |
| unsigned long util = cpu_util_freq(cpu); |
| long margin = schedtune_cpu_margin(util, cpu); |
| |
| trace_sched_boost_cpu(cpu, util, margin); |
| |
| return util + margin; |
| } |
| |
| static inline unsigned long |
| boosted_task_util(struct task_struct *task) |
| { |
| unsigned long util = task_util_est(task); |
| long margin = schedtune_task_margin(task); |
| unsigned long util_min = uclamp_task_effective_util(task, UCLAMP_MIN); |
| unsigned long util_max = uclamp_task_effective_util(task, UCLAMP_MAX); |
| |
| trace_sched_boost_task(task, util, margin, util_min); |
| |
| /* only boosted for heavy task */ |
| if (util >= stune_task_threshold) { |
| util = util + margin; |
| return clamp(util, util_min, util_max); |
| } else { |
| return clamp(util, util_min, util_max); |
| } |
| } |
| |
| void get_task_util(struct task_struct *p, unsigned long *util, |
| unsigned long *boost_util) |
| { |
| *boost_util = boosted_task_util(p); |
| *util = task_util(p); |
| } |
| |
| unsigned long cpu_util_without(int cpu, struct task_struct *p); |
| |
| unsigned long capacity_spare_without(int cpu, struct task_struct *p) |
| { |
| return max_t(long, capacity_of(cpu) - cpu_util_without(cpu, p), 0); |
| } |
| |
| #ifdef CONFIG_MTK_SCHED_INTEROP |
| #define MT_RT_LOAD (2*1023*NICE_0_LOAD) |
| static inline unsigned long mt_rt_load(int cpu) |
| { |
| if (likely(!is_rt_throttle(cpu))) |
| return cpu_rq(cpu)->rt.rt_nr_running * MT_RT_LOAD; |
| |
| return 0; |
| } |
| #endif |
| |
| /* |
| * find_idlest_group finds and returns the least busy CPU group within the |
| * domain. |
| * |
| * Assumes p is allowed on at least one CPU in sd. |
| */ |
| static struct sched_group * |
| find_idlest_group(struct sched_domain *sd, struct task_struct *p, |
| int this_cpu, int sd_flag) |
| { |
| struct sched_group *idlest = NULL, *group = sd->groups; |
| struct sched_group *most_spare_sg = NULL; |
| unsigned long min_runnable_load = ULONG_MAX; |
| unsigned long this_runnable_load = ULONG_MAX; |
| unsigned long min_avg_load = ULONG_MAX, this_avg_load = ULONG_MAX; |
| unsigned long most_spare = 0, this_spare = 0; |
| int load_idx = sd->forkexec_idx; |
| int imbalance_scale = 100 + (sd->imbalance_pct-100)/2; |
| unsigned long imbalance = scale_load_down(NICE_0_LOAD) * |
| (sd->imbalance_pct-100) / 100; |
| |
| if (sd_flag & SD_BALANCE_WAKE) |
| load_idx = sd->wake_idx; |
| |
| do { |
| unsigned long load, avg_load, runnable_load; |
| unsigned long spare_cap, max_spare_cap; |
| int local_group; |
| int i; |
| |
| /* Skip over this group if it has no CPUs allowed */ |
| if (!cpumask_intersects(sched_group_span(group), |
| &p->cpus_allowed)) |
| continue; |
| |
| local_group = cpumask_test_cpu(this_cpu, |
| sched_group_span(group)); |
| |
| /* |
| * Tally up the load of all CPUs in the group and find |
| * the group containing the CPU with most spare capacity. |
| */ |
| avg_load = 0; |
| runnable_load = 0; |
| max_spare_cap = 0; |
| |
| for_each_cpu(i, sched_group_span(group)) { |
| /* Bias balancing toward cpus of our domain */ |
| if (local_group) |
| load = source_load(i, load_idx); |
| else |
| load = target_load(i, load_idx); |
| |
| runnable_load += load; |
| |
| avg_load += cfs_rq_load_avg(&cpu_rq(i)->cfs); |
| |
| #if defined(CONFIG_MTK_SCHED_INTEROP) && defined(CONFIG_RT_GROUP_SCHED) |
| avg_load += mt_rt_load(i); |
| #endif |
| |
| spare_cap = capacity_spare_without(i, p); |
| |
| if (spare_cap > max_spare_cap) |
| max_spare_cap = spare_cap; |
| } |
| |
| /* Adjust by relative CPU capacity of the group */ |
| avg_load = (avg_load * SCHED_CAPACITY_SCALE) / |
| group->sgc->capacity; |
| runnable_load = (runnable_load * SCHED_CAPACITY_SCALE) / |
| group->sgc->capacity; |
| |
| if (local_group) { |
| this_runnable_load = runnable_load; |
| this_avg_load = avg_load; |
| this_spare = max_spare_cap; |
| } else { |
| if (min_runnable_load > (runnable_load + imbalance)) { |
| /* |
| * The runnable load is significantly smaller |
| * so we can pick this new cpu |
| */ |
| min_runnable_load = runnable_load; |
| min_avg_load = avg_load; |
| idlest = group; |
| } else if ((runnable_load < (min_runnable_load + imbalance)) && |
| (100*min_avg_load > imbalance_scale*avg_load)) { |
| /* |
| * The runnable loads are close so take the |
| * blocked load into account through avg_load. |
| */ |
| min_avg_load = avg_load; |
| idlest = group; |
| } |
| |
| if (most_spare < max_spare_cap) { |
| most_spare = max_spare_cap; |
| most_spare_sg = group; |
| } |
| } |
| } while (group = group->next, group != sd->groups); |
| |
| /* |
| * The cross-over point between using spare capacity or least load |
| * is too conservative for high utilization tasks on partially |
| * utilized systems if we require spare_capacity > task_util(p), |
| * so we allow for some task stuffing by using |
| * spare_capacity > task_util(p)/2. |
| * |
| * Spare capacity can't be used for fork because the utilization has |
| * not been set yet, we must first select a rq to compute the initial |
| * utilization. |
| */ |
| if (sd_flag & SD_BALANCE_FORK) |
| goto skip_spare; |
| |
| if (this_spare > task_util(p) / 2 && |
| imbalance_scale*this_spare > 100*most_spare) |
| return NULL; |
| |
| if (most_spare > task_util(p) / 2) |
| return most_spare_sg; |
| |
| skip_spare: |
| if (!idlest) |
| return NULL; |
| |
| if (min_runnable_load > (this_runnable_load + imbalance)) |
| return NULL; |
| |
| if ((this_runnable_load < (min_runnable_load + imbalance)) && |
| (100*this_avg_load < imbalance_scale*min_avg_load)) |
| return NULL; |
| |
| return idlest; |
| } |
| |
| /* |
| * find_idlest_group_cpu - find the idlest cpu among the cpus in group. |
| */ |
| static int |
| find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) |
| { |
| unsigned long load, min_load = ULONG_MAX; |
| unsigned int min_exit_latency = UINT_MAX; |
| u64 latest_idle_timestamp = 0; |
| int least_loaded_cpu = this_cpu; |
| int shallowest_idle_cpu = -1; |
| int i; |
| |
| /* Check if we have any choice: */ |
| if (group->group_weight == 1) |
| return cpumask_first(sched_group_span(group)); |
| |
| /* Traverse only the allowed CPUs */ |
| for_each_cpu_and(i, sched_group_span(group), &p->cpus_allowed) { |
| if (idle_cpu(i)) { |
| struct rq *rq = cpu_rq(i); |
| struct cpuidle_state *idle = idle_get_state(rq); |
| if (cpu_isolated(i)) |
| continue; |
| if (idle && idle->exit_latency < min_exit_latency) { |
| /* |
| * We give priority to a CPU whose idle state |
| * has the smallest exit latency irrespective |
| * of any idle timestamp. |
| */ |
| min_exit_latency = idle->exit_latency; |
| latest_idle_timestamp = rq->idle_stamp; |
| shallowest_idle_cpu = i; |
| } else if ((!idle || idle->exit_latency == min_exit_latency) && |
| rq->idle_stamp > latest_idle_timestamp) { |
| /* |
| * If equal or no active idle state, then |
| * the most recently idled CPU might have |
| * a warmer cache. |
| */ |
| latest_idle_timestamp = rq->idle_stamp; |
| shallowest_idle_cpu = i; |
| } |
| } else if (shallowest_idle_cpu == -1) { |
| load = weighted_cpuload(cpu_rq(i)); |
| #if defined(CONFIG_MTK_SCHED_INTEROP) && defined(CONFIG_RT_GROUP_SCHED) |
| load += mt_rt_load(i); |
| #endif |
| if (load < min_load || (load == min_load && i == this_cpu)) { |
| min_load = load; |
| least_loaded_cpu = i; |
| } |
| } |
| } |
| |
| return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu; |
| } |
| |
| static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p, |
| int cpu, int prev_cpu, int sd_flag) |
| { |
| int new_cpu = cpu; |
| |
| if (!cpumask_intersects(sched_domain_span(sd), &p->cpus_allowed)) |
| return prev_cpu; |
| |
| while (sd) { |
| struct sched_group *group; |
| struct sched_domain *tmp; |
| int weight; |
| |
| if (!(sd->flags & sd_flag)) { |
| sd = sd->child; |
| continue; |
| } |
| |
| group = find_idlest_group(sd, p, cpu, sd_flag); |
| if (!group) { |
| sd = sd->child; |
| continue; |
| } |
| |
| new_cpu = find_idlest_group_cpu(group, p, cpu); |
| if (new_cpu == cpu) { |
| /* Now try balancing at a lower domain level of cpu */ |
| sd = sd->child; |
| continue; |
| } |
| |
| /* Now try balancing at a lower domain level of new_cpu */ |
| cpu = new_cpu; |
| weight = sd->span_weight; |
| sd = NULL; |
| for_each_domain(cpu, tmp) { |
| if (weight <= tmp->span_weight) |
| break; |
| if (tmp->flags & sd_flag) |
| sd = tmp; |
| } |
| /* while loop will break here if sd == NULL */ |
| } |
| |
| return new_cpu; |
| } |
| |
| #ifdef CONFIG_SCHED_SMT |
| DEFINE_STATIC_KEY_FALSE(sched_smt_present); |
| EXPORT_SYMBOL_GPL(sched_smt_present); |
| |
| static inline void set_idle_cores(int cpu, int val) |
| { |
| struct sched_domain_shared *sds; |
| |
| sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); |
| if (sds) |
| WRITE_ONCE(sds->has_idle_cores, val); |
| } |
| |
| static inline bool test_idle_cores(int cpu, bool def) |
| { |
| struct sched_domain_shared *sds; |
| |
| sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); |
| if (sds) |
| return READ_ONCE(sds->has_idle_cores); |
| |
| return def; |
| } |
| |
| /* |
| * Scans the local SMT mask to see if the entire core is idle, and records this |
| * information in sd_llc_shared->has_idle_cores. |
| * |
| * Since SMT siblings share all cache levels, inspecting this limited remote |
| * state should be fairly cheap. |
| */ |
| void __update_idle_core(struct rq *rq) |
| { |
| int core = cpu_of(rq); |
| int cpu; |
| |
| rcu_read_lock(); |
| if (test_idle_cores(core, true)) |
| goto unlock; |
| |
| for_each_cpu(cpu, cpu_smt_mask(core)) { |
| if (cpu == core) |
| continue; |
| |
| if (!idle_cpu(cpu)) |
| goto unlock; |
| } |
| |
| set_idle_cores(core, 1); |
| unlock: |
| rcu_read_unlock(); |
| } |
| |
| /* |
| * Scan the entire LLC domain for idle cores; this dynamically switches off if |
| * there are no idle cores left in the system; tracked through |
| * sd_llc->shared->has_idle_cores and enabled through update_idle_core() above. |
| */ |
| static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int target) |
| { |
| struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask); |
| int core, cpu; |
| |
| if (!static_branch_likely(&sched_smt_present)) |
| return -1; |
| |
| if (!test_idle_cores(target, false)) |
| return -1; |
| |
| cpumask_and(cpus, sched_domain_span(sd), &p->cpus_allowed); |
| |
| for_each_cpu_wrap(core, cpus, target) { |
| bool idle = true; |
| |
| for_each_cpu(cpu, cpu_smt_mask(core)) { |
| cpumask_clear_cpu(cpu, cpus); |
| if (!idle_cpu(cpu)) |
| idle = false; |
| } |
| |
| if (idle) |
| return core; |
| } |
| |
| /* |
| * Failed to find an idle core; stop looking for one. |
| */ |
| set_idle_cores(target, 0); |
| |
| return -1; |
| } |
| |
| /* |
| * Scan the local SMT mask for idle CPUs. |
| */ |
| static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target) |
| { |
| int cpu; |
| |
| if (!static_branch_likely(&sched_smt_present)) |
| return -1; |
| |
| for_each_cpu(cpu, cpu_smt_mask(target)) { |
| if (!cpumask_test_cpu(cpu, &p->cpus_allowed)) |
| continue; |
| if (idle_cpu(cpu)) |
| return cpu; |
| } |
| |
| return -1; |
| } |
| |
| #else /* CONFIG_SCHED_SMT */ |
| |
| static inline int select_idle_core(struct task_struct *p, struct sched_domain *sd, int target) |
| { |
| return -1; |
| } |
| |
| static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target) |
| { |
| return -1; |
| } |
| |
| #endif /* CONFIG_SCHED_SMT */ |
| |
| /* |
| * Scan the LLC domain for idle CPUs; this is dynamically regulated by |
| * comparing the average scan cost (tracked in sd->avg_scan_cost) against the |
| * average idle time for this rq (as found in rq->avg_idle). |
| */ |
| static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int target) |
| { |
| struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask); |
| struct sched_domain *this_sd; |
| u64 avg_cost, avg_idle; |
| u64 time, cost; |
| s64 delta; |
| int cpu, nr = INT_MAX; |
| |
| this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); |
| if (!this_sd) |
| return -1; |
| |
| /* |
| * Due to large variance we need a large fuzz factor; hackbench in |
| * particularly is sensitive here. |
| */ |
| avg_idle = this_rq()->avg_idle / 512; |
| avg_cost = this_sd->avg_scan_cost + 1; |
| |
| if (sched_feat(SIS_AVG_CPU) && avg_idle < avg_cost) |
| return -1; |
| |
| if (sched_feat(SIS_PROP)) { |
| u64 span_avg = sd->span_weight * avg_idle; |
| if (span_avg > 4*avg_cost) |
| nr = div_u64(span_avg, avg_cost); |
| else |
| nr = 4; |
| } |
| |
| time = local_clock(); |
| |
| cpumask_and(cpus, sched_domain_span(sd), &p->cpus_allowed); |
| |
| for_each_cpu_wrap(cpu, cpus, target) { |
| if (!--nr) |
| return -1; |
| if (idle_cpu(cpu)) |
| break; |
| } |
| |
| time = local_clock() - time; |
| cost = this_sd->avg_scan_cost; |
| delta = (s64)(time - cost) / 8; |
| this_sd->avg_scan_cost += delta; |
| |
| return cpu; |
| } |
| |
| /* |
| * Try and locate an idle core/thread in the LLC cache domain. |
| */ |
| static inline int __select_idle_sibling(struct task_struct *p, int prev, int target) |
| { |
| struct sched_domain *sd; |
| int i; |
| |
| if (idle_cpu(target)) |
| return target; |
| |
| /* |
| * If the previous cpu is cache affine and idle, don't be stupid. |
| */ |
| if (prev != target && cpus_share_cache(prev, target) && idle_cpu(prev)) |
| return prev; |
| |
| sd = rcu_dereference(per_cpu(sd_llc, target)); |
| if (!sd) |
| return target; |
| |
| i = select_idle_core(p, sd, target); |
| if ((unsigned)i < nr_cpumask_bits) |
| return i; |
| |
| i = select_idle_cpu(p, sd, target); |
| if ((unsigned)i < nr_cpumask_bits) |
| return i; |
| |
| i = select_idle_smt(p, sd, target); |
| if ((unsigned)i < nr_cpumask_bits) |
| return i; |
| |
| return target; |
| } |
| |
| static inline int select_idle_sibling_cstate_aware(struct task_struct *p, int prev, int target) |
| { |
| struct sched_domain *sd; |
| struct sched_group *sg; |
| int best_idle_cpu = -1; |
| int best_idle_cstate = -1; |
| int best_idle_capacity = INT_MAX; |
| int i; |
| |
| /* |
| * Iterate the domains and find an elegible idle cpu. |
| */ |
| sd = rcu_dereference(per_cpu(sd_llc, target)); |
| for_each_lower_domain(sd) { |
| sg = sd->groups; |
| do { |
| if (!cpumask_intersects( |
| sched_group_span(sg), &p->cpus_allowed)) |
| goto next; |
| |
| for_each_cpu_and(i, &p->cpus_allowed, sched_group_span(sg)) { |
| int idle_idx; |
| unsigned long new_usage; |
| unsigned long capacity_orig; |
| |
| if (!idle_cpu(i)) |
| goto next; |
| |
| /* figure out if the task can fit here at all */ |
| new_usage = boosted_task_util(p); |
| capacity_orig = capacity_orig_of(i); |
| |
| if (new_usage > capacity_orig) |
| goto next; |
| |
| /* if the task fits without changing OPP and we |
| * intended to use this CPU, just proceed |
| */ |
| if (i == target && new_usage <= capacity_curr_of(target)) { |
| return target; |
| } |
| |
| /* otherwise select CPU with shallowest idle state |
| * to reduce wakeup latency. |
| */ |
| idle_idx = idle_get_state_idx(cpu_rq(i)); |
| |
| if (idle_idx < best_idle_cstate && |
| capacity_orig <= best_idle_capacity) { |
| best_idle_cpu = i; |
| best_idle_cstate = idle_idx; |
| best_idle_capacity = capacity_orig; |
| } |
| } |
| next: |
| sg = sg->next; |
| } while (sg != sd->groups); |
| } |
| |
| if (best_idle_cpu >= 0) |
| target = best_idle_cpu; |
| |
| return target; |
| } |
| |
| static int select_idle_sibling(struct task_struct *p, int prev, int target) |
| { |
| if (!sysctl_sched_cstate_aware) |
| return __select_idle_sibling(p, prev, target); |
| |
| return select_idle_sibling_cstate_aware(p, prev, target); |
| } |
| |
| static inline int task_fits_capacity(struct task_struct *p, long capacity) |
| { |
| return capacity * 1024 > boosted_task_util(p) * capacity_margin; |
| } |
| |
| static int start_cpu(struct task_struct *p, bool prefer_idle, |
| bool boosted) |
| { |
| struct root_domain *rd = cpu_rq(smp_processor_id())->rd; |
| |
| if (rd->min_cap_orig_cpu < 0) |
| return -1; |
| |
| #ifdef OPLUS_FEATURE_SPECIALOPT |
| // Liujie.Xie@TECH.Kernel.Sched, 2020/02/26, add for heavy load task |
| if (sysctl_cpu_multi_thread && !is_heavy_load_task(p)) |
| return rd->min_cap_orig_cpu; |
| #endif |
| |
| if (boosted && (task_util(p) >= stune_task_threshold)) |
| return boosted ? rd->max_cap_orig_cpu : rd->min_cap_orig_cpu; |
| |
| #if defined (CONFIG_SCHED_WALT) && defined (OPLUS_FEATURE_UIFIRST) |
| if (sysctl_uifirst_enabled && sysctl_slide_boost_enabled && p->static_ux == 2 && |
| (scale_demand(p->ravg.demand) >= sysctl_boost_task_threshold || |
| scale_demand(p->ravg.sum) >= sysctl_boost_task_threshold)) { |
| return rd->max_cap_orig_cpu; |
| } |
| #endif |
| return rd->min_cap_orig_cpu; |
| } |
| |
| static inline int find_best_target(struct task_struct *p, int *backup_cpu, |
| bool boosted, bool prefer_idle) |
| { |
| unsigned long best_idle_min_cap_orig = ULONG_MAX; |
| unsigned long min_util = uclamp_task_effective_util(p, UCLAMP_MIN); |
| unsigned long max_util = uclamp_task_effective_util(p, UCLAMP_MAX); |
| unsigned long target_capacity = ULONG_MAX; |
| unsigned long min_wake_util = ULONG_MAX; |
| unsigned long target_max_spare_cap = 0; |
| unsigned long target_orig_max_spare_cap = 0; |
| unsigned long target_util = ULONG_MAX; |
| unsigned long best_active_util = ULONG_MAX; |
| unsigned long max_capacity = cluster_max_capacity(); |
| unsigned long min_cpu_util = ULONG_MAX; |
| unsigned long backup_idle_min_cpu_util = ULONG_MAX; |
| unsigned long backup_idle_min_cpu_cap = ULONG_MAX; |
| unsigned long backup_active_min_cpu_util = ULONG_MAX; |
| unsigned long min_target_capacity = ULONG_MAX; |
| int best_idle_cstate = INT_MAX; |
| struct sched_domain *sd; |
| struct sched_group *sg; |
| int best_active_cpu = -1; |
| int best_idle_cpu = -1; |
| int target_cpu = -1; |
| int cpu, i; |
| int backup_idle_min_cpu = -1; |
| int backup_active_min_cpu = -1; |
| |
| /* |
| * In most cases, target_capacity tracks capacity_orig of the most |
| * energy efficient CPU candidate, thus requiring to minimise |
| * target_capacity. For these cases target_capacity is already |
| * initialized to ULONG_MAX. |
| * However, for prefer_idle and boosted tasks we look for a high |
| * performance CPU, thus requiring to maximise target_capacity. In this |
| * case we initialise target_capacity to 0. |
| */ |
| if (prefer_idle && boosted) |
| target_capacity = 0; |
| |
| /* Find start CPU based on boost value */ |
| cpu = start_cpu(p, prefer_idle, boosted); |
| if (cpu < 0) |
| return -1; |
| |
| |
| /* Find SD for the start CPU */ |
| sd = rcu_dereference(per_cpu(sd_ea, cpu)); |
| if (!sd) |
| return -1; |
| |
| /* Scan CPUs in all SDs */ |
| sg = sd->groups; |
| do { |
| for_each_cpu_and(i, &p->cpus_allowed, sched_group_span(sg)) { |
| unsigned long capacity_curr = capacity_curr_of(i); |
| unsigned long capacity = capacity_of(i); |
| unsigned long capacity_orig = capacity_orig_of(i); |
| unsigned long wake_util, new_util; |
| long spare_cap, real_spare_cap; |
| int idle_idx = INT_MAX; |
| bool turning; |
| |
| if (!cpu_online(i) || cpu_isolated(i)) |
| continue; |
| |
| if (walt_cpu_high_irqload(i)) |
| continue; |
| |
| #if defined(OPLUS_FEATURE_UIFIRST) && !defined(CONFIG_MTK_TASK_TURBO) |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/06/15, Add for UIFirst |
| if (sysctl_uifirst_enabled && test_task_ux(p)) { |
| if (sysctl_launcher_boost_enabled && is_heavy_ux_task(p) && !test_ux_task_cpu(i)) |
| continue; |
| |
| if (!sysctl_launcher_boost_enabled || !is_heavy_ux_task(p)) { |
| if (cpu_rq(i)->rt.rt_nr_running) |
| continue; |
| |
| if (!list_empty(&cpu_rq(i)->ux_thread_list)) |
| continue; |
| } |
| } |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| |
| /* |
| * p's blocked utilization is still accounted for on prev_cpu |
| * so prev_cpu will receive a negative bias due to the double |
| * accounting. However, the blocked utilization may be zero. |
| */ |
| wake_util = cpu_util_without(i, p); |
| new_util = wake_util + task_util_est(p); |
| real_spare_cap = capacity - new_util; |
| |
| /* |
| * Ensure minimum capacity to grant the required boost. |
| * The target CPU can be already at a capacity level higher |
| * than the one required to boost the task. |
| */ |
| max_util = min(max_capacity, max_util); |
| new_util = clamp(new_util, min_util, max_util); |
| if (new_util > capacity) |
| continue; |
| |
| /* |
| * Pre-compute the maximum possible capacity we expect |
| * to have available on this CPU once the task is |
| * enqueued here. |
| */ |
| spare_cap = capacity - new_util; |
| |
| if (idle_cpu(i)) |
| idle_idx = idle_get_state_idx(cpu_rq(i)); |
| |
| /* |
| * Check if little core will use frequency |
| * higher than truning point. |
| */ |
| if (hmp_cpu_is_slowest(i) && |
| freq_util(new_util) > cpu_eff_tp) |
| turning = true; |
| else |
| turning = false; |
| |
| |
| /* |
| * Case A) Latency sensitive tasks |
| * |
| * Unconditionally favoring tasks that prefer idle CPU to |
| * improve latency. |
| * |
| * Looking for: |
| * - an idle CPU, whatever its idle_state is, since |
| * the first CPUs we explore are more likely to be |
| * reserved for latency sensitive tasks. |
| * - a non idle CPU where the task fits in its current |
| * capacity and has the maximum spare capacity. |
| * - a non idle CPU with lower contention from other |
| * tasks and running at the lowest possible OPP. |
| * |
| * The last two goals tries to favor a non idle CPU |
| * where the task can run as if it is "almost alone". |
| * A maximum spare capacity CPU is favoured since |
| * the task already fits into that CPU's capacity |
| * without waiting for an OPP chance. |
| * |
| * The following code path is the only one in the CPUs |
| * exploration loop which is always used by |
| * prefer_idle tasks. It exits the loop with wither a |
| * best_active_cpu or a target_cpu which should |
| * represent an optimal choice for latency sensitive |
| * tasks. |
| */ |
| if (prefer_idle) { |
| |
| /* |
| * Case A.1: IDLE CPU |
| * Return the best IDLE CPU we find: |
| * - for boosted tasks: the CPU with the highest |
| * performance (i.e. biggest capacity_orig) |
| * - for !boosted tasks: the most energy |
| * efficient CPU (i.e. smallest capacity_orig) |
| */ |
| if (idle_cpu(i)) { |
| /* |
| * if we found an effcient cpu in L cpu, |
| * it's no need to search B cpu. |
| */ |
| if (capacity_orig > min_target_capacity) |
| continue; |
| |
| if (capacity_orig == min_target_capacity |
| && sysctl_sched_cstate_aware && |
| best_idle_cstate <= idle_idx) |
| continue; |
| |
| /* |
| * If little core will use frequency |
| * higher than truning point, store it |
| * as backup cpu. |
| */ |
| if (turning && |
| new_util < |
| backup_idle_min_cpu_util) { |
| backup_idle_min_cpu_util = |
| new_util; |
| backup_idle_min_cpu = i; |
| continue; |
| } |
| |
| /* find the max spare capacity cpu */ |
| if (!turning && |
| (new_util < min_cpu_util)) { |
| min_target_capacity = |
| capacity_orig; |
| min_cpu_util = new_util; |
| best_idle_cstate = idle_idx; |
| best_idle_cpu = i; |
| } |
| |
| continue; |
| } |
| if (best_idle_cpu != -1) |
| continue; |
| |
| /* |
| * Case A.2: Target ACTIVE CPU |
| * Favor CPUs with max spare capacity. |
| */ |
| if (capacity_curr > new_util && |
| spare_cap > target_max_spare_cap) { |
| target_max_spare_cap = spare_cap; |
| target_orig_max_spare_cap = |
| real_spare_cap; |
| target_cpu = i; |
| continue; |
| } |
| /* |
| * If util including uclamp are equal, |
| * then consider real |
| * spare capacity |
| */ |
| if (capacity_curr > new_util && |
| spare_cap == target_max_spare_cap) |
| if (real_spare_cap <= |
| target_orig_max_spare_cap) |
| continue; |
| |
| if (target_cpu != -1) |
| continue; |
| |
| /* |
| * Case A.3: Backup ACTIVE CPU |
| * Favor CPUs with: |
| * - lower utilization due to other tasks |
| * - lower utilization with the task in |
| */ |
| if (wake_util > min_wake_util) |
| continue; |
| if (new_util > best_active_util) |
| continue; |
| min_wake_util = wake_util; |
| best_active_util = new_util; |
| best_active_cpu = i; |
| continue; |
| } |
| |
| /* |
| * Case B) Non latency sensitive tasks on IDLE CPUs. |
| * |
| * Find an optimal backup IDLE CPU for non latency |
| * sensitive tasks. |
| * |
| * Looking for: |
| * - minimizing the capacity_orig, |
| * i.e. preferring LITTLE CPUs |
| * - favoring shallowest idle states |
| * i.e. avoid to wakeup deep-idle CPUs |
| * |
| * The following code path is used by non latency |
| * sensitive tasks if IDLE CPUs are available. If at |
| * least one of such CPUs are available it sets the |
| * best_idle_cpu to the most suitable idle CPU to be |
| * selected. |
| * |
| * If idle CPUs are available, favour these CPUs to |
| * improve performances by spreading tasks. |
| * Indeed, the energy_diff() computed by the caller |
| * will take care to ensure the minimization of energy |
| * consumptions without affecting performance. |
| */ |
| if (idle_cpu(i)) { |
| |
| /* |
| * Favor CPUs with smaller capacity for |
| * non latency sensitive tasks. |
| */ |
| if (capacity_orig > best_idle_min_cap_orig) |
| continue; |
| |
| /* |
| * Skip CPUs in deeper idle state, but only |
| * if they are also less energy efficient. |
| * IOW, prefer a deep IDLE LITTLE CPU vs a |
| * shallow idle big CPU. |
| */ |
| if (capacity_orig == best_idle_min_cap_orig && |
| sysctl_sched_cstate_aware && |
| best_idle_cstate <= idle_idx) |
| continue; |
| |
| /* |
| * If little core will use frequency |
| * higher than truning point, store it |
| * as backup cpu. |
| */ |
| if (turning && |
| new_util < backup_idle_min_cpu_util) { |
| backup_idle_min_cpu_util = new_util; |
| backup_idle_min_cpu = i; |
| backup_idle_min_cpu_cap = capacity_orig; |
| continue; |
| } |
| |
| /* find the max spare capacity cpu */ |
| if (!turning && (new_util < min_cpu_util)) { |
| best_idle_min_cap_orig = |
| capacity_orig; |
| min_cpu_util = new_util; |
| best_idle_cstate = idle_idx; |
| best_idle_cpu = i; |
| } |
| |
| continue; |
| } |
| |
| /* |
| * Case C) Non latency sensitive tasks on ACTIVE CPUs. |
| * |
| * Pack tasks in the most energy efficient capacities. |
| * |
| * This task packing strategy prefers more energy |
| * efficient CPUs (i.e. pack on smaller maximum |
| * capacity CPUs) while also trying to spread tasks to |
| * run them all at the lower OPP. |
| * |
| * This assumes for example that it's more energy |
| * efficient to run two tasks on two CPUs at a lower |
| * OPP than packing both on a single CPU but running |
| * that CPU at an higher OPP. |
| * |
| * Thus, this case keep track of the CPU with the |
| * smallest maximum capacity and highest spare maximum |
| * capacity. |
| */ |
| |
| /* |
| * Favor CPUs with smaller capacity for non latency |
| * sensitive tasks. |
| */ |
| if (capacity_orig > target_capacity) |
| continue; |
| |
| /* Favor CPUs with maximum spare capacity */ |
| if (capacity_orig == target_capacity && |
| spare_cap < target_max_spare_cap) |
| continue; |
| /* |
| * If spare_cap include uclamp util is equal, |
| * then consider real spare_cap. This could avoid |
| * all task fall back to the last cpu if all cpu |
| * running a task with uclamp |
| * min is 1024. |
| */ |
| if (capacity_orig == target_capacity && |
| spare_cap == target_max_spare_cap) |
| if (real_spare_cap <= target_orig_max_spare_cap) |
| continue; |
| |
| /* |
| * If little core will use frequency |
| * higher than truning point, store it |
| * as backup cpu. |
| */ |
| if (turning && |
| new_util < backup_active_min_cpu_util) { |
| backup_active_min_cpu_util = |
| new_util; |
| backup_active_min_cpu = i; |
| continue; |
| } |
| |
| if (!turning) { |
| target_max_spare_cap = spare_cap; |
| target_orig_max_spare_cap = real_spare_cap; |
| target_capacity = capacity_orig; |
| target_util = new_util; |
| target_cpu = i; |
| } |
| } |
| |
| } while (sg = sg->next, sg != sd->groups); |
| |
| |
| /* |
| * Policies priorities: |
| * |
| * - prefer_idle tasks: |
| * |
| * a) IDLE CPU available: best_idle_cpu |
| * (little core will not use frequency higher than turning point) |
| * b) IDLE CPU: backup_idle_min_cpu |
| * (little core will use frequency higher than turning point) |
| * c) ACTIVE CPU where task fits and has the bigger maximum spare |
| * capacity (i.e. target_cpu) |
| * d) ACTIVE CPU with less contention due to other tasks |
| * (i.e. best_active_cpu) |
| * |
| * - NON prefer_idle tasks: (in the sched domain will do load balance) |
| * |
| * a) IDLE little core and not use frequency higher than |
| * turning point: best_idle_cpu |
| * b) ACTIVE little core and not use frequency core higher than |
| * turning point: target_cpu |
| * c) IDLE big core: best_idle_cpu |
| * d) IDLE little core and use frequency core higher than |
| * turning point: backup_idle_min_cpu |
| * e) ACTIVE big core: target_cpu |
| * f) ACTIVE little core and use frequency core higher thane turning |
| * point: backup_active_min_cpu |
| */ |
| |
| if (prefer_idle) { |
| if (best_idle_cpu == -1) |
| best_idle_cpu = backup_idle_min_cpu; |
| } else { |
| if (best_idle_cpu != -1) { |
| if (target_capacity >= best_idle_min_cap_orig) |
| target_cpu = best_idle_cpu; |
| } else if (target_cpu != -1) { |
| if (target_capacity > backup_idle_min_cpu_cap) |
| target_cpu = backup_idle_min_cpu; |
| } else { |
| if (backup_active_min_cpu != -1) |
| target_cpu = backup_active_min_cpu; |
| if (backup_idle_min_cpu != -1) |
| target_cpu = backup_idle_min_cpu; |
| } |
| } |
| |
| if (prefer_idle && (best_idle_cpu != -1)) { |
| trace_sched_find_best_target(p, prefer_idle, min_util, cpu, |
| best_idle_cpu, best_active_cpu, |
| best_idle_cpu); |
| |
| return best_idle_cpu; |
| } |
| |
| if (target_cpu == -1) |
| target_cpu = prefer_idle |
| ? best_active_cpu |
| : best_idle_cpu; |
| else |
| *backup_cpu = prefer_idle |
| ? best_active_cpu |
| : best_idle_cpu; |
| |
| trace_sched_find_best_target(p, prefer_idle, min_util, cpu, |
| best_idle_cpu, best_active_cpu, |
| target_cpu); |
| |
| /* it is possible for target and backup |
| * to select same CPU - if so, drop backup |
| */ |
| if (*backup_cpu == target_cpu) |
| *backup_cpu = -1; |
| |
| return target_cpu; |
| } |
| |
| /* |
| * Disable WAKE_AFFINE in the case where task @p doesn't fit in the |
| * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu. |
| * |
| * In that case WAKE_AFFINE doesn't make sense and we'll let |
| * BALANCE_WAKE sort things out. |
| */ |
| static int wake_cap(struct task_struct *p, int cpu, int prev_cpu) |
| { |
| long min_cap, max_cap; |
| |
| if (!static_branch_unlikely(&sched_asym_cpucapacity)) |
| return 0; |
| |
| min_cap = min(capacity_orig_of(prev_cpu), capacity_orig_of(cpu)); |
| max_cap = cpu_rq(cpu)->rd->max_cpu_capacity.val; |
| |
| /* Minimum capacity is close to max, no need to abort wake_affine */ |
| if (max_cap - min_cap < max_cap >> 3) |
| return 0; |
| |
| /* Bring task utilization in sync with prev_cpu */ |
| sync_entity_load_avg(&p->se); |
| |
| return !task_fits_capacity(p, min_cap); |
| } |
| |
| static bool cpu_overutilized(int cpu) |
| { |
| return (capacity_of(cpu) * 1024) < (cpu_util(cpu) * capacity_margin); |
| } |
| |
| DEFINE_PER_CPU(struct energy_env, eenv_cache); |
| |
| /* kernels often have NR_CPUS defined to be much |
| * larger than exist in practise on booted systems. |
| * Allocate the cpu array for eenv calculations |
| * at boot time to avoid massive overprovisioning. |
| */ |
| #ifdef DEBUG_EENV_DECISIONS |
| static inline int eenv_debug_size_per_dbg_entry(void) |
| { |
| return sizeof(struct _eenv_debug) + (sizeof(unsigned long) * num_possible_cpus()); |
| } |
| |
| static inline int eenv_debug_size_per_cpu_entry(void) |
| { |
| /* each cpu struct has an array of _eenv_debug structs |
| * which have an array of unsigned longs at the end - |
| * the allocation should be extended so that there are |
| * at least 'num_possible_cpus' entries in the array. |
| */ |
| return EAS_EENV_DEBUG_LEVELS * eenv_debug_size_per_dbg_entry(); |
| } |
| /* given a per-_eenv_cpu debug env ptr, get the ptr for a given index */ |
| static inline struct _eenv_debug *eenv_debug_entry_ptr(struct _eenv_debug *base, int idx) |
| { |
| char *ptr = (char *)base; |
| ptr += (idx * eenv_debug_size_per_dbg_entry()); |
| return (struct _eenv_debug *)ptr; |
| } |
| /* given a pointer to the per-cpu global copy of _eenv_debug, get |
| * a pointer to the specified _eenv_cpu debug env. |
| */ |
| static inline struct _eenv_debug *eenv_debug_percpu_debug_env_ptr(struct _eenv_debug *base, int cpu_idx) |
| { |
| char *ptr = (char *)base; |
| ptr += (cpu_idx * eenv_debug_size_per_cpu_entry()); |
| return (struct _eenv_debug *)ptr; |
| } |
| |
| static inline int eenv_debug_size(void) |
| { |
| return num_possible_cpus() * eenv_debug_size_per_cpu_entry(); |
| } |
| #endif |
| |
| static inline void alloc_eenv(void) |
| { |
| int cpu; |
| int cpu_count = num_possible_cpus(); |
| |
| for_each_possible_cpu(cpu) { |
| struct energy_env *eenv = &per_cpu(eenv_cache, cpu); |
| eenv->cpu = kmalloc(sizeof(struct eenv_cpu) * cpu_count, GFP_KERNEL); |
| eenv->eenv_cpu_count = cpu_count; |
| #ifdef DEBUG_EENV_DECISIONS |
| eenv->debug = (struct _eenv_debug *)kmalloc(eenv_debug_size(), GFP_KERNEL); |
| #endif |
| } |
| } |
| |
| static inline void reset_eenv(struct energy_env *eenv) |
| { |
| int cpu_count; |
| struct eenv_cpu *cpu; |
| #ifdef DEBUG_EENV_DECISIONS |
| struct _eenv_debug *debug; |
| int cpu_idx; |
| debug = eenv->debug; |
| #endif |
| |
| cpu_count = eenv->eenv_cpu_count; |
| cpu = eenv->cpu; |
| memset(eenv, 0, sizeof(struct energy_env)); |
| eenv->cpu = cpu; |
| memset(eenv->cpu, 0, sizeof(struct eenv_cpu)*cpu_count); |
| eenv->eenv_cpu_count = cpu_count; |
| |
| #ifdef DEBUG_EENV_DECISIONS |
| memset(debug, 0, eenv_debug_size()); |
| eenv->debug = debug; |
| for(cpu_idx = 0; cpu_idx < eenv->eenv_cpu_count; cpu_idx++) |
| eenv->cpu[cpu_idx].debug = eenv_debug_percpu_debug_env_ptr(debug, cpu_idx); |
| #endif |
| } |
| /* |
| * get_eenv - reset the eenv struct cached for this CPU |
| * |
| * When the eenv is returned, it is configured to do |
| * energy calculations for the maximum number of CPUs |
| * the task can be placed on. The prev_cpu entry is |
| * filled in here. Callers are responsible for adding |
| * other CPU candidates up to eenv->max_cpu_count. |
| */ |
| static inline struct energy_env *get_eenv(struct task_struct *p, int prev_cpu) |
| { |
| struct energy_env *eenv; |
| cpumask_t cpumask_possible_cpus; |
| int cpu = smp_processor_id(); |
| int i; |
| |
| eenv = &(per_cpu(eenv_cache, cpu)); |
| reset_eenv(eenv); |
| |
| /* populate eenv */ |
| eenv->p = p; |
| /* use boosted task util for capacity selection |
| * during energy calculation, but unboosted task |
| * util for group utilization calculations |
| */ |
| eenv->util_delta = task_util_est(p); |
| eenv->util_delta_boosted = boosted_task_util(p); |
| |
| cpumask_and(&cpumask_possible_cpus, &p->cpus_allowed, cpu_online_mask); |
| eenv->max_cpu_count = cpumask_weight(&cpumask_possible_cpus); |
| |
| for (i=0; i < eenv->max_cpu_count; i++) |
| eenv->cpu[i].cpu_id = -1; |
| eenv->cpu[EAS_CPU_PRV].cpu_id = prev_cpu; |
| eenv->next_idx = EAS_CPU_PRV; |
| |
| return eenv; |
| } |
| |
| /* |
| * Needs to be called inside rcu_read_lock critical section. |
| * sd is a pointer to the sched domain we wish to use for an |
| * energy-aware placement option. |
| */ |
| static int find_energy_efficient_cpu(struct sched_domain *sd, |
| struct task_struct *p, |
| int cpu, int prev_cpu, |
| int sync) |
| { |
| int use_fbt = sched_feat(FIND_BEST_TARGET); |
| int cpu_iter, eas_cpu_idx = EAS_CPU_NXT; |
| int target_cpu = -1; |
| struct energy_env *eenv; |
| unsigned int task_clamped_util; |
| |
| if (sysctl_sched_sync_hint_enable && sync) { |
| if (cpumask_test_cpu(cpu, &p->cpus_allowed) && |
| !cpu_isolated(cpu)) { |
| return cpu; |
| } |
| } |
| |
| /* prepopulate energy diff environment */ |
| eenv = get_eenv(p, prev_cpu); |
| if (eenv->max_cpu_count < 2) |
| return -1; |
| |
| if (!boosted_task_util(p)) |
| return -1; |
| |
| if(!use_fbt) { |
| /* |
| * using this function outside wakeup balance will not supply |
| * an sd ptr. Instead, fetch the highest level with energy data. |
| */ |
| if (!sd) |
| sd = rcu_dereference(per_cpu(sd_ea, prev_cpu)); |
| |
| for_each_cpu_and(cpu_iter, &p->cpus_allowed, sched_domain_span(sd)) { |
| unsigned long spare; |
| |
| /* prev_cpu already in list */ |
| if (cpu_iter == prev_cpu) |
| continue; |
| |
| /* |
| * Consider only CPUs where the task is expected to |
| * fit without making the CPU overutilized. |
| */ |
| spare = capacity_spare_without(cpu_iter, p); |
| if (spare * 1024 < capacity_margin * task_util_est(p)) |
| continue; |
| |
| /* Add CPU candidate */ |
| eenv->cpu[eas_cpu_idx++].cpu_id = cpu_iter; |
| eenv->max_cpu_count = eas_cpu_idx; |
| |
| /* stop adding CPUs if we have no space left */ |
| if (eas_cpu_idx >= eenv->eenv_cpu_count) |
| break; |
| } |
| } else { |
| int boosted = (schedtune_task_boost(p) > 0); |
| int prefer_idle; |
| |
| /* |
| * give compiler a hint that if sched_features |
| * cannot be changed, it is safe to optimise out |
| * all if(prefer_idle) blocks. |
| */ |
| prefer_idle = sched_feat(EAS_PREFER_IDLE) ? |
| (schedtune_prefer_idle(p) > 0) : 0; |
| |
| eenv->max_cpu_count = EAS_CPU_BKP + 1; |
| |
| /* Find a cpu with sufficient capacity */ |
| target_cpu = find_best_target(p, &eenv->cpu[EAS_CPU_BKP].cpu_id, |
| boosted, prefer_idle); |
| |
| #if defined(OPLUS_FEATURE_UIFIRST) && !defined(CONFIG_MTK_TASK_TURBO) |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/05/25, Add for UIFirst |
| if (sysctl_uifirst_enabled && sysctl_launcher_boost_enabled && |
| is_heavy_ux_task(p) && !test_ux_prefer_cpu(p, target_cpu)) { |
| find_ux_task_cpu(p, &target_cpu); |
| if (target_cpu >= 0) |
| return target_cpu; |
| } |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| |
| /* Immediately return a found idle CPU for a prefer_idle task */ |
| if (prefer_idle && target_cpu >= 0 && idle_cpu(target_cpu) && |
| !cpu_isolated(target_cpu)) |
| return target_cpu; |
| |
| task_clamped_util = uclamp_task_effective_util(p, UCLAMP_MIN); |
| if (task_clamped_util > capacity_of(prev_cpu)) |
| return target_cpu; |
| |
| /* sched: no need energy calculation if the same domain */ |
| if (target_cpu >= 0 && |
| is_intra_domain(task_cpu(p), target_cpu) && |
| target_cpu != l_plus_cpu && !cpu_isolated(target_cpu)) { |
| |
| if (idle_cpu(prev_cpu) && idle_cpu(target_cpu)) { |
| struct rq *prev_rq, *target_rq; |
| int prev_idle_idx; |
| int target_idle_idx; |
| |
| prev_rq = cpu_rq(prev_cpu); |
| target_rq = cpu_rq(target_cpu); |
| |
| prev_idle_idx = idle_get_state_idx(prev_rq); |
| target_idle_idx = idle_get_state_idx(target_rq); |
| |
| /* favoring shallowest idle states */ |
| if ((prev_idle_idx <= target_idle_idx) || |
| target_idle_idx == -1) |
| target_cpu = prev_cpu; |
| } |
| return target_cpu; |
| |
| } |
| |
| /* Place target into NEXT slot */ |
| eenv->cpu[EAS_CPU_NXT].cpu_id = target_cpu; |
| |
| /* take note if no backup was found */ |
| if (eenv->cpu[EAS_CPU_BKP].cpu_id < 0 && |
| (eenv->cpu[EAS_CPU_BKP].cpu_id != prev_cpu)) |
| eenv->max_cpu_count = EAS_CPU_BKP; |
| |
| /* take note if no target was found */ |
| if (eenv->cpu[EAS_CPU_NXT].cpu_id < 0) |
| eenv->max_cpu_count = EAS_CPU_NXT; |
| } |
| |
| if (eenv->max_cpu_count == EAS_CPU_NXT) { |
| /* |
| * we did not find any energy-awareness |
| * candidates beyond prev_cpu, so we will |
| * fall-back to the regular slow-path. |
| */ |
| return -1; |
| } |
| |
| /* find most energy-efficient CPU */ |
| target_cpu = select_energy_cpu_idx(eenv) < 0 ? -1 : |
| eenv->cpu[eenv->next_idx].cpu_id; |
| |
| return target_cpu; |
| } |
| |
| static inline bool nohz_kick_needed(struct rq *rq, bool only_update); |
| static void nohz_balancer_kick(bool only_update); |
| |
| /* |
| * wake_energy: Make the decision if we want to use an energy-aware |
| * wakeup task placement or not. This is limited to situations where |
| * we cannot use energy-awareness right now. |
| * |
| * Returns TRUE if we should attempt energy-aware wakeup, FALSE if not. |
| * |
| * Should only be called from select_task_rq_fair inside the RCU |
| * read-side critical section. |
| */ |
| static inline int wake_energy(struct task_struct *p, int prev_cpu, |
| int sd_flag, int wake_flags) |
| { |
| struct sched_domain *sd = NULL; |
| int sync = wake_flags & WF_SYNC; |
| |
| sd = rcu_dereference_sched(cpu_rq(prev_cpu)->sd); |
| |
| /* |
| * Check all definite no-energy-awareness conditions |
| */ |
| if (!sd) |
| return false; |
| |
| if (!energy_aware()) |
| return false; |
| |
| if (sd_overutilized(sd)) |
| return false; |
| |
| /* |
| * we cannot do energy-aware wakeup placement sensibly |
| * for tasks with 0 utilization, so let them be placed |
| * according to the normal strategy. |
| * However if fbt is in use we may still benefit from |
| * the heuristics we use there in selecting candidate |
| * CPUs. |
| */ |
| if (unlikely(!sched_feat(FIND_BEST_TARGET) && !task_util_est(p))) |
| return false; |
| |
| if(!sched_feat(EAS_PREFER_IDLE)){ |
| /* |
| * Force prefer-idle tasks into the slow path, this may not happen |
| * if none of the sd flags matched. |
| */ |
| if (schedtune_prefer_idle(p) > 0 && !sync) |
| return false; |
| } |
| return true; |
| } |
| |
| /* |
| * select_task_rq_fair: Select target runqueue for the waking task in domains |
| * that have the 'sd_flag' flag set. In practice, this is SD_BALANCE_WAKE, |
| * SD_BALANCE_FORK, or SD_BALANCE_EXEC. |
| * |
| * Balances load by selecting the idlest cpu in the idlest group, or under |
| * certain conditions an idle sibling cpu if the domain has SD_WAKE_AFFINE set. |
| * |
| * Returns the target cpu number. |
| * |
| * preempt must be disabled. |
| */ |
| static int |
| SELECT_TASK_RQ_FAIR(struct task_struct *p, int prev_cpu, int sd_flag, |
| int wake_flags, int sibling_count_hint) |
| { |
| struct sched_domain *tmp, *affine_sd = NULL; |
| struct sched_domain *sd = NULL, *energy_sd = NULL; |
| int cpu = smp_processor_id(); |
| int new_cpu = prev_cpu; |
| int want_affine = 0; |
| int want_energy = 0; |
| int sync = wake_flags & WF_SYNC; |
| int select_reason = LB_PREV; |
| |
| if (should_hmp(cpu) && p->mm && (sd_flag & SD_BALANCE_FORK)) { |
| int hmp_cpu; |
| /* HMP fork balance: |
| * always put non-kernel forking tasks on a big domain |
| */ |
| hmp_cpu = hmp_fork_balance(p, prev_cpu); |
| |
| if (hmp_cpu >= 0 && (hmp_cpu < nr_cpu_ids)) |
| return LB_FORK | hmp_cpu; |
| } |
| |
| rcu_read_lock(); |
| |
| if (sd_flag & SD_BALANCE_WAKE) { |
| record_wakee(p); |
| want_energy = wake_energy(p, prev_cpu, sd_flag, wake_flags); |
| want_affine = !want_energy && |
| !wake_wide(p, sibling_count_hint) && |
| !wake_cap(p, cpu, prev_cpu) && |
| cpumask_test_cpu(cpu, &p->cpus_allowed); |
| } |
| |
| for_each_domain(cpu, tmp) { |
| if (!(tmp->flags & SD_LOAD_BALANCE)) |
| continue; |
| |
| /* |
| * If both cpu and prev_cpu are part of this domain, |
| * cpu is a valid SD_WAKE_AFFINE target. |
| */ |
| if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && |
| cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { |
| affine_sd = tmp; |
| break; |
| } |
| |
| /* |
| * If we are able to try an energy-aware wakeup, |
| * select the highest non-overutilized sched domain |
| * which includes this cpu and prev_cpu |
| * |
| * maybe want to not test prev_cpu and only consider |
| * the current one? |
| */ |
| if (want_energy && |
| !sd_overutilized(tmp) && |
| cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) |
| energy_sd = tmp; |
| |
| if (tmp->flags & sd_flag) |
| sd = tmp; |
| else if (!(want_affine || want_energy)) |
| break; |
| } |
| |
| if (affine_sd) { |
| sd = NULL; /* Prefer wake_affine over balance flags */ |
| if (cpu == prev_cpu) |
| goto pick_cpu; |
| |
| if (wake_affine(affine_sd, p, prev_cpu, sync)) { |
| new_cpu = cpu; |
| select_reason = LB_SMP; |
| } |
| } |
| |
| if (sd && !(sd_flag & SD_BALANCE_FORK)) { |
| /* |
| * We're going to need the task's util for capacity_spare_without |
| * in find_idlest_group. Sync it up to prev_cpu's |
| * last_update_time. |
| */ |
| sync_entity_load_avg(&p->se); |
| } |
| |
| if (!sd) { |
| pick_cpu: |
| if (sd_flag & SD_BALANCE_WAKE) { /* XXX always ? */ |
| new_cpu = ___select_idle_sibling(p, prev_cpu, new_cpu); |
| select_reason = LB_EAS_AFFINE; |
| } |
| |
| } else { |
| if (energy_sd) { |
| new_cpu = __find_energy_efficient_cpu(energy_sd, p, cpu, |
| prev_cpu, sync); |
| select_reason = LB_EAS; |
| } |
| |
| /* if we did an energy-aware placement and had no choices available |
| * then fall back to the default find_idlest_cpu choice |
| */ |
| if (!energy_sd || (energy_sd && new_cpu == -1)) { |
| new_cpu = ___select_idle_sibling(p, prev_cpu, prev_cpu); |
| select_reason = LB_EAS_LB; |
| } |
| } |
| |
| rcu_read_unlock(); |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| if (nohz_kick_needed(cpu_rq(new_cpu), true)) |
| nohz_balancer_kick(true); |
| #endif |
| if (should_hmp(cpu)) { |
| new_cpu = hmp_select_task_rq_fair(sd_flag, |
| p, prev_cpu, new_cpu); |
| select_reason = LB_HMP; |
| } |
| |
| return select_reason | new_cpu; |
| } |
| |
| static inline int |
| select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, |
| int wake_flags, int sibling_count_hint) |
| { |
| int result = 0; |
| int cpu; |
| |
| result = SELECT_TASK_RQ_FAIR(p, prev_cpu, sd_flag, wake_flags, |
| sibling_count_hint); |
| select_task_prefer_cpu_fair(p, &result); |
| cpu = (result & LB_CPU_MASK); |
| |
| trace_sched_select_task_rq(p, result, prev_cpu, cpu, |
| task_util(p), boosted_task_util(p), |
| (schedtune_prefer_idle(p) > 0), wake_flags); |
| return cpu; |
| |
| } |
| |
| /* |
| * Called immediately before a task is migrated to a new cpu; task_cpu(p) and |
| * cfs_rq_of(p) references at time of call are still valid and identify the |
| * previous cpu. The caller guarantees p->pi_lock or task_rq(p)->lock is held. |
| */ |
| static void migrate_task_rq_fair(struct task_struct *p) |
| { |
| /* |
| * As blocked tasks retain absolute vruntime the migration needs to |
| * deal with this by subtracting the old and adding the new |
| * min_vruntime -- the latter is done by enqueue_entity() when placing |
| * the task on the new runqueue. |
| */ |
| if (p->state == TASK_WAKING) { |
| struct sched_entity *se = &p->se; |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| u64 min_vruntime; |
| |
| #ifndef CONFIG_64BIT |
| u64 min_vruntime_copy; |
| |
| do { |
| min_vruntime_copy = cfs_rq->min_vruntime_copy; |
| smp_rmb(); |
| min_vruntime = cfs_rq->min_vruntime; |
| } while (min_vruntime != min_vruntime_copy); |
| #else |
| min_vruntime = cfs_rq->min_vruntime; |
| #endif |
| |
| se->vruntime -= min_vruntime; |
| } |
| |
| /* |
| * We are supposed to update the task to "current" time, then its up to date |
| * and ready to go to new CPU/cfs_rq. But we have difficulty in getting |
| * what current time is, so simply throw away the out-of-date time. This |
| * will result in the wakee task is less decayed, but giving the wakee more |
| * load sounds not bad. |
| */ |
| remove_entity_load_avg(&p->se); |
| |
| /* Tell new CPU we are migrated */ |
| p->se.avg.last_update_time = 0; |
| } |
| |
| static void task_dead_fair(struct task_struct *p) |
| { |
| remove_entity_load_avg(&p->se); |
| } |
| #endif /* CONFIG_SMP */ |
| |
| static unsigned long |
| wakeup_gran(struct sched_entity *curr, struct sched_entity *se) |
| { |
| unsigned long gran = sysctl_sched_wakeup_granularity; |
| |
| /* |
| * Since its curr running now, convert the gran from real-time |
| * to virtual-time in his units. |
| * |
| * By using 'se' instead of 'curr' we penalize light tasks, so |
| * they get preempted easier. That is, if 'se' < 'curr' then |
| * the resulting gran will be larger, therefore penalizing the |
| * lighter, if otoh 'se' > 'curr' then the resulting gran will |
| * be smaller, again penalizing the lighter task. |
| * |
| * This is especially important for buddies when the leftmost |
| * task is higher priority than the buddy. |
| */ |
| return calc_delta_fair(gran, se); |
| } |
| |
| /* |
| * Should 'se' preempt 'curr'. |
| * |
| * |s1 |
| * |s2 |
| * |s3 |
| * g |
| * |<--->|c |
| * |
| * w(c, s1) = -1 |
| * w(c, s2) = 0 |
| * w(c, s3) = 1 |
| * |
| */ |
| static int |
| wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) |
| { |
| s64 gran, vdiff = curr->vruntime - se->vruntime; |
| |
| if (vdiff <= 0) |
| return -1; |
| |
| gran = wakeup_gran(curr, se); |
| if (vdiff > gran) |
| return 1; |
| |
| return 0; |
| } |
| |
| static void set_last_buddy(struct sched_entity *se) |
| { |
| if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE)) |
| return; |
| |
| for_each_sched_entity(se) { |
| if (SCHED_WARN_ON(!se->on_rq)) |
| return; |
| cfs_rq_of(se)->last = se; |
| } |
| } |
| |
| static void set_next_buddy(struct sched_entity *se) |
| { |
| if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE)) |
| return; |
| |
| for_each_sched_entity(se) { |
| if (SCHED_WARN_ON(!se->on_rq)) |
| return; |
| cfs_rq_of(se)->next = se; |
| } |
| } |
| |
| static void set_skip_buddy(struct sched_entity *se) |
| { |
| for_each_sched_entity(se) |
| cfs_rq_of(se)->skip = se; |
| } |
| |
| /* |
| * Preempt the current task with a newly woken task if needed: |
| */ |
| static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
| { |
| struct task_struct *curr = rq->curr; |
| struct sched_entity *se = &curr->se, *pse = &p->se; |
| struct cfs_rq *cfs_rq = task_cfs_rq(curr); |
| int scale = cfs_rq->nr_running >= sched_nr_latency; |
| int next_buddy_marked = 0; |
| |
| if (unlikely(se == pse)) |
| return; |
| |
| #ifdef OPLUS_FEATURE_SPECIALOPT |
| // Liujie.Xie@TECH.Kernel.Sched, 2020/02/26, add for heavy load task |
| if (is_heavy_load_task(current)) |
| return; |
| #endif |
| |
| /* |
| * This is possible from callers such as attach_tasks(), in which we |
| * unconditionally check_prempt_curr() after an enqueue (which may have |
| * lead to a throttle). This both saves work and prevents false |
| * next-buddy nomination below. |
| */ |
| if (unlikely(throttled_hierarchy(cfs_rq_of(pse)))) |
| return; |
| |
| if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK)) { |
| set_next_buddy(pse); |
| next_buddy_marked = 1; |
| } |
| |
| /* |
| * We can come here with TIF_NEED_RESCHED already set from new task |
| * wake up path. |
| * |
| * Note: this also catches the edge-case of curr being in a throttled |
| * group (e.g. via set_curr_task), since update_curr() (in the |
| * enqueue of curr) will have resulted in resched being set. This |
| * prevents us from potentially nominating it as a false LAST_BUDDY |
| * below. |
| */ |
| if (test_tsk_need_resched(curr)) |
| return; |
| |
| /* Idle tasks are by definition preempted by non-idle tasks. */ |
| if (unlikely(curr->policy == SCHED_IDLE) && |
| likely(p->policy != SCHED_IDLE)) |
| goto preempt; |
| |
| /* |
| * Batch and idle tasks do not preempt non-idle tasks (their preemption |
| * is driven by the tick): |
| */ |
| if (unlikely(p->policy != SCHED_NORMAL) || !sched_feat(WAKEUP_PREEMPTION)) |
| return; |
| |
| find_matching_se(&se, &pse); |
| update_curr(cfs_rq_of(se)); |
| BUG_ON(!pse); |
| #ifdef OPLUS_FEATURE_UIFIRST |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/05/25, Add for UIFirst |
| if (should_ux_preempt_wakeup(p, curr)) |
| goto preempt; |
| else if (test_task_ux(curr)) |
| return; |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| if (wakeup_preempt_entity(se, pse) == 1) { |
| /* |
| * Bias pick_next to pick the sched entity that is |
| * triggering this preemption. |
| */ |
| if (!next_buddy_marked) |
| set_next_buddy(pse); |
| goto preempt; |
| } |
| |
| return; |
| |
| preempt: |
| resched_curr(rq); |
| /* |
| * Only set the backward buddy when the current task is still |
| * on the rq. This can happen when a wakeup gets interleaved |
| * with schedule on the ->pre_schedule() or idle_balance() |
| * point, either of which can * drop the rq lock. |
| * |
| * Also, during early boot the idle thread is in the fair class, |
| * for obvious reasons its a bad idea to schedule back to it. |
| */ |
| if (unlikely(!se->on_rq || curr == rq->idle)) |
| return; |
| |
| if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se)) |
| set_last_buddy(se); |
| } |
| |
| static struct task_struct * |
| pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) |
| { |
| struct cfs_rq *cfs_rq = &rq->cfs; |
| struct sched_entity *se; |
| struct task_struct *p; |
| int new_tasks; |
| |
| again: |
| if (!cfs_rq->nr_running) |
| goto idle; |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| if (prev->sched_class != &fair_sched_class) |
| goto simple; |
| |
| /* |
| * Because of the set_next_buddy() in dequeue_task_fair() it is rather |
| * likely that a next task is from the same cgroup as the current. |
| * |
| * Therefore attempt to avoid putting and setting the entire cgroup |
| * hierarchy, only change the part that actually changes. |
| */ |
| |
| do { |
| struct sched_entity *curr = cfs_rq->curr; |
| |
| /* |
| * Since we got here without doing put_prev_entity() we also |
| * have to consider cfs_rq->curr. If it is still a runnable |
| * entity, update_curr() will update its vruntime, otherwise |
| * forget we've ever seen it. |
| */ |
| if (curr) { |
| if (curr->on_rq) |
| update_curr(cfs_rq); |
| else |
| curr = NULL; |
| |
| /* |
| * This call to check_cfs_rq_runtime() will do the |
| * throttle and dequeue its entity in the parent(s). |
| * Therefore the nr_running test will indeed |
| * be correct. |
| */ |
| if (unlikely(check_cfs_rq_runtime(cfs_rq))) { |
| cfs_rq = &rq->cfs; |
| |
| if (!cfs_rq->nr_running) |
| goto idle; |
| |
| goto simple; |
| } |
| } |
| |
| se = pick_next_entity(cfs_rq, curr); |
| cfs_rq = group_cfs_rq(se); |
| } while (cfs_rq); |
| |
| p = task_of(se); |
| #if defined(OPLUS_FEATURE_UIFIRST) && !defined(CONFIG_MTK_TASK_TURBO) |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/05/25, Add for UIFirst |
| if (sysctl_uifirst_enabled) { |
| pick_ux_thread(rq, &p, &se); |
| } |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| |
| /* |
| * Since we haven't yet done put_prev_entity and if the selected task |
| * is a different task than we started out with, try and touch the |
| * least amount of cfs_rqs. |
| */ |
| if (prev != p) { |
| struct sched_entity *pse = &prev->se; |
| |
| while (!(cfs_rq = is_same_group(se, pse))) { |
| int se_depth = se->depth; |
| int pse_depth = pse->depth; |
| |
| if (se_depth <= pse_depth) { |
| put_prev_entity(cfs_rq_of(pse), pse); |
| pse = parent_entity(pse); |
| } |
| if (se_depth >= pse_depth) { |
| set_next_entity(cfs_rq_of(se), se); |
| se = parent_entity(se); |
| } |
| } |
| |
| put_prev_entity(cfs_rq, pse); |
| set_next_entity(cfs_rq, se); |
| } |
| |
| if (hrtick_enabled(rq)) |
| hrtick_start_fair(rq, p); |
| |
| update_misfit_status(p, rq); |
| |
| return p; |
| simple: |
| #endif |
| |
| put_prev_task(rq, prev); |
| |
| do { |
| se = pick_next_entity(cfs_rq, NULL); |
| #ifndef OPLUS_FEATURE_SPECIALOPT |
| // caichen@TECH.Kernel.Sched, 2019/03/10, add for heavy load task |
| set_next_entity(cfs_rq, se); |
| #endif |
| cfs_rq = group_cfs_rq(se); |
| } while (cfs_rq); |
| |
| p = task_of(se); |
| |
| #ifdef OPLUS_FEATURE_SPECIALOPT |
| // caichen@TECH.Kernel.Sched, 2020/03/10, add for heavy load task |
| struct task_struct *pos; |
| pos = list_first_entry(&rq->cfs_tasks, typeof(*pos), se.group_node); |
| if (sysctl_cpu_multi_thread && is_heavy_load_task(pos) && p != pos) { |
| p = pos; |
| se = &p->se; |
| } |
| for_each_sched_entity(se) { |
| set_next_entity(cfs_rq_of(se), se); |
| } |
| #endif |
| |
| if (hrtick_enabled(rq)) |
| hrtick_start_fair(rq, p); |
| |
| update_misfit_status(p, rq); |
| |
| return p; |
| |
| idle: |
| update_misfit_status(NULL, rq); |
| new_tasks = idle_balance(rq, rf); |
| |
| /* |
| * Because idle_balance() releases (and re-acquires) rq->lock, it is |
| * possible for any higher priority task to appear. In that case we |
| * must re-start the pick_next_entity() loop. |
| */ |
| if (new_tasks < 0) |
| return RETRY_TASK; |
| |
| if (new_tasks > 0) |
| goto again; |
| |
| return NULL; |
| } |
| |
| /* |
| * Account for a descheduled task: |
| */ |
| static void put_prev_task_fair(struct rq *rq, struct task_struct *prev) |
| { |
| struct sched_entity *se = &prev->se; |
| struct cfs_rq *cfs_rq; |
| |
| for_each_sched_entity(se) { |
| cfs_rq = cfs_rq_of(se); |
| put_prev_entity(cfs_rq, se); |
| } |
| } |
| |
| /* |
| * sched_yield() is very simple |
| * |
| * The magic of dealing with the ->skip buddy is in pick_next_entity. |
| */ |
| static void yield_task_fair(struct rq *rq) |
| { |
| struct task_struct *curr = rq->curr; |
| struct cfs_rq *cfs_rq = task_cfs_rq(curr); |
| struct sched_entity *se = &curr->se; |
| |
| /* |
| * Are we the only task in the tree? |
| */ |
| if (unlikely(rq->nr_running == 1)) |
| return; |
| |
| clear_buddies(cfs_rq, se); |
| |
| if (curr->policy != SCHED_BATCH) { |
| update_rq_clock(rq); |
| /* |
| * Update run-time statistics of the 'current'. |
| */ |
| update_curr(cfs_rq); |
| /* |
| * Tell update_rq_clock() that we've just updated, |
| * so we don't do microscopic update in schedule() |
| * and double the fastpath cost. |
| */ |
| rq_clock_skip_update(rq, true); |
| } |
| |
| set_skip_buddy(se); |
| } |
| |
| static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preempt) |
| { |
| struct sched_entity *se = &p->se; |
| |
| /* throttled hierarchies are not runnable */ |
| if (!se->on_rq || throttled_hierarchy(cfs_rq_of(se))) |
| return false; |
| |
| /* Tell the scheduler that we'd really like pse to run next. */ |
| set_next_buddy(se); |
| |
| yield_task_fair(rq); |
| |
| return true; |
| } |
| |
| #ifdef CONFIG_SMP |
| /************************************************** |
| * Fair scheduling class load-balancing methods. |
| * |
| * BASICS |
| * |
| * The purpose of load-balancing is to achieve the same basic fairness the |
| * per-cpu scheduler provides, namely provide a proportional amount of compute |
| * time to each task. This is expressed in the following equation: |
| * |
| * W_i,n/P_i == W_j,n/P_j for all i,j (1) |
| * |
| * Where W_i,n is the n-th weight average for cpu i. The instantaneous weight |
| * W_i,0 is defined as: |
| * |
| * W_i,0 = \Sum_j w_i,j (2) |
| * |
| * Where w_i,j is the weight of the j-th runnable task on cpu i. This weight |
| * is derived from the nice value as per sched_prio_to_weight[]. |
| * |
| * The weight average is an exponential decay average of the instantaneous |
| * weight: |
| * |
| * W'_i,n = (2^n - 1) / 2^n * W_i,n + 1 / 2^n * W_i,0 (3) |
| * |
| * C_i is the compute capacity of cpu i, typically it is the |
| * fraction of 'recent' time available for SCHED_OTHER task execution. But it |
| * can also include other factors [XXX]. |
| * |
| * To achieve this balance we define a measure of imbalance which follows |
| * directly from (1): |
| * |
| * imb_i,j = max{ avg(W/C), W_i/C_i } - min{ avg(W/C), W_j/C_j } (4) |
| * |
| * We them move tasks around to minimize the imbalance. In the continuous |
| * function space it is obvious this converges, in the discrete case we get |
| * a few fun cases generally called infeasible weight scenarios. |
| * |
| * [XXX expand on: |
| * - infeasible weights; |
| * - local vs global optima in the discrete case. ] |
| * |
| * |
| * SCHED DOMAINS |
| * |
| * In order to solve the imbalance equation (4), and avoid the obvious O(n^2) |
| * for all i,j solution, we create a tree of cpus that follows the hardware |
| * topology where each level pairs two lower groups (or better). This results |
| * in O(log n) layers. Furthermore we reduce the number of cpus going up the |
| * tree to only the first of the previous level and we decrease the frequency |
| * of load-balance at each level inv. proportional to the number of cpus in |
| * the groups. |
| * |
| * This yields: |
| * |
| * log_2 n 1 n |
| * \Sum { --- * --- * 2^i } = O(n) (5) |
| * i = 0 2^i 2^i |
| * `- size of each group |
| * | | `- number of cpus doing load-balance |
| * | `- freq |
| * `- sum over all levels |
| * |
| * Coupled with a limit on how many tasks we can migrate every balance pass, |
| * this makes (5) the runtime complexity of the balancer. |
| * |
| * An important property here is that each CPU is still (indirectly) connected |
| * to every other cpu in at most O(log n) steps: |
| * |
| * The adjacency matrix of the resulting graph is given by: |
| * |
| * log_2 n |
| * A_i,j = \Union (i % 2^k == 0) && i / 2^(k+1) == j / 2^(k+1) (6) |
| * k = 0 |
| * |
| * And you'll find that: |
| * |
| * A^(log_2 n)_i,j != 0 for all i,j (7) |
| * |
| * Showing there's indeed a path between every cpu in at most O(log n) steps. |
| * The task movement gives a factor of O(m), giving a convergence complexity |
| * of: |
| * |
| * O(nm log n), n := nr_cpus, m := nr_tasks (8) |
| * |
| * |
| * WORK CONSERVING |
| * |
| * In order to avoid CPUs going idle while there's still work to do, new idle |
| * balancing is more aggressive and has the newly idle cpu iterate up the domain |
| * tree itself instead of relying on other CPUs to bring it work. |
| * |
| * This adds some complexity to both (5) and (8) but it reduces the total idle |
| * time. |
| * |
| * [XXX more?] |
| * |
| * |
| * CGROUPS |
| * |
| * Cgroups make a horror show out of (2), instead of a simple sum we get: |
| * |
| * s_k,i |
| * W_i,0 = \Sum_j \Prod_k w_k * ----- (9) |
| * S_k |
| * |
| * Where |
| * |
| * s_k,i = \Sum_j w_i,j,k and S_k = \Sum_i s_k,i (10) |
| * |
| * w_i,j,k is the weight of the j-th runnable task in the k-th cgroup on cpu i. |
| * |
| * The big problem is S_k, its a global sum needed to compute a local (W_i) |
| * property. |
| * |
| * [XXX write more on how we solve this.. _after_ merging pjt's patches that |
| * rewrite all of this once again.] |
| */ |
| |
| static unsigned long __read_mostly max_load_balance_interval = HZ/10; |
| |
| enum fbq_type { regular, remote, all }; |
| |
| enum group_type { |
| group_other = 0, |
| group_misfit_task, |
| group_imbalanced, |
| group_overloaded, |
| }; |
| |
| #define LBF_ALL_PINNED 0x01 |
| #define LBF_NEED_BREAK 0x02 |
| #define LBF_DST_PINNED 0x04 |
| #define LBF_SOME_PINNED 0x08 |
| |
| struct lb_env { |
| struct sched_domain *sd; |
| |
| struct rq *src_rq; |
| int src_cpu; |
| |
| int dst_cpu; |
| struct rq *dst_rq; |
| |
| struct cpumask *dst_grpmask; |
| int new_dst_cpu; |
| enum cpu_idle_type idle; |
| long imbalance; |
| unsigned int src_grp_nr_running; |
| /* The set of CPUs under consideration for load-balancing */ |
| struct cpumask *cpus; |
| |
| unsigned int flags; |
| |
| unsigned int loop; |
| unsigned int loop_break; |
| unsigned int loop_max; |
| |
| enum fbq_type fbq_type; |
| enum group_type src_grp_type; |
| struct list_head tasks; |
| }; |
| |
| /* |
| * Is this task likely cache-hot: |
| */ |
| static int task_hot(struct task_struct *p, struct lb_env *env) |
| { |
| s64 delta; |
| |
| lockdep_assert_held(&env->src_rq->lock); |
| |
| if (p->sched_class != &fair_sched_class) |
| return 0; |
| |
| if (unlikely(p->policy == SCHED_IDLE)) |
| return 0; |
| |
| /* |
| * Buddy candidates are cache hot: |
| */ |
| if (sched_feat(CACHE_HOT_BUDDY) && env->dst_rq->nr_running && |
| (&p->se == cfs_rq_of(&p->se)->next || |
| &p->se == cfs_rq_of(&p->se)->last)) |
| return 1; |
| |
| if (sysctl_sched_migration_cost == -1) |
| return 1; |
| if (sysctl_sched_migration_cost == 0) |
| return 0; |
| |
| delta = rq_clock_task(env->src_rq) - p->se.exec_start; |
| |
| return delta < (s64)sysctl_sched_migration_cost; |
| } |
| |
| #ifdef CONFIG_NUMA_BALANCING |
| /* |
| * Returns 1, if task migration degrades locality |
| * Returns 0, if task migration improves locality i.e migration preferred. |
| * Returns -1, if task migration is not affected by locality. |
| */ |
| static int migrate_degrades_locality(struct task_struct *p, struct lb_env *env) |
| { |
| struct numa_group *numa_group = rcu_dereference(p->numa_group); |
| unsigned long src_faults, dst_faults; |
| int src_nid, dst_nid; |
| |
| if (!static_branch_likely(&sched_numa_balancing)) |
| return -1; |
| |
| if (!p->numa_faults || !(env->sd->flags & SD_NUMA)) |
| return -1; |
| |
| src_nid = cpu_to_node(env->src_cpu); |
| dst_nid = cpu_to_node(env->dst_cpu); |
| |
| if (src_nid == dst_nid) |
| return -1; |
| |
| /* Migrating away from the preferred node is always bad. */ |
| if (src_nid == p->numa_preferred_nid) { |
| if (env->src_rq->nr_running > env->src_rq->nr_preferred_running) |
| return 1; |
| else |
| return -1; |
| } |
| |
| /* Encourage migration to the preferred node. */ |
| if (dst_nid == p->numa_preferred_nid) |
| return 0; |
| |
| /* Leaving a core idle is often worse than degrading locality. */ |
| if (env->idle != CPU_NOT_IDLE) |
| return -1; |
| |
| if (numa_group) { |
| src_faults = group_faults(p, src_nid); |
| dst_faults = group_faults(p, dst_nid); |
| } else { |
| src_faults = task_faults(p, src_nid); |
| dst_faults = task_faults(p, dst_nid); |
| } |
| |
| return dst_faults < src_faults; |
| } |
| |
| #else |
| static inline int migrate_degrades_locality(struct task_struct *p, |
| struct lb_env *env) |
| { |
| return -1; |
| } |
| #endif |
| |
| /* |
| * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? |
| */ |
| static |
| int can_migrate_task(struct task_struct *p, struct lb_env *env) |
| { |
| int tsk_cache_hot; |
| |
| lockdep_assert_held(&env->src_rq->lock); |
| |
| /* |
| * We do not migrate tasks that are: |
| * 1) throttled_lb_pair, or |
| * 2) cannot be migrated to this CPU due to cpus_allowed, or |
| * 3) running (obviously), or |
| * 4) are cache-hot on their current CPU. |
| */ |
| if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu)) |
| return 0; |
| |
| if (!cpumask_test_cpu(env->dst_cpu, &p->cpus_allowed)) { |
| int cpu; |
| |
| schedstat_inc(p->se.statistics.nr_failed_migrations_affine); |
| |
| env->flags |= LBF_SOME_PINNED; |
| |
| /* |
| * Remember if this task can be migrated to any other cpu in |
| * our sched_group. We may want to revisit it if we couldn't |
| * meet load balance goals by pulling other tasks on src_cpu. |
| * |
| * Avoid computing new_dst_cpu for NEWLY_IDLE or if we have |
| * already computed one in current iteration. |
| */ |
| if (env->idle == CPU_NEWLY_IDLE || (env->flags & LBF_DST_PINNED)) |
| return 0; |
| |
| /* Prevent to re-select dst_cpu via env's cpus */ |
| for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) { |
| if (cpumask_test_cpu(cpu, &p->cpus_allowed)) { |
| env->flags |= LBF_DST_PINNED; |
| env->new_dst_cpu = cpu; |
| break; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Record that we found atleast one task that could run on dst_cpu */ |
| env->flags &= ~LBF_ALL_PINNED; |
| |
| if (task_running(env->src_rq, p)) { |
| schedstat_inc(p->se.statistics.nr_failed_migrations_running); |
| return 0; |
| } |
| |
| /* |
| * Aggressive migration if: |
| * 1) destination numa is preferred |
| * 2) task is cache cold, or |
| * 3) too many balance attempts have failed. |
| */ |
| tsk_cache_hot = migrate_degrades_locality(p, env); |
| if (tsk_cache_hot == -1) |
| tsk_cache_hot = task_hot(p, env); |
| |
| if (tsk_cache_hot <= 0 || |
| env->sd->nr_balance_failed > env->sd->cache_nice_tries) { |
| if (tsk_cache_hot == 1) { |
| schedstat_inc(env->sd->lb_hot_gained[env->idle]); |
| schedstat_inc(p->se.statistics.nr_forced_migrations); |
| } |
| return 1; |
| } |
| |
| schedstat_inc(p->se.statistics.nr_failed_migrations_hot); |
| return 0; |
| } |
| |
| /* |
| * detach_task() -- detach the task for the migration specified in env |
| */ |
| static void detach_task(struct task_struct *p, struct lb_env *env, |
| struct rq_flags *rf) |
| { |
| lockdep_assert_held(&env->src_rq->lock); |
| |
| p->on_rq = TASK_ON_RQ_MIGRATING; |
| deactivate_task(env->src_rq, p, DEQUEUE_NOCLOCK); |
| rq_unpin_lock(env->src_rq, rf); |
| double_lock_balance(env->src_rq, env->dst_rq); |
| set_task_cpu(p, env->dst_cpu); |
| double_unlock_balance(env->src_rq, env->dst_rq); |
| rq_repin_lock(env->src_rq, rf); |
| } |
| |
| /* |
| * detach_one_task() -- tries to dequeue exactly one task from env->src_rq, as |
| * part of active balancing operations within "domain". |
| * |
| * Returns a task if successful and NULL otherwise. |
| */ |
| static struct task_struct *detach_one_task(struct lb_env *env, |
| struct rq_flags *rf) |
| { |
| struct task_struct *p, *n; |
| |
| lockdep_assert_held(&env->src_rq->lock); |
| |
| list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) { |
| #if defined(CONFIG_SCHED_HMP) || defined(CONFIG_MTK_IDLE_BALANCE_ENHANCEMENT) |
| if (env->src_rq->migrate_task) { |
| struct task_struct *pm; |
| |
| pm = env->src_rq->migrate_task; |
| if (p != pm) |
| continue; |
| |
| env->src_rq->migrate_task = NULL; |
| |
| if (!cpumask_test_cpu(env->dst_cpu, &p->cpus_allowed)) |
| return NULL; |
| |
| } else if (!can_migrate_task(p, env)) { |
| continue; |
| } |
| #else |
| if (!can_migrate_task(p, env)) |
| continue; |
| #endif |
| detach_task(p, env, rf); |
| |
| /* |
| * Right now, this is only the second place where |
| * lb_gained[env->idle] is updated (other is detach_tasks) |
| * so we can safely collect stats here rather than |
| * inside detach_tasks(). |
| */ |
| schedstat_inc(env->sd->lb_gained[env->idle]); |
| return p; |
| } |
| return NULL; |
| } |
| |
| static const unsigned int sched_nr_migrate_break = 32; |
| |
| /* |
| * detach_tasks() -- tries to detach up to imbalance weighted load from |
| * busiest_rq, as part of a balancing operation within domain "sd". |
| * |
| * Returns number of detached tasks if successful and 0 otherwise. |
| */ |
| static int detach_tasks(struct lb_env *env, struct rq_flags *rf) |
| { |
| struct list_head *tasks = &env->src_rq->cfs_tasks; |
| struct task_struct *p; |
| unsigned long load; |
| int detached = 0; |
| |
| lockdep_assert_held(&env->src_rq->lock); |
| |
| if (env->imbalance <= 0) |
| return 0; |
| |
| while (!list_empty(tasks)) { |
| /* |
| * We don't want to steal all, otherwise we may be treated likewise, |
| * which could at worst lead to a livelock crash. |
| */ |
| if (env->idle != CPU_NOT_IDLE && env->src_rq->nr_running <= 1) |
| break; |
| |
| p = list_first_entry(tasks, struct task_struct, se.group_node); |
| |
| env->loop++; |
| /* We've more or less seen every task there is, call it quits */ |
| if (env->loop > env->loop_max) |
| break; |
| |
| /* take a breather every nr_migrate tasks */ |
| if (env->loop > env->loop_break) { |
| env->loop_break += sched_nr_migrate_break; |
| env->flags |= LBF_NEED_BREAK; |
| break; |
| } |
| |
| if (!can_migrate_task(p, env)) |
| goto next; |
| |
| #if defined(OPLUS_FEATURE_UIFIRST) && !defined(CONFIG_MTK_TASK_TURBO) |
| // XieLiujie@BSP.KERNEL.PERFORMANCE, 2020/05/25, Add for UIFirst |
| if (sysctl_uifirst_enabled && test_task_ux(p)) { |
| if (sysctl_launcher_boost_enabled && is_heavy_ux_task(p) && test_ux_task_cpu(task_cpu(p)) && |
| !test_ux_task_cpu(env->dst_cpu)) |
| goto next; |
| |
| if ((!sysctl_launcher_boost_enabled || is_heavy_ux_task(p)) && !list_empty(&env->dst_rq->ux_thread_list)) |
| goto next; |
| } |
| #endif /* OPLUS_FEATURE_UIFIRST */ |
| /* |
| * Depending of the number of CPUs and tasks and the |
| * cgroup hierarchy, task_h_load() can return a null |
| * value. Make sure that env->imbalance decreases |
| * otherwise detach_tasks() will stop only after |
| * detaching up to loop_max tasks. |
| */ |
| load = max_t(unsigned long, task_h_load(p), 1); |
| |
| |
| if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed) |
| goto next; |
| |
| if ((load / 2) > env->imbalance) |
| goto next; |
| |
| detach_task(p, env, rf); |
| list_add(&p->se.group_node, &env->tasks); |
| |
| detached++; |
| env->imbalance -= load; |
| |
| #ifdef CONFIG_PREEMPT |
| /* |
| * NEWIDLE balancing is a source of latency, so preemptible |
| * kernels will stop after the first task is detached to minimize |
| * the critical section. |
| */ |
| if (env->idle == CPU_NEWLY_IDLE) |
| break; |
| #endif |
| |
| /* |
| * We only want to steal up to the prescribed amount of |
| * weighted load. |
| */ |
| if (env->imbalance <= 0) |
| break; |
| |
| continue; |
| next: |
| list_move_tail(&p->se.group_node, tasks); |
| } |
| |
| /* |
| * Right now, this is one of only two places we collect this stat |
| * so we can safely collect detach_one_task() stats here rather |
| * than inside detach_one_task(). |
| */ |
| schedstat_add(env->sd->lb_gained[env->idle], detached); |
| |
| return detached; |
| } |
| |
| /* |
| * attach_task() -- attach the task detached by detach_task() to its new rq. |
| */ |
| static void attach_task(struct rq *rq, struct task_struct *p) |
| { |
| lockdep_assert_held(&rq->lock); |
| |
| BUG_ON(task_rq(p) != rq); |
| activate_task(rq, p, ENQUEUE_NOCLOCK); |
| p->on_rq = TASK_ON_RQ_QUEUED; |
| check_preempt_curr(rq, p, 0); |
| } |
| |
| /* |
| * attach_one_task() -- attaches the task returned from detach_one_task() to |
| * its new rq. |
| */ |
| static void attach_one_task(struct rq *rq, struct task_struct *p) |
| { |
| struct rq_flags rf; |
| |
| rq_lock(rq, &rf); |
| update_rq_clock(rq); |
| attach_task(rq, p); |
| rq_unlock(rq, &rf); |
| } |
| |
| /* |
| * attach_tasks() -- attaches all tasks detached by detach_tasks() to their |
| * new rq. |
| */ |
| static void attach_tasks(struct lb_env *env) |
| { |
| struct list_head *tasks = &env->tasks; |
| struct task_struct *p; |
| struct rq_flags rf; |
| |
| rq_lock(env->dst_rq, &rf); |
| update_rq_clock(env->dst_rq); |
| |
| while (!list_empty(tasks)) { |
| p = list_first_entry(tasks, struct task_struct, se.group_node); |
| list_del_init(&p->se.group_node); |
| |
| attach_task(env->dst_rq, p); |
| } |
| |
| rq_unlock(env->dst_rq, &rf); |
| } |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| |
| static void update_blocked_averages(int cpu) |
| { |
| struct rq *rq = cpu_rq(cpu); |
| struct cfs_rq *cfs_rq; |
| struct rq_flags rf; |
| |
| rq_lock_irqsave(rq, &rf); |
| update_rq_clock(rq); |
| |
| /* |
| * Iterates the task_group tree in a bottom up fashion, see |
| * list_add_leaf_cfs_rq() for details. |
| */ |
| for_each_leaf_cfs_rq(rq, cfs_rq) { |
| struct sched_entity *se; |
| |
| /* throttled entities do not contribute to load */ |
| if (throttled_hierarchy(cfs_rq)) |
| continue; |
| |
| if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq)) |
| update_tg_load_avg(cfs_rq, 0); |
| |
| /* Propagate pending load changes to the parent, if any: */ |
| se = cfs_rq->tg->se[cpu]; |
| if (se && !skip_blocked_update(se)) |
| update_load_avg(se, 0); |
| } |
| update_rt_rq_load_avg(rq_clock_task(rq), cpu, &rq->rt, 0); |
| #ifdef CONFIG_NO_HZ_COMMON |
| rq->last_blocked_load_update_tick = jiffies; |
| #endif |
| rq_unlock_irqrestore(rq, &rf); |
| } |
| |
| /* |
| * Compute the hierarchical load factor for cfs_rq and all its ascendants. |
| * This needs to be done in a top-down fashion because the load of a child |
| * group is a fraction of its parents load. |
| */ |
| static void update_cfs_rq_h_load(struct cfs_rq *cfs_rq) |
| { |
| struct rq *rq = rq_of(cfs_rq); |
| struct sched_entity *se = cfs_rq->tg->se[cpu_of(rq)]; |
| unsigned long now = jiffies; |
| unsigned long load; |
| |
| if (cfs_rq->last_h_load_update == now) |
| return; |
| |
| WRITE_ONCE(cfs_rq->h_load_next, NULL); |
| for_each_sched_entity(se) { |
| cfs_rq = cfs_rq_of(se); |
| WRITE_ONCE(cfs_rq->h_load_next, se); |
| if (cfs_rq->last_h_load_update == now) |
| break; |
| } |
| |
| if (!se) { |
| cfs_rq->h_load = cfs_rq_load_avg(cfs_rq); |
| cfs_rq->last_h_load_update = now; |
| } |
| |
| while ((se = READ_ONCE(cfs_rq->h_load_next)) != NULL) { |
| load = cfs_rq->h_load; |
| load = div64_ul(load * se->avg.load_avg, |
| cfs_rq_load_avg(cfs_rq) + 1); |
| cfs_rq = group_cfs_rq(se); |
| cfs_rq->h_load = load; |
| cfs_rq->last_h_load_update = now; |
| } |
| } |
| |
| static unsigned long task_h_load(struct task_struct *p) |
| { |
| struct cfs_rq *cfs_rq = task_cfs_rq(p); |
| |
| update_cfs_rq_h_load(cfs_rq); |
| return div64_ul(p->se.avg.load_avg * cfs_rq->h_load, |
| cfs_rq_load_avg(cfs_rq) + 1); |
| } |
| #else |
| static inline void update_blocked_averages(int cpu) |
| { |
| struct rq *rq = cpu_rq(cpu); |
| struct cfs_rq *cfs_rq = &rq->cfs; |
| struct rq_flags rf; |
| |
| rq_lock_irqsave(rq, &rf); |
| update_rq_clock(rq); |
| update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq); |
| update_rt_rq_load_avg(rq_clock_task(rq), cpu, &rq->rt, 0); |
| #ifdef CONFIG_NO_HZ_COMMON |
| rq->last_blocked_load_update_tick = jiffies; |
| #endif |
| rq_unlock_irqrestore(rq, &rf); |
| } |
| |
| static unsigned long task_h_load(struct task_struct *p) |
| { |
| return p->se.avg.load_avg; |
| } |
| #endif |
| |
| /********** Helpers for find_busiest_group ************************/ |
| |
| /* |
| * sg_lb_stats - stats of a sched_group required for load_balancing |
| */ |
| struct sg_lb_stats { |
| unsigned long avg_load; /*Avg load across the CPUs of the group */ |
| unsigned long group_load; /* Total load over the CPUs of the group */ |
| unsigned long sum_weighted_load; /* Weighted load of group's tasks */ |
| unsigned long load_per_task; |
| unsigned long group_capacity; |
| unsigned long group_util; /* Total utilization of the group */ |
| unsigned int sum_nr_running; /* Nr tasks running in the group */ |
| unsigned int idle_cpus; |
| unsigned int group_weight; |
| enum group_type group_type; |
| int group_no_capacity; |
| /* A cpu has a task too big for its capacity */ |
| unsigned long group_misfit_task_load; |
| #ifdef CONFIG_NUMA_BALANCING |
| unsigned int nr_numa_running; |
| unsigned int nr_preferred_running; |
| #endif |
| }; |
| |
| /* |
| * sd_lb_stats - Structure to store the statistics of a sched_domain |
| * during load balancing. |
| */ |
| struct sd_lb_stats { |
| struct sched_group *busiest; /* Busiest group in this sd */ |
| struct sched_group *local; /* Local group in this sd */ |
| unsigned long total_running; |
| unsigned long total_load; /* Total load of all groups in sd */ |
| unsigned long total_capacity; /* Total capacity of all groups in sd */ |
| unsigned long total_util; /* Total util of all groups in sd */ |
| unsigned long avg_load; /* Average load across all groups in sd */ |
| |
| struct sg_lb_stats busiest_stat;/* Statistics of the busiest group */ |
| struct sg_lb_stats local_stat; /* Statistics of the local group */ |
| }; |
| |
| static inline void init_sd_lb_stats(struct sd_lb_stats *sds) |
| { |
| /* |
| * Skimp on the clearing to avoid duplicate work. We can avoid clearing |
| * local_stat because update_sg_lb_stats() does a full clear/assignment. |
| * We must however clear busiest_stat::avg_load because |
| * update_sd_pick_busiest() reads this before assignment. |
| */ |
| *sds = (struct sd_lb_stats){ |
| .busiest = NULL, |
| .local = NULL, |
| .total_running = 0UL, |
| .total_load = 0UL, |
| .total_capacity = 0UL, |
| .total_util = 0UL, |
| .busiest_stat = { |
| .avg_load = 0UL, |
| .sum_nr_running = 0, |
| .group_type = group_other, |
| }, |
| }; |
| } |
| |
| /** |
| * get_sd_load_idx - Obtain the load index for a given sched domain. |
| * @sd: The sched_domain whose load_idx is to be obtained. |
| * @idle: The idle status of the CPU for whose sd load_idx is obtained. |
| * |
| * Return: The load index. |
| */ |
| static inline int get_sd_load_idx(struct sched_domain *sd, |
| enum cpu_idle_type idle) |
| { |
| int load_idx; |
| |
| switch (idle) { |
| case CPU_NOT_IDLE: |
| load_idx = sd->busy_idx; |
| break; |
| |
| case CPU_NEWLY_IDLE: |
| load_idx = sd->newidle_idx; |
| break; |
| default: |
| load_idx = sd->idle_idx; |
| break; |
| } |
| |
| return load_idx; |
| } |
| |
| static unsigned long scale_rt_capacity(int cpu) |
| { |
| struct rq *rq = cpu_rq(cpu); |
| u64 total, used, age_stamp, avg; |
| s64 delta; |
| |
| /* |
| * Since we're reading these variables without serialization make sure |
| * we read them once before doing sanity checks on them. |
| */ |
| age_stamp = READ_ONCE(rq->age_stamp); |
| #ifdef CONFIG_MTK_SCHED_INTEROP |
| if (unlikely(is_rt_throttle(cpu)) || !(rq->rt.rt_nr_running)) { |
| /* mtk: don't reduce capacity when rt task throttle or sleep*/ |
| avg = 0; |
| trace_sched_interop_lb(cpu, rq->rt.rt_nr_running); |
| } else |
| #endif |
| avg = READ_ONCE(rq->rt_avg); |
| delta = __rq_clock_broken(rq) - age_stamp; |
| |
| if (unlikely(delta < 0)) |
| delta = 0; |
| |
| total = sched_avg_period() + delta; |
| |
| used = div_u64(avg, total); |
| |
| if (likely(used < SCHED_CAPACITY_SCALE)) |
| return SCHED_CAPACITY_SCALE - used; |
| |
| return 1; |
| } |
| |
| void init_max_cpu_capacity(struct max_cpu_capacity *mcc) |
| { |
| raw_spin_lock_init(&mcc->lock); |
| mcc->val = 0; |
| mcc->cpu = -1; |
| } |
| |
| static void update_cpu_capacity(struct sched_domain *sd, int cpu) |
| { |
| unsigned long capacity = arch_scale_cpu_capacity(sd, cpu); |
| struct sched_group *sdg = sd->groups; |
| struct max_cpu_capacity *mcc; |
| unsigned long max_capacity; |
| int max_cap_cpu; |
| unsigned long flags; |
| |
| cpu_rq(cpu)->cpu_capacity_orig = capacity; |
| |
| capacity *= arch_scale_max_freq_capacity(sd, cpu); |
| capacity >>= SCHED_CAPACITY_SHIFT; |
| |
| mcc = &cpu_rq(cpu)->rd->max_cpu_capacity; |
| |
| raw_spin_lock_irqsave(&mcc->lock, flags); |
| max_capacity = mcc->val; |
| max_cap_cpu = mcc->cpu; |
| |
| if ((max_capacity > capacity && max_cap_cpu == cpu) || |
| max_capacity < capacity) { |
| mcc->val = capacity; |
| mcc->cpu = cpu; |
| #ifdef CONFIG_SCHED_DEBUG |
| raw_spin_unlock_irqrestore(&mcc->lock, flags); |
| printk_deferred("CPU%d: update max cpu_capacity %lu\n", |
| cpu, capacity); |
| goto skip_unlock; |
| #endif |
| } |
| raw_spin_unlock_irqrestore(&mcc->lock, flags); |
| |
| skip_unlock: __attribute__ ((unused)); |
| capacity *= scale_rt_capacity(cpu); |
| capacity >>= SCHED_CAPACITY_SHIFT; |
| |
| if (!capacity) |
| capacity = 1; |
| |
| cpu_rq(cpu)->cpu_capacity = capacity; |
| sdg->sgc->capacity = capacity; |
| sdg->sgc->min_capacity = capacity; |
| sdg->sgc->max_capacity = capacity; |
| } |
| |
| int update_cpu_capacity_cpumask(struct cpumask *cpus) |
| { |
| int cpu; |
| unsigned long capacity; |
| |
| for_each_cpu(cpu, cpus) { |
| capacity = arch_scale_cpu_capacity(NULL, cpu); |
| capacity *= arch_scale_max_freq_capacity(NULL, cpu); |
| capacity >>= SCHED_CAPACITY_SHIFT; |
| capacity *= scale_rt_capacity(cpu); |
| capacity >>= SCHED_CAPACITY_SHIFT; |
| |
| if (!capacity) |
| capacity = 1; |
| |
| cpu_rq(cpu)->cpu_capacity = capacity; |
| } |
| return 0; |
| } |
| |
| void update_group_capacity(struct sched_domain *sd, int cpu) |
| { |
| struct sched_domain *child = sd->child; |
| struct sched_group *group, *sdg = sd->groups; |
| unsigned long capacity, min_capacity, max_capacity; |
| unsigned long interval; |
| |
| interval = msecs_to_jiffies(sd->balance_interval); |
| interval = clamp(interval, 1UL, max_load_balance_interval); |
| sdg->sgc->next_update = jiffies + interval; |
| |
| if (!child) { |
| update_cpu_capacity(sd, cpu); |
| return; |
| } |
| |
| capacity = 0; |
| min_capacity = ULONG_MAX; |
| max_capacity = 0; |
| |
| if (child->flags & SD_OVERLAP) { |
| /* |
| * SD_OVERLAP domains cannot assume that child groups |
| * span the current group. |
| */ |
| |
| for_each_cpu(cpu, sched_group_span(sdg)) { |
| struct sched_group_capacity *sgc; |
| struct rq *rq = cpu_rq(cpu); |
| if (cpumask_test_cpu(cpu, cpu_isolated_mask)) |
| continue; |
| /* |
| * build_sched_domains() -> init_sched_groups_capacity() |
| * gets here before we've attached the domains to the |
| * runqueues. |
| * |
| * Use capacity_of(), which is set irrespective of domains |
| * in update_cpu_capacity(). |
| * |
| * This avoids capacity from being 0 and |
| * causing divide-by-zero issues on boot. |
| */ |
| if (unlikely(!rq->sd)) { |
| capacity += capacity_of(cpu); |
| } else { |
| sgc = rq->sd->groups->sgc; |
| capacity += sgc->capacity; |
| } |
| |
| min_capacity = min(capacity, min_capacity); |
| max_capacity = max(capacity, max_capacity); |
| } |
| } else { |
| /* |
| * !SD_OVERLAP domains can assume that child groups |
| * span the current group. |
| */ |
| |
| group = child->groups; |
| do { |
| struct sched_group_capacity *sgc = group->sgc; |
| cpumask_t *cpus = sched_group_cpus(group); |
| /* Revisit this later. This won't work for MT domain */ |
| if (!cpu_isolated(cpumask_first(cpus))) |
| capacity += sgc->capacity; |
| min_capacity = min(sgc->min_capacity, min_capacity); |
| max_capacity = max(sgc->max_capacity, max_capacity); |
| group = group->next; |
| } while (group != child->groups); |
| } |
| |
| sdg->sgc->capacity = capacity; |
| sdg->sgc->min_capacity = min_capacity; |
| sdg->sgc->max_capacity = max_capacity; |
| } |
| |
| /* |
| * Check whether the capacity of the rq has been noticeably reduced by side |
| * activity. The imbalance_pct is used for the threshold. |
| * Return true is the capacity is reduced |
| */ |
| static inline int |
| check_cpu_capacity(struct rq *rq, struct sched_domain *sd) |
| { |
| return ((rq->cpu_capacity * sd->imbalance_pct) < |
| (rq->cpu_capacity_orig * 100)); |
| } |
| |
| /* |
| * Group imbalance indicates (and tries to solve) the problem where balancing |
| * groups is inadequate due to ->cpus_allowed constraints. |
| * |
| * Imagine a situation of two groups of 4 cpus each and 4 tasks each with a |
| * cpumask covering 1 cpu of the first group and 3 cpus of the second group. |
| * Something like: |
| * |
| * { 0 1 2 3 } { 4 5 6 7 } |
| * * * * * |
| * |
| * If we were to balance group-wise we'd place two tasks in the first group and |
| * two tasks in the second group. Clearly this is undesired as it will overload |
| * cpu 3 and leave one of the cpus in the second group unused. |
| * |
| * The current solution to this issue is detecting the skew in the first group |
| * by noticing the lower domain failed to reach balance and had difficulty |
| * moving tasks due to affinity constraints. |
| * |
| * When this is so detected; this group becomes a candidate for busiest; see |
| * update_sd_pick_busiest(). And calculate_imbalance() and |
| * find_busiest_group() avoid some of the usual balance conditions to allow it |
| * to create an effective group imbalance. |
| * |
| * This is a somewhat tricky proposition since the next run might not find the |
| * group imbalance and decide the groups need to be balanced again. A most |
| * subtle and fragile situation. |
| */ |
| |
| static inline int sg_imbalanced(struct sched_group *group) |
| { |
| return group->sgc->imbalance; |
| } |
| |
| /* |
| * group_has_capacity returns true if the group has spare capacity that could |
| * be used by some tasks. |
| * We consider that a group has spare capacity if the * number of task is |
| * smaller than the number of CPUs or if the utilization is lower than the |
| * available capacity for CFS tasks. |
| * For the latter, we use a threshold to stabilize the state, to take into |
| * account the variance of the tasks' load and to return true if the available |
| * capacity in meaningful for the load balancer. |
| * As an example, an available capacity of 1% can appear but it doesn't make |
| * any benefit for the load balance. |
| */ |
| static inline bool |
| group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs) |
| { |
| if (sgs->sum_nr_running < sgs->group_weight) |
| return true; |
| |
| if ((sgs->group_capacity * 100) > |
| (sgs->group_util * env->sd->imbalance_pct)) |
| return true; |
| |
| return false; |
| } |
| |
| /* |
| * group_is_overloaded returns true if the group has more tasks than it can |
| * handle. |
| * group_is_overloaded is not equals to !group_has_capacity because a group |
| * with the exact right number of tasks, has no more spare capacity but is not |
| * overloaded so both group_has_capacity and group_is_overloaded return |
| * false. |
| */ |
| static inline bool |
| group_is_overloaded(struct lb_env *env, struct sg_lb_stats *sgs) |
| { |
| if (sgs->sum_nr_running <= sgs->group_weight) |
| return false; |
| |
| if ((sgs->group_capacity * 100) < |
| (sgs->group_util * env->sd->imbalance_pct)) |
| return true; |
| |
| return false; |
| } |
| |
| /* |
| * group_smaller_min_cpu_capacity: Returns true if sched_group sg has smaller |
| * per-CPU capacity than sched_group ref. |
| */ |
| static inline bool |
| group_smaller_min_cpu_capacity(struct sched_group *sg, struct sched_group *ref) |
| { |
| return sg->sgc->min_capacity * capacity_margin < |
| ref->sgc->min_capacity * 1024; |
| } |
| |
| /* |
| * group_smaller_max_cpu_capacity: Returns true if sched_group sg has smaller |
| * per-CPU capacity_orig than sched_group ref. |
| */ |
| static inline bool |
| group_smaller_max_cpu_capacity(struct sched_group *sg, struct sched_group *ref) |
| { |
| return sg->sgc->max_capacity * capacity_margin < |
| ref->sgc->max_capacity * 1024; |
| } |
| |
| /* |
| * group_similar_cpu_capacity: Returns true if the minimum capacity of the |
| * compared groups differ by less than 12.5%. |
| */ |
| static inline bool |
| group_similar_cpu_capacity(struct sched_group *sg, struct sched_group *ref) |
| { |
| long diff = sg->sgc->min_capacity - ref->sgc->min_capacity; |
| long max = max(sg->sgc->min_capacity, ref->sgc->min_capacity); |
| |
| return abs(diff) < max >> 3; |
| } |
| |
| static inline enum |
| group_type group_classify(struct sched_group *group, |
| struct sg_lb_stats *sgs) |
| { |
| if (sgs->group_no_capacity) |
| return group_overloaded; |
| |
| if (sg_imbalanced(group)) |
| return group_imbalanced; |
| |
| if (sgs->group_misfit_task_load) |
| return group_misfit_task; |
| |
| return group_other; |
| } |
| |
| /** |
| * update_sg_lb_stats - Update sched_group's statistics for load balancing. |
| * @env: The load balancing environment. |
| * @group: sched_group whose statistics are to be updated. |
| * @load_idx: Load index of sched_domain of this_cpu for load calc. |
| * @local_group: Does group contain this_cpu. |
| * @sgs: variable to hold the statistics for this group. |
| * @overload: Indicate pullable load (e.g. >1 runnable task). |
| * @overutilized: Indicate overutilization for any CPU. |
| */ |
| static inline void update_sg_lb_stats(struct lb_env *env, |
| struct sched_group *group, int load_idx, |
| int local_group, struct sg_lb_stats *sgs, |
| bool *overload, bool *overutilized, bool *misfit_task) |
| { |
| unsigned long load; |
| int i, nr_running; |
| |
| memset(sgs, 0, sizeof(*sgs)); |
| |
| for_each_cpu_and(i, sched_group_span(group), env->cpus) { |
| struct rq *rq = cpu_rq(i); |
| |
| if (cpu_isolated(i)) |
| continue; |
| /* Bias balancing toward cpus of our domain */ |
| if (local_group) |
| load = target_load(i, load_idx); |
| else |
| load = source_load(i, load_idx); |
| |
| sgs->group_load += load; |
| sgs->group_util += cpu_util(i); |
| sgs->sum_nr_running += rq->cfs.h_nr_running; |
| |
| nr_running = rq->nr_running; |
| if (nr_running > 1) |
| *overload = true; |
| |
| #ifdef CONFIG_NUMA_BALANCING |
| sgs->nr_numa_running += rq->nr_numa_running; |
| sgs->nr_preferred_running += rq->nr_preferred_running; |
| #endif |
| sgs->sum_weighted_load += weighted_cpuload(rq); |
| /* |
| * No need to call idle_cpu() if nr_running is not 0 |
| */ |
| if (!nr_running && idle_cpu(i)) |
| sgs->idle_cpus++; |
| |
| if (env->sd->flags & SD_ASYM_CPUCAPACITY && |
| sgs->group_misfit_task_load < rq->misfit_task_load) { |
| sgs->group_misfit_task_load = rq->misfit_task_load; |
| *overload = 1; |
| } |
| |
| |
| if (cpu_overutilized(i)) { |
| *overutilized = true; |
| |
| if (rq->misfit_task_load) |
| *misfit_task = true; |
| } |
| } |
| /* Isolated CPU has no weight */ |
| if (!group->group_weight) { |
| sgs->group_capacity = 0; |
| sgs->avg_load = 0; |
| sgs->group_no_capacity = 1; |
| sgs->group_type = group_other; |
| sgs->group_weight = group->group_weight; |
| } else { |
| /* Adjust by relative CPU capacity of the group */ |
| sgs->group_capacity = group->sgc->capacity; |
| sgs->avg_load = (sgs->group_load*SCHED_CAPACITY_SCALE) |
| / sgs->group_capacity; |
| |
| sgs->group_weight = group->group_weight; |
| sgs->group_no_capacity = group_is_overloaded(env, sgs); |
| sgs->group_type = group_classify(group, sgs); |
| } |
| if (sgs->sum_nr_running) |
| sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running; |
| |
| |
| trace_sched_update_lb_sg(sgs->avg_load, sgs->group_load, |
| sgs->group_capacity, |
| sgs->group_no_capacity, sgs->group_type); |
| } |
| |
| /** |
| * update_sd_pick_busiest - return 1 on busiest group |
| * @env: The load balancing environment. |
| * @sds: sched_domain statistics |
| * @sg: sched_group candidate to be checked for being the busiest |
| * @sgs: sched_group statistics |
| * |
| * Determine if @sg is a busier group than the previously selected |
| * busiest group. |
| * |
| * Return: %true if @sg is a busier group than the previously selected |
| * busiest group. %false otherwise. |
| */ |
| static bool update_sd_pick_busiest(struct lb_env *env, |
| struct sd_lb_stats *sds, |
| struct sched_group *sg, |
| struct sg_lb_stats *sgs) |
| { |
| struct sg_lb_stats *busiest = &sds->busiest_stat; |
| |
| /* |
| * Don't try to pull misfit tasks we can't help. |
| * We can use max_capacity here as reduction in capacity on some |
| * cpus in the group should either be possible to resolve |
| * internally or be covered by avg_load imbalance (eventually). |
| */ |
| if (sgs->group_type == group_misfit_task && |
| (!group_smaller_max_cpu_capacity(sg, sds->local) || |
| !group_has_capacity(env, &sds->local_stat))) |
| return false; |
| |
| if (sgs->group_type > busiest->group_type) |
| return true; |
| |
| if (sgs->group_type < busiest->group_type) |
| return false; |
| |
| if (sgs->avg_load <= busiest->avg_load) |
| return false; |
| |
| if (!(env->sd->flags & SD_ASYM_CPUCAPACITY)) |
| goto asym_packing; |
| |
| /* |
| * Candidate sg has no more than one task per CPU and |
| * has higher per-CPU capacity. Migrating tasks to less |
| * capable CPUs may harm throughput. Maximize throughput, |
| * power/energy consequences are not considered. |
| */ |
| if (sgs->sum_nr_running <= sgs->group_weight && |
| group_smaller_min_cpu_capacity(sds->local, sg)) |
| return false; |
| |
| /* |
| * Candidate sg doesn't face any severe imbalance issues so |
| * don't disturb unless the groups are of similar capacity |
| * where balancing is more harmless. |
| */ |
| if (sgs->group_type == group_other && |
| !group_similar_cpu_capacity(sds->local, sg)) |
| return false; |
| |
| /* |
| * If we have more than one misfit sg go with the biggest misfit. |
| */ |
| if (sgs->group_type == group_misfit_task && |
| sgs->group_misfit_task_load < busiest->group_misfit_task_load) |
| return false; |
| |
| asym_packing: |
| /* This is the busiest node in its class. */ |
| if (!(env->sd->flags & SD_ASYM_PACKING)) |
| return true; |
| |
| /* No ASYM_PACKING if target cpu is already busy */ |
| if (env->idle == CPU_NOT_IDLE) |
| return true; |
| /* |
| * ASYM_PACKING needs to move all the work to the highest |
| * prority CPUs in the group, therefore mark all groups |
| * of lower priority than ourself as busy. |
| */ |
| if (sgs->sum_nr_running && |
| sched_asym_prefer(env->dst_cpu, sg->asym_prefer_cpu)) { |
| if (!sds->busiest) |
| return true; |
| |
| /* Prefer to move from lowest priority cpu's work */ |
| if (sched_asym_prefer(sds->busiest->asym_prefer_cpu, |
| sg->asym_prefer_cpu)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| #ifdef CONFIG_NUMA_BALANCING |
| static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs) |
| { |
| if (sgs->sum_nr_running > sgs->nr_numa_running) |
| return regular; |
| if (sgs->sum_nr_running > sgs->nr_preferred_running) |
| return remote; |
| return all; |
| } |
| |
| static inline enum fbq_type fbq_classify_rq(struct rq *rq) |
| { |
| if (rq->nr_running > rq->nr_numa_running) |
| return regular; |
| if (rq->nr_running > rq->nr_preferred_running) |
| return remote; |
| return all; |
| } |
| #else |
| static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs) |
| { |
| return all; |
| } |
| |
| static inline enum fbq_type fbq_classify_rq(struct rq *rq) |
| { |
| return regular; |
| } |
| #endif /* CONFIG_NUMA_BALANCING */ |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| static struct { |
| cpumask_var_t idle_cpus_mask; |
| atomic_t nr_cpus; |
| unsigned long next_balance; /* in jiffy units */ |
| unsigned long next_update; /* in jiffy units */ |
| } nohz ____cacheline_aligned; |
| #endif |
| |
| #define lb_sd_parent(sd) \ |
| (sd->parent && sd->parent->groups != sd->parent->groups->next) |
| |
| /** |
| * update_sd_lb_stats - Update sched_domain's statistics for load balancing. |
| * @env: The load balancing environment. |
| * @sds: variable to hold the statistics for this sched_domain. |
| */ |
| static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sds) |
| { |
| struct sched_domain *child = env->sd->child; |
| struct sched_group *sg = env->sd->groups; |
| struct sg_lb_stats *local = &sds->local_stat; |
| struct sg_lb_stats tmp_sgs; |
| int load_idx; |
| bool overload = false, overutilized = false, misfit_task = false; |
| bool prefer_sibling = child && child->flags & SD_PREFER_SIBLING; |
| unsigned long sys_util = 0; |
| unsigned long sys_cap = 0; |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| if (env->idle == CPU_NEWLY_IDLE) { |
| int cpu; |
| |
| /* Update the stats of NOHZ idle CPUs in the sd */ |
| for_each_cpu_and(cpu, sched_domain_span(env->sd), |
| nohz.idle_cpus_mask) { |
| struct rq *rq = cpu_rq(cpu); |
| |
| /* ... Unless we've already done since the last tick */ |
| if (time_after(jiffies, |
| rq->last_blocked_load_update_tick)) |
| update_blocked_averages(cpu); |
| } |
| } |
| /* |
| * If we've just updated all of the NOHZ idle CPUs, then we can push |
| * back the next nohz.next_update, which will prevent an unnecessary |
| * wakeup for the nohz stats kick |
| */ |
| if (cpumask_subset(nohz.idle_cpus_mask, sched_domain_span(env->sd))) |
| nohz.next_update = jiffies + LOAD_AVG_PERIOD; |
| #endif |
| |
| load_idx = get_sd_load_idx(env->sd, env->idle); |
| |
| do { |
| struct sg_lb_stats *sgs = &tmp_sgs; |
| int local_group; |
| |
| local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(sg)); |
| if (local_group) { |
| sds->local = sg; |
| sgs = local; |
| |
| if (env->idle != CPU_NEWLY_IDLE || |
| time_after_eq(jiffies, sg->sgc->next_update)) |
| update_group_capacity(env->sd, env->dst_cpu); |
| } |
| |
| update_sg_lb_stats(env, sg, load_idx, local_group, sgs, |
| &overload, &overutilized, |
| &misfit_task); |
| |
| if (sg->group_weight > 1) { |
| sys_util += sgs->group_util; |
| sys_cap += sg->sgc->capacity; |
| } |
| if (local_group) |
| goto next_group; |
| |
| /* |
| * In case the child domain prefers tasks go to siblings |
| * first, lower the sg capacity so that we'll try |
| * and move all the excess tasks away. We lower the capacity |
| * of a group only if the local group has the capacity to fit |
| * these excess tasks. The extra check prevents the case where |
| * you always pull from the heaviest group when it is already |
| * under-utilized (possible with a large weight task outweighs |
| * the tasks on the system). |
| */ |
| if (prefer_sibling && sds->local && |
| group_has_capacity(env, local) && |
| (sgs->sum_nr_running > local->sum_nr_running + 1)) { |
| sgs->group_no_capacity = 1; |
| sgs->group_type = group_classify(sg, sgs); |
| } |
| |
| if (update_sd_pick_busiest(env, sds, sg, sgs)) { |
| sds->busiest = sg; |
| sds->busiest_stat = *sgs; |
| } |
| |
| next_group: |
| /* Now, start updating sd_lb_stats */ |
| sds->total_running += sgs->sum_nr_running; |
| sds->total_load += sgs->group_load; |
| sds->total_capacity += sgs->group_capacity; |
| sds->total_util += sgs->group_util; |
| |
| sg = sg->next; |
| } while (sg != env->sd->groups); |
| |
| if (env->sd->flags & SD_NUMA) |
| env->fbq_type = fbq_classify_group(&sds->busiest_stat); |
| |
| env->src_grp_nr_running = sds->busiest_stat.sum_nr_running; |
| |
| if (!env->sd->parent) { |
| /* update overload indicator if we are at root domain */ |
| if (READ_ONCE(env->dst_rq->rd->overload) != overload) |
| WRITE_ONCE(env->dst_rq->rd->overload, overload); |
| |
| update_sched_hint(sys_util, sys_cap); |
| } |
| |
| if (!sched_feat(SCHED_MTK_EAS)) { |
| if (overutilized) |
| set_sd_overutilized(env->sd); |
| else |
| clear_sd_overutilized(env->sd); |
| } |
| |
| /* |
| * If there is a misfit task in one cpu in this sched_domain |
| * it is likely that the imbalance cannot be sorted out among |
| * the cpu's in this sched_domain. In this case set the |
| * overutilized flag at the parent sched_domain. |
| */ |
| if (!sched_feat(SCHED_MTK_EAS) && misfit_task) { |
| struct sched_domain *sd = env->sd->parent; |
| |
| /* |
| * In case of a misfit task, load balance at the parent |
| * sched domain level will make sense only if the the cpus |
| * have a different capacity. If cpus at a domain level have |
| * the same capacity, the misfit task cannot be well |
| * accomodated in any of the cpus and there in no point in |
| * trying a load balance at this level |
| */ |
| while (sd) { |
| if (sd->flags & SD_ASYM_CPUCAPACITY) { |
| set_sd_overutilized(sd); |
| break; |
| } |
| sd = sd->parent; |
| } |
| } |
| |
| /* |
| * If the domain util is greater that domain capacity, load balancing |
| * needs to be done at the next sched domain level as well. |
| */ |
| if (!sched_feat(SCHED_MTK_EAS) && lb_sd_parent(env->sd) && |
| sds->total_capacity * 1024 < sds->total_util * capacity_margin) |
| set_sd_overutilized(env->sd->parent); |
| } |
| |
| /** |
| * check_asym_packing - Check to see if the group is packed into the |
| * sched domain. |
| * |
| * This is primarily intended to used at the sibling level. Some |
| * cores like POWER7 prefer to use lower numbered SMT threads. In the |
| * case of POWER7, it can move to lower SMT modes only when higher |
| * threads are idle. When in lower SMT modes, the threads will |
| * perform better since they share less core resources. Hence when we |
| * have idle threads, we want them to be the higher ones. |
| * |
| * This packing function is run on idle threads. It checks to see if |
| * the busiest CPU in this domain (core in the P7 case) has a higher |
| * CPU number than the packing function is being run on. Here we are |
| * assuming lower CPU number will be equivalent to lower a SMT thread |
| * number. |
| * |
| * Return: 1 when packing is required and a task should be moved to |
| * this CPU. The amount of the imbalance is returned in env->imbalance. |
| * |
| * @env: The load balancing environment. |
| * @sds: Statistics of the sched_domain which is to be packed |
| */ |
| static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds) |
| { |
| int busiest_cpu; |
| |
| if (!(env->sd->flags & SD_ASYM_PACKING)) |
| return 0; |
| |
| if (env->idle == CPU_NOT_IDLE) |
| return 0; |
| |
| if (!sds->busiest) |
| return 0; |
| |
| busiest_cpu = sds->busiest->asym_prefer_cpu; |
| if (sched_asym_prefer(busiest_cpu, env->dst_cpu)) |
| return 0; |
| |
| env->imbalance = DIV_ROUND_CLOSEST( |
| sds->busiest_stat.avg_load * sds->busiest_stat.group_capacity, |
| SCHED_CAPACITY_SCALE); |
| |
| return 1; |
| } |
| |
| /** |
| * fix_small_imbalance - Calculate the minor imbalance that exists |
| * amongst the groups of a sched_domain, during |
| * load balancing. |
| * @env: The load balancing environment. |
| * @sds: Statistics of the sched_domain whose imbalance is to be calculated. |
| */ |
| static inline |
| void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) |
| { |
| unsigned long tmp, capa_now = 0, capa_move = 0; |
| unsigned int imbn = 2; |
| unsigned long scaled_busy_load_per_task; |
| struct sg_lb_stats *local, *busiest; |
| |
| local = &sds->local_stat; |
| busiest = &sds->busiest_stat; |
| |
| if (!local->sum_nr_running) |
| local->load_per_task = cpu_avg_load_per_task(env->dst_cpu); |
| else if (busiest->load_per_task > local->load_per_task) |
| imbn = 1; |
| |
| scaled_busy_load_per_task = |
| (busiest->load_per_task * SCHED_CAPACITY_SCALE) / |
| busiest->group_capacity; |
| |
| if (busiest->avg_load + scaled_busy_load_per_task >= |
| local->avg_load + (scaled_busy_load_per_task * imbn)) { |
| env->imbalance = busiest->load_per_task; |
| return; |
| } |
| |
| /* |
| * OK, we don't have enough imbalance to justify moving tasks, |
| * however we may be able to increase total CPU capacity used by |
| * moving them. |
| */ |
| |
| capa_now += busiest->group_capacity * |
| min(busiest->load_per_task, busiest->avg_load); |
| capa_now += local->group_capacity * |
| min(local->load_per_task, local->avg_load); |
| capa_now /= SCHED_CAPACITY_SCALE; |
| |
| /* Amount of load we'd subtract */ |
| if (busiest->avg_load > scaled_busy_load_per_task) { |
| capa_move += busiest->group_capacity * |
| min(busiest->load_per_task, |
| busiest->avg_load - scaled_busy_load_per_task); |
| } |
| |
| /* Amount of load we'd add */ |
| if (busiest->avg_load * busiest->group_capacity < |
| busiest->load_per_task * SCHED_CAPACITY_SCALE) { |
| tmp = (busiest->avg_load * busiest->group_capacity) / |
| local->group_capacity; |
| } else { |
| tmp = (busiest->load_per_task * SCHED_CAPACITY_SCALE) / |
| local->group_capacity; |
| } |
| capa_move += local->group_capacity * |
| min(local->load_per_task, local->avg_load + tmp); |
| capa_move /= SCHED_CAPACITY_SCALE; |
| |
| /* Move if we gain throughput */ |
| if (capa_move > capa_now) { |
| env->imbalance = busiest->load_per_task; |
| return; |
| } |
| |
| /* We can't see throughput improvement with the load-based |
| * method, but it is possible depending upon group size and |
| * capacity range that there might still be an underutilized |
| * cpu available in an asymmetric capacity system. Do one last |
| * check just in case. |
| */ |
| if (env->sd->flags & SD_ASYM_CPUCAPACITY && |
| busiest->group_type == group_overloaded && |
| busiest->sum_nr_running > busiest->group_weight && |
| local->sum_nr_running < local->group_weight && |
| local->group_capacity < busiest->group_capacity) |
| env->imbalance = busiest->load_per_task; |
| } |
| |
| /** |
| * calculate_imbalance - Calculate the amount of imbalance present within the |
| * groups of a given sched_domain during load balance. |
| * @env: load balance environment |
| * @sds: statistics of the sched_domain whose imbalance is to be calculated. |
| */ |
| static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *sds) |
| { |
| unsigned long max_pull, load_above_capacity = ~0UL; |
| struct sg_lb_stats *local, *busiest; |
| |
| local = &sds->local_stat; |
| busiest = &sds->busiest_stat; |
| |
| if (busiest->group_type == group_imbalanced) { |
| /* |
| * In the group_imb case we cannot rely on group-wide averages |
| * to ensure cpu-load equilibrium, look at wider averages. XXX |
| */ |
| busiest->load_per_task = |
| min(busiest->load_per_task, sds->avg_load); |
| } |
| |
| /* |
| * Avg load of busiest sg can be less and avg load of local sg can |
| * be greater than avg load across all sgs of sd because avg load |
| * factors in sg capacity and sgs with smaller group_type are |
| * skipped when updating the busiest sg: |
| */ |
| if (busiest->group_type != group_misfit_task && |
| (busiest->avg_load <= sds->avg_load || |
| local->avg_load >= sds->avg_load)) { |
| env->imbalance = 0; |
| return fix_small_imbalance(env, sds); |
| } |
| |
| /* |
| * If there aren't any idle cpus, avoid creating some. |
| */ |
| if (busiest->group_type == group_overloaded && |
| local->group_type == group_overloaded) { |
| load_above_capacity = busiest->sum_nr_running * SCHED_CAPACITY_SCALE; |
| if (load_above_capacity > busiest->group_capacity) { |
| load_above_capacity -= busiest->group_capacity; |
| load_above_capacity *= scale_load_down(NICE_0_LOAD); |
| load_above_capacity /= busiest->group_capacity; |
| } else |
| load_above_capacity = ~0UL; |
| } |
| |
| /* |
| * We're trying to get all the cpus to the average_load, so we don't |
| * want to push ourselves above the average load, nor do we wish to |
| * reduce the max loaded cpu below the average load. At the same time, |
| * we also don't want to reduce the group load below the group |
| * capacity. Thus we look for the minimum possible imbalance. |
| */ |
| max_pull = min(busiest->avg_load - sds->avg_load, load_above_capacity); |
| |
| /* How much load to actually move to equalise the imbalance */ |
| env->imbalance = min( |
| max_pull * busiest->group_capacity, |
| (sds->avg_load - local->avg_load) * local->group_capacity |
| ) / SCHED_CAPACITY_SCALE; |
| |
| /* Boost imbalance to allow misfit task to be balanced. |
| * Always do this if we are doing a NEWLY_IDLE balance |
| * on the assumption that any tasks we have must not be |
| * long-running (and hence we cannot rely upon load). |
| * However if we are not idle, we should assume the tasks |
| * we have are longer running and not override load-based |
| * calculations above unless we are sure that the local |
| * group is underutilized. |
| */ |
| if (busiest->group_type == group_misfit_task && |
| (env->idle == CPU_NEWLY_IDLE || |
| local->sum_nr_running < local->group_weight)) { |
| env->imbalance = max_t(long, env->imbalance, |
| busiest->group_misfit_task_load); |
| } |
| |
| /* |
| * if *imbalance is less than the average load per runnable task |
| * there is no guarantee that any tasks will be moved so we'll have |
| * a think about bumping its value to force at least one task to be |
| * moved |
| */ |
| if (env->imbalance < busiest->load_per_task) |
| return fix_small_imbalance(env, sds); |
| } |
| |
| static void |
| update_system_overutilized(struct lb_env *env); |
| |
| /******* find_busiest_group() helpers end here *********************/ |
| |
| /** |
| * find_busiest_group - Returns the busiest group within the sched_domain |
| * if there is an imbalance. |
| * |
| * Also calculates the amount of weighted load which should be moved |
| * to restore balance. |
| * |
| * @env: The load balancing environment. |
| * |
| * Return: - The busiest group if imbalance exists. |
| */ |
| static struct sched_group *find_busiest_group(struct lb_env *env) |
| { |
| struct sg_lb_stats *local, *busiest; |
| struct sd_lb_stats sds; |
| int local_cpu = 0, busiest_cpu = 0, intra = 0; |
| struct cpumask *busiest_cpumask; |
| |
| init_sd_lb_stats(&sds); |
| |
| /* |
| * Compute the various statistics relavent for load balancing at |
| * this level. |
| */ |
| update_sd_lb_stats(env, &sds); |
| |
| update_system_overutilized(env); |
| |
| if (sds.busiest) { |
| busiest_cpumask = sched_group_span(sds.busiest); |
| local_cpu = env->dst_cpu; |
| busiest_cpu = group_first_cpu(sds.busiest); |
| |
| intra = is_intra_domain(local_cpu, busiest_cpu); |
| mt_sched_printf(sched_log, |
| "%s: local=%d, busiest=%d, busiest_mask=%lu, intra=%d", |
| __func__, local_cpu, busiest_cpu, |
| busiest_cpumask->bits[0], intra); |
| } |
| |
| |
| if (energy_aware() && !sd_overutilized(env->sd) && !intra) |
| goto out_balanced; |
| |
| local = &sds.local_stat; |
| busiest = &sds.busiest_stat; |
| |
| /* ASYM feature bypasses nice load balance check */ |
| if (check_asym_packing(env, &sds)) |
| return sds.busiest; |
| |
| /* There is no busy sibling group to pull tasks from */ |
| if (!sds.busiest || busiest->sum_nr_running == 0) |
| goto out_balanced; |
| |
| /* XXX broken for overlapping NUMA groups */ |
| sds.avg_load = (SCHED_CAPACITY_SCALE * sds.total_load) |
| / sds.total_capacity; |
| |
| /* |
| * If the busiest group is imbalanced the below checks don't |
| * work because they assume all things are equal, which typically |
| * isn't true due to cpus_allowed constraints and the like. |
| */ |
| if (busiest->group_type == group_imbalanced) |
| goto force_balance; |
| |
| /* |
| * When dst_cpu is idle, prevent SMP nice and/or asymmetric group |
| * capacities from resulting in underutilization due to avg_load. |
| */ |
| if (env->idle != CPU_NOT_IDLE && group_has_capacity(env, local) && |
| busiest->group_no_capacity) |
| goto force_balance; |
| |
| /* Misfit tasks should be dealt with regardless of the avg load */ |
| if (busiest->group_type == group_misfit_task) |
| goto force_balance; |
| |
| /* |
| * If the local group is busier than the selected busiest group |
| * don't try and pull any tasks. |
| */ |
| if (local->avg_load >= busiest->avg_load) |
| goto out_balanced; |
| |
| /* |
| * Don't pull any tasks if this group is already above the domain |
| * average load. |
| */ |
| if (local->avg_load >= sds.avg_load) |
| goto out_balanced; |
| |
| if (env->idle == CPU_IDLE) { |
| /* |
| * This cpu is idle. If the busiest group is not overloaded |
| * and there is no imbalance between this and busiest group |
| * wrt idle cpus, it is balanced. The imbalance becomes |
| * significant if the diff is greater than 1 otherwise we |
| * might end up to just move the imbalance on another group |
| */ |
| if ((busiest->group_type != group_overloaded) && |
| (local->idle_cpus <= (busiest->idle_cpus + 1))) |
| goto out_balanced; |
| } else { |
| /* |
| * In the CPU_NEWLY_IDLE, CPU_NOT_IDLE cases, use |
| * imbalance_pct to be conservative. |
| */ |
| if (100 * busiest->avg_load <= |
| env->sd->imbalance_pct * local->avg_load) |
| goto out_balanced; |
| } |
| |
| force_balance: |
| /* Looks like there is an imbalance. Compute it */ |
| env->src_grp_type = busiest->group_type; |
| calculate_imbalance(env, &sds); |
| return sds.busiest; |
| |
| out_balanced: |
| env->imbalance = 0; |
| return NULL; |
| } |
| |
| /* |
| * find_busiest_queue - find the busiest runqueue among the cpus in group. |
| */ |
| static struct rq *find_busiest_queue(struct lb_env *env, |
| struct sched_group *group) |
| { |
| struct rq *busiest = NULL, *rq; |
| unsigned long busiest_load = 0, busiest_capacity = 1; |
| int i; |
| |
| for_each_cpu_and(i, sched_group_span(group), env->cpus) { |
| unsigned long capacity, wl; |
| enum fbq_type rt; |
| |
| rq = cpu_rq(i); |
| rt = fbq_classify_rq(rq); |
| |
| /* |
| * We classify groups/runqueues into three groups: |
| * - regular: there are !numa tasks |
| * - remote: there are numa tasks that run on the 'wrong' node |
| * - all: there is no distinction |
| * |
| * In order to avoid migrating ideally placed numa tasks, |
| * ignore those when there's better options. |
| * |
| * If we ignore the actual busiest queue to migrate another |
| * task, the next balance pass can still reduce the busiest |
| * queue by moving tasks around inside the node. |
| * |
| * If we cannot move enough load due to this classification |
| * the next pass will adjust the group classification and |
| * allow migration of more tasks. |
| * |
| * Both cases only affect the total convergence complexity. |
| */ |
| if (rt > env->fbq_type) |
| continue; |
| |
| /* |
| * For ASYM_CPUCAPACITY domains with misfit tasks we simply |
| * seek the "biggest" misfit task. |
| */ |
| if (env->src_grp_type == group_misfit_task) { |
| if (rq->misfit_task_load > busiest_load) { |
| busiest_load = rq->misfit_task_load; |
| busiest = rq; |
| } |
| continue; |
| } |
| |
| capacity = capacity_of(i); |
| |
| /* |
| * For ASYM_CPUCAPACITY domains, don't pick a cpu that could |
| * eventually lead to active_balancing high->low capacity. |
| * Higher per-cpu capacity is considered better than balancing |
| * average load. |
| */ |
| if (env->sd->flags & SD_ASYM_CPUCAPACITY && |
| capacity_of(env->dst_cpu) < capacity && |
| rq->nr_running == 1) |
| continue; |
| |
| wl = weighted_cpuload(rq); |
| |
| #if defined(CONFIG_MTK_SCHED_INTEROP) && defined(CONFIG_RT_GROUP_SCHED) |
| wl += mt_rt_load(i); |
| #endif |
| |
| /* |
| * When comparing with imbalance, use weighted_cpuload() |
| * which is not scaled with the cpu capacity. |
| */ |
| |
| if (rq->nr_running == 1 && wl > env->imbalance && |
| !check_cpu_capacity(rq, env->sd)) |
| continue; |
| |
| /* |
| * For the load comparisons with the other cpu's, consider |
| * the weighted_cpuload() scaled with the cpu capacity, so |
| * that the load can be moved away from the cpu that is |
| * potentially running at a lower capacity. |
| * |
| * Thus we're looking for max(wl_i / capacity_i), crosswise |
| * multiplication to rid ourselves of the division works out |
| * to: wl_i * capacity_j > wl_j * capacity_i; where j is |
| * our previous maximum. |
| */ |
| if (wl * busiest_capacity > busiest_load * capacity) { |
| busiest_load = wl; |
| busiest_capacity = capacity; |
| busiest = rq; |
| } |
| } |
| |
| return busiest; |
| } |
| |
| /* |
| * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but |
| * so long as it is large enough. |
| */ |
| #define MAX_PINNED_INTERVAL 512 |
| |
| static int need_active_balance(struct lb_env *env) |
| { |
| struct sched_domain *sd = env->sd; |
| |
| if (env->idle == CPU_NEWLY_IDLE) { |
| |
| /* |
| * ASYM_PACKING needs to force migrate tasks from busy but |
| * lower priority CPUs in order to pack all tasks in the |
| * highest priority CPUs. |
| */ |
| if ((sd->flags & SD_ASYM_PACKING) && |
| sched_asym_prefer(env->dst_cpu, env->src_cpu)) |
| return 1; |
| } |
| |
| /* |
| * The dst_cpu is idle and the src_cpu CPU has only 1 CFS task. |
| * It's worth migrating the task if the src_cpu's capacity is reduced |
| * because of other sched_class or IRQs if more capacity stays |
| * available on dst_cpu. |
| */ |
| if ((env->idle != CPU_NOT_IDLE) && |
| (env->src_rq->cfs.h_nr_running == 1)) { |
| if ((check_cpu_capacity(env->src_rq, sd)) && |
| (capacity_of(env->src_cpu)*sd->imbalance_pct < capacity_of(env->dst_cpu)*100)) |
| return 1; |
| } |
| |
| if ((capacity_of(env->src_cpu) < capacity_of(env->dst_cpu)) && |
| ((capacity_orig_of(env->src_cpu) < capacity_orig_of(env->dst_cpu))) && |
| env->src_rq->cfs.h_nr_running == 1 && |
| cpu_overutilized(env->src_cpu) && |
| !cpu_overutilized(env->dst_cpu)) { |
| return 1; |
| } |
| |
| if (env->src_grp_type == group_misfit_task) |
| return 1; |
| |
| if (env->src_grp_type == group_overloaded && |
| env->src_rq->misfit_task_load) |
| return 1; |
| |
| return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2); |
| } |
| |
| static int active_load_balance_cpu_stop(void *data); |
| |
| static int group_balance_cpu_not_isolated(struct sched_group *sg) |
| { |
| cpumask_t cpus; |
| |
| cpumask_and(&cpus, sched_group_cpus(sg), sched_group_mask(sg)); |
| cpumask_andnot(&cpus, &cpus, cpu_isolated_mask); |
| return cpumask_first(&cpus); |
| } |
| |
| static int should_we_balance(struct lb_env *env) |
| { |
| struct sched_group *sg = env->sd->groups; |
| int cpu, balance_cpu = -1; |
| |
| /* |
| * Ensure the balancing environment is consistent; can happen |
| * when the softirq triggers 'during' hotplug. |
| */ |
| if (!cpumask_test_cpu(env->dst_cpu, env->cpus)) |
| return 0; |
| |
| /* |
| * In the newly idle case, we will allow all the cpu's |
| * to do the newly idle load balance. |
| */ |
| if (env->idle == CPU_NEWLY_IDLE) |
| return 1; |
| |
| /* Try to find first idle cpu */ |
| for_each_cpu_and(cpu, group_balance_mask(sg), env->cpus) { |
| if (!idle_cpu(cpu) || cpu_isolated(cpu)) |
| continue; |
| |
| balance_cpu = cpu; |
| break; |
| } |
| |
| if (balance_cpu == -1) |
| balance_cpu = group_balance_cpu_not_isolated(sg); |
| |
| /* |
| * First idle cpu or the first cpu(busiest) in this sched group |
| * is eligible for doing load balancing at this and above domains. |
| */ |
| return balance_cpu == env->dst_cpu; |
| } |
| |
| /* |
| * Check this_cpu to ensure it is balanced within domain. Attempt to move |
| * tasks if there is an imbalance. |
| */ |
| static int load_balance(int this_cpu, struct rq *this_rq, |
| struct sched_domain *sd, enum cpu_idle_type idle, |
| int *continue_balancing) |
| { |
| int ld_moved, cur_ld_moved, active_balance = 0; |
| struct sched_domain *sd_parent = sd->parent; |
| struct sched_group *group; |
| struct rq *busiest; |
| struct rq_flags rf; |
| struct cpumask *cpus = this_cpu_cpumask_var_ptr(load_balance_mask); |
| |
| struct lb_env env = { |
| .sd = sd, |
| .dst_cpu = this_cpu, |
| .dst_rq = this_rq, |
| .dst_grpmask = sched_group_span(sd->groups), |
| .idle = idle, |
| .loop_break = sched_nr_migrate_break, |
| .cpus = cpus, |
| .fbq_type = all, |
| .tasks = LIST_HEAD_INIT(env.tasks), |
| }; |
| |
| cpumask_and(cpus, sched_domain_span(sd), cpu_active_mask); |
| |
| schedstat_inc(sd->lb_count[idle]); |
| |
| redo: |
| if (!should_we_balance(&env)) { |
| *continue_balancing = 0; |
| goto out_balanced; |
| } |
| |
| group = find_busiest_group(&env); |
| if (!group) { |
| schedstat_inc(sd->lb_nobusyg[idle]); |
| goto out_balanced; |
| } |
| |
| busiest = find_busiest_queue(&env, group); |
| if (!busiest) { |
| schedstat_inc(sd->lb_nobusyq[idle]); |
| goto out_balanced; |
| } |
| |
| BUG_ON(busiest == env.dst_rq); |
| |
| schedstat_add(sd->lb_imbalance[idle], env.imbalance); |
| |
| env.src_cpu = busiest->cpu; |
| env.src_rq = busiest; |
| |
| ld_moved = 0; |
| if (busiest->nr_running > 1) { |
| /* |
| * Attempt to move tasks. If find_busiest_group has found |
| * an imbalance but busiest->nr_running <= 1, the group is |
| * still unbalanced. ld_moved simply stays zero, so it is |
| * correctly treated as an imbalance. |
| */ |
| env.flags |= LBF_ALL_PINNED; |
| env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running); |
| |
| more_balance: |
| rq_lock_irqsave(busiest, &rf); |
| update_rq_clock(busiest); |
| |
| /* |
| * cur_ld_moved - load moved in current iteration |
| * ld_moved - cumulative load moved across iterations |
| */ |
| cur_ld_moved = detach_tasks(&env, &rf); |
| |
| /* |
| * We've detached some tasks from busiest_rq. Every |
| * task is masked "TASK_ON_RQ_MIGRATING", so we can safely |
| * unlock busiest->lock, and we are able to be sure |
| * that nobody can manipulate the tasks in parallel. |
| * See task_rq_lock() family for the details. |
| */ |
| |
| rq_unlock(busiest, &rf); |
| |
| if (cur_ld_moved) { |
| attach_tasks(&env); |
| ld_moved += cur_ld_moved; |
| } |
| |
| local_irq_restore(rf.flags); |
| |
| if (env.flags & LBF_NEED_BREAK) { |
| env.flags &= ~LBF_NEED_BREAK; |
| goto more_balance; |
| } |
| |
| /* |
| * Revisit (affine) tasks on src_cpu that couldn't be moved to |
| * us and move them to an alternate dst_cpu in our sched_group |
| * where they can run. The upper limit on how many times we |
| * iterate on same src_cpu is dependent on number of cpus in our |
| * sched_group. |
| * |
| * This changes load balance semantics a bit on who can move |
| * load to a given_cpu. In addition to the given_cpu itself |
| * (or a ilb_cpu acting on its behalf where given_cpu is |
| * nohz-idle), we now have balance_cpu in a position to move |
| * load to given_cpu. In rare situations, this may cause |
| * conflicts (balance_cpu and given_cpu/ilb_cpu deciding |
| * _independently_ and at _same_ time to move some load to |
| * given_cpu) causing exceess load to be moved to given_cpu. |
| * This however should not happen so much in practice and |
| * moreover subsequent load balance cycles should correct the |
| * excess load moved. |
| */ |
| if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) { |
| |
| /* Prevent to re-select dst_cpu via env's cpus */ |
| cpumask_clear_cpu(env.dst_cpu, env.cpus); |
| |
| env.dst_rq = cpu_rq(env.new_dst_cpu); |
| env.dst_cpu = env.new_dst_cpu; |
| env.flags &= ~LBF_DST_PINNED; |
| env.loop = 0; |
| env.loop_break = sched_nr_migrate_break; |
| |
| /* |
| * Go back to "more_balance" rather than "redo" since we |
| * need to continue with same src_cpu. |
| */ |
| goto more_balance; |
| } |
| |
| /* |
| * We failed to reach balance because of affinity. |
| */ |
| if (sd_parent) { |
| int *group_imbalance = &sd_parent->groups->sgc->imbalance; |
| |
| if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) |
| *group_imbalance = 1; |
| } |
| |
| /* All tasks on this runqueue were pinned by CPU affinity */ |
| if (unlikely(env.flags & LBF_ALL_PINNED)) { |
| cpumask_clear_cpu(cpu_of(busiest), cpus); |
| /* |
| * Attempting to continue load balancing at the current |
| * sched_domain level only makes sense if there are |
| * active CPUs remaining as possible busiest CPUs to |
| * pull load from which are not contained within the |
| * destination group that is receiving any migrated |
| * load. |
| */ |
| if (!cpumask_subset(cpus, env.dst_grpmask)) { |
| env.loop = 0; |
| env.loop_break = sched_nr_migrate_break; |
| goto redo; |
| } |
| goto out_all_pinned; |
| } |
| } |
| |
| if (!ld_moved) { |
| schedstat_inc(sd->lb_failed[idle]); |
| /* |
| * Increment the failure counter only on periodic balance. |
| * We do not want newidle balance, which can be very |
| * frequent, pollute the failure counter causing |
| * excessive cache_hot migrations and active balances. |
| */ |
| if (idle != CPU_NEWLY_IDLE) |
| if (env.src_grp_nr_running > 1) |
| sd->nr_balance_failed++; |
| |
| if (need_active_balance(&env)) { |
| unsigned long flags; |
| |
| raw_spin_lock_irqsave(&busiest->lock, flags); |
| |
| /* don't kick the active_load_balance_cpu_stop, |
| * if the curr task on busiest cpu can't be |
| * moved to this_cpu |
| */ |
| if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { |
| raw_spin_unlock_irqrestore(&busiest->lock, |
| flags); |
| env.flags |= LBF_ALL_PINNED; |
| goto out_one_pinned; |
| } |
| |
| #ifdef CONFIG_MTK_SCHED_BOOST |
| if (task_prefer_fit(busiest->curr, cpu_of(busiest))) { |
| raw_spin_unlock_irqrestore(&busiest->lock, |
| flags); |
| env.flags |= LBF_ALL_PINNED; |
| goto out_one_pinned; |
| } |
| #endif |
| |
| #ifdef CONFIG_SCHED_HMP |
| /* |
| * If cpu_util + new task_util is overutil, |
| * we don't migrate this task. |
| */ |
| int cpu = env.dst_cpu; |
| unsigned long util = cpu_util_without(cpu, busiest->curr) + |
| task_util_est(busiest->curr); |
| if ((capacity_of(env.dst_cpu) * 1024) < |
| uclamp_rq_util_with(cpu_rq(cpu), util, busiest->curr) * capacity_margin) { |
| raw_spin_unlock_irqrestore(&busiest->lock, flags); |
| env.flags |= LBF_ALL_PINNED; |
| goto out_one_pinned; |
| } |
| #endif |
| |
| /* |
| * ->active_balance synchronizes accesses to |
| * ->active_balance_work. Once set, it's cleared |
| * only after active load balance is finished. |
| */ |
| if (!busiest->active_balance && |
| !cpu_isolated(cpu_of(busiest))) { |
| busiest->active_balance = MIGR_LOAD_BALANCE; |
| busiest->push_cpu = this_cpu; |
| active_balance = 1; |
| } |
| raw_spin_unlock_irqrestore(&busiest->lock, flags); |
| |
| if (active_balance) { |
| stop_one_cpu_nowait(cpu_of(busiest), |
| active_load_balance_cpu_stop, busiest, |
| &busiest->active_balance_work); |
| trace_sched_hmp_migrate(busiest->curr, |
| this_cpu, MIGR_LOAD_BALANCE); |
| } |
| |
| /* We've kicked active balancing, force task migration. */ |
| sd->nr_balance_failed = sd->cache_nice_tries+1; |
| } |
| } else |
| sd->nr_balance_failed = 0; |
| |
| if (likely(!active_balance)) { |
| /* We were unbalanced, so reset the balancing interval */ |
| sd->balance_interval = sd->min_interval; |
| } else { |
| /* |
| * If we've begun active balancing, start to back off. This |
| * case may not be covered by the all_pinned logic if there |
| * is only 1 task on the busy runqueue (because we don't call |
| * detach_tasks). |
| */ |
| if (sd->balance_interval < sd->max_interval) |
| sd->balance_interval *= 2; |
| } |
| |
| goto out; |
| |
| out_balanced: |
| /* |
| * We reach balance although we may have faced some affinity |
| * constraints. Clear the imbalance flag only if other tasks got |
| * a chance to move and fix the imbalance. |
| */ |
| if (sd_parent && !(env.flags & LBF_ALL_PINNED)) { |
| int *group_imbalance = &sd_parent->groups->sgc->imbalance; |
| |
| if (*group_imbalance) |
| *group_imbalance = 0; |
| } |
| |
| out_all_pinned: |
| /* |
| * We reach balance because all tasks are pinned at this level so |
| * we can't migrate them. Let the imbalance flag set so parent level |
| * can try to migrate them. |
| */ |
| schedstat_inc(sd->lb_balanced[idle]); |
| |
| sd->nr_balance_failed = 0; |
| |
| out_one_pinned: |
| ld_moved = 0; |
| |
| /* |
| * idle_balance() disregards balance intervals, so we could repeatedly |
| * reach this code, which would lead to balance_interval skyrocketting |
| * in a short amount of time. Skip the balance_interval increase logic |
| * to avoid that. |
| */ |
| if (env.idle == CPU_NEWLY_IDLE) |
| goto out; |
| |
| /* tune up the balancing interval */ |
| if (((env.flags & LBF_ALL_PINNED) && |
| sd->balance_interval < MAX_PINNED_INTERVAL) || |
| (sd->balance_interval < sd->max_interval)) |
| sd->balance_interval *= 2; |
| out: |
| return ld_moved; |
| } |
| |
| static inline unsigned long |
| get_sd_balance_interval(struct sched_domain *sd, int cpu_busy) |
| { |
| unsigned long interval = sd->balance_interval; |
| unsigned int cpu; |
| |
| if (cpu_busy) |
| interval *= sd->busy_factor; |
| |
| /* scale ms to jiffies */ |
| interval = msecs_to_jiffies(interval); |
| interval = clamp(interval, 1UL, max_load_balance_interval); |
| |
| /* |
| * check if sched domain is marked as overutilized |
| * we ought to only do this on systems which have SD_ASYMCAPACITY |
| * but we want to do it for all sched domains in those systems |
| * So for now, just check if overutilized as a proxy. |
| */ |
| /* |
| * If we are overutilized and we have a misfit task, then |
| * we want to balance as soon as practically possible, so |
| * we return an interval of zero. |
| */ |
| if (energy_aware() && sd_overutilized(sd)) { |
| /* we know the root is overutilized, let's check for a misfit task */ |
| for_each_cpu(cpu, sched_domain_span(sd)) { |
| if (cpu_rq(cpu)->misfit_task_load) |
| return 1; |
| } |
| } |
| return interval; |
| } |
| |
| static inline void |
| update_next_balance(struct sched_domain *sd, unsigned long *next_balance) |
| { |
| unsigned long interval, next; |
| |
| /* used by idle balance, so cpu_busy = 0 */ |
| interval = get_sd_balance_interval(sd, 0); |
| next = sd->last_balance + interval; |
| |
| if (time_after(*next_balance, next)) |
| *next_balance = next; |
| } |
| |
| /* |
| * idle_balance is called by schedule() if this_cpu is about to become |
| * idle. Attempts to pull tasks from other CPUs. |
| */ |
| static int idle_balance(struct rq *this_rq, struct rq_flags *rf) |
| { |
| unsigned long next_balance = jiffies + HZ; |
| int this_cpu = this_rq->cpu; |
| struct sched_domain *sd; |
| int pulled_task = 0; |
| u64 curr_cost = 0; |
| |
| if (cpu_isolated(this_cpu)) |
| return 0; |
| /* |
| * We must set idle_stamp _before_ calling idle_balance(), such that we |
| * measure the duration of idle_balance() as idle time. |
| */ |
| this_rq->idle_stamp = rq_clock(this_rq); |
| |
| /* |
| * Do not pull tasks towards !active CPUs... |
| */ |
| if (!cpu_active(this_cpu)) |
| return 0; |
| |
| /* |
| * This is OK, because current is on_cpu, which avoids it being picked |
| * for load-balance and preemption/IRQs are still disabled avoiding |
| * further scheduler activity on it and we're being very careful to |
| * re-start the picking loop. |
| */ |
| rq_unpin_lock(this_rq, rf); |
| |
| if (this_rq->avg_idle < sysctl_sched_migration_cost || |
| !READ_ONCE(this_rq->rd->overload)) { |
| rcu_read_lock(); |
| sd = rcu_dereference_check_sched_domain(this_rq->sd); |
| if (sd) |
| update_next_balance(sd, &next_balance); |
| rcu_read_unlock(); |
| |
| if (!this_rq->rd->overload) { |
| raw_spin_unlock(&this_rq->lock); |
| goto hinted_idle_pull; |
| } |
| |
| goto out; |
| } |
| |
| raw_spin_unlock(&this_rq->lock); |
| |
| update_blocked_averages(this_cpu); |
| rcu_read_lock(); |
| for_each_domain(this_cpu, sd) { |
| int continue_balancing = 1; |
| u64 t0, domain_cost; |
| |
| if (!(sd->flags & SD_LOAD_BALANCE)) { |
| if (time_after_eq(jiffies, |
| sd->groups->sgc->next_update)) |
| update_group_capacity(sd, this_cpu); |
| continue; |
| } |
| |
| if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) { |
| update_next_balance(sd, &next_balance); |
| break; |
| } |
| |
| if (sd->flags & SD_BALANCE_NEWIDLE) { |
| t0 = sched_clock_cpu(this_cpu); |
| |
| pulled_task = load_balance(this_cpu, this_rq, |
| sd, CPU_NEWLY_IDLE, |
| &continue_balancing); |
| |
| domain_cost = sched_clock_cpu(this_cpu) - t0; |
| if (domain_cost > sd->max_newidle_lb_cost) |
| sd->max_newidle_lb_cost = domain_cost; |
| |
| curr_cost += domain_cost; |
| } |
| |
| update_next_balance(sd, &next_balance); |
| |
| /* |
| * Stop searching for tasks to pull if there are |
| * now runnable tasks on this rq. |
| */ |
| if (pulled_task || this_rq->nr_running > 0) |
| break; |
| } |
| rcu_read_unlock(); |
| |
| hinted_idle_pull: |
| /* We could not pull task to this_cpu when this_rq offline */ |
| if (this_rq->online) { |
| if (!pulled_task) |
| pulled_task = aggressive_idle_pull(this_cpu); |
| if (should_hmp(this_cpu) && !pulled_task) |
| pulled_task = hmp_idle_pull(this_cpu); |
| } |
| raw_spin_lock(&this_rq->lock); |
| |
| if (curr_cost > this_rq->max_idle_balance_cost) |
| this_rq->max_idle_balance_cost = curr_cost; |
| |
| /* |
| * While browsing the domains, we released the rq lock, a task could |
| * have been enqueued in the meantime. Since we're not going idle, |
| * pretend we pulled a task. |
| */ |
| if (this_rq->cfs.h_nr_running && !pulled_task) |
| pulled_task = 1; |
| |
| out: |
| /* Move the next balance forward */ |
| if (time_after(this_rq->next_balance, next_balance)) |
| this_rq->next_balance = next_balance; |
| |
| /* Is there a task of a high priority class? */ |
| if (this_rq->nr_running != this_rq->cfs.h_nr_running) |
| pulled_task = -1; |
| |
| if (pulled_task) |
| this_rq->idle_stamp = 0; |
| |
| rq_repin_lock(this_rq, rf); |
| |
| return pulled_task; |
| } |
| |
| /* |
| * active_load_balance_cpu_stop is run by cpu stopper. It pushes |
| * running tasks off the busiest CPU onto idle CPUs. It requires at |
| * least 1 task to be running on each physical CPU where possible, and |
| * avoids physical / logical imbalances. |
| */ |
| static int active_load_balance_cpu_stop(void *data) |
| { |
| struct rq *busiest_rq = data; |
| int busiest_cpu = cpu_of(busiest_rq); |
| int target_cpu = busiest_rq->push_cpu; |
| struct rq *target_rq = cpu_rq(target_cpu); |
| struct sched_domain *sd; |
| struct task_struct *p = NULL; |
| struct rq_flags rf; |
| |
| rq_lock_irq(busiest_rq, &rf); |
| /* |
| * Between queueing the stop-work and running it is a hole in which |
| * CPUs can become inactive. We should not move tasks from or to |
| * inactive CPUs. |
| */ |
| if (!cpu_active(busiest_cpu) || !cpu_active(target_cpu)) |
| goto out_unlock; |
| |
| if (!cpu_online(busiest_cpu) || !cpu_online(target_cpu) || |
| cpu_isolated(busiest_cpu) || cpu_isolated(target_cpu)) |
| goto out_unlock; |
| |
| /* make sure the requested cpu hasn't gone down in the meantime */ |
| if (unlikely(busiest_cpu != smp_processor_id() || |
| !busiest_rq->active_balance)) |
| goto out_unlock; |
| |
| /* Is there any task to move? */ |
| if (busiest_rq->nr_running <= 1) |
| goto out_unlock; |
| |
| /* |
| * This condition is "impossible", if it occurs |
| * we need to fix it. Originally reported by |
| * Bjorn Helgaas on a 128-cpu setup. |
| */ |
| BUG_ON(busiest_rq == target_rq); |
| |
| /* Search for an sd spanning us and the target CPU. */ |
| rcu_read_lock(); |
| for_each_domain(target_cpu, sd) { |
| if ((sd->flags & SD_LOAD_BALANCE) && |
| cpumask_test_cpu(busiest_cpu, sched_domain_span(sd))) |
| break; |
| } |
| |
| if (likely(sd)) { |
| struct lb_env env = { |
| .sd = sd, |
| .dst_cpu = target_cpu, |
| .dst_rq = target_rq, |
| .src_cpu = busiest_rq->cpu, |
| .src_rq = busiest_rq, |
| .idle = CPU_IDLE, |
| /* |
| * can_migrate_task() doesn't need to compute new_dst_cpu |
| * for active balancing. Since we have CPU_IDLE, but no |
| * @dst_grpmask we need to make that test go away with lying |
| * about DST_PINNED. |
| */ |
| .flags = LBF_DST_PINNED, |
| }; |
| |
| schedstat_inc(sd->alb_count); |
| update_rq_clock(busiest_rq); |
| |
| p = detach_one_task(&env, &rf); |
| if (p) { |
| schedstat_inc(sd->alb_pushed); |
| /* Active balancing done, reset the failure counter. */ |
| sd->nr_balance_failed = 0; |
| } else { |
| schedstat_inc(sd->alb_failed); |
| } |
| } |
| rcu_read_unlock(); |
| out_unlock: |
| busiest_rq->active_balance = 0; |
| rq_unlock(busiest_rq, &rf); |
| |
| if (p) |
| attach_one_task(target_rq, p); |
| |
| local_irq_enable(); |
| |
| return 0; |
| } |
| |
| static inline int on_null_domain(struct rq *rq) |
| { |
| return unlikely(!rcu_dereference_sched(rq->sd)); |
| } |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| /* |
| * idle load balancing details |
| * - When one of the busy CPUs notice that there may be an idle rebalancing |
| * needed, they will kick the idle load balancer, which then does idle |
| * load balancing for all the idle CPUs. |
| */ |
| |
| static inline int find_new_ilb(void) |
| { |
| int ilb = cpumask_first(nohz.idle_cpus_mask); |
| |
| if (ilb < nr_cpu_ids && idle_cpu(ilb)) |
| return ilb; |
| |
| return nr_cpu_ids; |
| } |
| |
| /* |
| * Kick a CPU to do the nohz balancing, if it is time for it. We pick the |
| * nohz_load_balancer CPU (if there is one) otherwise fallback to any idle |
| * CPU (if there is one). |
| */ |
| static void nohz_balancer_kick(bool only_update) |
| { |
| int ilb_cpu; |
| |
| nohz.next_balance++; |
| |
| ilb_cpu = find_new_ilb(); |
| |
| if (ilb_cpu >= nr_cpu_ids) |
| return; |
| |
| if (test_and_set_bit(NOHZ_BALANCE_KICK, nohz_flags(ilb_cpu))) |
| return; |
| |
| if (only_update) |
| set_bit(NOHZ_STATS_KICK, nohz_flags(ilb_cpu)); |
| |
| /* |
| * Use smp_send_reschedule() instead of resched_cpu(). |
| * This way we generate a sched IPI on the target cpu which |
| * is idle. And the softirq performing nohz idle load balance |
| * will be run before returning from the IPI. |
| */ |
| smp_send_reschedule(ilb_cpu); |
| return; |
| } |
| |
| |
| void nohz_balance_clear_nohz_mask(int cpu) |
| { |
| if (likely(cpumask_test_cpu(cpu, nohz.idle_cpus_mask))) { |
| cpumask_clear_cpu(cpu, nohz.idle_cpus_mask); |
| atomic_dec(&nohz.nr_cpus); |
| } |
| } |
| |
| |
| void nohz_balance_exit_idle(unsigned int cpu) |
| { |
| if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) { |
| /* |
| * Completely isolated CPUs don't ever set, so we must test. |
| */ |
| nohz_balance_clear_nohz_mask(cpu); |
| clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)); |
| } |
| } |
| |
| static inline void set_cpu_sd_state_busy(void) |
| { |
| struct sched_domain *sd; |
| int cpu = smp_processor_id(); |
| |
| rcu_read_lock(); |
| sd = rcu_dereference(per_cpu(sd_llc, cpu)); |
| |
| if (!sd || !sd->nohz_idle) |
| goto unlock; |
| sd->nohz_idle = 0; |
| |
| atomic_inc(&sd->shared->nr_busy_cpus); |
| unlock: |
| rcu_read_unlock(); |
| } |
| |
| void set_cpu_sd_state_idle(void) |
| { |
| struct sched_domain *sd; |
| int cpu = smp_processor_id(); |
| |
| rcu_read_lock(); |
| sd = rcu_dereference(per_cpu(sd_llc, cpu)); |
| |
| if (!sd || sd->nohz_idle) |
| goto unlock; |
| sd->nohz_idle = 1; |
| |
| atomic_dec(&sd->shared->nr_busy_cpus); |
| unlock: |
| rcu_read_unlock(); |
| } |
| |
| /* |
| * This routine will record that the cpu is going idle with tick stopped. |
| * This info will be used in performing idle load balancing in the future. |
| */ |
| void nohz_balance_enter_idle(int cpu) |
| { |
| /* |
| * If this cpu is going down, then nothing needs to be done. |
| */ |
| if (!cpu_active(cpu)) |
| return; |
| |
| /* Spare idle load balancing on CPUs that don't want to be disturbed: */ |
| if (!is_housekeeping_cpu(cpu)) |
| return; |
| |
| if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu))) |
| return; |
| |
| /* |
| * If we're a completely isolated CPU, we don't play. |
| */ |
| if (on_null_domain(cpu_rq(cpu)) || cpu_isolated(cpu)) |
| return; |
| |
| cpumask_set_cpu(cpu, nohz.idle_cpus_mask); |
| atomic_inc(&nohz.nr_cpus); |
| set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)); |
| } |
| #else |
| static inline void nohz_balancer_kick(bool only_update) {} |
| #endif |
| |
| static DEFINE_SPINLOCK(balancing); |
| |
| /* |
| * Scale the max load_balance interval with the number of CPUs in the system. |
| * This trades load-balance latency on larger machines for less cross talk. |
| */ |
| void update_max_interval(void) |
| { |
| cpumask_t avail_mask; |
| unsigned int available_cpus; |
| |
| cpumask_andnot(&avail_mask, cpu_online_mask, cpu_isolated_mask); |
| available_cpus = cpumask_weight(&avail_mask); |
| |
| max_load_balance_interval = HZ*available_cpus/10; |
| } |
| |
| /* |
| * It checks each scheduling domain to see if it is due to be balanced, |
| * and initiates a balancing operation if so. |
| * |
| * Balancing parameters are set up in init_sched_domains. |
| */ |
| static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle) |
| { |
| int continue_balancing = 1; |
| int cpu = rq->cpu; |
| unsigned long interval; |
| struct sched_domain *sd; |
| /* Earliest time when we have to do rebalance again */ |
| unsigned long next_balance = jiffies + 60*HZ; |
| int update_next_balance = 0; |
| int need_serialize, need_decay = 0; |
| u64 max_cost = 0; |
| |
| rcu_read_lock(); |
| for_each_domain(cpu, sd) { |
| /* |
| * Decay the newidle max times here because this is a regular |
| * visit to all the domains. Decay ~1% per second. |
| */ |
| if (time_after(jiffies, sd->next_decay_max_lb_cost)) { |
| sd->max_newidle_lb_cost = |
| (sd->max_newidle_lb_cost * 253) / 256; |
| sd->next_decay_max_lb_cost = jiffies + HZ; |
| need_decay = 1; |
| } |
| max_cost += sd->max_newidle_lb_cost; |
| |
| if (energy_aware() && !sd_overutilized(sd)) |
| continue; |
| |
| if (!(sd->flags & SD_LOAD_BALANCE)) { |
| if (time_after_eq(jiffies, |
| sd->groups->sgc->next_update)) |
| update_group_capacity(sd, cpu); |
| continue; |
| } |
| |
| /* |
| * Stop the load balance at this level. There is another |
| * CPU in our sched group which is doing load balancing more |
| * actively. |
| */ |
| if (!continue_balancing) { |
| if (need_decay) |
| continue; |
| break; |
| } |
| |
| interval = get_sd_balance_interval(sd, idle != CPU_IDLE); |
| |
| need_serialize = sd->flags & SD_SERIALIZE; |
| if (need_serialize) { |
| if (!spin_trylock(&balancing)) |
| goto out; |
| } |
| |
| if (time_after_eq(jiffies, sd->last_balance + interval)) { |
| if (load_balance(cpu, rq, sd, idle, &continue_balancing)) { |
| /* |
| * The LBF_DST_PINNED logic could have changed |
| * env->dst_cpu, so we can't know our idle |
| * state even if we migrated tasks. Update it. |
| */ |
| idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE; |
| } |
| sd->last_balance = jiffies; |
| interval = get_sd_balance_interval(sd, idle != CPU_IDLE); |
| } |
| if (need_serialize) |
| spin_unlock(&balancing); |
| out: |
| if (time_after(next_balance, sd->last_balance + interval)) { |
| next_balance = sd->last_balance + interval; |
| update_next_balance = 1; |
| } |
| } |
| if (need_decay) { |
| /* |
| * Ensure the rq-wide value also decays but keep it at a |
| * reasonable floor to avoid funnies with rq->avg_idle. |
| */ |
| rq->max_idle_balance_cost = |
| max((u64)sysctl_sched_migration_cost, max_cost); |
| } |
| rcu_read_unlock(); |
| |
| /* |
| * next_balance will be updated only when there is a need. |
| * When the cpu is attached to null domain for ex, it will not be |
| * updated. |
| */ |
| if (likely(update_next_balance)) { |
| rq->next_balance = next_balance; |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| /* |
| * If this CPU has been elected to perform the nohz idle |
| * balance. Other idle CPUs have already rebalanced with |
| * nohz_idle_balance() and nohz.next_balance has been |
| * updated accordingly. This CPU is now running the idle load |
| * balance for itself and we need to update the |
| * nohz.next_balance accordingly. |
| */ |
| if ((idle == CPU_IDLE) && time_after(nohz.next_balance, rq->next_balance)) |
| nohz.next_balance = rq->next_balance; |
| #endif |
| } |
| } |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| /* |
| * In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the |
| * rebalancing for all the cpus for whom scheduler ticks are stopped. |
| */ |
| static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) |
| { |
| int this_cpu = this_rq->cpu; |
| struct rq *rq; |
| struct sched_domain *sd; |
| int balance_cpu; |
| /* Earliest time when we have to do rebalance again */ |
| unsigned long next_balance = jiffies + 60*HZ; |
| int update_next_balance = 0; |
| cpumask_t cpus; |
| if (idle != CPU_IDLE || |
| !test_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu))) |
| goto end; |
| |
| /* |
| * This cpu is going to update the blocked load of idle CPUs either |
| * before doing a rebalancing or just to keep metrics up to date. we |
| * can safely update the next update timestamp |
| */ |
| rcu_read_lock(); |
| sd = rcu_dereference(this_rq->sd); |
| /* |
| * Check whether there is a sched_domain available for this cpu. |
| * The last other cpu can have been unplugged since the ILB has been |
| * triggered and the sched_domain can now be null. The idle balance |
| * sequence will quickly be aborted as there is no more idle CPUs |
| */ |
| if (sd) |
| nohz.next_update = jiffies + msecs_to_jiffies(LOAD_AVG_PERIOD); |
| rcu_read_unlock(); |
| |
| cpumask_andnot(&cpus, nohz.idle_cpus_mask, cpu_isolated_mask); |
| for_each_cpu(balance_cpu, &cpus) { |
| if (balance_cpu == this_cpu || !idle_cpu(balance_cpu)) |
| continue; |
| |
| /* |
| * If this cpu gets work to do, stop the load balancing |
| * work being done for other cpus. Next load |
| * balancing owner will pick it up. |
| */ |
| if (need_resched()) |
| break; |
| |
| rq = cpu_rq(balance_cpu); |
| |
| /* |
| * If time for next balance is due, |
| * do the balance. |
| */ |
| if (time_after_eq(jiffies, rq->next_balance)) { |
| struct rq_flags rf; |
| |
| rq_lock_irq(rq, &rf); |
| update_rq_clock(rq); |
| cpu_load_update_idle(rq); |
| rq_unlock_irq(rq, &rf); |
| |
| update_blocked_averages(balance_cpu); |
| /* |
| * This idle load balance softirq may have been |
| * triggered only to update the blocked load and shares |
| * of idle CPUs (which we have just done for |
| * balance_cpu). In that case skip the actual balance. |
| */ |
| if (!test_bit(NOHZ_STATS_KICK, nohz_flags(this_cpu))) |
| rebalance_domains(rq, idle); |
| } |
| |
| if (time_after(next_balance, rq->next_balance)) { |
| next_balance = rq->next_balance; |
| update_next_balance = 1; |
| } |
| } |
| |
| /* |
| * next_balance will be updated only when there is a need. |
| * When the CPU is attached to null domain for ex, it will not be |
| * updated. |
| */ |
| if (likely(update_next_balance)) |
| nohz.next_balance = next_balance; |
| end: |
| clear_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu)); |
| } |
| |
| /* |
| * Current heuristic for kicking the idle load balancer in the presence |
| * of an idle cpu in the system. |
| * - This rq has more than one task. |
| * - This rq has at least one CFS task and the capacity of the CPU is |
| * significantly reduced because of RT tasks or IRQs. |
| * - At parent of LLC scheduler domain level, this cpu's scheduler group has |
| * multiple busy cpu. |
| * - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler |
| * domain span are idle. |
| */ |
| static inline bool nohz_kick_needed(struct rq *rq, bool only_update) |
| { |
| unsigned long now = jiffies; |
| struct sched_domain_shared *sds; |
| struct sched_domain *sd; |
| int nr_busy, i, cpu = rq->cpu; |
| bool kick = false; |
| |
| if (unlikely(rq->idle_balance) && !only_update) |
| return false; |
| |
| /* |
| * We may be recently in ticked or tickless idle mode. At the first |
| * busy tick after returning from idle, we will update the busy stats. |
| */ |
| set_cpu_sd_state_busy(); |
| nohz_balance_exit_idle(cpu); |
| |
| /* |
| * None are in tickless mode and hence no need for NOHZ idle load |
| * balancing. |
| */ |
| if (likely(!atomic_read(&nohz.nr_cpus))) |
| return false; |
| |
| if (only_update) { |
| if (time_before(now, nohz.next_update)) |
| return false; |
| else |
| return true; |
| } |
| |
| if (time_before(now, nohz.next_balance)) |
| return false; |
| |
| #if !defined(CONFIG_MTK_LOAD_BALANCE_ENHANCEMENT) && defined(CONFIG_HMP) |
| /* for more than two clusters, |
| * we still need wakup nohz CPUs and force balancing |
| * |
| * Bail out if there are no nohz CPUs in our |
| * HMP domain, since we will move tasks between |
| * domains through wakeup and force balancing |
| * as necessary based upon task load. |
| */ |
| if (sched_feat(SCHED_HMP) && cpumask_first_and(nohz.idle_cpus_mask, |
| &(hmp_cpu_domain(cpu))->cpus) >= nr_cpu_ids) |
| return false; |
| #endif |
| |
| if (rq->nr_running >= 2 && |
| (!energy_aware() || cpu_overutilized(cpu))) |
| return true; |
| |
| /* Do idle load balance if there have misfit task */ |
| if (energy_aware()) |
| return rq->misfit_task_load; |
| |
| rcu_read_lock(); |
| sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); |
| if (sds && !energy_aware()) { |
| /* |
| * XXX: write a coherent comment on why we do this. |
| * See also: http://lkml.kernel.org/r/20111202010832.602203411@sbsiddha-desk.sc.intel.com |
| */ |
| nr_busy = atomic_read(&sds->nr_busy_cpus); |
| if (nr_busy > 1) { |
| kick = true; |
| goto unlock; |
| } |
| |
| } |
| |
| sd = rcu_dereference(rq->sd); |
| if (sd) { |
| if ((rq->cfs.h_nr_running >= 1) && |
| check_cpu_capacity(rq, sd)) { |
| kick = true; |
| goto unlock; |
| } |
| } |
| |
| sd = rcu_dereference(per_cpu(sd_asym, cpu)); |
| if (sd) { |
| for_each_cpu(i, sched_domain_span(sd)) { |
| if (i == cpu || |
| !cpumask_test_cpu(i, nohz.idle_cpus_mask)) |
| continue; |
| |
| if (sched_asym_prefer(i, cpu)) { |
| kick = true; |
| goto unlock; |
| } |
| } |
| } |
| unlock: |
| rcu_read_unlock(); |
| return kick; |
| } |
| #else |
| static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) { } |
| static inline bool nohz_kick_needed(struct rq *rq, bool only_update) { return false; } |
| #endif |
| |
| /* |
| * run_rebalance_domains is triggered when needed from the scheduler tick. |
| * Also triggered for nohz idle balancing (with nohz_balancing_kick set). |
| */ |
| static __latent_entropy void run_rebalance_domains(struct softirq_action *h) |
| { |
| struct rq *this_rq = this_rq(); |
| enum cpu_idle_type idle = this_rq->idle_balance ? |
| CPU_IDLE : CPU_NOT_IDLE; |
| int this_cpu = cpu_of(this_rq); |
| |
| /* bypass load balance of HMP if EAS consideration */ |
| if (should_hmp(this_cpu)) |
| hmp_force_up_migration(this_cpu); |
| |
| /* |
| * If this cpu has a pending nohz_balance_kick, then do the |
| * balancing on behalf of the other idle cpus whose ticks are |
| * stopped. Do nohz_idle_balance *before* rebalance_domains to |
| * give the idle cpus a chance to load balance. Else we may |
| * load balance only within the local sched_domain hierarchy |
| * and abort nohz_idle_balance altogether if we pull some load. |
| */ |
| nohz_idle_balance(this_rq, idle); |
| update_blocked_averages(this_rq->cpu); |
| #ifdef CONFIG_NO_HZ_COMMON |
| if (!test_bit(NOHZ_STATS_KICK, nohz_flags(this_rq->cpu))) |
| rebalance_domains(this_rq, idle); |
| clear_bit(NOHZ_STATS_KICK, nohz_flags(this_rq->cpu)); |
| #else |
| rebalance_domains(this_rq, idle); |
| #endif |
| } |
| |
| /* |
| * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing. |
| */ |
| void trigger_load_balance(struct rq *rq) |
| { |
| /* Don't need to rebalance while attached to NULL domain |
| * or cpu is isolated. |
| */ |
| if (unlikely(on_null_domain(rq)) || cpu_isolated(cpu_of(rq))) |
| return; |
| |
| if (time_after_eq(jiffies, rq->next_balance)) |
| raise_softirq(SCHED_SOFTIRQ); |
| #ifdef CONFIG_NO_HZ_COMMON |
| if (nohz_kick_needed(rq, false)) |
| nohz_balancer_kick(false); |
| #endif |
| } |
| |
| static void rq_online_fair(struct rq *rq) |
| { |
| if (sched_feat(SCHED_HMP)) |
| hmp_online_cpu(rq->cpu); |
| |
| update_sysctl(); |
| |
| update_runtime_enabled(rq); |
| } |
| |
| static void rq_offline_fair(struct rq *rq) |
| { |
| if (sched_feat(SCHED_HMP)) |
| hmp_offline_cpu(rq->cpu); |
| |
| update_sysctl(); |
| |
| /* Ensure any throttled groups are reachable by pick_next_task */ |
| unthrottle_offline_cfs_rqs(rq); |
| } |
| |
| #if defined (CONFIG_SCHED_WALT) && defined (OPLUS_FEATURE_UIFIRST) |
| bool ux_task_misfit(struct task_struct *p, int cpu) |
| { |
| int num_mincpu = cpumask_weight(topology_core_cpumask(0)); |
| if ((scale_demand(p->ravg.sum) >= sysctl_boost_task_threshold || |
| scale_demand(p->ravg.demand) >= sysctl_boost_task_threshold) && cpu < num_mincpu) |
| return true; |
| |
| return false; |
| } |
| #endif |
| |
| static DEFINE_RAW_SPINLOCK(migration_lock); |
| void check_for_migration(struct rq *rq, struct task_struct *p) |
| { |
| int new_cpu; |
| int cpu = task_cpu(p); |
| int force = 0; |
| int i, heavy_task = 0; |
| struct task_rotate_reset_uclamp_work *wr = NULL; |
| |
| for_each_possible_cpu(i) { |
| struct rq *rq = cpu_rq(i); |
| struct task_struct *curr_task = rq->curr; |
| |
| if (curr_task && |
| !task_fits_capacity(curr_task, capacity_of(i))) |
| heavy_task += 1; |
| } |
| |
| if (heavy_task < HEAVY_TASK_NUM && set_uclamp) { |
| wr = &task_rotate_reset_uclamp_works; |
| if (wr) { |
| queue_work_on(cpu, system_highpri_wq, &wr->w); |
| } |
| } |
| |
| #if defined (CONFIG_SCHED_WALT) && defined (OPLUS_FEATURE_UIFIRST) |
| if (rq->misfit_task_load || (sysctl_uifirst_enabled && sysctl_slide_boost_enabled && |
| p->static_ux == 2 && ux_task_misfit(p, cpu))) { |
| #else |
| if (rq->misfit_task_load) { |
| #endif |
| if (rq->curr->state != TASK_RUNNING || |
| rq->curr->nr_cpus_allowed == 1) |
| return; |
| |
| raw_spin_lock(&migration_lock); |
| rcu_read_lock(); |
| new_cpu = select_task_rq_fair(p, cpu, SD_BALANCE_WAKE, 0, 1); |
| rcu_read_unlock(); |
| if (capacity_orig_of(new_cpu) > capacity_orig_of(cpu) && |
| !should_hmp(cpu)) { |
| #if defined(CONFIG_SCHED_HMP) || defined(CONFIG_MTK_IDLE_BALANCE_ENHANCEMENT) |
| raw_spin_unlock(&migration_lock); |
| get_task_struct(p); |
| force = migrate_running_task(new_cpu, p, rq); |
| put_task_struct(p); |
| return; |
| #endif |
| } else if (capacity_orig_of(new_cpu) <= capacity_orig_of(cpu)) |
| task_check_for_rotation(rq); |
| raw_spin_unlock(&migration_lock); |
| } |
| } |
| |
| #endif /* CONFIG_SMP */ |
| |
| /* |
| * scheduler tick hitting a task of our scheduling class: |
| */ |
| static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) |
| { |
| struct cfs_rq *cfs_rq; |
| struct sched_entity *se = &curr->se; |
| |
| for_each_sched_entity(se) { |
| cfs_rq = cfs_rq_of(se); |
| entity_tick(cfs_rq, se, queued); |
| } |
| |
| if (static_branch_unlikely(&sched_numa_balancing)) |
| task_tick_numa(rq, curr); |
| |
| update_misfit_status(curr, rq); |
| |
| update_overutilized_status(rq); |
| } |
| |
| /* |
| * called on fork with the child task as argument from the parent's context |
| * - child not yet on the tasklist |
| * - preemption disabled |
| */ |
| static void task_fork_fair(struct task_struct *p) |
| { |
| struct cfs_rq *cfs_rq; |
| struct sched_entity *se = &p->se, *curr; |
| struct rq *rq = this_rq(); |
| struct rq_flags rf; |
| |
| rq_lock(rq, &rf); |
| update_rq_clock(rq); |
| |
| cfs_rq = task_cfs_rq(current); |
| curr = cfs_rq->curr; |
| if (curr) { |
| update_curr(cfs_rq); |
| se->vruntime = curr->vruntime; |
| } |
| place_entity(cfs_rq, se, 1); |
| |
| if (sysctl_sched_child_runs_first && curr && entity_before(curr, se)) { |
| /* |
| * Upon rescheduling, sched_class::put_prev_task() will place |
| * 'current' within the tree based on its new key value. |
| */ |
| swap(curr->vruntime, se->vruntime); |
| resched_curr(rq); |
| } |
| |
| se->vruntime -= cfs_rq->min_vruntime; |
| rq_unlock(rq, &rf); |
| } |
| |
| /* |
| * Priority of the task has changed. Check to see if we preempt |
| * the current task. |
| */ |
| static void |
| prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio) |
| { |
| if (!task_on_rq_queued(p)) |
| return; |
| |
| /* |
| * Reschedule if we are currently running on this runqueue and |
| * our priority decreased, or if we are not currently running on |
| * this runqueue and our priority is higher than the current's |
| */ |
| if (rq->curr == p) { |
| if (p->prio > oldprio) |
| resched_curr(rq); |
| } else |
| check_preempt_curr(rq, p, 0); |
| } |
| |
| static inline bool vruntime_normalized(struct task_struct *p) |
| { |
| struct sched_entity *se = &p->se; |
| |
| /* |
| * In both the TASK_ON_RQ_QUEUED and TASK_ON_RQ_MIGRATING cases, |
| * the dequeue_entity(.flags=0) will already have normalized the |
| * vruntime. |
| */ |
| if (p->on_rq) |
| return true; |
| |
| /* |
| * When !on_rq, vruntime of the task has usually NOT been normalized. |
| * But there are some cases where it has already been normalized: |
| * |
| * - A forked child which is waiting for being woken up by |
| * wake_up_new_task(). |
| * - A task which has been woken up by try_to_wake_up() and |
| * waiting for actually being woken up by sched_ttwu_pending(). |
| */ |
| if (!se->sum_exec_runtime || |
| (p->state == TASK_WAKING && p->sched_remote_wakeup)) |
| return true; |
| |
| return false; |
| } |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| /* |
| * Propagate the changes of the sched_entity across the tg tree to make it |
| * visible to the root |
| */ |
| static void propagate_entity_cfs_rq(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq; |
| |
| /* Start to propagate at parent */ |
| se = se->parent; |
| |
| for_each_sched_entity(se) { |
| cfs_rq = cfs_rq_of(se); |
| |
| if (cfs_rq_throttled(cfs_rq)) |
| break; |
| |
| update_load_avg(se, UPDATE_TG); |
| } |
| } |
| #else |
| static void propagate_entity_cfs_rq(struct sched_entity *se) { } |
| #endif |
| |
| static void detach_entity_cfs_rq(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| |
| /* Catch up with the cfs_rq and remove our load when we leave */ |
| update_load_avg(se, 0); |
| detach_entity_load_avg(cfs_rq, se); |
| update_tg_load_avg(cfs_rq, false); |
| propagate_entity_cfs_rq(se); |
| } |
| |
| static void attach_entity_cfs_rq(struct sched_entity *se) |
| { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| /* |
| * Since the real-depth could have been changed (only FAIR |
| * class maintain depth value), reset depth properly. |
| */ |
| se->depth = se->parent ? se->parent->depth + 1 : 0; |
| #endif |
| |
| /* Synchronize entity with its cfs_rq */ |
| update_load_avg(se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD); |
| attach_entity_load_avg(cfs_rq, se); |
| update_tg_load_avg(cfs_rq, false); |
| propagate_entity_cfs_rq(se); |
| } |
| |
| static void detach_task_cfs_rq(struct task_struct *p) |
| { |
| struct sched_entity *se = &p->se; |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| |
| if (!vruntime_normalized(p)) { |
| /* |
| * Fix up our vruntime so that the current sleep doesn't |
| * cause 'unlimited' sleep bonus. |
| */ |
| place_entity(cfs_rq, se, 0); |
| se->vruntime -= cfs_rq->min_vruntime; |
| } |
| |
| detach_entity_cfs_rq(se); |
| } |
| |
| static void attach_task_cfs_rq(struct task_struct *p) |
| { |
| struct sched_entity *se = &p->se; |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| |
| attach_entity_cfs_rq(se); |
| |
| if (!vruntime_normalized(p)) |
| se->vruntime += cfs_rq->min_vruntime; |
| } |
| |
| static void switched_from_fair(struct rq *rq, struct task_struct *p) |
| { |
| detach_task_cfs_rq(p); |
| } |
| |
| static void switched_to_fair(struct rq *rq, struct task_struct *p) |
| { |
| attach_task_cfs_rq(p); |
| |
| if (task_on_rq_queued(p)) { |
| /* |
| * We were most likely switched from sched_rt, so |
| * kick off the schedule if running, otherwise just see |
| * if we can still preempt the current task. |
| */ |
| if (rq->curr == p) |
| resched_curr(rq); |
| else |
| check_preempt_curr(rq, p, 0); |
| } |
| } |
| |
| /* Account for a task changing its policy or group. |
| * |
| * This routine is mostly called to set cfs_rq->curr field when a task |
| * migrates between groups/classes. |
| */ |
| static void set_curr_task_fair(struct rq *rq) |
| { |
| struct sched_entity *se = &rq->curr->se; |
| |
| for_each_sched_entity(se) { |
| struct cfs_rq *cfs_rq = cfs_rq_of(se); |
| |
| set_next_entity(cfs_rq, se); |
| /* ensure bandwidth has been allocated on our new cfs_rq */ |
| account_cfs_rq_runtime(cfs_rq, 0); |
| } |
| } |
| |
| void init_cfs_rq(struct cfs_rq *cfs_rq) |
| { |
| cfs_rq->tasks_timeline = RB_ROOT_CACHED; |
| cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
| #ifndef CONFIG_64BIT |
| cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; |
| #endif |
| #ifdef CONFIG_SMP |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| cfs_rq->propagate_avg = 0; |
| #endif |
| atomic_long_set(&cfs_rq->removed_load_avg, 0); |
| atomic_long_set(&cfs_rq->removed_util_avg, 0); |
| #endif |
| } |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| static void task_set_group_fair(struct task_struct *p) |
| { |
| struct sched_entity *se = &p->se; |
| |
| set_task_rq(p, task_cpu(p)); |
| se->depth = se->parent ? se->parent->depth + 1 : 0; |
| } |
| |
| static void task_move_group_fair(struct task_struct *p) |
| { |
| detach_task_cfs_rq(p); |
| set_task_rq(p, task_cpu(p)); |
| |
| #ifdef CONFIG_SMP |
| /* Tell se's cfs_rq has been changed -- migrated */ |
| p->se.avg.last_update_time = 0; |
| #endif |
| attach_task_cfs_rq(p); |
| } |
| |
| static void task_change_group_fair(struct task_struct *p, int type) |
| { |
| switch (type) { |
| case TASK_SET_GROUP: |
| task_set_group_fair(p); |
| break; |
| |
| case TASK_MOVE_GROUP: |
| task_move_group_fair(p); |
| break; |
| } |
| } |
| |
| void free_fair_sched_group(struct task_group *tg) |
| { |
| int i; |
| |
| destroy_cfs_bandwidth(tg_cfs_bandwidth(tg)); |
| |
| for_each_possible_cpu(i) { |
| if (tg->cfs_rq) |
| kfree(tg->cfs_rq[i]); |
| if (tg->se) |
| kfree(tg->se[i]); |
| } |
| |
| kfree(tg->cfs_rq); |
| kfree(tg->se); |
| } |
| |
| int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) |
| { |
| struct sched_entity *se; |
| struct cfs_rq *cfs_rq; |
| int i; |
| |
| tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
| if (!tg->cfs_rq) |
| goto err; |
| tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
| if (!tg->se) |
| goto err; |
| |
| tg->shares = NICE_0_LOAD; |
| |
| init_cfs_bandwidth(tg_cfs_bandwidth(tg)); |
| |
| for_each_possible_cpu(i) { |
| cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
| GFP_KERNEL, cpu_to_node(i)); |
| if (!cfs_rq) |
| goto err; |
| |
| se = kzalloc_node(sizeof(struct sched_entity), |
| GFP_KERNEL, cpu_to_node(i)); |
| if (!se) |
| goto err_free_rq; |
| |
| init_cfs_rq(cfs_rq); |
| init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]); |
| init_entity_runnable_average(se); |
| } |
| |
| return 1; |
| |
| err_free_rq: |
| kfree(cfs_rq); |
| err: |
| return 0; |
| } |
| |
| void online_fair_sched_group(struct task_group *tg) |
| { |
| struct sched_entity *se; |
| struct rq_flags rf; |
| struct rq *rq; |
| int i; |
| |
| for_each_possible_cpu(i) { |
| rq = cpu_rq(i); |
| se = tg->se[i]; |
| rq_lock_irq(rq, &rf); |
| update_rq_clock(rq); |
| attach_entity_cfs_rq(se); |
| sync_throttle(tg, i); |
| rq_unlock_irq(rq, &rf); |
| } |
| } |
| |
| void unregister_fair_sched_group(struct task_group *tg) |
| { |
| unsigned long flags; |
| struct rq *rq; |
| int cpu; |
| |
| for_each_possible_cpu(cpu) { |
| if (tg->se[cpu]) |
| remove_entity_load_avg(tg->se[cpu]); |
| |
| /* |
| * Only empty task groups can be destroyed; so we can speculatively |
| * check on_list without danger of it being re-added. |
| */ |
| if (!tg->cfs_rq[cpu]->on_list) |
| continue; |
| |
| rq = cpu_rq(cpu); |
| |
| raw_spin_lock_irqsave(&rq->lock, flags); |
| list_del_leaf_cfs_rq(tg->cfs_rq[cpu]); |
| raw_spin_unlock_irqrestore(&rq->lock, flags); |
| } |
| } |
| |
| void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
| struct sched_entity *se, int cpu, |
| struct sched_entity *parent) |
| { |
| struct rq *rq = cpu_rq(cpu); |
| |
| cfs_rq->tg = tg; |
| cfs_rq->rq = rq; |
| init_cfs_rq_runtime(cfs_rq); |
| |
| tg->cfs_rq[cpu] = cfs_rq; |
| tg->se[cpu] = se; |
| |
| /* se could be NULL for root_task_group */ |
| if (!se) |
| return; |
| |
| if (!parent) { |
| se->cfs_rq = &rq->cfs; |
| se->depth = 0; |
| } else { |
| se->cfs_rq = parent->my_q; |
| se->depth = parent->depth + 1; |
| } |
| |
| se->my_q = cfs_rq; |
| /* guarantee group entities always have weight */ |
| update_load_set(&se->load, NICE_0_LOAD); |
| se->parent = parent; |
| } |
| |
| static DEFINE_MUTEX(shares_mutex); |
| |
| int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
| { |
| int i; |
| |
| /* |
| * We can't change the weight of the root cgroup. |
| */ |
| if (!tg->se[0]) |
| return -EINVAL; |
| |
| shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); |
| |
| mutex_lock(&shares_mutex); |
| if (tg->shares == shares) |
| goto done; |
| |
| tg->shares = shares; |
| for_each_possible_cpu(i) { |
| struct rq *rq = cpu_rq(i); |
| struct sched_entity *se = tg->se[i]; |
| struct rq_flags rf; |
| |
| /* Propagate contribution to hierarchy */ |
| rq_lock_irqsave(rq, &rf); |
| update_rq_clock(rq); |
| for_each_sched_entity(se) { |
| update_load_avg(se, UPDATE_TG); |
| update_cfs_shares(se); |
| } |
| rq_unlock_irqrestore(rq, &rf); |
| } |
| |
| done: |
| mutex_unlock(&shares_mutex); |
| return 0; |
| } |
| #else /* CONFIG_FAIR_GROUP_SCHED */ |
| |
| void free_fair_sched_group(struct task_group *tg) { } |
| |
| int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) |
| { |
| return 1; |
| } |
| |
| void online_fair_sched_group(struct task_group *tg) { } |
| |
| void unregister_fair_sched_group(struct task_group *tg) { } |
| |
| #endif /* CONFIG_FAIR_GROUP_SCHED */ |
| |
| |
| static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task) |
| { |
| struct sched_entity *se = &task->se; |
| unsigned int rr_interval = 0; |
| |
| /* |
| * Time slice is 0 for SCHED_OTHER tasks that are on an otherwise |
| * idle runqueue: |
| */ |
| if (rq->cfs.load.weight) |
| rr_interval = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se)); |
| |
| return rr_interval; |
| } |
| |
| /* |
| * All the scheduling class methods: |
| */ |
| const struct sched_class fair_sched_class = { |
| .next = &idle_sched_class, |
| .enqueue_task = enqueue_task_fair, |
| .dequeue_task = dequeue_task_fair, |
| .yield_task = yield_task_fair, |
| .yield_to_task = yield_to_task_fair, |
| |
| .check_preempt_curr = check_preempt_wakeup, |
| |
| .pick_next_task = pick_next_task_fair, |
| .put_prev_task = put_prev_task_fair, |
| |
| #ifdef CONFIG_SMP |
| .select_task_rq = select_task_rq_fair, |
| .migrate_task_rq = migrate_task_rq_fair, |
| |
| .rq_online = rq_online_fair, |
| .rq_offline = rq_offline_fair, |
| |
| .task_dead = task_dead_fair, |
| .set_cpus_allowed = set_cpus_allowed_common, |
| #endif |
| |
| .set_curr_task = set_curr_task_fair, |
| .task_tick = task_tick_fair, |
| .task_fork = task_fork_fair, |
| |
| .prio_changed = prio_changed_fair, |
| .switched_from = switched_from_fair, |
| .switched_to = switched_to_fair, |
| |
| .get_rr_interval = get_rr_interval_fair, |
| |
| .update_curr = update_curr_fair, |
| |
| #ifdef CONFIG_FAIR_GROUP_SCHED |
| .task_change_group = task_change_group_fair, |
| #endif |
| |
| #ifdef CONFIG_UCLAMP_TASK |
| .uclamp_enabled = 1, |
| #endif |
| |
| #ifdef CONFIG_SCHED_WALT |
| .fixup_cumulative_runnable_avg = |
| walt_fixup_cumulative_runnable_avg_fair, |
| #endif |
| }; |
| |
| #ifdef CONFIG_SCHED_DEBUG |
| void print_cfs_stats(struct seq_file *m, int cpu) |
| { |
| struct cfs_rq *cfs_rq; |
| |
| rcu_read_lock(); |
| for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq) |
| print_cfs_rq(m, cpu, cfs_rq); |
| rcu_read_unlock(); |
| } |
| |
| #ifdef CONFIG_NUMA_BALANCING |
| void show_numa_stats(struct task_struct *p, struct seq_file *m) |
| { |
| int node; |
| unsigned long tsf = 0, tpf = 0, gsf = 0, gpf = 0; |
| |
| for_each_online_node(node) { |
| if (p->numa_faults) { |
| tsf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 0)]; |
| tpf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 1)]; |
| } |
| if (p->numa_group) { |
| gsf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 0)], |
| gpf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 1)]; |
| } |
| print_numa_stats(m, node, tsf, tpf, gsf, gpf); |
| } |
| } |
| #endif /* CONFIG_NUMA_BALANCING */ |
| #endif /* CONFIG_SCHED_DEBUG */ |
| |
| __init void init_sched_fair_class(void) |
| { |
| #ifdef CONFIG_SMP |
| open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
| |
| #ifdef CONFIG_NO_HZ_COMMON |
| nohz.next_balance = jiffies; |
| nohz.next_update = jiffies; |
| zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); |
| #endif |
| |
| alloc_eenv(); |
| #endif /* SMP */ |
| |
| arch_build_cpu_topology_domain(); |
| } |
| #include "eas_plus.c" |
| #include "hmp.c" |