Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 1 | /* |
| 2 | * CPUFreq governor based on scheduler-provided CPU utilization data. |
| 3 | * |
| 4 | * Copyright (C) 2016, Intel Corporation |
| 5 | * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | |
Viresh Kumar | 60f05e8 | 2016-05-18 17:55:28 +0530 | [diff] [blame] | 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 13 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 14 | #include <linux/cpufreq.h> |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 15 | #include <linux/kthread.h> |
Ingo Molnar | ae7e81c | 2017-02-01 18:07:51 +0100 | [diff] [blame] | 16 | #include <uapi/linux/sched/types.h> |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 17 | #include <linux/slab.h> |
| 18 | #include <trace/events/power.h> |
| 19 | |
| 20 | #include "sched.h" |
| 21 | |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 22 | #define SUGOV_KTHREAD_PRIORITY 50 |
| 23 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 24 | struct sugov_tunables { |
| 25 | struct gov_attr_set attr_set; |
| 26 | unsigned int rate_limit_us; |
| 27 | }; |
| 28 | |
| 29 | struct sugov_policy { |
| 30 | struct cpufreq_policy *policy; |
| 31 | |
| 32 | struct sugov_tunables *tunables; |
| 33 | struct list_head tunables_hook; |
| 34 | |
| 35 | raw_spinlock_t update_lock; /* For shared policies */ |
| 36 | u64 last_freq_update_time; |
| 37 | s64 freq_update_delay_ns; |
| 38 | unsigned int next_freq; |
Viresh Kumar | 6c4f0fa | 2017-03-02 14:03:20 +0530 | [diff] [blame] | 39 | unsigned int cached_raw_freq; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 40 | |
| 41 | /* The next fields are only needed if fast switch cannot be used. */ |
| 42 | struct irq_work irq_work; |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 43 | struct kthread_work work; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 44 | struct mutex work_lock; |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 45 | struct kthread_worker worker; |
| 46 | struct task_struct *thread; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 47 | bool work_in_progress; |
| 48 | |
| 49 | bool need_freq_update; |
| 50 | }; |
| 51 | |
| 52 | struct sugov_cpu { |
| 53 | struct update_util_data update_util; |
| 54 | struct sugov_policy *sg_policy; |
| 55 | |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 56 | unsigned long iowait_boost; |
| 57 | unsigned long iowait_boost_max; |
| 58 | u64 last_update; |
Steve Muckle | 5cbea46 | 2016-07-13 13:25:26 -0700 | [diff] [blame] | 59 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 60 | /* The fields below are only needed when sharing a policy. */ |
| 61 | unsigned long util; |
| 62 | unsigned long max; |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 63 | unsigned int flags; |
Rafael J. Wysocki | b7eaf1a | 2017-03-22 00:08:50 +0100 | [diff] [blame] | 64 | |
| 65 | /* The field below is for single-CPU policies only. */ |
| 66 | #ifdef CONFIG_NO_HZ_COMMON |
| 67 | unsigned long saved_idle_calls; |
| 68 | #endif |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 69 | }; |
| 70 | |
| 71 | static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu); |
| 72 | |
| 73 | /************************ Governor internals ***********************/ |
| 74 | |
| 75 | static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time) |
| 76 | { |
| 77 | s64 delta_ns; |
| 78 | |
| 79 | if (sg_policy->work_in_progress) |
| 80 | return false; |
| 81 | |
| 82 | if (unlikely(sg_policy->need_freq_update)) { |
| 83 | sg_policy->need_freq_update = false; |
| 84 | /* |
| 85 | * This happens when limits change, so forget the previous |
| 86 | * next_freq value and force an update. |
| 87 | */ |
| 88 | sg_policy->next_freq = UINT_MAX; |
| 89 | return true; |
| 90 | } |
| 91 | |
| 92 | delta_ns = time - sg_policy->last_freq_update_time; |
| 93 | return delta_ns >= sg_policy->freq_update_delay_ns; |
| 94 | } |
| 95 | |
| 96 | static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time, |
| 97 | unsigned int next_freq) |
| 98 | { |
| 99 | struct cpufreq_policy *policy = sg_policy->policy; |
| 100 | |
Rafael J. Wysocki | 38d4ea2 | 2017-03-22 18:32:47 +0100 | [diff] [blame] | 101 | if (sg_policy->next_freq == next_freq) |
| 102 | return; |
| 103 | |
| 104 | sg_policy->next_freq = next_freq; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 105 | sg_policy->last_freq_update_time = time; |
| 106 | |
| 107 | if (policy->fast_switch_enabled) { |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 108 | next_freq = cpufreq_driver_fast_switch(policy, next_freq); |
| 109 | if (next_freq == CPUFREQ_ENTRY_INVALID) |
| 110 | return; |
| 111 | |
| 112 | policy->cur = next_freq; |
| 113 | trace_cpu_frequency(next_freq, smp_processor_id()); |
Rafael J. Wysocki | 38d4ea2 | 2017-03-22 18:32:47 +0100 | [diff] [blame] | 114 | } else { |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 115 | sg_policy->work_in_progress = true; |
| 116 | irq_work_queue(&sg_policy->irq_work); |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * get_next_freq - Compute a new frequency for a given cpufreq policy. |
Viresh Kumar | 655cb1e | 2017-03-02 14:03:21 +0530 | [diff] [blame] | 122 | * @sg_policy: schedutil policy object to compute the new frequency for. |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 123 | * @util: Current CPU utilization. |
| 124 | * @max: CPU capacity. |
| 125 | * |
| 126 | * If the utilization is frequency-invariant, choose the new frequency to be |
| 127 | * proportional to it, that is |
| 128 | * |
| 129 | * next_freq = C * max_freq * util / max |
| 130 | * |
| 131 | * Otherwise, approximate the would-be frequency-invariant utilization by |
| 132 | * util_raw * (curr_freq / max_freq) which leads to |
| 133 | * |
| 134 | * next_freq = C * curr_freq * util_raw / max |
| 135 | * |
| 136 | * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8. |
Steve Muckle | 5cbea46 | 2016-07-13 13:25:26 -0700 | [diff] [blame] | 137 | * |
| 138 | * The lowest driver-supported frequency which is equal or greater than the raw |
| 139 | * next_freq (as calculated above) is returned, subject to policy min/max and |
| 140 | * cpufreq driver limitations. |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 141 | */ |
Viresh Kumar | 655cb1e | 2017-03-02 14:03:21 +0530 | [diff] [blame] | 142 | static unsigned int get_next_freq(struct sugov_policy *sg_policy, |
| 143 | unsigned long util, unsigned long max) |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 144 | { |
Steve Muckle | 5cbea46 | 2016-07-13 13:25:26 -0700 | [diff] [blame] | 145 | struct cpufreq_policy *policy = sg_policy->policy; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 146 | unsigned int freq = arch_scale_freq_invariant() ? |
| 147 | policy->cpuinfo.max_freq : policy->cur; |
| 148 | |
Steve Muckle | 5cbea46 | 2016-07-13 13:25:26 -0700 | [diff] [blame] | 149 | freq = (freq + (freq >> 2)) * util / max; |
| 150 | |
Viresh Kumar | 6c4f0fa | 2017-03-02 14:03:20 +0530 | [diff] [blame] | 151 | if (freq == sg_policy->cached_raw_freq && sg_policy->next_freq != UINT_MAX) |
Steve Muckle | 5cbea46 | 2016-07-13 13:25:26 -0700 | [diff] [blame] | 152 | return sg_policy->next_freq; |
Viresh Kumar | 6c4f0fa | 2017-03-02 14:03:20 +0530 | [diff] [blame] | 153 | sg_policy->cached_raw_freq = freq; |
Steve Muckle | 5cbea46 | 2016-07-13 13:25:26 -0700 | [diff] [blame] | 154 | return cpufreq_driver_resolve_freq(policy, freq); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 155 | } |
| 156 | |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 157 | static void sugov_get_util(unsigned long *util, unsigned long *max) |
| 158 | { |
| 159 | struct rq *rq = this_rq(); |
Steve Muckle | 8314bc8 | 2016-08-26 11:40:47 -0700 | [diff] [blame] | 160 | unsigned long cfs_max; |
| 161 | |
| 162 | cfs_max = arch_scale_cpu_capacity(NULL, smp_processor_id()); |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 163 | |
| 164 | *util = min(rq->cfs.avg.util_avg, cfs_max); |
| 165 | *max = cfs_max; |
| 166 | } |
| 167 | |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 168 | static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, |
| 169 | unsigned int flags) |
| 170 | { |
| 171 | if (flags & SCHED_CPUFREQ_IOWAIT) { |
| 172 | sg_cpu->iowait_boost = sg_cpu->iowait_boost_max; |
| 173 | } else if (sg_cpu->iowait_boost) { |
| 174 | s64 delta_ns = time - sg_cpu->last_update; |
| 175 | |
| 176 | /* Clear iowait_boost if the CPU apprears to have been idle. */ |
| 177 | if (delta_ns > TICK_NSEC) |
| 178 | sg_cpu->iowait_boost = 0; |
| 179 | } |
| 180 | } |
| 181 | |
| 182 | static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, unsigned long *util, |
| 183 | unsigned long *max) |
| 184 | { |
| 185 | unsigned long boost_util = sg_cpu->iowait_boost; |
| 186 | unsigned long boost_max = sg_cpu->iowait_boost_max; |
| 187 | |
| 188 | if (!boost_util) |
| 189 | return; |
| 190 | |
| 191 | if (*util * boost_max < *max * boost_util) { |
| 192 | *util = boost_util; |
| 193 | *max = boost_max; |
| 194 | } |
| 195 | sg_cpu->iowait_boost >>= 1; |
| 196 | } |
| 197 | |
Rafael J. Wysocki | b7eaf1a | 2017-03-22 00:08:50 +0100 | [diff] [blame] | 198 | #ifdef CONFIG_NO_HZ_COMMON |
| 199 | static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) |
| 200 | { |
| 201 | unsigned long idle_calls = tick_nohz_get_idle_calls(); |
| 202 | bool ret = idle_calls == sg_cpu->saved_idle_calls; |
| 203 | |
| 204 | sg_cpu->saved_idle_calls = idle_calls; |
| 205 | return ret; |
| 206 | } |
| 207 | #else |
| 208 | static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } |
| 209 | #endif /* CONFIG_NO_HZ_COMMON */ |
| 210 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 211 | static void sugov_update_single(struct update_util_data *hook, u64 time, |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 212 | unsigned int flags) |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 213 | { |
| 214 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); |
| 215 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; |
| 216 | struct cpufreq_policy *policy = sg_policy->policy; |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 217 | unsigned long util, max; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 218 | unsigned int next_f; |
Rafael J. Wysocki | b7eaf1a | 2017-03-22 00:08:50 +0100 | [diff] [blame] | 219 | bool busy; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 220 | |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 221 | sugov_set_iowait_boost(sg_cpu, time, flags); |
| 222 | sg_cpu->last_update = time; |
| 223 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 224 | if (!sugov_should_update_freq(sg_policy, time)) |
| 225 | return; |
| 226 | |
Rafael J. Wysocki | b7eaf1a | 2017-03-22 00:08:50 +0100 | [diff] [blame] | 227 | busy = sugov_cpu_is_busy(sg_cpu); |
| 228 | |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 229 | if (flags & SCHED_CPUFREQ_RT_DL) { |
| 230 | next_f = policy->cpuinfo.max_freq; |
| 231 | } else { |
| 232 | sugov_get_util(&util, &max); |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 233 | sugov_iowait_boost(sg_cpu, &util, &max); |
Viresh Kumar | 655cb1e | 2017-03-02 14:03:21 +0530 | [diff] [blame] | 234 | next_f = get_next_freq(sg_policy, util, max); |
Rafael J. Wysocki | b7eaf1a | 2017-03-22 00:08:50 +0100 | [diff] [blame] | 235 | /* |
| 236 | * Do not reduce the frequency if the CPU has not been idle |
| 237 | * recently, as the reduction is likely to be premature then. |
| 238 | */ |
| 239 | if (busy && next_f < sg_policy->next_freq) |
| 240 | next_f = sg_policy->next_freq; |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 241 | } |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 242 | sugov_update_commit(sg_policy, time, next_f); |
| 243 | } |
| 244 | |
Juri Lelli | d86ab9c | 2017-05-03 14:30:48 +0100 | [diff] [blame] | 245 | static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 246 | { |
Steve Muckle | 5cbea46 | 2016-07-13 13:25:26 -0700 | [diff] [blame] | 247 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 248 | struct cpufreq_policy *policy = sg_policy->policy; |
Viresh Kumar | cba1dfb | 2017-03-09 09:34:54 +0530 | [diff] [blame] | 249 | unsigned long util = 0, max = 1; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 250 | unsigned int j; |
| 251 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 252 | for_each_cpu(j, policy->cpus) { |
Viresh Kumar | cba1dfb | 2017-03-09 09:34:54 +0530 | [diff] [blame] | 253 | struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 254 | unsigned long j_util, j_max; |
| 255 | s64 delta_ns; |
| 256 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 257 | /* |
| 258 | * If the CPU utilization was last updated before the previous |
| 259 | * frequency update and the time elapsed between the last update |
| 260 | * of the CPU utilization and the last frequency update is long |
| 261 | * enough, don't take the CPU into account as it probably is |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 262 | * idle now (and clear iowait_boost for it). |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 263 | */ |
Juri Lelli | d86ab9c | 2017-05-03 14:30:48 +0100 | [diff] [blame] | 264 | delta_ns = time - j_sg_cpu->last_update; |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 265 | if (delta_ns > TICK_NSEC) { |
| 266 | j_sg_cpu->iowait_boost = 0; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 267 | continue; |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 268 | } |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 269 | if (j_sg_cpu->flags & SCHED_CPUFREQ_RT_DL) |
Viresh Kumar | cba1dfb | 2017-03-09 09:34:54 +0530 | [diff] [blame] | 270 | return policy->cpuinfo.max_freq; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 271 | |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 272 | j_util = j_sg_cpu->util; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 273 | j_max = j_sg_cpu->max; |
| 274 | if (j_util * max > j_max * util) { |
| 275 | util = j_util; |
| 276 | max = j_max; |
| 277 | } |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 278 | |
| 279 | sugov_iowait_boost(j_sg_cpu, &util, &max); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 280 | } |
| 281 | |
Viresh Kumar | 655cb1e | 2017-03-02 14:03:21 +0530 | [diff] [blame] | 282 | return get_next_freq(sg_policy, util, max); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 283 | } |
| 284 | |
| 285 | static void sugov_update_shared(struct update_util_data *hook, u64 time, |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 286 | unsigned int flags) |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 287 | { |
| 288 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); |
| 289 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 290 | unsigned long util, max; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 291 | unsigned int next_f; |
| 292 | |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 293 | sugov_get_util(&util, &max); |
| 294 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 295 | raw_spin_lock(&sg_policy->update_lock); |
| 296 | |
| 297 | sg_cpu->util = util; |
| 298 | sg_cpu->max = max; |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 299 | sg_cpu->flags = flags; |
Rafael J. Wysocki | 21ca6d2 | 2016-09-10 00:00:31 +0200 | [diff] [blame] | 300 | |
| 301 | sugov_set_iowait_boost(sg_cpu, time, flags); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 302 | sg_cpu->last_update = time; |
| 303 | |
| 304 | if (sugov_should_update_freq(sg_policy, time)) { |
Viresh Kumar | cba1dfb | 2017-03-09 09:34:54 +0530 | [diff] [blame] | 305 | if (flags & SCHED_CPUFREQ_RT_DL) |
| 306 | next_f = sg_policy->policy->cpuinfo.max_freq; |
| 307 | else |
Juri Lelli | d86ab9c | 2017-05-03 14:30:48 +0100 | [diff] [blame] | 308 | next_f = sugov_next_freq_shared(sg_cpu, time); |
Viresh Kumar | cba1dfb | 2017-03-09 09:34:54 +0530 | [diff] [blame] | 309 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 310 | sugov_update_commit(sg_policy, time, next_f); |
| 311 | } |
| 312 | |
| 313 | raw_spin_unlock(&sg_policy->update_lock); |
| 314 | } |
| 315 | |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 316 | static void sugov_work(struct kthread_work *work) |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 317 | { |
| 318 | struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work); |
| 319 | |
| 320 | mutex_lock(&sg_policy->work_lock); |
| 321 | __cpufreq_driver_target(sg_policy->policy, sg_policy->next_freq, |
| 322 | CPUFREQ_RELATION_L); |
| 323 | mutex_unlock(&sg_policy->work_lock); |
| 324 | |
| 325 | sg_policy->work_in_progress = false; |
| 326 | } |
| 327 | |
| 328 | static void sugov_irq_work(struct irq_work *irq_work) |
| 329 | { |
| 330 | struct sugov_policy *sg_policy; |
| 331 | |
| 332 | sg_policy = container_of(irq_work, struct sugov_policy, irq_work); |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 333 | |
| 334 | /* |
Viresh Kumar | d06e622 | 2016-11-24 13:51:11 +0530 | [diff] [blame] | 335 | * For RT and deadline tasks, the schedutil governor shoots the |
| 336 | * frequency to maximum. Special care must be taken to ensure that this |
| 337 | * kthread doesn't result in the same behavior. |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 338 | * |
| 339 | * This is (mostly) guaranteed by the work_in_progress flag. The flag is |
Viresh Kumar | d06e622 | 2016-11-24 13:51:11 +0530 | [diff] [blame] | 340 | * updated only at the end of the sugov_work() function and before that |
| 341 | * the schedutil governor rejects all other frequency scaling requests. |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 342 | * |
Viresh Kumar | d06e622 | 2016-11-24 13:51:11 +0530 | [diff] [blame] | 343 | * There is a very rare case though, where the RT thread yields right |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 344 | * after the work_in_progress flag is cleared. The effects of that are |
| 345 | * neglected for now. |
| 346 | */ |
| 347 | kthread_queue_work(&sg_policy->worker, &sg_policy->work); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 348 | } |
| 349 | |
| 350 | /************************** sysfs interface ************************/ |
| 351 | |
| 352 | static struct sugov_tunables *global_tunables; |
| 353 | static DEFINE_MUTEX(global_tunables_lock); |
| 354 | |
| 355 | static inline struct sugov_tunables *to_sugov_tunables(struct gov_attr_set *attr_set) |
| 356 | { |
| 357 | return container_of(attr_set, struct sugov_tunables, attr_set); |
| 358 | } |
| 359 | |
| 360 | static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf) |
| 361 | { |
| 362 | struct sugov_tunables *tunables = to_sugov_tunables(attr_set); |
| 363 | |
| 364 | return sprintf(buf, "%u\n", tunables->rate_limit_us); |
| 365 | } |
| 366 | |
| 367 | static ssize_t rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, |
| 368 | size_t count) |
| 369 | { |
| 370 | struct sugov_tunables *tunables = to_sugov_tunables(attr_set); |
| 371 | struct sugov_policy *sg_policy; |
| 372 | unsigned int rate_limit_us; |
| 373 | |
| 374 | if (kstrtouint(buf, 10, &rate_limit_us)) |
| 375 | return -EINVAL; |
| 376 | |
| 377 | tunables->rate_limit_us = rate_limit_us; |
| 378 | |
| 379 | list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook) |
| 380 | sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC; |
| 381 | |
| 382 | return count; |
| 383 | } |
| 384 | |
| 385 | static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us); |
| 386 | |
| 387 | static struct attribute *sugov_attributes[] = { |
| 388 | &rate_limit_us.attr, |
| 389 | NULL |
| 390 | }; |
| 391 | |
| 392 | static struct kobj_type sugov_tunables_ktype = { |
| 393 | .default_attrs = sugov_attributes, |
| 394 | .sysfs_ops = &governor_sysfs_ops, |
| 395 | }; |
| 396 | |
| 397 | /********************** cpufreq governor interface *********************/ |
| 398 | |
| 399 | static struct cpufreq_governor schedutil_gov; |
| 400 | |
| 401 | static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy) |
| 402 | { |
| 403 | struct sugov_policy *sg_policy; |
| 404 | |
| 405 | sg_policy = kzalloc(sizeof(*sg_policy), GFP_KERNEL); |
| 406 | if (!sg_policy) |
| 407 | return NULL; |
| 408 | |
| 409 | sg_policy->policy = policy; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 410 | raw_spin_lock_init(&sg_policy->update_lock); |
| 411 | return sg_policy; |
| 412 | } |
| 413 | |
| 414 | static void sugov_policy_free(struct sugov_policy *sg_policy) |
| 415 | { |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 416 | kfree(sg_policy); |
| 417 | } |
| 418 | |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 419 | static int sugov_kthread_create(struct sugov_policy *sg_policy) |
| 420 | { |
| 421 | struct task_struct *thread; |
| 422 | struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO / 2 }; |
| 423 | struct cpufreq_policy *policy = sg_policy->policy; |
| 424 | int ret; |
| 425 | |
| 426 | /* kthread only required for slow path */ |
| 427 | if (policy->fast_switch_enabled) |
| 428 | return 0; |
| 429 | |
| 430 | kthread_init_work(&sg_policy->work, sugov_work); |
| 431 | kthread_init_worker(&sg_policy->worker); |
| 432 | thread = kthread_create(kthread_worker_fn, &sg_policy->worker, |
| 433 | "sugov:%d", |
| 434 | cpumask_first(policy->related_cpus)); |
| 435 | if (IS_ERR(thread)) { |
| 436 | pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread)); |
| 437 | return PTR_ERR(thread); |
| 438 | } |
| 439 | |
| 440 | ret = sched_setscheduler_nocheck(thread, SCHED_FIFO, ¶m); |
| 441 | if (ret) { |
| 442 | kthread_stop(thread); |
| 443 | pr_warn("%s: failed to set SCHED_FIFO\n", __func__); |
| 444 | return ret; |
| 445 | } |
| 446 | |
| 447 | sg_policy->thread = thread; |
| 448 | kthread_bind_mask(thread, policy->related_cpus); |
Viresh Kumar | 21ef572 | 2016-11-15 13:53:23 +0530 | [diff] [blame] | 449 | init_irq_work(&sg_policy->irq_work, sugov_irq_work); |
| 450 | mutex_init(&sg_policy->work_lock); |
| 451 | |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 452 | wake_up_process(thread); |
| 453 | |
| 454 | return 0; |
| 455 | } |
| 456 | |
| 457 | static void sugov_kthread_stop(struct sugov_policy *sg_policy) |
| 458 | { |
| 459 | /* kthread only required for slow path */ |
| 460 | if (sg_policy->policy->fast_switch_enabled) |
| 461 | return; |
| 462 | |
| 463 | kthread_flush_worker(&sg_policy->worker); |
| 464 | kthread_stop(sg_policy->thread); |
Viresh Kumar | 21ef572 | 2016-11-15 13:53:23 +0530 | [diff] [blame] | 465 | mutex_destroy(&sg_policy->work_lock); |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 466 | } |
| 467 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 468 | static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_policy) |
| 469 | { |
| 470 | struct sugov_tunables *tunables; |
| 471 | |
| 472 | tunables = kzalloc(sizeof(*tunables), GFP_KERNEL); |
| 473 | if (tunables) { |
| 474 | gov_attr_set_init(&tunables->attr_set, &sg_policy->tunables_hook); |
| 475 | if (!have_governor_per_policy()) |
| 476 | global_tunables = tunables; |
| 477 | } |
| 478 | return tunables; |
| 479 | } |
| 480 | |
| 481 | static void sugov_tunables_free(struct sugov_tunables *tunables) |
| 482 | { |
| 483 | if (!have_governor_per_policy()) |
| 484 | global_tunables = NULL; |
| 485 | |
| 486 | kfree(tunables); |
| 487 | } |
| 488 | |
| 489 | static int sugov_init(struct cpufreq_policy *policy) |
| 490 | { |
| 491 | struct sugov_policy *sg_policy; |
| 492 | struct sugov_tunables *tunables; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 493 | int ret = 0; |
| 494 | |
| 495 | /* State should be equivalent to EXIT */ |
| 496 | if (policy->governor_data) |
| 497 | return -EBUSY; |
| 498 | |
Viresh Kumar | 4a71ce4 | 2016-11-15 13:53:21 +0530 | [diff] [blame] | 499 | cpufreq_enable_fast_switch(policy); |
| 500 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 501 | sg_policy = sugov_policy_alloc(policy); |
Viresh Kumar | 4a71ce4 | 2016-11-15 13:53:21 +0530 | [diff] [blame] | 502 | if (!sg_policy) { |
| 503 | ret = -ENOMEM; |
| 504 | goto disable_fast_switch; |
| 505 | } |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 506 | |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 507 | ret = sugov_kthread_create(sg_policy); |
| 508 | if (ret) |
| 509 | goto free_sg_policy; |
| 510 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 511 | mutex_lock(&global_tunables_lock); |
| 512 | |
| 513 | if (global_tunables) { |
| 514 | if (WARN_ON(have_governor_per_policy())) { |
| 515 | ret = -EINVAL; |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 516 | goto stop_kthread; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 517 | } |
| 518 | policy->governor_data = sg_policy; |
| 519 | sg_policy->tunables = global_tunables; |
| 520 | |
| 521 | gov_attr_set_get(&global_tunables->attr_set, &sg_policy->tunables_hook); |
| 522 | goto out; |
| 523 | } |
| 524 | |
| 525 | tunables = sugov_tunables_alloc(sg_policy); |
| 526 | if (!tunables) { |
| 527 | ret = -ENOMEM; |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 528 | goto stop_kthread; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 529 | } |
| 530 | |
Rafael J. Wysocki | 1b72e7f | 2017-04-11 00:20:41 +0200 | [diff] [blame] | 531 | if (policy->transition_delay_us) { |
| 532 | tunables->rate_limit_us = policy->transition_delay_us; |
| 533 | } else { |
| 534 | unsigned int lat; |
| 535 | |
| 536 | tunables->rate_limit_us = LATENCY_MULTIPLIER; |
| 537 | lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC; |
| 538 | if (lat) |
| 539 | tunables->rate_limit_us *= lat; |
| 540 | } |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 541 | |
| 542 | policy->governor_data = sg_policy; |
| 543 | sg_policy->tunables = tunables; |
| 544 | |
| 545 | ret = kobject_init_and_add(&tunables->attr_set.kobj, &sugov_tunables_ktype, |
| 546 | get_governor_parent_kobj(policy), "%s", |
| 547 | schedutil_gov.name); |
| 548 | if (ret) |
| 549 | goto fail; |
| 550 | |
Viresh Kumar | 8e2ddb0 | 2016-11-15 13:53:20 +0530 | [diff] [blame] | 551 | out: |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 552 | mutex_unlock(&global_tunables_lock); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 553 | return 0; |
| 554 | |
Viresh Kumar | 8e2ddb0 | 2016-11-15 13:53:20 +0530 | [diff] [blame] | 555 | fail: |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 556 | policy->governor_data = NULL; |
| 557 | sugov_tunables_free(tunables); |
| 558 | |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 559 | stop_kthread: |
| 560 | sugov_kthread_stop(sg_policy); |
| 561 | |
Viresh Kumar | 8e2ddb0 | 2016-11-15 13:53:20 +0530 | [diff] [blame] | 562 | free_sg_policy: |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 563 | mutex_unlock(&global_tunables_lock); |
| 564 | |
| 565 | sugov_policy_free(sg_policy); |
Viresh Kumar | 4a71ce4 | 2016-11-15 13:53:21 +0530 | [diff] [blame] | 566 | |
| 567 | disable_fast_switch: |
| 568 | cpufreq_disable_fast_switch(policy); |
| 569 | |
Viresh Kumar | 60f05e8 | 2016-05-18 17:55:28 +0530 | [diff] [blame] | 570 | pr_err("initialization failed (error %d)\n", ret); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 571 | return ret; |
| 572 | } |
| 573 | |
Rafael J. Wysocki | e788892 | 2016-06-02 23:24:15 +0200 | [diff] [blame] | 574 | static void sugov_exit(struct cpufreq_policy *policy) |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 575 | { |
| 576 | struct sugov_policy *sg_policy = policy->governor_data; |
| 577 | struct sugov_tunables *tunables = sg_policy->tunables; |
| 578 | unsigned int count; |
| 579 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 580 | mutex_lock(&global_tunables_lock); |
| 581 | |
| 582 | count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook); |
| 583 | policy->governor_data = NULL; |
| 584 | if (!count) |
| 585 | sugov_tunables_free(tunables); |
| 586 | |
| 587 | mutex_unlock(&global_tunables_lock); |
| 588 | |
Viresh Kumar | 02a7b1e | 2016-11-15 13:53:22 +0530 | [diff] [blame] | 589 | sugov_kthread_stop(sg_policy); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 590 | sugov_policy_free(sg_policy); |
Viresh Kumar | 4a71ce4 | 2016-11-15 13:53:21 +0530 | [diff] [blame] | 591 | cpufreq_disable_fast_switch(policy); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 592 | } |
| 593 | |
| 594 | static int sugov_start(struct cpufreq_policy *policy) |
| 595 | { |
| 596 | struct sugov_policy *sg_policy = policy->governor_data; |
| 597 | unsigned int cpu; |
| 598 | |
| 599 | sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC; |
| 600 | sg_policy->last_freq_update_time = 0; |
| 601 | sg_policy->next_freq = UINT_MAX; |
| 602 | sg_policy->work_in_progress = false; |
| 603 | sg_policy->need_freq_update = false; |
Viresh Kumar | 6c4f0fa | 2017-03-02 14:03:20 +0530 | [diff] [blame] | 604 | sg_policy->cached_raw_freq = 0; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 605 | |
| 606 | for_each_cpu(cpu, policy->cpus) { |
| 607 | struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); |
| 608 | |
Rafael J. Wysocki | 4296f23 | 2017-03-19 14:30:02 +0100 | [diff] [blame] | 609 | memset(sg_cpu, 0, sizeof(*sg_cpu)); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 610 | sg_cpu->sg_policy = sg_policy; |
Rafael J. Wysocki | 4296f23 | 2017-03-19 14:30:02 +0100 | [diff] [blame] | 611 | sg_cpu->flags = SCHED_CPUFREQ_RT; |
| 612 | sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq; |
Vikram Mulukutla | ab2f7cf | 2017-07-06 10:53:20 -0700 | [diff] [blame] | 613 | } |
| 614 | |
| 615 | for_each_cpu(cpu, policy->cpus) { |
| 616 | struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); |
| 617 | |
Rafael J. Wysocki | 4296f23 | 2017-03-19 14:30:02 +0100 | [diff] [blame] | 618 | cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util, |
| 619 | policy_is_shared(policy) ? |
| 620 | sugov_update_shared : |
| 621 | sugov_update_single); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 622 | } |
| 623 | return 0; |
| 624 | } |
| 625 | |
Rafael J. Wysocki | e788892 | 2016-06-02 23:24:15 +0200 | [diff] [blame] | 626 | static void sugov_stop(struct cpufreq_policy *policy) |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 627 | { |
| 628 | struct sugov_policy *sg_policy = policy->governor_data; |
| 629 | unsigned int cpu; |
| 630 | |
| 631 | for_each_cpu(cpu, policy->cpus) |
| 632 | cpufreq_remove_update_util_hook(cpu); |
| 633 | |
| 634 | synchronize_sched(); |
| 635 | |
Viresh Kumar | 21ef572 | 2016-11-15 13:53:23 +0530 | [diff] [blame] | 636 | if (!policy->fast_switch_enabled) { |
| 637 | irq_work_sync(&sg_policy->irq_work); |
| 638 | kthread_cancel_work_sync(&sg_policy->work); |
| 639 | } |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 640 | } |
| 641 | |
Rafael J. Wysocki | e788892 | 2016-06-02 23:24:15 +0200 | [diff] [blame] | 642 | static void sugov_limits(struct cpufreq_policy *policy) |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 643 | { |
| 644 | struct sugov_policy *sg_policy = policy->governor_data; |
| 645 | |
| 646 | if (!policy->fast_switch_enabled) { |
| 647 | mutex_lock(&sg_policy->work_lock); |
Viresh Kumar | bf2be2d | 2016-05-18 17:55:31 +0530 | [diff] [blame] | 648 | cpufreq_policy_apply_limits(policy); |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 649 | mutex_unlock(&sg_policy->work_lock); |
| 650 | } |
| 651 | |
| 652 | sg_policy->need_freq_update = true; |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 653 | } |
| 654 | |
| 655 | static struct cpufreq_governor schedutil_gov = { |
| 656 | .name = "schedutil", |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 657 | .owner = THIS_MODULE, |
Rafael J. Wysocki | e788892 | 2016-06-02 23:24:15 +0200 | [diff] [blame] | 658 | .init = sugov_init, |
| 659 | .exit = sugov_exit, |
| 660 | .start = sugov_start, |
| 661 | .stop = sugov_stop, |
| 662 | .limits = sugov_limits, |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 663 | }; |
| 664 | |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 665 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL |
| 666 | struct cpufreq_governor *cpufreq_default_governor(void) |
| 667 | { |
| 668 | return &schedutil_gov; |
| 669 | } |
Rafael J. Wysocki | 9bdcb44 | 2016-04-02 01:09:12 +0200 | [diff] [blame] | 670 | #endif |
Rafael J. Wysocki | 58919e8 | 2016-08-16 22:14:55 +0200 | [diff] [blame] | 671 | |
| 672 | static int __init sugov_register(void) |
| 673 | { |
| 674 | return cpufreq_register_governor(&schedutil_gov); |
| 675 | } |
| 676 | fs_initcall(sugov_register); |