| /* |
| * linux/mm/slab.c |
| * Written by Mark Hemment, 1996/97. |
| * (markhe@nextd.demon.co.uk) |
| * |
| * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli |
| * |
| * Major cleanup, different bufctl logic, per-cpu arrays |
| * (c) 2000 Manfred Spraul |
| * |
| * Cleanup, make the head arrays unconditional, preparation for NUMA |
| * (c) 2002 Manfred Spraul |
| * |
| * An implementation of the Slab Allocator as described in outline in; |
| * UNIX Internals: The New Frontiers by Uresh Vahalia |
| * Pub: Prentice Hall ISBN 0-13-101908-2 |
| * or with a little more detail in; |
| * The Slab Allocator: An Object-Caching Kernel Memory Allocator |
| * Jeff Bonwick (Sun Microsystems). |
| * Presented at: USENIX Summer 1994 Technical Conference |
| * |
| * The memory is organized in caches, one cache for each object type. |
| * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct) |
| * Each cache consists out of many slabs (they are small (usually one |
| * page long) and always contiguous), and each slab contains multiple |
| * initialized objects. |
| * |
| * This means, that your constructor is used only for newly allocated |
| * slabs and you must pass objects with the same initializations to |
| * kmem_cache_free. |
| * |
| * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM, |
| * normal). If you need a special memory type, then must create a new |
| * cache for that memory type. |
| * |
| * In order to reduce fragmentation, the slabs are sorted in 3 groups: |
| * full slabs with 0 free objects |
| * partial slabs |
| * empty slabs with no allocated objects |
| * |
| * If partial slabs exist, then new allocations come from these slabs, |
| * otherwise from empty slabs or new slabs are allocated. |
| * |
| * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache |
| * during kmem_cache_destroy(). The caller must prevent concurrent allocs. |
| * |
| * Each cache has a short per-cpu head array, most allocs |
| * and frees go into that array, and if that array overflows, then 1/2 |
| * of the entries in the array are given back into the global cache. |
| * The head array is strictly LIFO and should improve the cache hit rates. |
| * On SMP, it additionally reduces the spinlock operations. |
| * |
| * The c_cpuarray may not be read with enabled local interrupts - |
| * it's changed with a smp_call_function(). |
| * |
| * SMP synchronization: |
| * constructors and destructors are called without any locking. |
| * Several members in struct kmem_cache and struct slab never change, they |
| * are accessed without any locking. |
| * The per-cpu arrays are never accessed from the wrong cpu, no locking, |
| * and local interrupts are disabled so slab code is preempt-safe. |
| * The non-constant members are protected with a per-cache irq spinlock. |
| * |
| * Many thanks to Mark Hemment, who wrote another per-cpu slab patch |
| * in 2000 - many ideas in the current implementation are derived from |
| * his patch. |
| * |
| * Further notes from the original documentation: |
| * |
| * 11 April '97. Started multi-threading - markhe |
| * The global cache-chain is protected by the mutex 'slab_mutex'. |
| * The sem is only needed when accessing/extending the cache-chain, which |
| * can never happen inside an interrupt (kmem_cache_create(), |
| * kmem_cache_shrink() and kmem_cache_reap()). |
| * |
| * At present, each engine can be growing a cache. This should be blocked. |
| * |
| * 15 March 2005. NUMA slab allocator. |
| * Shai Fultheim <shai@scalex86.org>. |
| * Shobhit Dayal <shobhit@calsoftinc.com> |
| * Alok N Kataria <alokk@calsoftinc.com> |
| * Christoph Lameter <christoph@lameter.com> |
| * |
| * Modified the slab allocator to be node aware on NUMA systems. |
| * Each node has its own list of partial, free and full slabs. |
| * All object allocations for a node occur from node specific slab lists. |
| */ |
| |
| #include <linux/slab.h> |
| #include <linux/mm.h> |
| #include <linux/poison.h> |
| #include <linux/swap.h> |
| #include <linux/cache.h> |
| #include <linux/interrupt.h> |
| #include <linux/init.h> |
| #include <linux/compiler.h> |
| #include <linux/cpuset.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/notifier.h> |
| #include <linux/kallsyms.h> |
| #include <linux/cpu.h> |
| #include <linux/sysctl.h> |
| #include <linux/module.h> |
| #include <linux/rcupdate.h> |
| #include <linux/string.h> |
| #include <linux/uaccess.h> |
| #include <linux/nodemask.h> |
| #include <linux/kmemleak.h> |
| #include <linux/mempolicy.h> |
| #include <linux/mutex.h> |
| #include <linux/fault-inject.h> |
| #include <linux/rtmutex.h> |
| #include <linux/reciprocal_div.h> |
| #include <linux/debugobjects.h> |
| #include <linux/kmemcheck.h> |
| #include <linux/memory.h> |
| #include <linux/prefetch.h> |
| |
| #include <net/sock.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/tlbflush.h> |
| #include <asm/page.h> |
| |
| #include <trace/events/kmem.h> |
| |
| #include "internal.h" |
| |
| #include "slab.h" |
| |
| /* |
| * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. |
| * 0 for faster, smaller code (especially in the critical paths). |
| * |
| * STATS - 1 to collect stats for /proc/slabinfo. |
| * 0 for faster, smaller code (especially in the critical paths). |
| * |
| * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) |
| */ |
| |
| #ifdef CONFIG_DEBUG_SLAB |
| #define DEBUG 1 |
| #define STATS 1 |
| #define FORCED_DEBUG 1 |
| #else |
| #define DEBUG 0 |
| #define STATS 0 |
| #define FORCED_DEBUG 0 |
| #endif |
| |
| /* Shouldn't this be in a header file somewhere? */ |
| #define BYTES_PER_WORD sizeof(void *) |
| #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) |
| |
| #ifndef ARCH_KMALLOC_FLAGS |
| #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN |
| #endif |
| |
| #define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \ |
| <= SLAB_OBJ_MIN_SIZE) ? 1 : 0) |
| |
| #if FREELIST_BYTE_INDEX |
| typedef unsigned char freelist_idx_t; |
| #else |
| typedef unsigned short freelist_idx_t; |
| #endif |
| |
| #define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1) |
| |
| /* |
| * true if a page was allocated from pfmemalloc reserves for network-based |
| * swap |
| */ |
| static bool pfmemalloc_active __read_mostly; |
| |
| /* |
| * struct array_cache |
| * |
| * Purpose: |
| * - LIFO ordering, to hand out cache-warm objects from _alloc |
| * - reduce the number of linked list operations |
| * - reduce spinlock operations |
| * |
| * The limit is stored in the per-cpu structure to reduce the data cache |
| * footprint. |
| * |
| */ |
| struct array_cache { |
| unsigned int avail; |
| unsigned int limit; |
| unsigned int batchcount; |
| unsigned int touched; |
| void *entry[]; /* |
| * Must have this definition in here for the proper |
| * alignment of array_cache. Also simplifies accessing |
| * the entries. |
| * |
| * Entries should not be directly dereferenced as |
| * entries belonging to slabs marked pfmemalloc will |
| * have the lower bits set SLAB_OBJ_PFMEMALLOC |
| */ |
| }; |
| |
| struct alien_cache { |
| spinlock_t lock; |
| struct array_cache ac; |
| }; |
| |
| #define SLAB_OBJ_PFMEMALLOC 1 |
| static inline bool is_obj_pfmemalloc(void *objp) |
| { |
| return (unsigned long)objp & SLAB_OBJ_PFMEMALLOC; |
| } |
| |
| static inline void set_obj_pfmemalloc(void **objp) |
| { |
| *objp = (void *)((unsigned long)*objp | SLAB_OBJ_PFMEMALLOC); |
| return; |
| } |
| |
| static inline void clear_obj_pfmemalloc(void **objp) |
| { |
| *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC); |
| } |
| |
| /* |
| * bootstrap: The caches do not work without cpuarrays anymore, but the |
| * cpuarrays are allocated from the generic caches... |
| */ |
| #define BOOT_CPUCACHE_ENTRIES 1 |
| struct arraycache_init { |
| struct array_cache cache; |
| void *entries[BOOT_CPUCACHE_ENTRIES]; |
| }; |
| |
| /* |
| * Need this for bootstrapping a per node allocator. |
| */ |
| #define NUM_INIT_LISTS (2 * MAX_NUMNODES) |
| static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS]; |
| #define CACHE_CACHE 0 |
| #define SIZE_NODE (MAX_NUMNODES) |
| |
| static int drain_freelist(struct kmem_cache *cache, |
| struct kmem_cache_node *n, int tofree); |
| static void free_block(struct kmem_cache *cachep, void **objpp, int len, |
| int node, struct list_head *list); |
| static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list); |
| static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); |
| static void cache_reap(struct work_struct *unused); |
| |
| static int slab_early_init = 1; |
| |
| #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) |
| |
| static void kmem_cache_node_init(struct kmem_cache_node *parent) |
| { |
| INIT_LIST_HEAD(&parent->slabs_full); |
| INIT_LIST_HEAD(&parent->slabs_partial); |
| INIT_LIST_HEAD(&parent->slabs_free); |
| parent->shared = NULL; |
| parent->alien = NULL; |
| parent->colour_next = 0; |
| spin_lock_init(&parent->list_lock); |
| parent->free_objects = 0; |
| parent->free_touched = 0; |
| } |
| |
| #define MAKE_LIST(cachep, listp, slab, nodeid) \ |
| do { \ |
| INIT_LIST_HEAD(listp); \ |
| list_splice(&get_node(cachep, nodeid)->slab, listp); \ |
| } while (0) |
| |
| #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ |
| do { \ |
| MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ |
| MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ |
| MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ |
| } while (0) |
| |
| #define CFLGS_OFF_SLAB (0x80000000UL) |
| #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) |
| #define OFF_SLAB_MIN_SIZE (max_t(size_t, PAGE_SIZE >> 5, KMALLOC_MIN_SIZE + 1)) |
| |
| #define BATCHREFILL_LIMIT 16 |
| /* |
| * Optimization question: fewer reaps means less probability for unnessary |
| * cpucache drain/refill cycles. |
| * |
| * OTOH the cpuarrays can contain lots of objects, |
| * which could lock up otherwise freeable slabs. |
| */ |
| #define REAPTIMEOUT_AC (2*HZ) |
| #define REAPTIMEOUT_NODE (4*HZ) |
| |
| #if STATS |
| #define STATS_INC_ACTIVE(x) ((x)->num_active++) |
| #define STATS_DEC_ACTIVE(x) ((x)->num_active--) |
| #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) |
| #define STATS_INC_GROWN(x) ((x)->grown++) |
| #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) |
| #define STATS_SET_HIGH(x) \ |
| do { \ |
| if ((x)->num_active > (x)->high_mark) \ |
| (x)->high_mark = (x)->num_active; \ |
| } while (0) |
| #define STATS_INC_ERR(x) ((x)->errors++) |
| #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) |
| #define STATS_INC_NODEFREES(x) ((x)->node_frees++) |
| #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) |
| #define STATS_SET_FREEABLE(x, i) \ |
| do { \ |
| if ((x)->max_freeable < i) \ |
| (x)->max_freeable = i; \ |
| } while (0) |
| #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) |
| #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) |
| #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) |
| #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) |
| #else |
| #define STATS_INC_ACTIVE(x) do { } while (0) |
| #define STATS_DEC_ACTIVE(x) do { } while (0) |
| #define STATS_INC_ALLOCED(x) do { } while (0) |
| #define STATS_INC_GROWN(x) do { } while (0) |
| #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) |
| #define STATS_SET_HIGH(x) do { } while (0) |
| #define STATS_INC_ERR(x) do { } while (0) |
| #define STATS_INC_NODEALLOCS(x) do { } while (0) |
| #define STATS_INC_NODEFREES(x) do { } while (0) |
| #define STATS_INC_ACOVERFLOW(x) do { } while (0) |
| #define STATS_SET_FREEABLE(x, i) do { } while (0) |
| #define STATS_INC_ALLOCHIT(x) do { } while (0) |
| #define STATS_INC_ALLOCMISS(x) do { } while (0) |
| #define STATS_INC_FREEHIT(x) do { } while (0) |
| #define STATS_INC_FREEMISS(x) do { } while (0) |
| #endif |
| |
| #if DEBUG |
| |
| /* |
| * memory layout of objects: |
| * 0 : objp |
| * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that |
| * the end of an object is aligned with the end of the real |
| * allocation. Catches writes behind the end of the allocation. |
| * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: |
| * redzone word. |
| * cachep->obj_offset: The real object. |
| * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
| * cachep->size - 1* BYTES_PER_WORD: last caller address |
| * [BYTES_PER_WORD long] |
| */ |
| static int obj_offset(struct kmem_cache *cachep) |
| { |
| return cachep->obj_offset; |
| } |
| |
| static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) |
| { |
| BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
| return (unsigned long long*) (objp + obj_offset(cachep) - |
| sizeof(unsigned long long)); |
| } |
| |
| static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) |
| { |
| BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
| if (cachep->flags & SLAB_STORE_USER) |
| return (unsigned long long *)(objp + cachep->size - |
| sizeof(unsigned long long) - |
| REDZONE_ALIGN); |
| return (unsigned long long *) (objp + cachep->size - |
| sizeof(unsigned long long)); |
| } |
| |
| static void **dbg_userword(struct kmem_cache *cachep, void *objp) |
| { |
| BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
| return (void **)(objp + cachep->size - BYTES_PER_WORD); |
| } |
| |
| #else |
| |
| #define obj_offset(x) 0 |
| #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
| #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
| #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
| |
| #endif |
| |
| #define OBJECT_FREE (0) |
| #define OBJECT_ACTIVE (1) |
| |
| #ifdef CONFIG_DEBUG_SLAB_LEAK |
| |
| static void set_obj_status(struct page *page, int idx, int val) |
| { |
| int freelist_size; |
| char *status; |
| struct kmem_cache *cachep = page->slab_cache; |
| |
| freelist_size = cachep->num * sizeof(freelist_idx_t); |
| status = (char *)page->freelist + freelist_size; |
| status[idx] = val; |
| } |
| |
| static inline unsigned int get_obj_status(struct page *page, int idx) |
| { |
| int freelist_size; |
| char *status; |
| struct kmem_cache *cachep = page->slab_cache; |
| |
| freelist_size = cachep->num * sizeof(freelist_idx_t); |
| status = (char *)page->freelist + freelist_size; |
| |
| return status[idx]; |
| } |
| |
| #else |
| static inline void set_obj_status(struct page *page, int idx, int val) {} |
| |
| #endif |
| |
| /* |
| * Do not go above this order unless 0 objects fit into the slab or |
| * overridden on the command line. |
| */ |
| #define SLAB_MAX_ORDER_HI 1 |
| #define SLAB_MAX_ORDER_LO 0 |
| static int slab_max_order = SLAB_MAX_ORDER_LO; |
| static bool slab_max_order_set __initdata; |
| |
| static inline struct kmem_cache *virt_to_cache(const void *obj) |
| { |
| struct page *page = virt_to_head_page(obj); |
| return page->slab_cache; |
| } |
| |
| static inline void *index_to_obj(struct kmem_cache *cache, struct page *page, |
| unsigned int idx) |
| { |
| return page->s_mem + cache->size * idx; |
| } |
| |
| /* |
| * We want to avoid an expensive divide : (offset / cache->size) |
| * Using the fact that size is a constant for a particular cache, |
| * we can replace (offset / cache->size) by |
| * reciprocal_divide(offset, cache->reciprocal_buffer_size) |
| */ |
| static inline unsigned int obj_to_index(const struct kmem_cache *cache, |
| const struct page *page, void *obj) |
| { |
| u32 offset = (obj - page->s_mem); |
| return reciprocal_divide(offset, cache->reciprocal_buffer_size); |
| } |
| |
| /* internal cache of cache description objs */ |
| static struct kmem_cache kmem_cache_boot = { |
| .batchcount = 1, |
| .limit = BOOT_CPUCACHE_ENTRIES, |
| .shared = 1, |
| .size = sizeof(struct kmem_cache), |
| .name = "kmem_cache", |
| }; |
| |
| #define BAD_ALIEN_MAGIC 0x01020304ul |
| |
| static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); |
| |
| static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) |
| { |
| return this_cpu_ptr(cachep->cpu_cache); |
| } |
| |
| static size_t calculate_freelist_size(int nr_objs, size_t align) |
| { |
| size_t freelist_size; |
| |
| freelist_size = nr_objs * sizeof(freelist_idx_t); |
| if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK)) |
| freelist_size += nr_objs * sizeof(char); |
| |
| if (align) |
| freelist_size = ALIGN(freelist_size, align); |
| |
| return freelist_size; |
| } |
| |
| static int calculate_nr_objs(size_t slab_size, size_t buffer_size, |
| size_t idx_size, size_t align) |
| { |
| int nr_objs; |
| size_t remained_size; |
| size_t freelist_size; |
| int extra_space = 0; |
| |
| if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK)) |
| extra_space = sizeof(char); |
| /* |
| * Ignore padding for the initial guess. The padding |
| * is at most @align-1 bytes, and @buffer_size is at |
| * least @align. In the worst case, this result will |
| * be one greater than the number of objects that fit |
| * into the memory allocation when taking the padding |
| * into account. |
| */ |
| nr_objs = slab_size / (buffer_size + idx_size + extra_space); |
| |
| /* |
| * This calculated number will be either the right |
| * amount, or one greater than what we want. |
| */ |
| remained_size = slab_size - nr_objs * buffer_size; |
| freelist_size = calculate_freelist_size(nr_objs, align); |
| if (remained_size < freelist_size) |
| nr_objs--; |
| |
| return nr_objs; |
| } |
| |
| /* |
| * Calculate the number of objects and left-over bytes for a given buffer size. |
| */ |
| static void cache_estimate(unsigned long gfporder, size_t buffer_size, |
| size_t align, int flags, size_t *left_over, |
| unsigned int *num) |
| { |
| int nr_objs; |
| size_t mgmt_size; |
| size_t slab_size = PAGE_SIZE << gfporder; |
| |
| /* |
| * The slab management structure can be either off the slab or |
| * on it. For the latter case, the memory allocated for a |
| * slab is used for: |
| * |
| * - One unsigned int for each object |
| * - Padding to respect alignment of @align |
| * - @buffer_size bytes for each object |
| * |
| * If the slab management structure is off the slab, then the |
| * alignment will already be calculated into the size. Because |
| * the slabs are all pages aligned, the objects will be at the |
| * correct alignment when allocated. |
| */ |
| if (flags & CFLGS_OFF_SLAB) { |
| mgmt_size = 0; |
| nr_objs = slab_size / buffer_size; |
| |
| } else { |
| nr_objs = calculate_nr_objs(slab_size, buffer_size, |
| sizeof(freelist_idx_t), align); |
| mgmt_size = calculate_freelist_size(nr_objs, align); |
| } |
| *num = nr_objs; |
| *left_over = slab_size - nr_objs*buffer_size - mgmt_size; |
| } |
| |
| #if DEBUG |
| #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) |
| |
| static void __slab_error(const char *function, struct kmem_cache *cachep, |
| char *msg) |
| { |
| printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", |
| function, cachep->name, msg); |
| dump_stack(); |
| add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); |
| } |
| #endif |
| |
| /* |
| * By default on NUMA we use alien caches to stage the freeing of |
| * objects allocated from other nodes. This causes massive memory |
| * inefficiencies when using fake NUMA setup to split memory into a |
| * large number of small nodes, so it can be disabled on the command |
| * line |
| */ |
| |
| static int use_alien_caches __read_mostly = 1; |
| static int __init noaliencache_setup(char *s) |
| { |
| use_alien_caches = 0; |
| return 1; |
| } |
| __setup("noaliencache", noaliencache_setup); |
| |
| static int __init slab_max_order_setup(char *str) |
| { |
| get_option(&str, &slab_max_order); |
| slab_max_order = slab_max_order < 0 ? 0 : |
| min(slab_max_order, MAX_ORDER - 1); |
| slab_max_order_set = true; |
| |
| return 1; |
| } |
| __setup("slab_max_order=", slab_max_order_setup); |
| |
| #ifdef CONFIG_NUMA |
| /* |
| * Special reaping functions for NUMA systems called from cache_reap(). |
| * These take care of doing round robin flushing of alien caches (containing |
| * objects freed on different nodes from which they were allocated) and the |
| * flushing of remote pcps by calling drain_node_pages. |
| */ |
| static DEFINE_PER_CPU(unsigned long, slab_reap_node); |
| |
| static void init_reap_node(int cpu) |
| { |
| int node; |
| |
| node = next_node(cpu_to_mem(cpu), node_online_map); |
| if (node == MAX_NUMNODES) |
| node = first_node(node_online_map); |
| |
| per_cpu(slab_reap_node, cpu) = node; |
| } |
| |
| static void next_reap_node(void) |
| { |
| int node = __this_cpu_read(slab_reap_node); |
| |
| node = next_node(node, node_online_map); |
| if (unlikely(node >= MAX_NUMNODES)) |
| node = first_node(node_online_map); |
| __this_cpu_write(slab_reap_node, node); |
| } |
| |
| #else |
| #define init_reap_node(cpu) do { } while (0) |
| #define next_reap_node(void) do { } while (0) |
| #endif |
| |
| /* |
| * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz |
| * via the workqueue/eventd. |
| * Add the CPU number into the expiration time to minimize the possibility of |
| * the CPUs getting into lockstep and contending for the global cache chain |
| * lock. |
| */ |
| static void start_cpu_timer(int cpu) |
| { |
| struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); |
| |
| /* |
| * When this gets called from do_initcalls via cpucache_init(), |
| * init_workqueues() has already run, so keventd will be setup |
| * at that time. |
| */ |
| if (keventd_up() && reap_work->work.func == NULL) { |
| init_reap_node(cpu); |
| INIT_DEFERRABLE_WORK(reap_work, cache_reap); |
| schedule_delayed_work_on(cpu, reap_work, |
| __round_jiffies_relative(HZ, cpu)); |
| } |
| } |
| |
| static void init_arraycache(struct array_cache *ac, int limit, int batch) |
| { |
| /* |
| * The array_cache structures contain pointers to free object. |
| * However, when such objects are allocated or transferred to another |
| * cache the pointers are not cleared and they could be counted as |
| * valid references during a kmemleak scan. Therefore, kmemleak must |
| * not scan such objects. |
| */ |
| kmemleak_no_scan(ac); |
| if (ac) { |
| ac->avail = 0; |
| ac->limit = limit; |
| ac->batchcount = batch; |
| ac->touched = 0; |
| } |
| } |
| |
| static struct array_cache *alloc_arraycache(int node, int entries, |
| int batchcount, gfp_t gfp) |
| { |
| size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache); |
| struct array_cache *ac = NULL; |
| |
| ac = kmalloc_node(memsize, gfp, node); |
| init_arraycache(ac, entries, batchcount); |
| return ac; |
| } |
| |
| static inline bool is_slab_pfmemalloc(struct page *page) |
| { |
| return PageSlabPfmemalloc(page); |
| } |
| |
| /* Clears pfmemalloc_active if no slabs have pfmalloc set */ |
| static void recheck_pfmemalloc_active(struct kmem_cache *cachep, |
| struct array_cache *ac) |
| { |
| struct kmem_cache_node *n = get_node(cachep, numa_mem_id()); |
| struct page *page; |
| unsigned long flags; |
| |
| if (!pfmemalloc_active) |
| return; |
| |
| spin_lock_irqsave(&n->list_lock, flags); |
| list_for_each_entry(page, &n->slabs_full, lru) |
| if (is_slab_pfmemalloc(page)) |
| goto out; |
| |
| list_for_each_entry(page, &n->slabs_partial, lru) |
| if (is_slab_pfmemalloc(page)) |
| goto out; |
| |
| list_for_each_entry(page, &n->slabs_free, lru) |
| if (is_slab_pfmemalloc(page)) |
| goto out; |
| |
| pfmemalloc_active = false; |
| out: |
| spin_unlock_irqrestore(&n->list_lock, flags); |
| } |
| |
| static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac, |
| gfp_t flags, bool force_refill) |
| { |
| int i; |
| void *objp = ac->entry[--ac->avail]; |
| |
| /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */ |
| if (unlikely(is_obj_pfmemalloc(objp))) { |
| struct kmem_cache_node *n; |
| |
| if (gfp_pfmemalloc_allowed(flags)) { |
| clear_obj_pfmemalloc(&objp); |
| return objp; |
| } |
| |
| /* The caller cannot use PFMEMALLOC objects, find another one */ |
| for (i = 0; i < ac->avail; i++) { |
| /* If a !PFMEMALLOC object is found, swap them */ |
| if (!is_obj_pfmemalloc(ac->entry[i])) { |
| objp = ac->entry[i]; |
| ac->entry[i] = ac->entry[ac->avail]; |
| ac->entry[ac->avail] = objp; |
| return objp; |
| } |
| } |
| |
| /* |
| * If there are empty slabs on the slabs_free list and we are |
| * being forced to refill the cache, mark this one !pfmemalloc. |
| */ |
| n = get_node(cachep, numa_mem_id()); |
| if (!list_empty(&n->slabs_free) && force_refill) { |
| struct page *page = virt_to_head_page(objp); |
| ClearPageSlabPfmemalloc(page); |
| clear_obj_pfmemalloc(&objp); |
| recheck_pfmemalloc_active(cachep, ac); |
| return objp; |
| } |
| |
| /* No !PFMEMALLOC objects available */ |
| ac->avail++; |
| objp = NULL; |
| } |
| |
| return objp; |
| } |
| |
| static inline void *ac_get_obj(struct kmem_cache *cachep, |
| struct array_cache *ac, gfp_t flags, bool force_refill) |
| { |
| void *objp; |
| |
| if (unlikely(sk_memalloc_socks())) |
| objp = __ac_get_obj(cachep, ac, flags, force_refill); |
| else |
| objp = ac->entry[--ac->avail]; |
| |
| return objp; |
| } |
| |
| static noinline void *__ac_put_obj(struct kmem_cache *cachep, |
| struct array_cache *ac, void *objp) |
| { |
| if (unlikely(pfmemalloc_active)) { |
| /* Some pfmemalloc slabs exist, check if this is one */ |
| struct page *page = virt_to_head_page(objp); |
| if (PageSlabPfmemalloc(page)) |
| set_obj_pfmemalloc(&objp); |
| } |
| |
| return objp; |
| } |
| |
| static inline void ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, |
| void *objp) |
| { |
| if (unlikely(sk_memalloc_socks())) |
| objp = __ac_put_obj(cachep, ac, objp); |
| |
| ac->entry[ac->avail++] = objp; |
| } |
| |
| /* |
| * Transfer objects in one arraycache to another. |
| * Locking must be handled by the caller. |
| * |
| * Return the number of entries transferred. |
| */ |
| static int transfer_objects(struct array_cache *to, |
| struct array_cache *from, unsigned int max) |
| { |
| /* Figure out how many entries to transfer */ |
| int nr = min3(from->avail, max, to->limit - to->avail); |
| |
| if (!nr) |
| return 0; |
| |
| memcpy(to->entry + to->avail, from->entry + from->avail -nr, |
| sizeof(void *) *nr); |
| |
| from->avail -= nr; |
| to->avail += nr; |
| return nr; |
| } |
| |
| #ifndef CONFIG_NUMA |
| |
| #define drain_alien_cache(cachep, alien) do { } while (0) |
| #define reap_alien(cachep, n) do { } while (0) |
| |
| static inline struct alien_cache **alloc_alien_cache(int node, |
| int limit, gfp_t gfp) |
| { |
| return (struct alien_cache **)BAD_ALIEN_MAGIC; |
| } |
| |
| static inline void free_alien_cache(struct alien_cache **ac_ptr) |
| { |
| } |
| |
| static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
| { |
| return 0; |
| } |
| |
| static inline void *alternate_node_alloc(struct kmem_cache *cachep, |
| gfp_t flags) |
| { |
| return NULL; |
| } |
| |
| static inline void *____cache_alloc_node(struct kmem_cache *cachep, |
| gfp_t flags, int nodeid) |
| { |
| return NULL; |
| } |
| |
| static inline gfp_t gfp_exact_node(gfp_t flags) |
| { |
| return flags; |
| } |
| |
| #else /* CONFIG_NUMA */ |
| |
| static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); |
| static void *alternate_node_alloc(struct kmem_cache *, gfp_t); |
| |
| static struct alien_cache *__alloc_alien_cache(int node, int entries, |
| int batch, gfp_t gfp) |
| { |
| size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache); |
| struct alien_cache *alc = NULL; |
| |
| alc = kmalloc_node(memsize, gfp, node); |
| init_arraycache(&alc->ac, entries, batch); |
| spin_lock_init(&alc->lock); |
| return alc; |
| } |
| |
| static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
| { |
| struct alien_cache **alc_ptr; |
| size_t memsize = sizeof(void *) * nr_node_ids; |
| int i; |
| |
| if (limit > 1) |
| limit = 12; |
| alc_ptr = kzalloc_node(memsize, gfp, node); |
| if (!alc_ptr) |
| return NULL; |
| |
| for_each_node(i) { |
| if (i == node || !node_online(i)) |
| continue; |
| alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp); |
| if (!alc_ptr[i]) { |
| for (i--; i >= 0; i--) |
| kfree(alc_ptr[i]); |
| kfree(alc_ptr); |
| return NULL; |
| } |
| } |
| return alc_ptr; |
| } |
| |
| static void free_alien_cache(struct alien_cache **alc_ptr) |
| { |
| int i; |
| |
| if (!alc_ptr) |
| return; |
| for_each_node(i) |
| kfree(alc_ptr[i]); |
| kfree(alc_ptr); |
| } |
| |
| static void __drain_alien_cache(struct kmem_cache *cachep, |
| struct array_cache *ac, int node, |
| struct list_head *list) |
| { |
| struct kmem_cache_node *n = get_node(cachep, node); |
| |
| if (ac->avail) { |
| spin_lock(&n->list_lock); |
| /* |
| * Stuff objects into the remote nodes shared array first. |
| * That way we could avoid the overhead of putting the objects |
| * into the free lists and getting them back later. |
| */ |
| if (n->shared) |
| transfer_objects(n->shared, ac, ac->limit); |
| |
| free_block(cachep, ac->entry, ac->avail, node, list); |
| ac->avail = 0; |
| spin_unlock(&n->list_lock); |
| } |
| } |
| |
| /* |
| * Called from cache_reap() to regularly drain alien caches round robin. |
| */ |
| static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n) |
| { |
| int node = __this_cpu_read(slab_reap_node); |
| |
| if (n->alien) { |
| struct alien_cache *alc = n->alien[node]; |
| struct array_cache *ac; |
| |
| if (alc) { |
| ac = &alc->ac; |
| if (ac->avail && spin_trylock_irq(&alc->lock)) { |
| LIST_HEAD(list); |
| |
| __drain_alien_cache(cachep, ac, node, &list); |
| spin_unlock_irq(&alc->lock); |
| slabs_destroy(cachep, &list); |
| } |
| } |
| } |
| } |
| |
| static void drain_alien_cache(struct kmem_cache *cachep, |
| struct alien_cache **alien) |
| { |
| int i = 0; |
| struct alien_cache *alc; |
| struct array_cache *ac; |
| unsigned long flags; |
| |
| for_each_online_node(i) { |
| alc = alien[i]; |
| if (alc) { |
| LIST_HEAD(list); |
| |
| ac = &alc->ac; |
| spin_lock_irqsave(&alc->lock, flags); |
| __drain_alien_cache(cachep, ac, i, &list); |
| spin_unlock_irqrestore(&alc->lock, flags); |
| slabs_destroy(cachep, &list); |
| } |
| } |
| } |
| |
| static int __cache_free_alien(struct kmem_cache *cachep, void *objp, |
| int node, int page_node) |
| { |
| struct kmem_cache_node *n; |
| struct alien_cache *alien = NULL; |
| struct array_cache *ac; |
| LIST_HEAD(list); |
| |
| n = get_node(cachep, node); |
| STATS_INC_NODEFREES(cachep); |
| if (n->alien && n->alien[page_node]) { |
| alien = n->alien[page_node]; |
| ac = &alien->ac; |
| spin_lock(&alien->lock); |
| if (unlikely(ac->avail == ac->limit)) { |
| STATS_INC_ACOVERFLOW(cachep); |
| __drain_alien_cache(cachep, ac, page_node, &list); |
| } |
| ac_put_obj(cachep, ac, objp); |
| spin_unlock(&alien->lock); |
| slabs_destroy(cachep, &list); |
| } else { |
| n = get_node(cachep, page_node); |
| spin_lock(&n->list_lock); |
| free_block(cachep, &objp, 1, page_node, &list); |
| spin_unlock(&n->list_lock); |
| slabs_destroy(cachep, &list); |
| } |
| return 1; |
| } |
| |
| static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
| { |
| int page_node = page_to_nid(virt_to_page(objp)); |
| int node = numa_mem_id(); |
| /* |
| * Make sure we are not freeing a object from another node to the array |
| * cache on this cpu. |
| */ |
| if (likely(node == page_node)) |
| return 0; |
| |
| return __cache_free_alien(cachep, objp, node, page_node); |
| } |
| |
| /* |
| * Construct gfp mask to allocate from a specific node but do not invoke reclaim |
| * or warn about failures. |
| */ |
| static inline gfp_t gfp_exact_node(gfp_t flags) |
| { |
| return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~__GFP_WAIT; |
| } |
| #endif |
| |
| /* |
| * Allocates and initializes node for a node on each slab cache, used for |
| * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node |
| * will be allocated off-node since memory is not yet online for the new node. |
| * When hotplugging memory or a cpu, existing node are not replaced if |
| * already in use. |
| * |
| * Must hold slab_mutex. |
| */ |
| static int init_cache_node_node(int node) |
| { |
| struct kmem_cache *cachep; |
| struct kmem_cache_node *n; |
| const size_t memsize = sizeof(struct kmem_cache_node); |
| |
| list_for_each_entry(cachep, &slab_caches, list) { |
| /* |
| * Set up the kmem_cache_node for cpu before we can |
| * begin anything. Make sure some other cpu on this |
| * node has not already allocated this |
| */ |
| n = get_node(cachep, node); |
| if (!n) { |
| n = kmalloc_node(memsize, GFP_KERNEL, node); |
| if (!n) |
| return -ENOMEM; |
| kmem_cache_node_init(n); |
| n->next_reap = jiffies + REAPTIMEOUT_NODE + |
| ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
| |
| /* |
| * The kmem_cache_nodes don't come and go as CPUs |
| * come and go. slab_mutex is sufficient |
| * protection here. |
| */ |
| cachep->node[node] = n; |
| } |
| |
| spin_lock_irq(&n->list_lock); |
| n->free_limit = |
| (1 + nr_cpus_node(node)) * |
| cachep->batchcount + cachep->num; |
| spin_unlock_irq(&n->list_lock); |
| } |
| return 0; |
| } |
| |
| static inline int slabs_tofree(struct kmem_cache *cachep, |
| struct kmem_cache_node *n) |
| { |
| return (n->free_objects + cachep->num - 1) / cachep->num; |
| } |
| |
| static void cpuup_canceled(long cpu) |
| { |
| struct kmem_cache *cachep; |
| struct kmem_cache_node *n = NULL; |
| int node = cpu_to_mem(cpu); |
| const struct cpumask *mask = cpumask_of_node(node); |
| |
| list_for_each_entry(cachep, &slab_caches, list) { |
| struct array_cache *nc; |
| struct array_cache *shared; |
| struct alien_cache **alien; |
| LIST_HEAD(list); |
| |
| n = get_node(cachep, node); |
| if (!n) |
| continue; |
| |
| spin_lock_irq(&n->list_lock); |
| |
| /* Free limit for this kmem_cache_node */ |
| n->free_limit -= cachep->batchcount; |
| |
| /* cpu is dead; no one can alloc from it. */ |
| nc = per_cpu_ptr(cachep->cpu_cache, cpu); |
| if (nc) { |
| free_block(cachep, nc->entry, nc->avail, node, &list); |
| nc->avail = 0; |
| } |
| |
| if (!cpumask_empty(mask)) { |
| spin_unlock_irq(&n->list_lock); |
| goto free_slab; |
| } |
| |
| shared = n->shared; |
| if (shared) { |
| free_block(cachep, shared->entry, |
| shared->avail, node, &list); |
| n->shared = NULL; |
| } |
| |
| alien = n->alien; |
| n->alien = NULL; |
| |
| spin_unlock_irq(&n->list_lock); |
| |
| kfree(shared); |
| if (alien) { |
| drain_alien_cache(cachep, alien); |
| free_alien_cache(alien); |
| } |
| |
| free_slab: |
| slabs_destroy(cachep, &list); |
| } |
| /* |
| * In the previous loop, all the objects were freed to |
| * the respective cache's slabs, now we can go ahead and |
| * shrink each nodelist to its limit. |
| */ |
| list_for_each_entry(cachep, &slab_caches, list) { |
| n = get_node(cachep, node); |
| if (!n) |
| continue; |
| drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
| } |
| } |
| |
| static int cpuup_prepare(long cpu) |
| { |
| struct kmem_cache *cachep; |
| struct kmem_cache_node *n = NULL; |
| int node = cpu_to_mem(cpu); |
| int err; |
| |
| /* |
| * We need to do this right in the beginning since |
| * alloc_arraycache's are going to use this list. |
| * kmalloc_node allows us to add the slab to the right |
| * kmem_cache_node and not this cpu's kmem_cache_node |
| */ |
| err = init_cache_node_node(node); |
| if (err < 0) |
| goto bad; |
| |
| /* |
| * Now we can go ahead with allocating the shared arrays and |
| * array caches |
| */ |
| list_for_each_entry(cachep, &slab_caches, list) { |
| struct array_cache *shared = NULL; |
| struct alien_cache **alien = NULL; |
| |
| if (cachep->shared) { |
| shared = alloc_arraycache(node, |
| cachep->shared * cachep->batchcount, |
| 0xbaadf00d, GFP_KERNEL); |
| if (!shared) |
| goto bad; |
| } |
| if (use_alien_caches) { |
| alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); |
| if (!alien) { |
| kfree(shared); |
| goto bad; |
| } |
| } |
| n = get_node(cachep, node); |
| BUG_ON(!n); |
| |
| spin_lock_irq(&n->list_lock); |
| if (!n->shared) { |
| /* |
| * We are serialised from CPU_DEAD or |
| * CPU_UP_CANCELLED by the cpucontrol lock |
| */ |
| n->shared = shared; |
| shared = NULL; |
| } |
| #ifdef CONFIG_NUMA |
| if (!n->alien) { |
| n->alien = alien; |
| alien = NULL; |
| } |
| #endif |
| spin_unlock_irq(&n->list_lock); |
| kfree(shared); |
| free_alien_cache(alien); |
| } |
| |
| return 0; |
| bad: |
| cpuup_canceled(cpu); |
| return -ENOMEM; |
| } |
| |
| static int cpuup_callback(struct notifier_block *nfb, |
| unsigned long action, void *hcpu) |
| { |
| long cpu = (long)hcpu; |
| int err = 0; |
| |
| switch (action) { |
| case CPU_UP_PREPARE: |
| case CPU_UP_PREPARE_FROZEN: |
| mutex_lock(&slab_mutex); |
| err = cpuup_prepare(cpu); |
| mutex_unlock(&slab_mutex); |
| break; |
| case CPU_ONLINE: |
| case CPU_ONLINE_FROZEN: |
| start_cpu_timer(cpu); |
| break; |
| #ifdef CONFIG_HOTPLUG_CPU |
| case CPU_DOWN_PREPARE: |
| case CPU_DOWN_PREPARE_FROZEN: |
| /* |
| * Shutdown cache reaper. Note that the slab_mutex is |
| * held so that if cache_reap() is invoked it cannot do |
| * anything expensive but will only modify reap_work |
| * and reschedule the timer. |
| */ |
| cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); |
| /* Now the cache_reaper is guaranteed to be not running. */ |
| per_cpu(slab_reap_work, cpu).work.func = NULL; |
| break; |
| case CPU_DOWN_FAILED: |
| case CPU_DOWN_FAILED_FROZEN: |
| start_cpu_timer(cpu); |
| break; |
| case CPU_DEAD: |
| case CPU_DEAD_FROZEN: |
| /* |
| * Even if all the cpus of a node are down, we don't free the |
| * kmem_cache_node of any cache. This to avoid a race between |
| * cpu_down, and a kmalloc allocation from another cpu for |
| * memory from the node of the cpu going down. The node |
| * structure is usually allocated from kmem_cache_create() and |
| * gets destroyed at kmem_cache_destroy(). |
| */ |
| /* fall through */ |
| #endif |
| case CPU_UP_CANCELED: |
| case CPU_UP_CANCELED_FROZEN: |
| mutex_lock(&slab_mutex); |
| cpuup_canceled(cpu); |
| mutex_unlock(&slab_mutex); |
| break; |
| } |
| return notifier_from_errno(err); |
| } |
| |
| static struct notifier_block cpucache_notifier = { |
| &cpuup_callback, NULL, 0 |
| }; |
| |
| #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) |
| /* |
| * Drains freelist for a node on each slab cache, used for memory hot-remove. |
| * Returns -EBUSY if all objects cannot be drained so that the node is not |
| * removed. |
| * |
| * Must hold slab_mutex. |
| */ |
| static int __meminit drain_cache_node_node(int node) |
| { |
| struct kmem_cache *cachep; |
| int ret = 0; |
| |
| list_for_each_entry(cachep, &slab_caches, list) { |
| struct kmem_cache_node *n; |
| |
| n = get_node(cachep, node); |
| if (!n) |
| continue; |
| |
| drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
| |
| if (!list_empty(&n->slabs_full) || |
| !list_empty(&n->slabs_partial)) { |
| ret = -EBUSY; |
| break; |
| } |
| } |
| return ret; |
| } |
| |
| static int __meminit slab_memory_callback(struct notifier_block *self, |
| unsigned long action, void *arg) |
| { |
| struct memory_notify *mnb = arg; |
| int ret = 0; |
| int nid; |
| |
| nid = mnb->status_change_nid; |
| if (nid < 0) |
| goto out; |
| |
| switch (action) { |
| case MEM_GOING_ONLINE: |
| mutex_lock(&slab_mutex); |
| ret = init_cache_node_node(nid); |
| mutex_unlock(&slab_mutex); |
| break; |
| case MEM_GOING_OFFLINE: |
| mutex_lock(&slab_mutex); |
| ret = drain_cache_node_node(nid); |
| mutex_unlock(&slab_mutex); |
| break; |
| case MEM_ONLINE: |
| case MEM_OFFLINE: |
| case MEM_CANCEL_ONLINE: |
| case MEM_CANCEL_OFFLINE: |
| break; |
| } |
| out: |
| return notifier_from_errno(ret); |
| } |
| #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ |
| |
| /* |
| * swap the static kmem_cache_node with kmalloced memory |
| */ |
| static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list, |
| int nodeid) |
| { |
| struct kmem_cache_node *ptr; |
| |
| ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid); |
| BUG_ON(!ptr); |
| |
| memcpy(ptr, list, sizeof(struct kmem_cache_node)); |
| /* |
| * Do not assume that spinlocks can be initialized via memcpy: |
| */ |
| spin_lock_init(&ptr->list_lock); |
| |
| MAKE_ALL_LISTS(cachep, ptr, nodeid); |
| cachep->node[nodeid] = ptr; |
| } |
| |
| /* |
| * For setting up all the kmem_cache_node for cache whose buffer_size is same as |
| * size of kmem_cache_node. |
| */ |
| static void __init set_up_node(struct kmem_cache *cachep, int index) |
| { |
| int node; |
| |
| for_each_online_node(node) { |
| cachep->node[node] = &init_kmem_cache_node[index + node]; |
| cachep->node[node]->next_reap = jiffies + |
| REAPTIMEOUT_NODE + |
| ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
| } |
| } |
| |
| /* |
| * Initialisation. Called after the page allocator have been initialised and |
| * before smp_init(). |
| */ |
| void __init kmem_cache_init(void) |
| { |
| int i; |
| |
| BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) < |
| sizeof(struct rcu_head)); |
| kmem_cache = &kmem_cache_boot; |
| |
| if (num_possible_nodes() == 1) |
| use_alien_caches = 0; |
| |
| for (i = 0; i < NUM_INIT_LISTS; i++) |
| kmem_cache_node_init(&init_kmem_cache_node[i]); |
| |
| /* |
| * Fragmentation resistance on low memory - only use bigger |
| * page orders on machines with more than 32MB of memory if |
| * not overridden on the command line. |
| */ |
| if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) |
| slab_max_order = SLAB_MAX_ORDER_HI; |
| |
| /* Bootstrap is tricky, because several objects are allocated |
| * from caches that do not exist yet: |
| * 1) initialize the kmem_cache cache: it contains the struct |
| * kmem_cache structures of all caches, except kmem_cache itself: |
| * kmem_cache is statically allocated. |
| * Initially an __init data area is used for the head array and the |
| * kmem_cache_node structures, it's replaced with a kmalloc allocated |
| * array at the end of the bootstrap. |
| * 2) Create the first kmalloc cache. |
| * The struct kmem_cache for the new cache is allocated normally. |
| * An __init data area is used for the head array. |
| * 3) Create the remaining kmalloc caches, with minimally sized |
| * head arrays. |
| * 4) Replace the __init data head arrays for kmem_cache and the first |
| * kmalloc cache with kmalloc allocated arrays. |
| * 5) Replace the __init data for kmem_cache_node for kmem_cache and |
| * the other cache's with kmalloc allocated memory. |
| * 6) Resize the head arrays of the kmalloc caches to their final sizes. |
| */ |
| |
| /* 1) create the kmem_cache */ |
| |
| /* |
| * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids |
| */ |
| create_boot_cache(kmem_cache, "kmem_cache", |
| offsetof(struct kmem_cache, node) + |
| nr_node_ids * sizeof(struct kmem_cache_node *), |
| SLAB_HWCACHE_ALIGN); |
| list_add(&kmem_cache->list, &slab_caches); |
| slab_state = PARTIAL; |
| |
| /* |
| * Initialize the caches that provide memory for the kmem_cache_node |
| * structures first. Without this, further allocations will bug. |
| */ |
| kmalloc_caches[INDEX_NODE] = create_kmalloc_cache("kmalloc-node", |
| kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); |
| slab_state = PARTIAL_NODE; |
| setup_kmalloc_cache_index_table(); |
| |
| slab_early_init = 0; |
| |
| /* 5) Replace the bootstrap kmem_cache_node */ |
| { |
| int nid; |
| |
| for_each_online_node(nid) { |
| init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid); |
| |
| init_list(kmalloc_caches[INDEX_NODE], |
| &init_kmem_cache_node[SIZE_NODE + nid], nid); |
| } |
| } |
| |
| create_kmalloc_caches(ARCH_KMALLOC_FLAGS); |
| } |
| |
| void __init kmem_cache_init_late(void) |
| { |
| struct kmem_cache *cachep; |
| |
| slab_state = UP; |
| |
| /* 6) resize the head arrays to their final sizes */ |
| mutex_lock(&slab_mutex); |
| list_for_each_entry(cachep, &slab_caches, list) |
| if (enable_cpucache(cachep, GFP_NOWAIT)) |
| BUG(); |
| mutex_unlock(&slab_mutex); |
| |
| /* Done! */ |
| slab_state = FULL; |
| |
| /* |
| * Register a cpu startup notifier callback that initializes |
| * cpu_cache_get for all new cpus |
| */ |
| register_cpu_notifier(&cpucache_notifier); |
| |
| #ifdef CONFIG_NUMA |
| /* |
| * Register a memory hotplug callback that initializes and frees |
| * node. |
| */ |
| hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
| #endif |
| |
| /* |
| * The reap timers are started later, with a module init call: That part |
| * of the kernel is not yet operational. |
| */ |
| } |
| |
| static int __init cpucache_init(void) |
| { |
| int cpu; |
| |
| /* |
| * Register the timers that return unneeded pages to the page allocator |
| */ |
| for_each_online_cpu(cpu) |
| start_cpu_timer(cpu); |
| |
| /* Done! */ |
| slab_state = FULL; |
| return 0; |
| } |
| __initcall(cpucache_init); |
| |
| static noinline void |
| slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) |
| { |
| #if DEBUG |
| struct kmem_cache_node *n; |
| struct page *page; |
| unsigned long flags; |
| int node; |
| static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL, |
| DEFAULT_RATELIMIT_BURST); |
| |
| if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs)) |
| return; |
| |
| printk(KERN_WARNING |
| "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", |
| nodeid, gfpflags); |
| printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n", |
| cachep->name, cachep->size, cachep->gfporder); |
| |
| for_each_kmem_cache_node(cachep, node, n) { |
| unsigned long active_objs = 0, num_objs = 0, free_objects = 0; |
| unsigned long active_slabs = 0, num_slabs = 0; |
| |
| spin_lock_irqsave(&n->list_lock, flags); |
| list_for_each_entry(page, &n->slabs_full, lru) { |
| active_objs += cachep->num; |
| active_slabs++; |
| } |
| list_for_each_entry(page, &n->slabs_partial, lru) { |
| active_objs += page->active; |
| active_slabs++; |
| } |
| list_for_each_entry(page, &n->slabs_free, lru) |
| num_slabs++; |
| |
| free_objects += n->free_objects; |
| spin_unlock_irqrestore(&n->list_lock, flags); |
| |
| num_slabs += active_slabs; |
| num_objs = num_slabs * cachep->num; |
| printk(KERN_WARNING |
| " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n", |
| node, active_slabs, num_slabs, active_objs, num_objs, |
| free_objects); |
| } |
| #endif |
| } |
| |
| /* |
| * Interface to system's page allocator. No need to hold the |
| * kmem_cache_node ->list_lock. |
| * |
| * If we requested dmaable memory, we will get it. Even if we |
| * did not request dmaable memory, we might get it, but that |
| * would be relatively rare and ignorable. |
| */ |
| static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, |
| int nodeid) |
| { |
| struct page *page; |
| int nr_pages; |
| |
| flags |= cachep->allocflags; |
| if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
| flags |= __GFP_RECLAIMABLE; |
| |
| if (memcg_charge_slab(cachep, flags, cachep->gfporder)) |
| return NULL; |
| |
| page = __alloc_pages_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); |
| if (!page) { |
| memcg_uncharge_slab(cachep, cachep->gfporder); |
| slab_out_of_memory(cachep, flags, nodeid); |
| return NULL; |
| } |
| |
| /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ |
| if (page_is_pfmemalloc(page)) |
| pfmemalloc_active = true; |
| |
| nr_pages = (1 << cachep->gfporder); |
| if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
| add_zone_page_state(page_zone(page), |
| NR_SLAB_RECLAIMABLE, nr_pages); |
| else |
| add_zone_page_state(page_zone(page), |
| NR_SLAB_UNRECLAIMABLE, nr_pages); |
| __SetPageSlab(page); |
| if (page_is_pfmemalloc(page)) |
| SetPageSlabPfmemalloc(page); |
| |
| if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { |
| kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); |
| |
| if (cachep->ctor) |
| kmemcheck_mark_uninitialized_pages(page, nr_pages); |
| else |
| kmemcheck_mark_unallocated_pages(page, nr_pages); |
| } |
| |
| return page; |
| } |
| |
| /* |
| * Interface to system's page release. |
| */ |
| static void kmem_freepages(struct kmem_cache *cachep, struct page *page) |
| { |
| const unsigned long nr_freed = (1 << cachep->gfporder); |
| |
| kmemcheck_free_shadow(page, cachep->gfporder); |
| |
| if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
| sub_zone_page_state(page_zone(page), |
| NR_SLAB_RECLAIMABLE, nr_freed); |
| else |
| sub_zone_page_state(page_zone(page), |
| NR_SLAB_UNRECLAIMABLE, nr_freed); |
| |
| BUG_ON(!PageSlab(page)); |
| __ClearPageSlabPfmemalloc(page); |
| __ClearPageSlab(page); |
| page_mapcount_reset(page); |
| page->mapping = NULL; |
| |
| if (current->reclaim_state) |
| current->reclaim_state->reclaimed_slab += nr_freed; |
| __free_pages(page, cachep->gfporder); |
| memcg_uncharge_slab(cachep, cachep->gfporder); |
| } |
| |
| static void kmem_rcu_free(struct rcu_head *head) |
| { |
| struct kmem_cache *cachep; |
| struct page *page; |
| |
| page = container_of(head, struct page, rcu_head); |
| cachep = page->slab_cache; |
| |
| kmem_freepages(cachep, page); |
| } |
| |
| #if DEBUG |
| |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, |
| unsigned long caller) |
| { |
| int size = cachep->object_size; |
| |
| addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; |
| |
| if (size < 5 * sizeof(unsigned long)) |
| return; |
| |
| *addr++ = 0x12345678; |
| *addr++ = caller; |
| *addr++ = smp_processor_id(); |
| size -= 3 * sizeof(unsigned long); |
| { |
| unsigned long *sptr = &caller; |
| unsigned long svalue; |
| |
| while (!kstack_end(sptr)) { |
| svalue = *sptr++; |
| if (kernel_text_address(svalue)) { |
| *addr++ = svalue; |
| size -= sizeof(unsigned long); |
| if (size <= sizeof(unsigned long)) |
| break; |
| } |
| } |
| |
| } |
| *addr++ = 0x87654321; |
| } |
| #endif |
| |
| static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) |
| { |
| int size = cachep->object_size; |
| addr = &((char *)addr)[obj_offset(cachep)]; |
| |
| memset(addr, val, size); |
| *(unsigned char *)(addr + size - 1) = POISON_END; |
| } |
| |
| static void dump_line(char *data, int offset, int limit) |
| { |
| int i; |
| unsigned char error = 0; |
| int bad_count = 0; |
| |
| printk(KERN_ERR "%03x: ", offset); |
| for (i = 0; i < limit; i++) { |
| if (data[offset + i] != POISON_FREE) { |
| error = data[offset + i]; |
| bad_count++; |
| } |
| } |
| print_hex_dump(KERN_CONT, "", 0, 16, 1, |
| &data[offset], limit, 1); |
| |
| if (bad_count == 1) { |
| error ^= POISON_FREE; |
| if (!(error & (error - 1))) { |
| printk(KERN_ERR "Single bit error detected. Probably " |
| "bad RAM.\n"); |
| #ifdef CONFIG_X86 |
| printk(KERN_ERR "Run memtest86+ or a similar memory " |
| "test tool.\n"); |
| #else |
| printk(KERN_ERR "Run a memory test tool.\n"); |
| #endif |
| } |
| } |
| } |
| #endif |
| |
| #if DEBUG |
| |
| static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) |
| { |
| int i, size; |
| char *realobj; |
| |
| if (cachep->flags & SLAB_RED_ZONE) { |
| printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", |
| *dbg_redzone1(cachep, objp), |
| *dbg_redzone2(cachep, objp)); |
| } |
| |
| if (cachep->flags & SLAB_STORE_USER) { |
| printk(KERN_ERR "Last user: [<%p>](%pSR)\n", |
| *dbg_userword(cachep, objp), |
| *dbg_userword(cachep, objp)); |
| } |
| realobj = (char *)objp + obj_offset(cachep); |
| size = cachep->object_size; |
| for (i = 0; i < size && lines; i += 16, lines--) { |
| int limit; |
| limit = 16; |
| if (i + limit > size) |
| limit = size - i; |
| dump_line(realobj, i, limit); |
| } |
| } |
| |
| static void check_poison_obj(struct kmem_cache *cachep, void *objp) |
| { |
| char *realobj; |
| int size, i; |
| int lines = 0; |
| |
| realobj = (char *)objp + obj_offset(cachep); |
| size = cachep->object_size; |
| |
| for (i = 0; i < size; i++) { |
| char exp = POISON_FREE; |
| if (i == size - 1) |
| exp = POISON_END; |
| if (realobj[i] != exp) { |
| int limit; |
| /* Mismatch ! */ |
| /* Print header */ |
| if (lines == 0) { |
| printk(KERN_ERR |
| "Slab corruption (%s): %s start=%p, len=%d\n", |
| print_tainted(), cachep->name, realobj, size); |
| print_objinfo(cachep, objp, 0); |
| } |
| /* Hexdump the affected line */ |
| i = (i / 16) * 16; |
| limit = 16; |
| if (i + limit > size) |
| limit = size - i; |
| dump_line(realobj, i, limit); |
| i += 16; |
| lines++; |
| /* Limit to 5 lines */ |
| if (lines > 5) |
| break; |
| } |
| } |
| if (lines != 0) { |
| /* Print some data about the neighboring objects, if they |
| * exist: |
| */ |
| struct page *page = virt_to_head_page(objp); |
| unsigned int objnr; |
| |
| objnr = obj_to_index(cachep, page, objp); |
| if (objnr) { |
| objp = index_to_obj(cachep, page, objnr - 1); |
| realobj = (char *)objp + obj_offset(cachep); |
| printk(KERN_ERR "Prev obj: start=%p, len=%d\n", |
| realobj, size); |
| print_objinfo(cachep, objp, 2); |
| } |
| if (objnr + 1 < cachep->num) { |
| objp = index_to_obj(cachep, page, objnr + 1); |
| realobj = (char *)objp + obj_offset(cachep); |
| printk(KERN_ERR "Next obj: start=%p, len=%d\n", |
| realobj, size); |
| print_objinfo(cachep, objp, 2); |
| } |
| } |
| } |
| #endif |
| |
| #if DEBUG |
| static void slab_destroy_debugcheck(struct kmem_cache *cachep, |
| struct page *page) |
| { |
| int i; |
| for (i = 0; i < cachep->num; i++) { |
| void *objp = index_to_obj(cachep, page, i); |
| |
| if (cachep->flags & SLAB_POISON) { |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if (cachep->size % PAGE_SIZE == 0 && |
| OFF_SLAB(cachep)) |
| kernel_map_pages(virt_to_page(objp), |
| cachep->size / PAGE_SIZE, 1); |
| else |
| check_poison_obj(cachep, objp); |
| #else |
| check_poison_obj(cachep, objp); |
| #endif |
| } |
| if (cachep->flags & SLAB_RED_ZONE) { |
| if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
| slab_error(cachep, "start of a freed object " |
| "was overwritten"); |
| if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
| slab_error(cachep, "end of a freed object " |
| "was overwritten"); |
| } |
| } |
| } |
| #else |
| static void slab_destroy_debugcheck(struct kmem_cache *cachep, |
| struct page *page) |
| { |
| } |
| #endif |
| |
| /** |
| * slab_destroy - destroy and release all objects in a slab |
| * @cachep: cache pointer being destroyed |
| * @page: page pointer being destroyed |
| * |
| * Destroy all the objs in a slab page, and release the mem back to the system. |
| * Before calling the slab page must have been unlinked from the cache. The |
| * kmem_cache_node ->list_lock is not held/needed. |
| */ |
| static void slab_destroy(struct kmem_cache *cachep, struct page *page) |
| { |
| void *freelist; |
| |
| freelist = page->freelist; |
| slab_destroy_debugcheck(cachep, page); |
| if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { |
| struct rcu_head *head; |
| |
| /* |
| * RCU free overloads the RCU head over the LRU. |
| * slab_page has been overloeaded over the LRU, |
| * however it is not used from now on so that |
| * we can use it safely. |
| */ |
| head = (void *)&page->rcu_head; |
| call_rcu(head, kmem_rcu_free); |
| |
| } else { |
| kmem_freepages(cachep, page); |
| } |
| |
| /* |
| * From now on, we don't use freelist |
| * although actual page can be freed in rcu context |
| */ |
| if (OFF_SLAB(cachep)) |
| kmem_cache_free(cachep->freelist_cache, freelist); |
| } |
| |
| static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list) |
| { |
| struct page *page, *n; |
| |
| list_for_each_entry_safe(page, n, list, lru) { |
| list_del(&page->lru); |
| slab_destroy(cachep, page); |
| } |
| } |
| |
| /** |
| * calculate_slab_order - calculate size (page order) of slabs |
| * @cachep: pointer to the cache that is being created |
| * @size: size of objects to be created in this cache. |
| * @align: required alignment for the objects. |
| * @flags: slab allocation flags |
| * |
| * Also calculates the number of objects per slab. |
| * |
| * This could be made much more intelligent. For now, try to avoid using |
| * high order pages for slabs. When the gfp() functions are more friendly |
| * towards high-order requests, this should be changed. |
| */ |
| static size_t calculate_slab_order(struct kmem_cache *cachep, |
| size_t size, size_t align, unsigned long flags) |
| { |
| unsigned long offslab_limit; |
| size_t left_over = 0; |
| int gfporder; |
| |
| for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { |
| unsigned int num; |
| size_t remainder; |
| |
| cache_estimate(gfporder, size, align, flags, &remainder, &num); |
| if (!num) |
| continue; |
| |
| /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */ |
| if (num > SLAB_OBJ_MAX_NUM) |
| break; |
| |
| if (flags & CFLGS_OFF_SLAB) { |
| size_t freelist_size_per_obj = sizeof(freelist_idx_t); |
| /* |
| * Max number of objs-per-slab for caches which |
| * use off-slab slabs. Needed to avoid a possible |
| * looping condition in cache_grow(). |
| */ |
| if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK)) |
| freelist_size_per_obj += sizeof(char); |
| offslab_limit = size; |
| offslab_limit /= freelist_size_per_obj; |
| |
| if (num > offslab_limit) |
| break; |
| } |
| |
| /* Found something acceptable - save it away */ |
| cachep->num = num; |
| cachep->gfporder = gfporder; |
| left_over = remainder; |
| |
| /* |
| * A VFS-reclaimable slab tends to have most allocations |
| * as GFP_NOFS and we really don't want to have to be allocating |
| * higher-order pages when we are unable to shrink dcache. |
| */ |
| if (flags & SLAB_RECLAIM_ACCOUNT) |
| break; |
| |
| /* |
| * Large number of objects is good, but very large slabs are |
| * currently bad for the gfp()s. |
| */ |
| if (gfporder >= slab_max_order) |
| break; |
| |
| /* |
| * Acceptable internal fragmentation? |
| */ |
| if (left_over * 8 <= (PAGE_SIZE << gfporder)) |
| break; |
| } |
| return left_over; |
| } |
| |
| static struct array_cache __percpu *alloc_kmem_cache_cpus( |
| struct kmem_cache *cachep, int entries, int batchcount) |
| { |
| int cpu; |
| size_t size; |
| struct array_cache __percpu *cpu_cache; |
| |
| size = sizeof(void *) * entries + sizeof(struct array_cache); |
| cpu_cache = __alloc_percpu(size, sizeof(void *)); |
| |
| if (!cpu_cache) |
| return NULL; |
| |
| for_each_possible_cpu(cpu) { |
| init_arraycache(per_cpu_ptr(cpu_cache, cpu), |
| entries, batchcount); |
| } |
| |
| return cpu_cache; |
| } |
| |
| static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) |
| { |
| if (slab_state >= FULL) |
| return enable_cpucache(cachep, gfp); |
| |
| cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1); |
| if (!cachep->cpu_cache) |
| return 1; |
| |
| if (slab_state == DOWN) { |
| /* Creation of first cache (kmem_cache). */ |
| set_up_node(kmem_cache, CACHE_CACHE); |
| } else if (slab_state == PARTIAL) { |
| /* For kmem_cache_node */ |
| set_up_node(cachep, SIZE_NODE); |
| } else { |
| int node; |
| |
| for_each_online_node(node) { |
| cachep->node[node] = kmalloc_node( |
| sizeof(struct kmem_cache_node), gfp, node); |
| BUG_ON(!cachep->node[node]); |
| kmem_cache_node_init(cachep->node[node]); |
| } |
| } |
| |
| cachep->node[numa_mem_id()]->next_reap = |
| jiffies + REAPTIMEOUT_NODE + |
| ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
| |
| cpu_cache_get(cachep)->avail = 0; |
| cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
| cpu_cache_get(cachep)->batchcount = 1; |
| cpu_cache_get(cachep)->touched = 0; |
| cachep->batchcount = 1; |
| cachep->limit = BOOT_CPUCACHE_ENTRIES; |
| return 0; |
| } |
| |
| unsigned long kmem_cache_flags(unsigned long object_size, |
| unsigned long flags, const char *name, |
| void (*ctor)(void *)) |
| { |
| return flags; |
| } |
| |
| struct kmem_cache * |
| __kmem_cache_alias(const char *name, size_t size, size_t align, |
| unsigned long flags, void (*ctor)(void *)) |
| { |
| struct kmem_cache *cachep; |
| |
| cachep = find_mergeable(size, align, flags, name, ctor); |
| if (cachep) { |
| cachep->refcount++; |
| |
| /* |
| * Adjust the object sizes so that we clear |
| * the complete object on kzalloc. |
| */ |
| cachep->object_size = max_t(int, cachep->object_size, size); |
| } |
| return cachep; |
| } |
| |
| /** |
| * __kmem_cache_create - Create a cache. |
| * @cachep: cache management descriptor |
| * @flags: SLAB flags |
| * |
| * Returns a ptr to the cache on success, NULL on failure. |
| * Cannot be called within a int, but can be interrupted. |
| * The @ctor is run when new pages are allocated by the cache. |
| * |
| * The flags are |
| * |
| * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) |
| * to catch references to uninitialised memory. |
| * |
| * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check |
| * for buffer overruns. |
| * |
| * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware |
| * cacheline. This can be beneficial if you're counting cycles as closely |
| * as davem. |
| */ |
| int |
| __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) |
| { |
| size_t left_over, freelist_size; |
| size_t ralign = BYTES_PER_WORD; |
| gfp_t gfp; |
| int err; |
| size_t size = cachep->size; |
| |
| #if DEBUG |
| #if FORCED_DEBUG |
| /* |
| * Enable redzoning and last user accounting, except for caches with |
| * large objects, if the increased size would increase the object size |
| * above the next power of two: caches with object sizes just above a |
| * power of two have a significant amount of internal fragmentation. |
| */ |
| if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + |
| 2 * sizeof(unsigned long long))) |
| flags |= SLAB_RED_ZONE | SLAB_STORE_USER; |
| if (!(flags & SLAB_DESTROY_BY_RCU)) |
| flags |= SLAB_POISON; |
| #endif |
| if (flags & SLAB_DESTROY_BY_RCU) |
| BUG_ON(flags & SLAB_POISON); |
| #endif |
| |
| /* |
| * Check that size is in terms of words. This is needed to avoid |
| * unaligned accesses for some archs when redzoning is used, and makes |
| * sure any on-slab bufctl's are also correctly aligned. |
| */ |
| if (size & (BYTES_PER_WORD - 1)) { |
| size += (BYTES_PER_WORD - 1); |
| size &= ~(BYTES_PER_WORD - 1); |
| } |
| |
| if (flags & SLAB_RED_ZONE) { |
| ralign = REDZONE_ALIGN; |
| /* If redzoning, ensure that the second redzone is suitably |
| * aligned, by adjusting the object size accordingly. */ |
| size += REDZONE_ALIGN - 1; |
| size &= ~(REDZONE_ALIGN - 1); |
| } |
| |
| /* 3) caller mandated alignment */ |
| if (ralign < cachep->align) { |
| ralign = cachep->align; |
| } |
| /* disable debug if necessary */ |
| if (ralign > __alignof__(unsigned long long)) |
| flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
| /* |
| * 4) Store it. |
| */ |
| cachep->align = ralign; |
| |
| if (slab_is_available()) |
| gfp = GFP_KERNEL; |
| else |
| gfp = GFP_NOWAIT; |
| |
| #if DEBUG |
| |
| /* |
| * Both debugging options require word-alignment which is calculated |
| * into align above. |
| */ |
| if (flags & SLAB_RED_ZONE) { |
| /* add space for red zone words */ |
| cachep->obj_offset += sizeof(unsigned long long); |
| size += 2 * sizeof(unsigned long long); |
| } |
| if (flags & SLAB_STORE_USER) { |
| /* user store requires one word storage behind the end of |
| * the real object. But if the second red zone needs to be |
| * aligned to 64 bits, we must allow that much space. |
| */ |
| if (flags & SLAB_RED_ZONE) |
| size += REDZONE_ALIGN; |
| else |
| size += BYTES_PER_WORD; |
| } |
| #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) |
| /* |
| * To activate debug pagealloc, off-slab management is necessary |
| * requirement. In early phase of initialization, small sized slab |
| * doesn't get initialized so it would not be possible. So, we need |
| * to check size >= 256. It guarantees that all necessary small |
| * sized slab is initialized in current slab initialization sequence. |
| */ |
| if (!slab_early_init && size >= kmalloc_size(INDEX_NODE) && |
| size >= 256 && cachep->object_size > cache_line_size() && |
| ALIGN(size, cachep->align) < PAGE_SIZE) { |
| cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align); |
| size = PAGE_SIZE; |
| } |
| #endif |
| #endif |
| |
| /* |
| * Determine if the slab management is 'on' or 'off' slab. |
| * (bootstrapping cannot cope with offslab caches so don't do |
| * it too early on. Always use on-slab management when |
| * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) |
| */ |
| if (size >= OFF_SLAB_MIN_SIZE && !slab_early_init && |
| !(flags & SLAB_NOLEAKTRACE)) |
| /* |
| * Size is large, assume best to place the slab management obj |
| * off-slab (should allow better packing of objs). |
| */ |
| flags |= CFLGS_OFF_SLAB; |
| |
| size = ALIGN(size, cachep->align); |
| /* |
| * We should restrict the number of objects in a slab to implement |
| * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition. |
| */ |
| if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE) |
| size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align); |
| |
| left_over = calculate_slab_order(cachep, size, cachep->align, flags); |
| |
| if (!cachep->num) |
| return -E2BIG; |
| |
| freelist_size = calculate_freelist_size(cachep->num, cachep->align); |
| |
| /* |
| * If the slab has been placed off-slab, and we have enough space then |
| * move it on-slab. This is at the expense of any extra colouring. |
| */ |
| if (flags & CFLGS_OFF_SLAB && left_over >= freelist_size) { |
| flags &= ~CFLGS_OFF_SLAB; |
| left_over -= freelist_size; |
| } |
| |
| if (flags & CFLGS_OFF_SLAB) { |
| /* really off slab. No need for manual alignment */ |
| freelist_size = calculate_freelist_size(cachep->num, 0); |
| |
| #ifdef CONFIG_PAGE_POISONING |
| /* If we're going to use the generic kernel_map_pages() |
| * poisoning, then it's going to smash the contents of |
| * the redzone and userword anyhow, so switch them off. |
| */ |
| if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) |
| flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
| #endif |
| } |
| |
| cachep->colour_off = cache_line_size(); |
| /* Offset must be a multiple of the alignment. */ |
| if (cachep->colour_off < cachep->align) |
| cachep->colour_off = cachep->align; |
| cachep->colour = left_over / cachep->colour_off; |
| cachep->freelist_size = freelist_size; |
| cachep->flags = flags; |
| cachep->allocflags = __GFP_COMP; |
| if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) |
| cachep->allocflags |= GFP_DMA; |
| cachep->size = size; |
| cachep->reciprocal_buffer_size = reciprocal_value(size); |
| |
| if (flags & CFLGS_OFF_SLAB) { |
| cachep->freelist_cache = kmalloc_slab(freelist_size, 0u); |
| /* |
| * This is a possibility for one of the kmalloc_{dma,}_caches. |
| * But since we go off slab only for object size greater than |
| * OFF_SLAB_MIN_SIZE, and kmalloc_{dma,}_caches get created |
| * in ascending order,this should not happen at all. |
| * But leave a BUG_ON for some lucky dude. |
| */ |
| BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache)); |
| } |
| |
| err = setup_cpu_cache(cachep, gfp); |
| if (err) { |
| __kmem_cache_shutdown(cachep); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| #if DEBUG |
| static void check_irq_off(void) |
| { |
| BUG_ON(!irqs_disabled()); |
| } |
| |
| static void check_irq_on(void) |
| { |
| BUG_ON(irqs_disabled()); |
| } |
| |
| static void check_spinlock_acquired(struct kmem_cache *cachep) |
| { |
| #ifdef CONFIG_SMP |
| check_irq_off(); |
| assert_spin_locked(&get_node(cachep, numa_mem_id())->list_lock); |
| #endif |
| } |
| |
| static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) |
| { |
| #ifdef CONFIG_SMP |
| check_irq_off(); |
| assert_spin_locked(&get_node(cachep, node)->list_lock); |
| #endif |
| } |
| |
| #else |
| #define check_irq_off() do { } while(0) |
| #define check_irq_on() do { } while(0) |
| #define check_spinlock_acquired(x) do { } while(0) |
| #define check_spinlock_acquired_node(x, y) do { } while(0) |
| #endif |
| |
| static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
| struct array_cache *ac, |
| int force, int node); |
| |
| static void do_drain(void *arg) |
| { |
| struct kmem_cache *cachep = arg; |
| struct array_cache *ac; |
| int node = numa_mem_id(); |
| struct kmem_cache_node *n; |
| LIST_HEAD(list); |
| |
| check_irq_off(); |
| ac = cpu_cache_get(cachep); |
| n = get_node(cachep, node); |
| spin_lock(&n->list_lock); |
| free_block(cachep, ac->entry, ac->avail, node, &list); |
| spin_unlock(&n->list_lock); |
| slabs_destroy(cachep, &list); |
| ac->avail = 0; |
| } |
| |
| static void drain_cpu_caches(struct kmem_cache *cachep) |
| { |
| struct kmem_cache_node *n; |
| int node; |
| |
| on_each_cpu(do_drain, cachep, 1); |
| check_irq_on(); |
| for_each_kmem_cache_node(cachep, node, n) |
| if (n->alien) |
| drain_alien_cache(cachep, n->alien); |
| |
| for_each_kmem_cache_node(cachep, node, n) |
| drain_array(cachep, n, n->shared, 1, node); |
| } |
| |
| /* |
| * Remove slabs from the list of free slabs. |
| * Specify the number of slabs to drain in tofree. |
| * |
| * Returns the actual number of slabs released. |
| */ |
| static int drain_freelist(struct kmem_cache *cache, |
| struct kmem_cache_node *n, int tofree) |
| { |
| struct list_head *p; |
| int nr_freed; |
| struct page *page; |
| |
| nr_freed = 0; |
| while (nr_freed < tofree && !list_empty(&n->slabs_free)) { |
| |
| spin_lock_irq(&n->list_lock); |
| p = n->slabs_free.prev; |
| if (p == &n->slabs_free) { |
| spin_unlock_irq(&n->list_lock); |
| goto out; |
| } |
| |
| page = list_entry(p, struct page, lru); |
| #if DEBUG |
| BUG_ON(page->active); |
| #endif |
| list_del(&page->lru); |
| /* |
| * Safe to drop the lock. The slab is no longer linked |
| * to the cache. |
| */ |
| n->free_objects -= cache->num; |
| spin_unlock_irq(&n->list_lock); |
| slab_destroy(cache, page); |
| nr_freed++; |
| } |
| out: |
| return nr_freed; |
| } |
| |
| int __kmem_cache_shrink(struct kmem_cache *cachep, bool deactivate) |
| { |
| int ret = 0; |
| int node; |
| struct kmem_cache_node *n; |
| |
| drain_cpu_caches(cachep); |
| |
| check_irq_on(); |
| for_each_kmem_cache_node(cachep, node, n) { |
| drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
| |
| ret += !list_empty(&n->slabs_full) || |
| !list_empty(&n->slabs_partial); |
| } |
| return (ret ? 1 : 0); |
| } |
| |
| int __kmem_cache_shutdown(struct kmem_cache *cachep) |
| { |
| int i; |
| struct kmem_cache_node *n; |
| int rc = __kmem_cache_shrink(cachep, false); |
| |
| if (rc) |
| return rc; |
| |
| free_percpu(cachep->cpu_cache); |
| |
| /* NUMA: free the node structures */ |
| for_each_kmem_cache_node(cachep, i, n) { |
| kfree(n->shared); |
| free_alien_cache(n->alien); |
| kfree(n); |
| cachep->node[i] = NULL; |
| } |
| return 0; |
| } |
| |
| /* |
| * Get the memory for a slab management obj. |
| * |
| * For a slab cache when the slab descriptor is off-slab, the |
| * slab descriptor can't come from the same cache which is being created, |
| * Because if it is the case, that means we defer the creation of |
| * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point. |
| * And we eventually call down to __kmem_cache_create(), which |
| * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one. |
| * This is a "chicken-and-egg" problem. |
| * |
| * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches, |
| * which are all initialized during kmem_cache_init(). |
| */ |
| static void *alloc_slabmgmt(struct kmem_cache *cachep, |
| struct page *page, int colour_off, |
| gfp_t local_flags, int nodeid) |
| { |
| void *freelist; |
| void *addr = page_address(page); |
| |
| if (OFF_SLAB(cachep)) { |
| /* Slab management obj is off-slab. */ |
| freelist = kmem_cache_alloc_node(cachep->freelist_cache, |
| local_flags, nodeid); |
| if (!freelist) |
| return NULL; |
| } else { |
| freelist = addr + colour_off; |
| colour_off += cachep->freelist_size; |
| } |
| page->active = 0; |
| page->s_mem = addr + colour_off; |
| return freelist; |
| } |
| |
| static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx) |
| { |
| return ((freelist_idx_t *)page->freelist)[idx]; |
| } |
| |
| static inline void set_free_obj(struct page *page, |
| unsigned int idx, freelist_idx_t val) |
| { |
| ((freelist_idx_t *)(page->freelist))[idx] = val; |
| } |
| |
| static void cache_init_objs(struct kmem_cache *cachep, |
| struct page *page) |
| { |
| int i; |
| |
| for (i = 0; i < cachep->num; i++) { |
| void *objp = index_to_obj(cachep, page, i); |
| #if DEBUG |
| /* need to poison the objs? */ |
| if (cachep->flags & SLAB_POISON) |
| poison_obj(cachep, objp, POISON_FREE); |
| if (cachep->flags & SLAB_STORE_USER) |
| *dbg_userword(cachep, objp) = NULL; |
| |
| if (cachep->flags & SLAB_RED_ZONE) { |
| *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
| *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
| } |
| /* |
| * Constructors are not allowed to allocate memory from the same |
| * cache which they are a constructor for. Otherwise, deadlock. |
| * They must also be threaded. |
| */ |
| if (cachep->ctor && !(cachep->flags & SLAB_POISON)) |
| cachep->ctor(objp + obj_offset(cachep)); |
| |
| if (cachep->flags & SLAB_RED_ZONE) { |
| if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
| slab_error(cachep, "constructor overwrote the" |
| " end of an object"); |
| if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
| slab_error(cachep, "constructor overwrote the" |
| " start of an object"); |
| } |
| if ((cachep->size % PAGE_SIZE) == 0 && |
| OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) |
| kernel_map_pages(virt_to_page(objp), |
| cachep->size / PAGE_SIZE, 0); |
| #else |
| if (cachep->ctor) |
| cachep->ctor(objp); |
| #endif |
| set_obj_status(page, i, OBJECT_FREE); |
| set_free_obj(page, i, i); |
| } |
| } |
| |
| static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) |
| { |
| if (CONFIG_ZONE_DMA_FLAG) { |
| if (flags & GFP_DMA) |
| BUG_ON(!(cachep->allocflags & GFP_DMA)); |
| else |
| BUG_ON(cachep->allocflags & GFP_DMA); |
| } |
| } |
| |
| static void *slab_get_obj(struct kmem_cache *cachep, struct page *page, |
| int nodeid) |
| { |
| void *objp; |
| |
| objp = index_to_obj(cachep, page, get_free_obj(page, page->active)); |
| page->active++; |
| #if DEBUG |
| WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); |
| #endif |
| |
| return objp; |
| } |
| |
| static void slab_put_obj(struct kmem_cache *cachep, struct page *page, |
| void *objp, int nodeid) |
| { |
| unsigned int objnr = obj_to_index(cachep, page, objp); |
| #if DEBUG |
| unsigned int i; |
| |
| /* Verify that the slab belongs to the intended node */ |
| WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); |
| |
| /* Verify double free bug */ |
| for (i = page->active; i < cachep->num; i++) { |
| if (get_free_obj(page, i) == objnr) { |
| printk(KERN_ERR "slab: double free detected in cache " |
| "'%s', objp %p\n", cachep->name, objp); |
| BUG(); |
| } |
| } |
| #endif |
| page->active--; |
| set_free_obj(page, page->active, objnr); |
| } |
| |
| /* |
| * Map pages beginning at addr to the given cache and slab. This is required |
| * for the slab allocator to be able to lookup the cache and slab of a |
| * virtual address for kfree, ksize, and slab debugging. |
| */ |
| static void slab_map_pages(struct kmem_cache *cache, struct page *page, |
| void *freelist) |
| { |
| page->slab_cache = cache; |
| page->freelist = freelist; |
| } |
| |
| /* |
| * Grow (by 1) the number of slabs within a cache. This is called by |
| * kmem_cache_alloc() when there are no active objs left in a cache. |
| */ |
| static int cache_grow(struct kmem_cache *cachep, |
| gfp_t flags, int nodeid, struct page *page) |
| { |
| void *freelist; |
| size_t offset; |
| gfp_t local_flags; |
| struct kmem_cache_node *n; |
| |
| /* |
| * Be lazy and only check for valid flags here, keeping it out of the |
| * critical path in kmem_cache_alloc(). |
| */ |
| if (unlikely(flags & GFP_SLAB_BUG_MASK)) { |
| pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK); |
| BUG(); |
| } |
| local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
| |
| /* Take the node list lock to change the colour_next on this node */ |
| check_irq_off(); |
| n = get_node(cachep, nodeid); |
| spin_lock(&n->list_lock); |
| |
| /* Get colour for the slab, and cal the next value. */ |
| offset = n->colour_next; |
| n->colour_next++; |
| if (n->colour_next >= cachep->colour) |
| n->colour_next = 0; |
| spin_unlock(&n->list_lock); |
| |
| offset *= cachep->colour_off; |
| |
| if (local_flags & __GFP_WAIT) |
| local_irq_enable(); |
| |
| /* |
| * The test for missing atomic flag is performed here, rather than |
| * the more obvious place, simply to reduce the critical path length |
| * in kmem_cache_alloc(). If a caller is seriously mis-behaving they |
| * will eventually be caught here (where it matters). |
| */ |
| kmem_flagcheck(cachep, flags); |
| |
| /* |
| * Get mem for the objs. Attempt to allocate a physical page from |
| * 'nodeid'. |
| */ |
| if (!page) |
| page = kmem_getpages(cachep, local_flags, nodeid); |
| if (!page) |
| goto failed; |
| |
| /* Get slab management. */ |
| freelist = alloc_slabmgmt(cachep, page, offset, |
| local_flags & ~GFP_CONSTRAINT_MASK, nodeid); |
| if (!freelist) |
| goto opps1; |
| |
| slab_map_pages(cachep, page, freelist); |
| |
| cache_init_objs(cachep, page); |
| |
| if (local_flags & __GFP_WAIT) |
| local_irq_disable(); |
| check_irq_off(); |
| spin_lock(&n->list_lock); |
| |
| /* Make slab active. */ |
| list_add_tail(&page->lru, &(n->slabs_free)); |
| STATS_INC_GROWN(cachep); |
| n->free_objects += cachep->num; |
| spin_unlock(&n->list_lock); |
| return 1; |
| opps1: |
| kmem_freepages(cachep, page); |
| failed: |
| if (local_flags & __GFP_WAIT) |
| local_irq_disable(); |
| return 0; |
| } |
| |
| #if DEBUG |
| |
| /* |
| * Perform extra freeing checks: |
| * - detect bad pointers. |
| * - POISON/RED_ZONE checking |
| */ |
| static void kfree_debugcheck(const void *objp) |
| { |
| if (!virt_addr_valid(objp)) { |
| printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", |
| (unsigned long)objp); |
| BUG(); |
| } |
| } |
| |
| static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) |
| { |
| unsigned long long redzone1, redzone2; |
| |
| redzone1 = *dbg_redzone1(cache, obj); |
| redzone2 = *dbg_redzone2(cache, obj); |
| |
| /* |
| * Redzone is ok. |
| */ |
| if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) |
| return; |
| |
| if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) |
| slab_error(cache, "double free detected"); |
| else |
| slab_error(cache, "memory outside object was overwritten"); |
| |
| printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", |
| obj, redzone1, redzone2); |
| } |
| |
| static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, |
| unsigned long caller) |
| { |
| unsigned int objnr; |
| struct page *page; |
| |
| BUG_ON(virt_to_cache(objp) != cachep); |
| |
| objp -= obj_offset(cachep); |
| kfree_debugcheck(objp); |
| page = virt_to_head_page(objp); |
| |
| if (cachep->flags & SLAB_RED_ZONE) { |
| verify_redzone_free(cachep, objp); |
| *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
| *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
| } |
| if (cachep->flags & SLAB_STORE_USER) |
| *dbg_userword(cachep, objp) = (void *)caller; |
| |
| objnr = obj_to_index(cachep, page, objp); |
| |
| BUG_ON(objnr >= cachep->num); |
| BUG_ON(objp != index_to_obj(cachep, page, objnr)); |
| |
| set_obj_status(page, objnr, OBJECT_FREE); |
| if (cachep->flags & SLAB_POISON) { |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { |
| store_stackinfo(cachep, objp, caller); |
| kernel_map_pages(virt_to_page(objp), |
| cachep->size / PAGE_SIZE, 0); |
| } else { |
| poison_obj(cachep, objp, POISON_FREE); |
| } |
| #else |
| poison_obj(cachep, objp, POISON_FREE); |
| #endif |
| } |
| return objp; |
| } |
| |
| #else |
| #define kfree_debugcheck(x) do { } while(0) |
| #define cache_free_debugcheck(x,objp,z) (objp) |
| #endif |
| |
| static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, |
| bool force_refill) |
| { |
| int batchcount; |
| struct kmem_cache_node *n; |
| struct array_cache *ac; |
| int node; |
| |
| check_irq_off(); |
| node = numa_mem_id(); |
| if (unlikely(force_refill)) |
| goto force_grow; |
| retry: |
| ac = cpu_cache_get(cachep); |
| batchcount = ac->batchcount; |
| if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { |
| /* |
| * If there was little recent activity on this cache, then |
| * perform only a partial refill. Otherwise we could generate |
| * refill bouncing. |
| */ |
| batchcount = BATCHREFILL_LIMIT; |
| } |
| n = get_node(cachep, node); |
| |
| BUG_ON(ac->avail > 0 || !n); |
| spin_lock(&n->list_lock); |
| |
| /* See if we can refill from the shared array */ |
| if (n->shared && transfer_objects(ac, n->shared, batchcount)) { |
| n->shared->touched = 1; |
| goto alloc_done; |
| } |
| |
| while (batchcount > 0) { |
| struct list_head *entry; |
| struct page *page; |
| /* Get slab alloc is to come from. */ |
| entry = n->slabs_partial.next; |
| if (entry == &n->slabs_partial) { |
| n->free_touched = 1; |
| entry = n->slabs_free.next; |
| if (entry == &n->slabs_free) |
| goto must_grow; |
| } |
| |
| page = list_entry(entry, struct page, lru); |
| check_spinlock_acquired(cachep); |
| |
| /* |
| * The slab was either on partial or free list so |
| * there must be at least one object available for |
| * allocation. |
| */ |
| BUG_ON(page->active >= cachep->num); |
| |
| while (page->active < cachep->num && batchcount--) { |
| STATS_INC_ALLOCED(cachep); |
| STATS_INC_ACTIVE(cachep); |
| STATS_SET_HIGH(cachep); |
| |
| ac_put_obj(cachep, ac, slab_get_obj(cachep, page, |
| node)); |
| } |
| |
| /* move slabp to correct slabp list: */ |
| list_del(&page->lru); |
| if (page->active == cachep->num) |
| list_add(&page->lru, &n->slabs_full); |
| else |
| list_add(&page->lru, &n->slabs_partial); |
| } |
| |
| must_grow: |
| n->free_objects -= ac->avail; |
| alloc_done: |
| spin_unlock(&n->list_lock); |
| |
| if (unlikely(!ac->avail)) { |
| int x; |
| force_grow: |
| x = cache_grow(cachep, gfp_exact_node(flags), node, NULL); |
| |
| /* cache_grow can reenable interrupts, then ac could change. */ |
| ac = cpu_cache_get(cachep); |
| node = numa_mem_id(); |
| |
| /* no objects in sight? abort */ |
| if (!x && (ac->avail == 0 || force_refill)) |
| return NULL; |
| |
| if (!ac->avail) /* objects refilled by interrupt? */ |
| goto retry; |
| } |
| ac->touched = 1; |
| |
| return ac_get_obj(cachep, ac, flags, force_refill); |
| } |
| |
| static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, |
| gfp_t flags) |
| { |
| might_sleep_if(flags & __GFP_WAIT); |
| #if DEBUG |
| kmem_flagcheck(cachep, flags); |
| #endif |
| } |
| |
| #if DEBUG |
| static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, |
| gfp_t flags, void *objp, unsigned long caller) |
| { |
| struct page *page; |
| |
| if (!objp) |
| return objp; |
| if (cachep->flags & SLAB_POISON) { |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) |
| kernel_map_pages(virt_to_page(objp), |
| cachep->size / PAGE_SIZE, 1); |
| else |
| check_poison_obj(cachep, objp); |
| #else |
| check_poison_obj(cachep, objp); |
| #endif |
| poison_obj(cachep, objp, POISON_INUSE); |
| } |
| if (cachep->flags & SLAB_STORE_USER) |
| *dbg_userword(cachep, objp) = (void *)caller; |
| |
| if (cachep->flags & SLAB_RED_ZONE) { |
| if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || |
| *dbg_redzone2(cachep, objp) != RED_INACTIVE) { |
| slab_error(cachep, "double free, or memory outside" |
| " object was overwritten"); |
| printk(KERN_ERR |
| "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", |
| objp, *dbg_redzone1(cachep, objp), |
| *dbg_redzone2(cachep, objp)); |
| } |
| *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
| *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
| } |
| |
| page = virt_to_head_page(objp); |
| set_obj_status(page, obj_to_index(cachep, page, objp), OBJECT_ACTIVE); |
| objp += obj_offset(cachep); |
| if (cachep->ctor && cachep->flags & SLAB_POISON) |
| cachep->ctor(objp); |
| if (ARCH_SLAB_MINALIGN && |
| ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { |
| printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", |
| objp, (int)ARCH_SLAB_MINALIGN); |
| } |
| return objp; |
| } |
| #else |
| #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
| #endif |
| |
| static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) |
| { |
| if (unlikely(cachep == kmem_cache)) |
| return false; |
| |
| return should_failslab(cachep->object_size, flags, cachep->flags); |
| } |
| |
| static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
| { |
| void *objp; |
| struct array_cache *ac; |
| bool force_refill = false; |
| |
| check_irq_off(); |
| |
| ac = cpu_cache_get(cachep); |
| if (likely(ac->avail)) { |
| ac->touched = 1; |
| objp = ac_get_obj(cachep, ac, flags, false); |
| |
| /* |
| * Allow for the possibility all avail objects are not allowed |
| * by the current flags |
| */ |
| if (objp) { |
| STATS_INC_ALLOCHIT(cachep); |
| goto out; |
| } |
| force_refill = true; |
| } |
| |
| STATS_INC_ALLOCMISS(cachep); |
| objp = cache_alloc_refill(cachep, flags, force_refill); |
| /* |
| * the 'ac' may be updated by cache_alloc_refill(), |
| * and kmemleak_erase() requires its correct value. |
| */ |
| ac = cpu_cache_get(cachep); |
| |
| out: |
| /* |
| * To avoid a false negative, if an object that is in one of the |
| * per-CPU caches is leaked, we need to make sure kmemleak doesn't |
| * treat the array pointers as a reference to the object. |
| */ |
| if (objp) |
| kmemleak_erase(&ac->entry[ac->avail]); |
| return objp; |
| } |
| |
| #ifdef CONFIG_NUMA |
| /* |
| * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set. |
| * |
| * If we are in_interrupt, then process context, including cpusets and |
| * mempolicy, may not apply and should not be used for allocation policy. |
| */ |
| static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) |
| { |
| int nid_alloc, nid_here; |
| |
| if (in_interrupt() || (flags & __GFP_THISNODE)) |
| return NULL; |
| nid_alloc = nid_here = numa_mem_id(); |
| if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) |
| nid_alloc = cpuset_slab_spread_node(); |
| else if (current->mempolicy) |
| nid_alloc = mempolicy_slab_node(); |
| if (nid_alloc != nid_here) |
| return ____cache_alloc_node(cachep, flags, nid_alloc); |
| return NULL; |
| } |
| |
| /* |
| * Fallback function if there was no memory available and no objects on a |
| * certain node and fall back is permitted. First we scan all the |
| * available node for available objects. If that fails then we |
| * perform an allocation without specifying a node. This allows the page |
| * allocator to do its reclaim / fallback magic. We then insert the |
| * slab into the proper nodelist and then allocate from it. |
| */ |
| static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) |
| { |
| struct zonelist *zonelist; |
| gfp_t local_flags; |
| struct zoneref *z; |
| struct zone *zone; |
| enum zone_type high_zoneidx = gfp_zone(flags); |
| void *obj = NULL; |
| int nid; |
| unsigned int cpuset_mems_cookie; |
| |
| if (flags & __GFP_THISNODE) |
| return NULL; |
| |
| local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
| |
| retry_cpuset: |
| cpuset_mems_cookie = read_mems_allowed_begin(); |
| zonelist = node_zonelist(mempolicy_slab_node(), flags); |
| |
| retry: |
| /* |
| * Look through allowed nodes for objects available |
| * from existing per node queues. |
| */ |
| for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
| nid = zone_to_nid(zone); |
| |
| if (cpuset_zone_allowed(zone, flags) && |
| get_node(cache, nid) && |
| get_node(cache, nid)->free_objects) { |
| obj = ____cache_alloc_node(cache, |
| gfp_exact_node(flags), nid); |
| if (obj) |
| break; |
| } |
| } |
| |
| if (!obj) { |
| /* |
| * This allocation will be performed within the constraints |
| * of the current cpuset / memory policy requirements. |
| * We may trigger various forms of reclaim on the allowed |
| * set and go into memory reserves if necessary. |
| */ |
| struct page *page; |
| |
| if (local_flags & __GFP_WAIT) |
| local_irq_enable(); |
| kmem_flagcheck(cache, flags); |
| page = kmem_getpages(cache, local_flags, numa_mem_id()); |
| if (local_flags & __GFP_WAIT) |
| local_irq_disable(); |
| if (page) { |
| /* |
| * Insert into the appropriate per node queues |
| */ |
| nid = page_to_nid(page); |
| if (cache_grow(cache, flags, nid, page)) { |
| obj = ____cache_alloc_node(cache, |
| gfp_exact_node(flags), nid); |
| if (!obj) |
| /* |
| * Another processor may allocate the |
| * objects in the slab since we are |
| * not holding any locks. |
| */ |
| goto retry; |
| } else { |
| /* cache_grow already freed obj */ |
| obj = NULL; |
| } |
| } |
| } |
| |
| if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie))) |
| goto retry_cpuset; |
| return obj; |
| } |
| |
| /* |
| * A interface to enable slab creation on nodeid |
| */ |
| static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, |
| int nodeid) |
| { |
| struct list_head *entry; |
| struct page *page; |
| struct kmem_cache_node *n; |
| void *obj; |
| int x; |
| |
| VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES); |
| n = get_node(cachep, nodeid); |
| BUG_ON(!n); |
| |
| retry: |
| check_irq_off(); |
| spin_lock(&n->list_lock); |
| entry = n->slabs_partial.next; |
| if (entry == &n->slabs_partial) { |
| n->free_touched = 1; |
| entry = n->slabs_free.next; |
| if (entry == &n->slabs_free) |
| goto must_grow; |
| } |
| |
| page = list_entry(entry, struct page, lru); |
| check_spinlock_acquired_node(cachep, nodeid); |
| |
| STATS_INC_NODEALLOCS(cachep); |
| STATS_INC_ACTIVE(cachep); |
| STATS_SET_HIGH(cachep); |
| |
| BUG_ON(page->active == cachep->num); |
| |
| obj = slab_get_obj(cachep, page, nodeid); |
| n->free_objects--; |
| /* move slabp to correct slabp list: */ |
| list_del(&page->lru); |
| |
| if (page->active == cachep->num) |
| list_add(&page->lru, &n->slabs_full); |
| else |
| list_add(&page->lru, &n->slabs_partial); |
| |
| spin_unlock(&n->list_lock); |
| goto done; |
| |
| must_grow: |
| spin_unlock(&n->list_lock); |
| x = cache_grow(cachep, gfp_exact_node(flags), nodeid, NULL); |
| if (x) |
| goto retry; |
| |
| return fallback_alloc(cachep, flags); |
| |
| done: |
| return obj; |
| } |
| |
| static __always_inline void * |
| slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, |
| unsigned long caller) |
| { |
| unsigned long save_flags; |
| void *ptr; |
| int slab_node = numa_mem_id(); |
| |
| flags &= gfp_allowed_mask; |
| |
| lockdep_trace_alloc(flags); |
| |
| if (slab_should_failslab(cachep, flags)) |
| return NULL; |
| |
| cachep = memcg_kmem_get_cache(cachep, flags); |
| |
| cache_alloc_debugcheck_before(cachep, flags); |
| local_irq_save(save_flags); |
| |
| if (nodeid == NUMA_NO_NODE) |
| nodeid = slab_node; |
| |
| if (unlikely(!get_node(cachep, nodeid))) { |
| /* Node not bootstrapped yet */ |
| ptr = fallback_alloc(cachep, flags); |
| goto out; |
| } |
| |
| if (nodeid == slab_node) { |
| /* |
| * Use the locally cached objects if possible. |
| * However ____cache_alloc does not allow fallback |
| * to other nodes. It may fail while we still have |
| * objects on other nodes available. |
| */ |
| ptr = ____cache_alloc(cachep, flags); |
| if (ptr) |
| goto out; |
| } |
| /* ___cache_alloc_node can fall back to other nodes */ |
| ptr = ____cache_alloc_node(cachep, flags, nodeid); |
| out: |
| local_irq_restore(save_flags); |
| ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); |
| kmemleak_alloc_recursive(ptr, cachep->object_size, 1, cachep->flags, |
| flags); |
| |
| if (likely(ptr)) { |
| kmemcheck_slab_alloc(cachep, flags, ptr, cachep->object_size); |
| if (unlikely(flags & __GFP_ZERO)) |
| memset(ptr, 0, cachep->object_size); |
| } |
| |
| memcg_kmem_put_cache(cachep); |
| return ptr; |
| } |
| |
| static __always_inline void * |
| __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) |
| { |
| void *objp; |
| |
| if (current->mempolicy || cpuset_do_slab_mem_spread()) { |
| objp = alternate_node_alloc(cache, flags); |
| if (objp) |
| goto out; |
| } |
| objp = ____cache_alloc(cache, flags); |
| |
| /* |
| * We may just have run out of memory on the local node. |
| * ____cache_alloc_node() knows how to locate memory on other nodes |
| */ |
| if (!objp) |
| objp = ____cache_alloc_node(cache, flags, numa_mem_id()); |
| |
| out: |
| return objp; |
| } |
| #else |
| |
| static __always_inline void * |
| __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
| { |
| return ____cache_alloc(cachep, flags); |
| } |
| |
| #endif /* CONFIG_NUMA */ |
| |
| static __always_inline void * |
| slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) |
| { |
| unsigned long save_flags; |
| void *objp; |
| |
| flags &= gfp_allowed_mask; |
| |
| lockdep_trace_alloc(flags); |
| |
| if (slab_should_failslab(cachep, flags)) |
| return NULL; |
| |
| cachep = memcg_kmem_get_cache(cachep, flags); |
| |
| cache_alloc_debugcheck_before(cachep, flags); |
| local_irq_save(save_flags); |
| objp = __do_cache_alloc(cachep, flags); |
| local_irq_restore(save_flags); |
| objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); |
| kmemleak_alloc_recursive(objp, cachep->object_size, 1, cachep->flags, |
| flags); |
| prefetchw(objp); |
| |
| if (likely(objp)) { |
| kmemcheck_slab_alloc(cachep, flags, objp, cachep->object_size); |
| if (unlikely(flags & __GFP_ZERO)) |
| memset(objp, 0, cachep->object_size); |
| } |
| |
| memcg_kmem_put_cache(cachep); |
| return objp; |
| } |
| |
| /* |
| * Caller needs to acquire correct kmem_cache_node's list_lock |
| * @list: List of detached free slabs should be freed by caller |
| */ |
| static void free_block(struct kmem_cache *cachep, void **objpp, |
| int nr_objects, int node, struct list_head *list) |
| { |
| int i; |
| struct kmem_cache_node *n = get_node(cachep, node); |
| |
| for (i = 0; i < nr_objects; i++) { |
| void *objp; |
| struct page *page; |
| |
| clear_obj_pfmemalloc(&objpp[i]); |
| objp = objpp[i]; |
| |
| page = virt_to_head_page(objp); |
| list_del(&page->lru); |
| check_spinlock_acquired_node(cachep, node); |
| slab_put_obj(cachep, page, objp, node); |
| STATS_DEC_ACTIVE(cachep); |
| n->free_objects++; |
| |
| /* fixup slab chains */ |
| if (page->active == 0) { |
| if (n->free_objects > n->free_limit) { |
| n->free_objects -= cachep->num; |
| list_add_tail(&page->lru, list); |
| } else { |
| list_add(&page->lru, &n->slabs_free); |
| } |
| } else { |
| /* Unconditionally move a slab to the end of the |
| * partial list on free - maximum time for the |
| * other objects to be freed, too. |
| */ |
| list_add_tail(&page->lru, &n->slabs_partial); |
| } |
| } |
| } |
| |
| static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) |
| { |
| int batchcount; |
| struct kmem_cache_node *n; |
| int node = numa_mem_id(); |
| LIST_HEAD(list); |
| |
| batchcount = ac->batchcount; |
| #if DEBUG |
| BUG_ON(!batchcount || batchcount > ac->avail); |
| #endif |
| check_irq_off(); |
| n = get_node(cachep, node); |
| spin_lock(&n->list_lock); |
| if (n->shared) { |
| struct array_cache *shared_array = n->shared; |
| int max = shared_array->limit - shared_array->avail; |
| if (max) { |
| if (batchcount > max) |
| batchcount = max; |
| memcpy(&(shared_array->entry[shared_array->avail]), |
| ac->entry, sizeof(void *) * batchcount); |
| shared_array->avail += batchcount; |
| goto free_done; |
| } |
| } |
| |
| free_block(cachep, ac->entry, batchcount, node, &list); |
| free_done: |
| #if STATS |
| { |
| int i = 0; |
| struct list_head *p; |
| |
| p = n->slabs_free.next; |
| while (p != &(n->slabs_free)) { |
| struct page *page; |
| |
| page = list_entry(p, struct page, lru); |
| BUG_ON(page->active); |
| |
| i++; |
| p = p->next; |
| } |
| STATS_SET_FREEABLE(cachep, i); |
| } |
| #endif |
| spin_unlock(&n->list_lock); |
| slabs_destroy(cachep, &list); |
| ac->avail -= batchcount; |
| memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); |
| } |
| |
| /* |
| * Release an obj back to its cache. If the obj has a constructed state, it must |
| * be in this state _before_ it is released. Called with disabled ints. |
| */ |
| static inline void __cache_free(struct kmem_cache *cachep, void *objp, |
| unsigned long caller) |
| { |
| struct array_cache *ac = cpu_cache_get(cachep); |
| |
| check_irq_off(); |
| kmemleak_free_recursive(objp, cachep->flags); |
| objp = cache_free_debugcheck(cachep, objp, caller); |
| |
| kmemcheck_slab_free(cachep, objp, cachep->object_size); |
| |
| /* |
| * Skip calling cache_free_alien() when the platform is not numa. |
| * This will avoid cache misses that happen while accessing slabp (which |
| * is per page memory reference) to get nodeid. Instead use a global |
| * variable to skip the call, which is mostly likely to be present in |
| * the cache. |
| */ |
| if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) |
| return; |
| |
| if (ac->avail < ac->limit) { |
| STATS_INC_FREEHIT(cachep); |
| } else { |
| STATS_INC_FREEMISS(cachep); |
| cache_flusharray(cachep, ac); |
| } |
| |
| ac_put_obj(cachep, ac, objp); |
| } |
| |
| /** |
| * kmem_cache_alloc - Allocate an object |
| * @cachep: The cache to allocate from. |
| * @flags: See kmalloc(). |
| * |
| * Allocate an object from this cache. The flags are only relevant |
| * if the cache has no available objects. |
| */ |
| void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
| { |
| void *ret = slab_alloc(cachep, flags, _RET_IP_); |
| |
| trace_kmem_cache_alloc(_RET_IP_, ret, |
| cachep->object_size, cachep->size, flags); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(kmem_cache_alloc); |
| |
| void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p) |
| { |
| __kmem_cache_free_bulk(s, size, p); |
| } |
| EXPORT_SYMBOL(kmem_cache_free_bulk); |
| |
| bool kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, |
| void **p) |
| { |
| return __kmem_cache_alloc_bulk(s, flags, size, p); |
| } |
| EXPORT_SYMBOL(kmem_cache_alloc_bulk); |
| |
| #ifdef CONFIG_TRACING |
| void * |
| kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size) |
| { |
| void *ret; |
| |
| ret = slab_alloc(cachep, flags, _RET_IP_); |
| |
| trace_kmalloc(_RET_IP_, ret, |
| size, cachep->size, flags); |
| return ret; |
| } |
| EXPORT_SYMBOL(kmem_cache_alloc_trace); |
| #endif |
| |
| #ifdef CONFIG_NUMA |
| /** |
| * kmem_cache_alloc_node - Allocate an object on the specified node |
| * @cachep: The cache to allocate from. |
| * @flags: See kmalloc(). |
| * @nodeid: node number of the target node. |
| * |
| * Identical to kmem_cache_alloc but it will allocate memory on the given |
| * node, which can improve the performance for cpu bound structures. |
| * |
| * Fallback to other node is possible if __GFP_THISNODE is not set. |
| */ |
| void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
| { |
| void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
| |
| trace_kmem_cache_alloc_node(_RET_IP_, ret, |
| cachep->object_size, cachep->size, |
| flags, nodeid); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(kmem_cache_alloc_node); |
| |
| #ifdef CONFIG_TRACING |
| void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep, |
| gfp_t flags, |
| int nodeid, |
| size_t size) |
| { |
| void *ret; |
| |
| ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
| |
| trace_kmalloc_node(_RET_IP_, ret, |
| size, cachep->size, |
| flags, nodeid); |
| return ret; |
| } |
| EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
| #endif |
| |
| static __always_inline void * |
| __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) |
| { |
| struct kmem_cache *cachep; |
| |
| cachep = kmalloc_slab(size, flags); |
| if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
| return cachep; |
| return kmem_cache_alloc_node_trace(cachep, flags, node, size); |
| } |
| |
| void *__kmalloc_node(size_t size, gfp_t flags, int node) |
| { |
| return __do_kmalloc_node(size, flags, node, _RET_IP_); |
| } |
| EXPORT_SYMBOL(__kmalloc_node); |
| |
| void *__kmalloc_node_track_caller(size_t size, gfp_t flags, |
| int node, unsigned long caller) |
| { |
| return __do_kmalloc_node(size, flags, node, caller); |
| } |
| EXPORT_SYMBOL(__kmalloc_node_track_caller); |
| #endif /* CONFIG_NUMA */ |
| |
| /** |
| * __do_kmalloc - allocate memory |
| * @size: how many bytes of memory are required. |
| * @flags: the type of memory to allocate (see kmalloc). |
| * @caller: function caller for debug tracking of the caller |
| */ |
| static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, |
| unsigned long caller) |
| { |
| struct kmem_cache *cachep; |
| void *ret; |
| |
| cachep = kmalloc_slab(size, flags); |
| if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
| return cachep; |
| ret = slab_alloc(cachep, flags, caller); |
| |
| trace_kmalloc(caller, ret, |
| size, cachep->size, flags); |
| |
| return ret; |
| } |
| |
| void *__kmalloc(size_t size, gfp_t flags) |
| { |
| return __do_kmalloc(size, flags, _RET_IP_); |
| } |
| EXPORT_SYMBOL(__kmalloc); |
| |
| void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) |
| { |
| return __do_kmalloc(size, flags, caller); |
| } |
| EXPORT_SYMBOL(__kmalloc_track_caller); |
| |
| /** |
| * kmem_cache_free - Deallocate an object |
| * @cachep: The cache the allocation was from. |
| * @objp: The previously allocated object. |
| * |
| * Free an object which was previously allocated from this |
| * cache. |
| */ |
| void kmem_cache_free(struct kmem_cache *cachep, void *objp) |
| { |
| unsigned long flags; |
| cachep = cache_from_obj(cachep, objp); |
| if (!cachep) |
| return; |
| |
| local_irq_save(flags); |
| debug_check_no_locks_freed(objp, cachep->object_size); |
| if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) |
| debug_check_no_obj_freed(objp, cachep->object_size); |
| __cache_free(cachep, objp, _RET_IP_); |
| local_irq_restore(flags); |
| |
| trace_kmem_cache_free(_RET_IP_, objp); |
| } |
| EXPORT_SYMBOL(kmem_cache_free); |
| |
| /** |
| * kfree - free previously allocated memory |
| * @objp: pointer returned by kmalloc. |
| * |
| * If @objp is NULL, no operation is performed. |
| * |
| * Don't free memory not originally allocated by kmalloc() |
| * or you will run into trouble. |
| */ |
| void kfree(const void *objp) |
| { |
| struct kmem_cache *c; |
| unsigned long flags; |
| |
| trace_kfree(_RET_IP_, objp); |
| |
| if (unlikely(ZERO_OR_NULL_PTR(objp))) |
| return; |
| local_irq_save(flags); |
| kfree_debugcheck(objp); |
| c = virt_to_cache(objp); |
| debug_check_no_locks_freed(objp, c->object_size); |
| |
| debug_check_no_obj_freed(objp, c->object_size); |
| __cache_free(c, (void *)objp, _RET_IP_); |
| local_irq_restore(flags); |
| } |
| EXPORT_SYMBOL(kfree); |
| |
| /* |
| * This initializes kmem_cache_node or resizes various caches for all nodes. |
| */ |
| static int alloc_kmem_cache_node(struct kmem_cache *cachep, gfp_t gfp) |
| { |
| int node; |
| struct kmem_cache_node *n; |
| struct array_cache *new_shared; |
| struct alien_cache **new_alien = NULL; |
| |
| for_each_online_node(node) { |
| |
| if (use_alien_caches) { |
| new_alien = alloc_alien_cache(node, cachep->limit, gfp); |
| if (!new_alien) |
| goto fail; |
| } |
| |
| new_shared = NULL; |
| if (cachep->shared) { |
| new_shared = alloc_arraycache(node, |
| cachep->shared*cachep->batchcount, |
| 0xbaadf00d, gfp); |
| if (!new_shared) { |
| free_alien_cache(new_alien); |
| goto fail; |
| } |
| } |
| |
| n = get_node(cachep, node); |
| if (n) { |
| struct array_cache *shared = n->shared; |
| LIST_HEAD(list); |
| |
| spin_lock_irq(&n->list_lock); |
| |
| if (shared) |
| free_block(cachep, shared->entry, |
| shared->avail, node, &list); |
| |
| n->shared = new_shared; |
| if (!n->alien) { |
| n->alien = new_alien; |
| new_alien = NULL; |
| } |
| n->free_limit = (1 + nr_cpus_node(node)) * |
| cachep->batchcount + cachep->num; |
| spin_unlock_irq(&n->list_lock); |
| slabs_destroy(cachep, &list); |
| kfree(shared); |
| free_alien_cache(new_alien); |
| continue; |
| } |
| n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node); |
| if (!n) { |
| free_alien_cache(new_alien); |
| kfree(new_shared); |
| goto fail; |
| } |
| |
| kmem_cache_node_init(n); |
| n->next_reap = jiffies + REAPTIMEOUT_NODE + |
| ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
| n->shared = new_shared; |
| n->alien = new_alien; |
| n->free_limit = (1 + nr_cpus_node(node)) * |
| cachep->batchcount + cachep->num; |
| cachep->node[node] = n; |
| } |
| return 0; |
| |
| fail: |
| if (!cachep->list.next) { |
| /* Cache is not active yet. Roll back what we did */ |
| node--; |
| while (node >= 0) { |
| n = get_node(cachep, node); |
| if (n) { |
| kfree(n->shared); |
| free_alien_cache(n->alien); |
| kfree(n); |
| cachep->node[node] = NULL; |
| } |
| node--; |
| } |
| } |
| return -ENOMEM; |
| } |
| |
| /* Always called with the slab_mutex held */ |
| static int __do_tune_cpucache(struct kmem_cache *cachep, int limit, |
| int batchcount, int shared, gfp_t gfp) |
| { |
| struct array_cache __percpu *cpu_cache, *prev; |
| int cpu; |
| |
| cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount); |
| if (!cpu_cache) |
| return -ENOMEM; |
| |
| prev = cachep->cpu_cache; |
| cachep->cpu_cache = cpu_cache; |
| kick_all_cpus_sync(); |
| |
| check_irq_on(); |
| cachep->batchcount = batchcount; |
| cachep->limit = limit; |
| cachep->shared = shared; |
| |
| if (!prev) |
| goto alloc_node; |
| |
| for_each_online_cpu(cpu) { |
| LIST_HEAD(list); |
| int node; |
| struct kmem_cache_node *n; |
| struct array_cache *ac = per_cpu_ptr(prev, cpu); |
| |
| node = cpu_to_mem(cpu); |
| n = get_node(cachep, node); |
| spin_lock_irq(&n->list_lock); |
| free_block(cachep, ac->entry, ac->avail, node, &list); |
| spin_unlock_irq(&n->list_lock); |
| slabs_destroy(cachep, &list); |
| } |
| free_percpu(prev); |
| |
| alloc_node: |
| return alloc_kmem_cache_node(cachep, gfp); |
| } |
| |
| static int do_tune_cpucache(struct kmem_cache *cachep, int limit, |
| int batchcount, int shared, gfp_t gfp) |
| { |
| int ret; |
| struct kmem_cache *c; |
| |
| ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
| |
| if (slab_state < FULL) |
| return ret; |
| |
| if ((ret < 0) || !is_root_cache(cachep)) |
| return ret; |
| |
| lockdep_assert_held(&slab_mutex); |
| for_each_memcg_cache(c, cachep) { |
| /* return value determined by the root cache only */ |
| __do_tune_cpucache(c, limit, batchcount, shared, gfp); |
| } |
| |
| return ret; |
| } |
| |
| /* Called with slab_mutex held always */ |
| static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) |
| { |
| int err; |
| int limit = 0; |
| int shared = 0; |
| int batchcount = 0; |
| |
| if (!is_root_cache(cachep)) { |
| struct kmem_cache *root = memcg_root_cache(cachep); |
| limit = root->limit; |
| shared = root->shared; |
| batchcount = root->batchcount; |
| } |
| |
| if (limit && shared && batchcount) |
| goto skip_setup; |
| /* |
| * The head array serves three purposes: |
| * - create a LIFO ordering, i.e. return objects that are cache-warm |
| * - reduce the number of spinlock operations. |
| * - reduce the number of linked list operations on the slab and |
| * bufctl chains: array operations are cheaper. |
| * The numbers are guessed, we should auto-tune as described by |
| * Bonwick. |
| */ |
| if (cachep->size > 131072) |
| limit = 1; |
| else if (cachep->size > PAGE_SIZE) |
| limit = 8; |
| else if (cachep->size > 1024) |
| limit = 24; |
| else if (cachep->size > 256) |
| limit = 54; |
| else |
| limit = 120; |
| |
| /* |
| * CPU bound tasks (e.g. network routing) can exhibit cpu bound |
| * allocation behaviour: Most allocs on one cpu, most free operations |
| * on another cpu. For these cases, an efficient object passing between |
| * cpus is necessary. This is provided by a shared array. The array |
| * replaces Bonwick's magazine layer. |
| * On uniprocessor, it's functionally equivalent (but less efficient) |
| * to a larger limit. Thus disabled by default. |
| */ |
| shared = 0; |
| if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) |
| shared = 8; |
| |
| #if DEBUG |
| /* |
| * With debugging enabled, large batchcount lead to excessively long |
| * periods with disabled local interrupts. Limit the batchcount |
| */ |
| if (limit > 32) |
| limit = 32; |
| #endif |
| batchcount = (limit + 1) / 2; |
| skip_setup: |
| err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
| if (err) |
| printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", |
| cachep->name, -err); |
| return err; |
| } |
| |
| /* |
| * Drain an array if it contains any elements taking the node lock only if |
| * necessary. Note that the node listlock also protects the array_cache |
| * if drain_array() is used on the shared array. |
| */ |
| static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
| struct array_cache *ac, int force, int node) |
| { |
| LIST_HEAD(list); |
| int tofree; |
| |
| if (!ac || !ac->avail) |
| return; |
| if (ac->touched && !force) { |
| ac->touched = 0; |
| } else { |
| spin_lock_irq(&n->list_lock); |
| if (ac->avail) { |
| tofree = force ? ac->avail : (ac->limit + 4) / 5; |
| if (tofree > ac->avail) |
| tofree = (ac->avail + 1) / 2; |
| free_block(cachep, ac->entry, tofree, node, &list); |
| ac->avail -= tofree; |
| memmove(ac->entry, &(ac->entry[tofree]), |
| sizeof(void *) * ac->avail); |
| } |
| spin_unlock_irq(&n->list_lock); |
| slabs_destroy(cachep, &list); |
| } |
| } |
| |
| /** |
| * cache_reap - Reclaim memory from caches. |
| * @w: work descriptor |
| * |
| * Called from workqueue/eventd every few seconds. |
| * Purpose: |
| * - clear the per-cpu caches for this CPU. |
| * - return freeable pages to the main free memory pool. |
| * |
| * If we cannot acquire the cache chain mutex then just give up - we'll try |
| * again on the next iteration. |
| */ |
| static void cache_reap(struct work_struct *w) |
| { |
| struct kmem_cache *searchp; |
| struct kmem_cache_node *n; |
| int node = numa_mem_id(); |
| struct delayed_work *work = to_delayed_work(w); |
| |
| if (!mutex_trylock(&slab_mutex)) |
| /* Give up. Setup the next iteration. */ |
| goto out; |
| |
| list_for_each_entry(searchp, &slab_caches, list) { |
| check_irq_on(); |
| |
| /* |
| * We only take the node lock if absolutely necessary and we |
| * have established with reasonable certainty that |
| * we can do some work if the lock was obtained. |
| */ |
| n = get_node(searchp, node); |
| |
| reap_alien(searchp, n); |
| |
| drain_array(searchp, n, cpu_cache_get(searchp), 0, node); |
| |
| /* |
| * These are racy checks but it does not matter |
| * if we skip one check or scan twice. |
| */ |
| if (time_after(n->next_reap, jiffies)) |
| goto next; |
| |
| n->next_reap = jiffies + REAPTIMEOUT_NODE; |
| |
| drain_array(searchp, n, n->shared, 0, node); |
| |
| if (n->free_touched) |
| n->free_touched = 0; |
| else { |
| int freed; |
| |
| freed = drain_freelist(searchp, n, (n->free_limit + |
| 5 * searchp->num - 1) / (5 * searchp->num)); |
| STATS_ADD_REAPED(searchp, freed); |
| } |
| next: |
| cond_resched(); |
| } |
| check_irq_on(); |
| mutex_unlock(&slab_mutex); |
| next_reap_node(); |
| out: |
| /* Set up the next iteration */ |
| schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC)); |
| } |
| |
| #ifdef CONFIG_SLABINFO |
| void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo) |
| { |
| struct page *page; |
| unsigned long active_objs; |
| unsigned long num_objs; |
| unsigned long active_slabs = 0; |
| unsigned long num_slabs, free_objects = 0, shared_avail = 0; |
| const char *name; |
| char *error = NULL; |
| int node; |
| struct kmem_cache_node *n; |
| |
| active_objs = 0; |
| num_slabs = 0; |
| for_each_kmem_cache_node(cachep, node, n) { |
| |
| check_irq_on(); |
| spin_lock_irq(&n->list_lock); |
| |
| list_for_each_entry(page, &n->slabs_full, lru) { |
| if (page->active != cachep->num && !error) |
| error = "slabs_full accounting error"; |
| active_objs += cachep->num; |
| active_slabs++; |
| } |
| list_for_each_entry(page, &n->slabs_partial, lru) { |
| if (page->active == cachep->num && !error) |
| error = "slabs_partial accounting error"; |
| if (!page->active && !error) |
| error = "slabs_partial accounting error"; |
| active_objs += page->active; |
| active_slabs++; |
| } |
| list_for_each_entry(page, &n->slabs_free, lru) { |
| if (page->active && !error) |
| error = "slabs_free accounting error"; |
| num_slabs++; |
| } |
| free_objects += n->free_objects; |
| if (n->shared) |
| shared_avail += n->shared->avail; |
| |
| spin_unlock_irq(&n->list_lock); |
| } |
| num_slabs += active_slabs; |
| num_objs = num_slabs * cachep->num; |
| if (num_objs - active_objs != free_objects && !error) |
| error = "free_objects accounting error"; |
| |
| name = cachep->name; |
| if (error) |
| printk(KERN_ERR "slab: cache %s error: %s\n", name, error); |
| |
| sinfo->active_objs = active_objs; |
| sinfo->num_objs = num_objs; |
| sinfo->active_slabs = active_slabs; |
| sinfo->num_slabs = num_slabs; |
| sinfo->shared_avail = shared_avail; |
| sinfo->limit = cachep->limit; |
| sinfo->batchcount = cachep->batchcount; |
| sinfo->shared = cachep->shared; |
| sinfo->objects_per_slab = cachep->num; |
| sinfo->cache_order = cachep->gfporder; |
| } |
| |
| void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep) |
| { |
| #if STATS |
| { /* node stats */ |
| unsigned long high = cachep->high_mark; |
| unsigned long allocs = cachep->num_allocations; |
| unsigned long grown = cachep->grown; |
| unsigned long reaped = cachep->reaped; |
| unsigned long errors = cachep->errors; |
| unsigned long max_freeable = cachep->max_freeable; |
| unsigned long node_allocs = cachep->node_allocs; |
| unsigned long node_frees = cachep->node_frees; |
| unsigned long overflows = cachep->node_overflow; |
| |
| seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " |
| "%4lu %4lu %4lu %4lu %4lu", |
| allocs, high, grown, |
| reaped, errors, max_freeable, node_allocs, |
| node_frees, overflows); |
| } |
| /* cpu stats */ |
| { |
| unsigned long allochit = atomic_read(&cachep->allochit); |
| unsigned long allocmiss = atomic_read(&cachep->allocmiss); |
| unsigned long freehit = atomic_read(&cachep->freehit); |
| unsigned long freemiss = atomic_read(&cachep->freemiss); |
| |
| seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
| allochit, allocmiss, freehit, freemiss); |
| } |
| #endif |
| } |
| |
| #define MAX_SLABINFO_WRITE 128 |
| /** |
| * slabinfo_write - Tuning for the slab allocator |
| * @file: unused |
| * @buffer: user buffer |
| * @count: data length |
| * @ppos: unused |
| */ |
| ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
| size_t count, loff_t *ppos) |
| { |
| char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; |
| int limit, batchcount, shared, res; |
| struct kmem_cache *cachep; |
| |
| if (count > MAX_SLABINFO_WRITE) |
| return -EINVAL; |
| if (copy_from_user(&kbuf, buffer, count)) |
| return -EFAULT; |
| kbuf[MAX_SLABINFO_WRITE] = '\0'; |
| |
| tmp = strchr(kbuf, ' '); |
| if (!tmp) |
| return -EINVAL; |
| *tmp = '\0'; |
| tmp++; |
| if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) |
| return -EINVAL; |
| |
| /* Find the cache in the chain of caches. */ |
| mutex_lock(&slab_mutex); |
| res = -EINVAL; |
| list_for_each_entry(cachep, &slab_caches, list) { |
| if (!strcmp(cachep->name, kbuf)) { |
| if (limit < 1 || batchcount < 1 || |
| batchcount > limit || shared < 0) { |
| res = 0; |
| } else { |
| res = do_tune_cpucache(cachep, limit, |
| batchcount, shared, |
| GFP_KERNEL); |
| } |
| break; |
| } |
| } |
| mutex_unlock(&slab_mutex); |
| if (res >= 0) |
| res = count; |
| return res; |
| } |
| |
| #ifdef CONFIG_DEBUG_SLAB_LEAK |
| |
| static inline int add_caller(unsigned long *n, unsigned long v) |
| { |
| unsigned long *p; |
| int l; |
| if (!v) |
| return 1; |
| l = n[1]; |
| p = n + 2; |
| while (l) { |
| int i = l/2; |
| unsigned long *q = p + 2 * i; |
| if (*q == v) { |
| q[1]++; |
| return 1; |
| } |
| if (*q > v) { |
| l = i; |
| } else { |
| p = q + 2; |
| l -= i + 1; |
| } |
| } |
| if (++n[1] == n[0]) |
| return 0; |
| memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); |
| p[0] = v; |
| p[1] = 1; |
| return 1; |
| } |
| |
| static void handle_slab(unsigned long *n, struct kmem_cache *c, |
| struct page *page) |
| { |
| void *p; |
| int i; |
| |
| if (n[0] == n[1]) |
| return; |
| for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) { |
| if (get_obj_status(page, i) != OBJECT_ACTIVE) |
| continue; |
| |
| if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) |
| return; |
| } |
| } |
| |
| static void show_symbol(struct seq_file *m, unsigned long address) |
| { |
| #ifdef CONFIG_KALLSYMS |
| unsigned long offset, size; |
| char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; |
| |
| if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { |
| seq_printf(m, "%s+%#lx/%#lx", name, offset, size); |
| if (modname[0]) |
| seq_printf(m, " [%s]", modname); |
| return; |
| } |
| #endif |
| seq_printf(m, "%p", (void *)address); |
| } |
| |
| static int leaks_show(struct seq_file *m, void *p) |
| { |
| struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); |
| struct page *page; |
| struct kmem_cache_node *n; |
| const char *name; |
| unsigned long *x = m->private; |
| int node; |
| int i; |
| |
| if (!(cachep->flags & SLAB_STORE_USER)) |
| return 0; |
| if (!(cachep->flags & SLAB_RED_ZONE)) |
| return 0; |
| |
| /* OK, we can do it */ |
| |
| x[1] = 0; |
| |
| for_each_kmem_cache_node(cachep, node, n) { |
| |
| check_irq_on(); |
| spin_lock_irq(&n->list_lock); |
| |
| list_for_each_entry(page, &n->slabs_full, lru) |
| handle_slab(x, cachep, page); |
| list_for_each_entry(page, &n->slabs_partial, lru) |
| handle_slab(x, cachep, page); |
| spin_unlock_irq(&n->list_lock); |
| } |
| name = cachep->name; |
| if (x[0] == x[1]) { |
| /* Increase the buffer size */ |
| mutex_unlock(&slab_mutex); |
| m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL); |
| if (!m->private) { |
| /* Too bad, we are really out */ |
| m->private = x; |
| mutex_lock(&slab_mutex); |
| return -ENOMEM; |
| } |
| *(unsigned long *)m->private = x[0] * 2; |
| kfree(x); |
| mutex_lock(&slab_mutex); |
| /* Now make sure this entry will be retried */ |
| m->count = m->size; |
| return 0; |
| } |
| for (i = 0; i < x[1]; i++) { |
| seq_printf(m, "%s: %lu ", name, x[2*i+3]); |
| show_symbol(m, x[2*i+2]); |
| seq_putc(m, '\n'); |
| } |
| |
| return 0; |
| } |
| |
| static const struct seq_operations slabstats_op = { |
| .start = slab_start, |
| .next = slab_next, |
| .stop = slab_stop, |
| .show = leaks_show, |
| }; |
| |
| static int slabstats_open(struct inode *inode, struct file *file) |
| { |
| unsigned long *n; |
| |
| n = __seq_open_private(file, &slabstats_op, PAGE_SIZE); |
| if (!n) |
| return -ENOMEM; |
| |
| *n = PAGE_SIZE / (2 * sizeof(unsigned long)); |
| |
| return 0; |
| } |
| |
| static const struct file_operations proc_slabstats_operations = { |
| .open = slabstats_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| #endif |
| |
| static int __init slab_proc_init(void) |
| { |
| #ifdef CONFIG_DEBUG_SLAB_LEAK |
| proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); |
| #endif |
| return 0; |
| } |
| module_init(slab_proc_init); |
| #endif |
| |
| /** |
| * ksize - get the actual amount of memory allocated for a given object |
| * @objp: Pointer to the object |
| * |
| * kmalloc may internally round up allocations and return more memory |
| * than requested. ksize() can be used to determine the actual amount of |
| * memory allocated. The caller may use this additional memory, even though |
| * a smaller amount of memory was initially specified with the kmalloc call. |
| * The caller must guarantee that objp points to a valid object previously |
| * allocated with either kmalloc() or kmem_cache_alloc(). The object |
| * must not be freed during the duration of the call. |
| */ |
| size_t ksize(const void *objp) |
| { |
| BUG_ON(!objp); |
| if (unlikely(objp == ZERO_SIZE_PTR)) |
| return 0; |
| |
| return virt_to_cache(objp)->object_size; |
| } |
| EXPORT_SYMBOL(ksize); |