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Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 4564 |
1 files changed, 4564 insertions, 0 deletions
diff --git a/mm/slab.c b/mm/slab.c new file mode 100644 index 00000000..d96e223d --- /dev/null +++ b/mm/slab.c @@ -0,0 +1,4564 @@ +/* + * 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 'cache_chain_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 <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/page.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 + +/* Legal flag mask for kmem_cache_create(). */ +#if DEBUG +# define CREATE_MASK (SLAB_RED_ZONE | \ + SLAB_POISON | SLAB_HWCACHE_ALIGN | \ + SLAB_CACHE_DMA | \ + SLAB_STORE_USER | \ + SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ + SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ + SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK) +#else +# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ + SLAB_CACHE_DMA | \ + SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ + SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ + SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK) +#endif + +/* + * kmem_bufctl_t: + * + * Bufctl's are used for linking objs within a slab + * linked offsets. + * + * This implementation relies on "struct page" for locating the cache & + * slab an object belongs to. + * This allows the bufctl structure to be small (one int), but limits + * the number of objects a slab (not a cache) can contain when off-slab + * bufctls are used. The limit is the size of the largest general cache + * that does not use off-slab slabs. + * For 32bit archs with 4 kB pages, is this 56. + * This is not serious, as it is only for large objects, when it is unwise + * to have too many per slab. + * Note: This limit can be raised by introducing a general cache whose size + * is less than 512 (PAGE_SIZE<<3), but greater than 256. + */ + +typedef unsigned int kmem_bufctl_t; +#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) +#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) +#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2) +#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) + +/* + * struct slab_rcu + * + * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to + * arrange for kmem_freepages to be called via RCU. This is useful if + * we need to approach a kernel structure obliquely, from its address + * obtained without the usual locking. We can lock the structure to + * stabilize it and check it's still at the given address, only if we + * can be sure that the memory has not been meanwhile reused for some + * other kind of object (which our subsystem's lock might corrupt). + * + * rcu_read_lock before reading the address, then rcu_read_unlock after + * taking the spinlock within the structure expected at that address. + */ +struct slab_rcu { + struct rcu_head head; + struct kmem_cache *cachep; + void *addr; +}; + +/* + * struct slab + * + * Manages the objs in a slab. Placed either at the beginning of mem allocated + * for a slab, or allocated from an general cache. + * Slabs are chained into three list: fully used, partial, fully free slabs. + */ +struct slab { + union { + struct { + struct list_head list; + unsigned long colouroff; + void *s_mem; /* including colour offset */ + unsigned int inuse; /* num of objs active in slab */ + kmem_bufctl_t free; + unsigned short nodeid; + }; + struct slab_rcu __slab_cover_slab_rcu; + }; +}; + +/* + * 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; + spinlock_t lock; + void *entry[]; /* + * Must have this definition in here for the proper + * alignment of array_cache. Also simplifies accessing + * the entries. + */ +}; + +/* + * 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]; +}; + +/* + * The slab lists for all objects. + */ +struct kmem_list3 { + struct list_head slabs_partial; /* partial list first, better asm code */ + struct list_head slabs_full; + struct list_head slabs_free; + unsigned long free_objects; + unsigned int free_limit; + unsigned int colour_next; /* Per-node cache coloring */ + spinlock_t list_lock; + struct array_cache *shared; /* shared per node */ + struct array_cache **alien; /* on other nodes */ + unsigned long next_reap; /* updated without locking */ + int free_touched; /* updated without locking */ +}; + +/* + * Need this for bootstrapping a per node allocator. + */ +#define NUM_INIT_LISTS (3 * MAX_NUMNODES) +static struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; +#define CACHE_CACHE 0 +#define SIZE_AC MAX_NUMNODES +#define SIZE_L3 (2 * MAX_NUMNODES) + +static int drain_freelist(struct kmem_cache *cache, + struct kmem_list3 *l3, int tofree); +static void free_block(struct kmem_cache *cachep, void **objpp, int len, + int node); +static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); +static void cache_reap(struct work_struct *unused); + +/* + * This function must be completely optimized away if a constant is passed to + * it. Mostly the same as what is in linux/slab.h except it returns an index. + */ +static __always_inline int index_of(const size_t size) +{ + extern void __bad_size(void); + + if (__builtin_constant_p(size)) { + int i = 0; + +#define CACHE(x) \ + if (size <=x) \ + return i; \ + else \ + i++; +#include <linux/kmalloc_sizes.h> +#undef CACHE + __bad_size(); + } else + __bad_size(); + return 0; +} + +static int slab_early_init = 1; + +#define INDEX_AC index_of(sizeof(struct arraycache_init)) +#define INDEX_L3 index_of(sizeof(struct kmem_list3)) + +static void kmem_list3_init(struct kmem_list3 *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(&(cachep->nodelists[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 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_CPUC (2*HZ) +#define REAPTIMEOUT_LIST3 (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->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] + * cachep->buffer_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 int obj_size(struct kmem_cache *cachep) +{ + return cachep->obj_size; +} + +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->buffer_size - + sizeof(unsigned long long) - + REDZONE_ALIGN); + return (unsigned long long *) (objp + cachep->buffer_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->buffer_size - BYTES_PER_WORD); +} + +#else + +#define obj_offset(x) 0 +#define obj_size(cachep) (cachep->buffer_size) +#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 + +#ifdef CONFIG_TRACING +size_t slab_buffer_size(struct kmem_cache *cachep) +{ + return cachep->buffer_size; +} +EXPORT_SYMBOL(slab_buffer_size); +#endif + +/* + * Do not go above this order unless 0 objects fit into the slab. + */ +#define BREAK_GFP_ORDER_HI 1 +#define BREAK_GFP_ORDER_LO 0 +static int slab_break_gfp_order = BREAK_GFP_ORDER_LO; + +/* + * Functions for storing/retrieving the cachep and or slab from the page + * allocator. These are used to find the slab an obj belongs to. With kfree(), + * these are used to find the cache which an obj belongs to. + */ +static inline void page_set_cache(struct page *page, struct kmem_cache *cache) +{ + page->lru.next = (struct list_head *)cache; +} + +static inline struct kmem_cache *page_get_cache(struct page *page) +{ + page = compound_head(page); + BUG_ON(!PageSlab(page)); + return (struct kmem_cache *)page->lru.next; +} + +static inline void page_set_slab(struct page *page, struct slab *slab) +{ + page->lru.prev = (struct list_head *)slab; +} + +static inline struct slab *page_get_slab(struct page *page) +{ + BUG_ON(!PageSlab(page)); + return (struct slab *)page->lru.prev; +} + +static inline struct kmem_cache *virt_to_cache(const void *obj) +{ + struct page *page = virt_to_head_page(obj); + return page_get_cache(page); +} + +static inline struct slab *virt_to_slab(const void *obj) +{ + struct page *page = virt_to_head_page(obj); + return page_get_slab(page); +} + +static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, + unsigned int idx) +{ + return slab->s_mem + cache->buffer_size * idx; +} + +/* + * We want to avoid an expensive divide : (offset / cache->buffer_size) + * Using the fact that buffer_size is a constant for a particular cache, + * we can replace (offset / cache->buffer_size) by + * reciprocal_divide(offset, cache->reciprocal_buffer_size) + */ +static inline unsigned int obj_to_index(const struct kmem_cache *cache, + const struct slab *slab, void *obj) +{ + u32 offset = (obj - slab->s_mem); + return reciprocal_divide(offset, cache->reciprocal_buffer_size); +} + +/* + * These are the default caches for kmalloc. Custom caches can have other sizes. + */ +struct cache_sizes malloc_sizes[] = { +#define CACHE(x) { .cs_size = (x) }, +#include <linux/kmalloc_sizes.h> + CACHE(ULONG_MAX) +#undef CACHE +}; +EXPORT_SYMBOL(malloc_sizes); + +/* Must match cache_sizes above. Out of line to keep cache footprint low. */ +struct cache_names { + char *name; + char *name_dma; +}; + +static struct cache_names __initdata cache_names[] = { +#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" }, +#include <linux/kmalloc_sizes.h> + {NULL,} +#undef CACHE +}; + +static struct arraycache_init initarray_cache __initdata = + { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; +static struct arraycache_init initarray_generic = + { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; + +/* internal cache of cache description objs */ +static struct kmem_cache cache_cache = { + .batchcount = 1, + .limit = BOOT_CPUCACHE_ENTRIES, + .shared = 1, + .buffer_size = sizeof(struct kmem_cache), + .name = "kmem_cache", +}; + +#define BAD_ALIEN_MAGIC 0x01020304ul + +/* + * chicken and egg problem: delay the per-cpu array allocation + * until the general caches are up. + */ +static enum { + NONE, + PARTIAL_AC, + PARTIAL_L3, + EARLY, + FULL +} g_cpucache_up; + +/* + * used by boot code to determine if it can use slab based allocator + */ +int slab_is_available(void) +{ + return g_cpucache_up >= EARLY; +} + +#ifdef CONFIG_LOCKDEP + +/* + * Slab sometimes uses the kmalloc slabs to store the slab headers + * for other slabs "off slab". + * The locking for this is tricky in that it nests within the locks + * of all other slabs in a few places; to deal with this special + * locking we put on-slab caches into a separate lock-class. + * + * We set lock class for alien array caches which are up during init. + * The lock annotation will be lost if all cpus of a node goes down and + * then comes back up during hotplug + */ +static struct lock_class_key on_slab_l3_key; +static struct lock_class_key on_slab_alc_key; + +static void init_node_lock_keys(int q) +{ + struct cache_sizes *s = malloc_sizes; + + if (g_cpucache_up != FULL) + return; + + for (s = malloc_sizes; s->cs_size != ULONG_MAX; s++) { + struct array_cache **alc; + struct kmem_list3 *l3; + int r; + + l3 = s->cs_cachep->nodelists[q]; + if (!l3 || OFF_SLAB(s->cs_cachep)) + continue; + lockdep_set_class(&l3->list_lock, &on_slab_l3_key); + alc = l3->alien; + /* + * FIXME: This check for BAD_ALIEN_MAGIC + * should go away when common slab code is taught to + * work even without alien caches. + * Currently, non NUMA code returns BAD_ALIEN_MAGIC + * for alloc_alien_cache, + */ + if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) + continue; + for_each_node(r) { + if (alc[r]) + lockdep_set_class(&alc[r]->lock, + &on_slab_alc_key); + } + } +} + +static inline void init_lock_keys(void) +{ + int node; + + for_each_node(node) + init_node_lock_keys(node); +} +#else +static void init_node_lock_keys(int q) +{ +} + +static inline void init_lock_keys(void) +{ +} +#endif + +/* + * Guard access to the cache-chain. + */ +static DEFINE_MUTEX(cache_chain_mutex); +static struct list_head cache_chain; + +static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); + +static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) +{ + return cachep->array[smp_processor_id()]; +} + +static inline struct kmem_cache *__find_general_cachep(size_t size, + gfp_t gfpflags) +{ + struct cache_sizes *csizep = malloc_sizes; + +#if DEBUG + /* This happens if someone tries to call + * kmem_cache_create(), or __kmalloc(), before + * the generic caches are initialized. + */ + BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL); +#endif + if (!size) + return ZERO_SIZE_PTR; + + while (size > csizep->cs_size) + csizep++; + + /* + * Really subtle: The last entry with cs->cs_size==ULONG_MAX + * has cs_{dma,}cachep==NULL. Thus no special case + * for large kmalloc calls required. + */ +#ifdef CONFIG_ZONE_DMA + if (unlikely(gfpflags & GFP_DMA)) + return csizep->cs_dmacachep; +#endif + return csizep->cs_cachep; +} + +static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags) +{ + return __find_general_cachep(size, gfpflags); +} + +static size_t slab_mgmt_size(size_t nr_objs, size_t align) +{ + return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); +} + +/* + * 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: + * + * - The struct slab + * - One kmem_bufctl_t 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; + + if (nr_objs > SLAB_LIMIT) + nr_objs = SLAB_LIMIT; + } else { + /* + * 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 - sizeof(struct slab)) / + (buffer_size + sizeof(kmem_bufctl_t)); + + /* + * This calculated number will be either the right + * amount, or one greater than what we want. + */ + if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size + > slab_size) + nr_objs--; + + if (nr_objs > SLAB_LIMIT) + nr_objs = SLAB_LIMIT; + + mgmt_size = slab_mgmt_size(nr_objs, align); + } + *num = nr_objs; + *left_over = slab_size - nr_objs*buffer_size - mgmt_size; +} + +#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(); +} + +/* + * 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); + +#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 __cpuinit 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_DELAYED_WORK_DEFERRABLE(reap_work, cache_reap); + schedule_delayed_work_on(cpu, reap_work, + __round_jiffies_relative(HZ, cpu)); + } +} + +static struct array_cache *alloc_arraycache(int node, int entries, + int batchcount, gfp_t gfp) +{ + int memsize = sizeof(void *) * entries + sizeof(struct array_cache); + struct array_cache *nc = NULL; + + nc = kmalloc_node(memsize, gfp, node); + /* + * 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(nc); + if (nc) { + nc->avail = 0; + nc->limit = entries; + nc->batchcount = batchcount; + nc->touched = 0; + spin_lock_init(&nc->lock); + } + return nc; +} + +/* + * 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, l3) do { } while (0) + +static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) +{ + return (struct array_cache **)BAD_ALIEN_MAGIC; +} + +static inline void free_alien_cache(struct array_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; +} + +#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 array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) +{ + struct array_cache **ac_ptr; + int memsize = sizeof(void *) * nr_node_ids; + int i; + + if (limit > 1) + limit = 12; + ac_ptr = kzalloc_node(memsize, gfp, node); + if (ac_ptr) { + for_each_node(i) { + if (i == node || !node_online(i)) + continue; + ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp); + if (!ac_ptr[i]) { + for (i--; i >= 0; i--) + kfree(ac_ptr[i]); + kfree(ac_ptr); + return NULL; + } + } + } + return ac_ptr; +} + +static void free_alien_cache(struct array_cache **ac_ptr) +{ + int i; + + if (!ac_ptr) + return; + for_each_node(i) + kfree(ac_ptr[i]); + kfree(ac_ptr); +} + +static void __drain_alien_cache(struct kmem_cache *cachep, + struct array_cache *ac, int node) +{ + struct kmem_list3 *rl3 = cachep->nodelists[node]; + + if (ac->avail) { + spin_lock(&rl3->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 (rl3->shared) + transfer_objects(rl3->shared, ac, ac->limit); + + free_block(cachep, ac->entry, ac->avail, node); + ac->avail = 0; + spin_unlock(&rl3->list_lock); + } +} + +/* + * Called from cache_reap() to regularly drain alien caches round robin. + */ +static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3) +{ + int node = __this_cpu_read(slab_reap_node); + + if (l3->alien) { + struct array_cache *ac = l3->alien[node]; + + if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { + __drain_alien_cache(cachep, ac, node); + spin_unlock_irq(&ac->lock); + } + } +} + +static void drain_alien_cache(struct kmem_cache *cachep, + struct array_cache **alien) +{ + int i = 0; + struct array_cache *ac; + unsigned long flags; + + for_each_online_node(i) { + ac = alien[i]; + if (ac) { + spin_lock_irqsave(&ac->lock, flags); + __drain_alien_cache(cachep, ac, i); + spin_unlock_irqrestore(&ac->lock, flags); + } + } +} + +static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) +{ + struct slab *slabp = virt_to_slab(objp); + int nodeid = slabp->nodeid; + struct kmem_list3 *l3; + struct array_cache *alien = NULL; + int node; + + node = numa_mem_id(); + + /* + * Make sure we are not freeing a object from another node to the array + * cache on this cpu. + */ + if (likely(slabp->nodeid == node)) + return 0; + + l3 = cachep->nodelists[node]; + STATS_INC_NODEFREES(cachep); + if (l3->alien && l3->alien[nodeid]) { + alien = l3->alien[nodeid]; + spin_lock(&alien->lock); + if (unlikely(alien->avail == alien->limit)) { + STATS_INC_ACOVERFLOW(cachep); + __drain_alien_cache(cachep, alien, nodeid); + } + alien->entry[alien->avail++] = objp; + spin_unlock(&alien->lock); + } else { + spin_lock(&(cachep->nodelists[nodeid])->list_lock); + free_block(cachep, &objp, 1, nodeid); + spin_unlock(&(cachep->nodelists[nodeid])->list_lock); + } + return 1; +} +#endif + +/* + * Allocates and initializes nodelists for a node on each slab cache, used for + * either memory or cpu hotplug. If memory is being hot-added, the kmem_list3 + * will be allocated off-node since memory is not yet online for the new node. + * When hotplugging memory or a cpu, existing nodelists are not replaced if + * already in use. + * + * Must hold cache_chain_mutex. + */ +static int init_cache_nodelists_node(int node) +{ + struct kmem_cache *cachep; + struct kmem_list3 *l3; + const int memsize = sizeof(struct kmem_list3); + + list_for_each_entry(cachep, &cache_chain, next) { + /* + * Set up the size64 kmemlist for cpu before we can + * begin anything. Make sure some other cpu on this + * node has not already allocated this + */ + if (!cachep->nodelists[node]) { + l3 = kmalloc_node(memsize, GFP_KERNEL, node); + if (!l3) + return -ENOMEM; + kmem_list3_init(l3); + l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + + ((unsigned long)cachep) % REAPTIMEOUT_LIST3; + + /* + * The l3s don't come and go as CPUs come and + * go. cache_chain_mutex is sufficient + * protection here. + */ + cachep->nodelists[node] = l3; + } + + spin_lock_irq(&cachep->nodelists[node]->list_lock); + cachep->nodelists[node]->free_limit = + (1 + nr_cpus_node(node)) * + cachep->batchcount + cachep->num; + spin_unlock_irq(&cachep->nodelists[node]->list_lock); + } + return 0; +} + +static void __cpuinit cpuup_canceled(long cpu) +{ + struct kmem_cache *cachep; + struct kmem_list3 *l3 = NULL; + int node = cpu_to_mem(cpu); + const struct cpumask *mask = cpumask_of_node(node); + + list_for_each_entry(cachep, &cache_chain, next) { + struct array_cache *nc; + struct array_cache *shared; + struct array_cache **alien; + + /* cpu is dead; no one can alloc from it. */ + nc = cachep->array[cpu]; + cachep->array[cpu] = NULL; + l3 = cachep->nodelists[node]; + + if (!l3) + goto free_array_cache; + + spin_lock_irq(&l3->list_lock); + + /* Free limit for this kmem_list3 */ + l3->free_limit -= cachep->batchcount; + if (nc) + free_block(cachep, nc->entry, nc->avail, node); + + if (!cpumask_empty(mask)) { + spin_unlock_irq(&l3->list_lock); + goto free_array_cache; + } + + shared = l3->shared; + if (shared) { + free_block(cachep, shared->entry, + shared->avail, node); + l3->shared = NULL; + } + + alien = l3->alien; + l3->alien = NULL; + + spin_unlock_irq(&l3->list_lock); + + kfree(shared); + if (alien) { + drain_alien_cache(cachep, alien); + free_alien_cache(alien); + } +free_array_cache: + kfree(nc); + } + /* + * 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, &cache_chain, next) { + l3 = cachep->nodelists[node]; + if (!l3) + continue; + drain_freelist(cachep, l3, l3->free_objects); + } +} + +static int __cpuinit cpuup_prepare(long cpu) +{ + struct kmem_cache *cachep; + struct kmem_list3 *l3 = 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_list3 and not this cpu's kmem_list3 + */ + err = init_cache_nodelists_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, &cache_chain, next) { + struct array_cache *nc; + struct array_cache *shared = NULL; + struct array_cache **alien = NULL; + + nc = alloc_arraycache(node, cachep->limit, + cachep->batchcount, GFP_KERNEL); + if (!nc) + goto bad; + if (cachep->shared) { + shared = alloc_arraycache(node, + cachep->shared * cachep->batchcount, + 0xbaadf00d, GFP_KERNEL); + if (!shared) { + kfree(nc); + goto bad; + } + } + if (use_alien_caches) { + alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); + if (!alien) { + kfree(shared); + kfree(nc); + goto bad; + } + } + cachep->array[cpu] = nc; + l3 = cachep->nodelists[node]; + BUG_ON(!l3); + + spin_lock_irq(&l3->list_lock); + if (!l3->shared) { + /* + * We are serialised from CPU_DEAD or + * CPU_UP_CANCELLED by the cpucontrol lock + */ + l3->shared = shared; + shared = NULL; + } +#ifdef CONFIG_NUMA + if (!l3->alien) { + l3->alien = alien; + alien = NULL; + } +#endif + spin_unlock_irq(&l3->list_lock); + kfree(shared); + free_alien_cache(alien); + } + init_node_lock_keys(node); + + return 0; +bad: + cpuup_canceled(cpu); + return -ENOMEM; +} + +static int __cpuinit 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(&cache_chain_mutex); + err = cpuup_prepare(cpu); + mutex_unlock(&cache_chain_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 cache_chain_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_list3 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 list3 + * 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(&cache_chain_mutex); + cpuup_canceled(cpu); + mutex_unlock(&cache_chain_mutex); + break; + } + return notifier_from_errno(err); +} + +static struct notifier_block __cpuinitdata 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 cache_chain_mutex. + */ +static int __meminit drain_cache_nodelists_node(int node) +{ + struct kmem_cache *cachep; + int ret = 0; + + list_for_each_entry(cachep, &cache_chain, next) { + struct kmem_list3 *l3; + + l3 = cachep->nodelists[node]; + if (!l3) + continue; + + drain_freelist(cachep, l3, l3->free_objects); + + if (!list_empty(&l3->slabs_full) || + !list_empty(&l3->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(&cache_chain_mutex); + ret = init_cache_nodelists_node(nid); + mutex_unlock(&cache_chain_mutex); + break; + case MEM_GOING_OFFLINE: + mutex_lock(&cache_chain_mutex); + ret = drain_cache_nodelists_node(nid); + mutex_unlock(&cache_chain_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_list3 with kmalloced memory + */ +static void __init init_list(struct kmem_cache *cachep, struct kmem_list3 *list, + int nodeid) +{ + struct kmem_list3 *ptr; + + ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_NOWAIT, nodeid); + BUG_ON(!ptr); + + memcpy(ptr, list, sizeof(struct kmem_list3)); + /* + * Do not assume that spinlocks can be initialized via memcpy: + */ + spin_lock_init(&ptr->list_lock); + + MAKE_ALL_LISTS(cachep, ptr, nodeid); + cachep->nodelists[nodeid] = ptr; +} + +/* + * For setting up all the kmem_list3s for cache whose buffer_size is same as + * size of kmem_list3. + */ +static void __init set_up_list3s(struct kmem_cache *cachep, int index) +{ + int node; + + for_each_online_node(node) { + cachep->nodelists[node] = &initkmem_list3[index + node]; + cachep->nodelists[node]->next_reap = jiffies + + REAPTIMEOUT_LIST3 + + ((unsigned long)cachep) % REAPTIMEOUT_LIST3; + } +} + +/* + * Initialisation. Called after the page allocator have been initialised and + * before smp_init(). + */ +void __init kmem_cache_init(void) +{ + size_t left_over; + struct cache_sizes *sizes; + struct cache_names *names; + int i; + int order; + int node; + + if (num_possible_nodes() == 1) + use_alien_caches = 0; + + for (i = 0; i < NUM_INIT_LISTS; i++) { + kmem_list3_init(&initkmem_list3[i]); + if (i < MAX_NUMNODES) + cache_cache.nodelists[i] = NULL; + } + set_up_list3s(&cache_cache, CACHE_CACHE); + + /* + * Fragmentation resistance on low memory - only use bigger + * page orders on machines with more than 32MB of memory. + */ + if (totalram_pages > (32 << 20) >> PAGE_SHIFT) + slab_break_gfp_order = BREAK_GFP_ORDER_HI; + + /* Bootstrap is tricky, because several objects are allocated + * from caches that do not exist yet: + * 1) initialize the cache_cache cache: it contains the struct + * kmem_cache structures of all caches, except cache_cache itself: + * cache_cache is statically allocated. + * Initially an __init data area is used for the head array and the + * kmem_list3 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 cache_cache and the first + * kmalloc cache with kmalloc allocated arrays. + * 5) Replace the __init data for kmem_list3 for cache_cache and + * the other cache's with kmalloc allocated memory. + * 6) Resize the head arrays of the kmalloc caches to their final sizes. + */ + + node = numa_mem_id(); + + /* 1) create the cache_cache */ + INIT_LIST_HEAD(&cache_chain); + list_add(&cache_cache.next, &cache_chain); + cache_cache.colour_off = cache_line_size(); + cache_cache.array[smp_processor_id()] = &initarray_cache.cache; + cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE + node]; + + /* + * struct kmem_cache size depends on nr_node_ids, which + * can be less than MAX_NUMNODES. + */ + cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) + + nr_node_ids * sizeof(struct kmem_list3 *); +#if DEBUG + cache_cache.obj_size = cache_cache.buffer_size; +#endif + cache_cache.buffer_size = ALIGN(cache_cache.buffer_size, + cache_line_size()); + cache_cache.reciprocal_buffer_size = + reciprocal_value(cache_cache.buffer_size); + + for (order = 0; order < MAX_ORDER; order++) { + cache_estimate(order, cache_cache.buffer_size, + cache_line_size(), 0, &left_over, &cache_cache.num); + if (cache_cache.num) + break; + } + BUG_ON(!cache_cache.num); + cache_cache.gfporder = order; + cache_cache.colour = left_over / cache_cache.colour_off; + cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) + + sizeof(struct slab), cache_line_size()); + + /* 2+3) create the kmalloc caches */ + sizes = malloc_sizes; + names = cache_names; + + /* + * Initialize the caches that provide memory for the array cache and the + * kmem_list3 structures first. Without this, further allocations will + * bug. + */ + + sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name, + sizes[INDEX_AC].cs_size, + ARCH_KMALLOC_MINALIGN, + ARCH_KMALLOC_FLAGS|SLAB_PANIC, + NULL); + + if (INDEX_AC != INDEX_L3) { + sizes[INDEX_L3].cs_cachep = + kmem_cache_create(names[INDEX_L3].name, + sizes[INDEX_L3].cs_size, + ARCH_KMALLOC_MINALIGN, + ARCH_KMALLOC_FLAGS|SLAB_PANIC, + NULL); + } + + slab_early_init = 0; + + while (sizes->cs_size != ULONG_MAX) { + /* + * For performance, all the general caches are L1 aligned. + * This should be particularly beneficial on SMP boxes, as it + * eliminates "false sharing". + * Note for systems short on memory removing the alignment will + * allow tighter packing of the smaller caches. + */ + if (!sizes->cs_cachep) { + sizes->cs_cachep = kmem_cache_create(names->name, + sizes->cs_size, + ARCH_KMALLOC_MINALIGN, + ARCH_KMALLOC_FLAGS|SLAB_PANIC, + NULL); + } +#ifdef CONFIG_ZONE_DMA + sizes->cs_dmacachep = kmem_cache_create( + names->name_dma, + sizes->cs_size, + ARCH_KMALLOC_MINALIGN, + ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA| + SLAB_PANIC, + NULL); +#endif + sizes++; + names++; + } + /* 4) Replace the bootstrap head arrays */ + { + struct array_cache *ptr; + + ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); + + BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache); + memcpy(ptr, cpu_cache_get(&cache_cache), + sizeof(struct arraycache_init)); + /* + * Do not assume that spinlocks can be initialized via memcpy: + */ + spin_lock_init(&ptr->lock); + + cache_cache.array[smp_processor_id()] = ptr; + + ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); + + BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep) + != &initarray_generic.cache); + memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep), + sizeof(struct arraycache_init)); + /* + * Do not assume that spinlocks can be initialized via memcpy: + */ + spin_lock_init(&ptr->lock); + + malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = + ptr; + } + /* 5) Replace the bootstrap kmem_list3's */ + { + int nid; + + for_each_online_node(nid) { + init_list(&cache_cache, &initkmem_list3[CACHE_CACHE + nid], nid); + + init_list(malloc_sizes[INDEX_AC].cs_cachep, + &initkmem_list3[SIZE_AC + nid], nid); + + if (INDEX_AC != INDEX_L3) { + init_list(malloc_sizes[INDEX_L3].cs_cachep, + &initkmem_list3[SIZE_L3 + nid], nid); + } + } + } + + g_cpucache_up = EARLY; +} + +void __init kmem_cache_init_late(void) +{ + struct kmem_cache *cachep; + + /* 6) resize the head arrays to their final sizes */ + mutex_lock(&cache_chain_mutex); + list_for_each_entry(cachep, &cache_chain, next) + if (enable_cpucache(cachep, GFP_NOWAIT)) + BUG(); + mutex_unlock(&cache_chain_mutex); + + /* Done! */ + g_cpucache_up = FULL; + + /* Annotate slab for lockdep -- annotate the malloc caches */ + init_lock_keys(); + + /* + * 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 + * nodelists. + */ + 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); + return 0; +} +__initcall(cpucache_init); + +/* + * Interface to system's page allocator. No need to hold the cache-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 void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) +{ + struct page *page; + int nr_pages; + int i; + +#ifndef CONFIG_MMU + /* + * Nommu uses slab's for process anonymous memory allocations, and thus + * requires __GFP_COMP to properly refcount higher order allocations + */ + flags |= __GFP_COMP; +#endif + + flags |= cachep->gfpflags; + if (cachep->flags & SLAB_RECLAIM_ACCOUNT) + flags |= __GFP_RECLAIMABLE; + + page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); + if (!page) + return NULL; + + 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); + for (i = 0; i < nr_pages; i++) + __SetPageSlab(page + i); + + 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_address(page); +} + +/* + * Interface to system's page release. + */ +static void kmem_freepages(struct kmem_cache *cachep, void *addr) +{ + unsigned long i = (1 << cachep->gfporder); + struct page *page = virt_to_page(addr); + const unsigned long nr_freed = i; + + 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); + while (i--) { + BUG_ON(!PageSlab(page)); + __ClearPageSlab(page); + page++; + } + if (current->reclaim_state) + current->reclaim_state->reclaimed_slab += nr_freed; + free_pages((unsigned long)addr, cachep->gfporder); +} + +static void kmem_rcu_free(struct rcu_head *head) +{ + struct slab_rcu *slab_rcu = (struct slab_rcu *)head; + struct kmem_cache *cachep = slab_rcu->cachep; + + kmem_freepages(cachep, slab_rcu->addr); + if (OFF_SLAB(cachep)) + kmem_cache_free(cachep->slabp_cache, slab_rcu); +} + +#if DEBUG + +#ifdef CONFIG_DEBUG_PAGEALLOC +static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, + unsigned long caller) +{ + int size = obj_size(cachep); + + 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 = obj_size(cachep); + 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++; + } + printk(" %02x", (unsigned char)data[offset + i]); + } + printk("\n"); + + 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>]", + *dbg_userword(cachep, objp)); + print_symbol("(%s)", + (unsigned long)*dbg_userword(cachep, objp)); + printk("\n"); + } + realobj = (char *)objp + obj_offset(cachep); + size = obj_size(cachep); + 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 = obj_size(cachep); + + 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 start=%p, len=%d\n", + 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 slab *slabp = virt_to_slab(objp); + unsigned int objnr; + + objnr = obj_to_index(cachep, slabp, objp); + if (objnr) { + objp = index_to_obj(cachep, slabp, 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, slabp, 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 slab *slabp) +{ + int i; + for (i = 0; i < cachep->num; i++) { + void *objp = index_to_obj(cachep, slabp, i); + + if (cachep->flags & SLAB_POISON) { +#ifdef CONFIG_DEBUG_PAGEALLOC + if (cachep->buffer_size % PAGE_SIZE == 0 && + OFF_SLAB(cachep)) + kernel_map_pages(virt_to_page(objp), + cachep->buffer_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 slab *slabp) +{ +} +#endif + +/** + * slab_destroy - destroy and release all objects in a slab + * @cachep: cache pointer being destroyed + * @slabp: slab pointer being destroyed + * + * Destroy all the objs in a slab, and release the mem back to the system. + * Before calling the slab must have been unlinked from the cache. The + * cache-lock is not held/needed. + */ +static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp) +{ + void *addr = slabp->s_mem - slabp->colouroff; + + slab_destroy_debugcheck(cachep, slabp); + if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { + struct slab_rcu *slab_rcu; + + slab_rcu = (struct slab_rcu *)slabp; + slab_rcu->cachep = cachep; + slab_rcu->addr = addr; + call_rcu(&slab_rcu->head, kmem_rcu_free); + } else { + kmem_freepages(cachep, addr); + if (OFF_SLAB(cachep)) + kmem_cache_free(cachep->slabp_cache, slabp); + } +} + +static void __kmem_cache_destroy(struct kmem_cache *cachep) +{ + int i; + struct kmem_list3 *l3; + + for_each_online_cpu(i) + kfree(cachep->array[i]); + + /* NUMA: free the list3 structures */ + for_each_online_node(i) { + l3 = cachep->nodelists[i]; + if (l3) { + kfree(l3->shared); + free_alien_cache(l3->alien); + kfree(l3); + } + } + kmem_cache_free(&cache_cache, cachep); +} + + +/** + * 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; + + if (flags & CFLGS_OFF_SLAB) { + /* + * Max number of objs-per-slab for caches which + * use off-slab slabs. Needed to avoid a possible + * looping condition in cache_grow(). + */ + offslab_limit = size - sizeof(struct slab); + offslab_limit /= sizeof(kmem_bufctl_t); + + 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_break_gfp_order) + break; + + /* + * Acceptable internal fragmentation? + */ + if (left_over * 8 <= (PAGE_SIZE << gfporder)) + break; + } + return left_over; +} + +static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) +{ + if (g_cpucache_up == FULL) + return enable_cpucache(cachep, gfp); + + if (g_cpucache_up == NONE) { + /* + * Note: the first kmem_cache_create must create the cache + * that's used by kmalloc(24), otherwise the creation of + * further caches will BUG(). + */ + cachep->array[smp_processor_id()] = &initarray_generic.cache; + + /* + * If the cache that's used by kmalloc(sizeof(kmem_list3)) is + * the first cache, then we need to set up all its list3s, + * otherwise the creation of further caches will BUG(). + */ + set_up_list3s(cachep, SIZE_AC); + if (INDEX_AC == INDEX_L3) + g_cpucache_up = PARTIAL_L3; + else + g_cpucache_up = PARTIAL_AC; + } else { + cachep->array[smp_processor_id()] = + kmalloc(sizeof(struct arraycache_init), gfp); + + if (g_cpucache_up == PARTIAL_AC) { + set_up_list3s(cachep, SIZE_L3); + g_cpucache_up = PARTIAL_L3; + } else { + int node; + for_each_online_node(node) { + cachep->nodelists[node] = + kmalloc_node(sizeof(struct kmem_list3), + gfp, node); + BUG_ON(!cachep->nodelists[node]); + kmem_list3_init(cachep->nodelists[node]); + } + } + } + cachep->nodelists[numa_mem_id()]->next_reap = + jiffies + REAPTIMEOUT_LIST3 + + ((unsigned long)cachep) % REAPTIMEOUT_LIST3; + + 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; +} + +/** + * kmem_cache_create - Create a cache. + * @name: A string which is used in /proc/slabinfo to identify this cache. + * @size: The size of objects to be created in this cache. + * @align: The required alignment for the objects. + * @flags: SLAB flags + * @ctor: A constructor for the objects. + * + * 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. + * + * @name must be valid until the cache is destroyed. This implies that + * the module calling this has to destroy the cache before getting unloaded. + * + * 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. + */ +struct kmem_cache * +kmem_cache_create (const char *name, size_t size, size_t align, + unsigned long flags, void (*ctor)(void *)) +{ + size_t left_over, slab_size, ralign; + struct kmem_cache *cachep = NULL, *pc; + gfp_t gfp; + + /* + * Sanity checks... these are all serious usage bugs. + */ + if (!name || in_interrupt() || (size < BYTES_PER_WORD) || + size > KMALLOC_MAX_SIZE) { + printk(KERN_ERR "%s: Early error in slab %s\n", __func__, + name); + BUG(); + } + + /* + * We use cache_chain_mutex to ensure a consistent view of + * cpu_online_mask as well. Please see cpuup_callback + */ + if (slab_is_available()) { + get_online_cpus(); + mutex_lock(&cache_chain_mutex); + } + + list_for_each_entry(pc, &cache_chain, next) { + char tmp; + int res; + + /* + * This happens when the module gets unloaded and doesn't + * destroy its slab cache and no-one else reuses the vmalloc + * area of the module. Print a warning. + */ + res = probe_kernel_address(pc->name, tmp); + if (res) { + printk(KERN_ERR + "SLAB: cache with size %d has lost its name\n", + pc->buffer_size); + continue; + } + + if (!strcmp(pc->name, name)) { + printk(KERN_ERR + "kmem_cache_create: duplicate cache %s\n", name); + dump_stack(); + goto oops; + } + } + +#if DEBUG + WARN_ON(strchr(name, ' ')); /* It confuses parsers */ +#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 + /* + * Always checks flags, a caller might be expecting debug support which + * isn't available. + */ + BUG_ON(flags & ~CREATE_MASK); + + /* + * 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); + } + + /* calculate the final buffer alignment: */ + + /* 1) arch recommendation: can be overridden for debug */ + if (flags & SLAB_HWCACHE_ALIGN) { + /* + * Default alignment: as specified by the arch code. Except if + * an object is really small, then squeeze multiple objects into + * one cacheline. + */ + ralign = cache_line_size(); + while (size <= ralign / 2) + ralign /= 2; + } else { + ralign = BYTES_PER_WORD; + } + + /* + * Redzoning and user store require word alignment or possibly larger. + * Note this will be overridden by architecture or caller mandated + * alignment if either is greater than BYTES_PER_WORD. + */ + if (flags & SLAB_STORE_USER) + ralign = BYTES_PER_WORD; + + 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); + } + + /* 2) arch mandated alignment */ + if (ralign < ARCH_SLAB_MINALIGN) { + ralign = ARCH_SLAB_MINALIGN; + } + /* 3) caller mandated alignment */ + if (ralign < align) { + ralign = align; + } + /* disable debug if necessary */ + if (ralign > __alignof__(unsigned long long)) + flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); + /* + * 4) Store it. + */ + align = ralign; + + if (slab_is_available()) + gfp = GFP_KERNEL; + else + gfp = GFP_NOWAIT; + + /* Get cache's description obj. */ + cachep = kmem_cache_zalloc(&cache_cache, gfp); + if (!cachep) + goto oops; + +#if DEBUG + cachep->obj_size = size; + + /* + * 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) + if (size >= malloc_sizes[INDEX_L3 + 1].cs_size + && cachep->obj_size > cache_line_size() && ALIGN(size, align) < PAGE_SIZE) { + cachep->obj_offset += PAGE_SIZE - ALIGN(size, 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 >= (PAGE_SIZE >> 3)) && !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, align); + + left_over = calculate_slab_order(cachep, size, align, flags); + + if (!cachep->num) { + printk(KERN_ERR + "kmem_cache_create: couldn't create cache %s.\n", name); + kmem_cache_free(&cache_cache, cachep); + cachep = NULL; + goto oops; + } + slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t) + + sizeof(struct slab), 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 >= slab_size) { + flags &= ~CFLGS_OFF_SLAB; + left_over -= slab_size; + } + + if (flags & CFLGS_OFF_SLAB) { + /* really off slab. No need for manual alignment */ + slab_size = + cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab); + +#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 < align) + cachep->colour_off = align; + cachep->colour = left_over / cachep->colour_off; + cachep->slab_size = slab_size; + cachep->flags = flags; + cachep->gfpflags = 0; + if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) + cachep->gfpflags |= GFP_DMA; + cachep->buffer_size = size; + cachep->reciprocal_buffer_size = reciprocal_value(size); + + if (flags & CFLGS_OFF_SLAB) { + cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); + /* + * This is a possibility for one of the malloc_sizes caches. + * But since we go off slab only for object size greater than + * PAGE_SIZE/8, and malloc_sizes gets 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->slabp_cache)); + } + cachep->ctor = ctor; + cachep->name = name; + + if (setup_cpu_cache(cachep, gfp)) { + __kmem_cache_destroy(cachep); + cachep = NULL; + goto oops; + } + + /* cache setup completed, link it into the list */ + list_add(&cachep->next, &cache_chain); +oops: + if (!cachep && (flags & SLAB_PANIC)) + panic("kmem_cache_create(): failed to create slab `%s'\n", + name); + if (slab_is_available()) { + mutex_unlock(&cache_chain_mutex); + put_online_cpus(); + } + return cachep; +} +EXPORT_SYMBOL(kmem_cache_create); + +#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(&cachep->nodelists[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(&cachep->nodelists[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_list3 *l3, + 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(); + + check_irq_off(); + ac = cpu_cache_get(cachep); + spin_lock(&cachep->nodelists[node]->list_lock); + free_block(cachep, ac->entry, ac->avail, node); + spin_unlock(&cachep->nodelists[node]->list_lock); + ac->avail = 0; +} + +static void drain_cpu_caches(struct kmem_cache *cachep) +{ + struct kmem_list3 *l3; + int node; + + on_each_cpu(do_drain, cachep, 1); + check_irq_on(); + for_each_online_node(node) { + l3 = cachep->nodelists[node]; + if (l3 && l3->alien) + drain_alien_cache(cachep, l3->alien); + } + + for_each_online_node(node) { + l3 = cachep->nodelists[node]; + if (l3) + drain_array(cachep, l3, l3->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_list3 *l3, int tofree) +{ + struct list_head *p; + int nr_freed; + struct slab *slabp; + + nr_freed = 0; + while (nr_freed < tofree && !list_empty(&l3->slabs_free)) { + + spin_lock_irq(&l3->list_lock); + p = l3->slabs_free.prev; + if (p == &l3->slabs_free) { + spin_unlock_irq(&l3->list_lock); + goto out; + } + + slabp = list_entry(p, struct slab, list); +#if DEBUG + BUG_ON(slabp->inuse); +#endif + list_del(&slabp->list); + /* + * Safe to drop the lock. The slab is no longer linked + * to the cache. + */ + l3->free_objects -= cache->num; + spin_unlock_irq(&l3->list_lock); + slab_destroy(cache, slabp); + nr_freed++; + } +out: + return nr_freed; +} + +/* Called with cache_chain_mutex held to protect against cpu hotplug */ +static int __cache_shrink(struct kmem_cache *cachep) +{ + int ret = 0, i = 0; + struct kmem_list3 *l3; + + drain_cpu_caches(cachep); + + check_irq_on(); + for_each_online_node(i) { + l3 = cachep->nodelists[i]; + if (!l3) + continue; + + drain_freelist(cachep, l3, l3->free_objects); + + ret += !list_empty(&l3->slabs_full) || + !list_empty(&l3->slabs_partial); + } + return (ret ? 1 : 0); +} + +/** + * kmem_cache_shrink - Shrink a cache. + * @cachep: The cache to shrink. + * + * Releases as many slabs as possible for a cache. + * To help debugging, a zero exit status indicates all slabs were released. + */ +int kmem_cache_shrink(struct kmem_cache *cachep) +{ + int ret; + BUG_ON(!cachep || in_interrupt()); + + get_online_cpus(); + mutex_lock(&cache_chain_mutex); + ret = __cache_shrink(cachep); + mutex_unlock(&cache_chain_mutex); + put_online_cpus(); + return ret; +} +EXPORT_SYMBOL(kmem_cache_shrink); + +/** + * kmem_cache_destroy - delete a cache + * @cachep: the cache to destroy + * + * Remove a &struct kmem_cache object from the slab cache. + * + * It is expected this function will be called by a module when it is + * unloaded. This will remove the cache completely, and avoid a duplicate + * cache being allocated each time a module is loaded and unloaded, if the + * module doesn't have persistent in-kernel storage across loads and unloads. + * + * The cache must be empty before calling this function. + * + * The caller must guarantee that no one will allocate memory from the cache + * during the kmem_cache_destroy(). + */ +void kmem_cache_destroy(struct kmem_cache *cachep) +{ + BUG_ON(!cachep || in_interrupt()); + + /* Find the cache in the chain of caches. */ + get_online_cpus(); + mutex_lock(&cache_chain_mutex); + /* + * the chain is never empty, cache_cache is never destroyed + */ + list_del(&cachep->next); + if (__cache_shrink(cachep)) { + slab_error(cachep, "Can't free all objects"); + list_add(&cachep->next, &cache_chain); + mutex_unlock(&cache_chain_mutex); + put_online_cpus(); + return; + } + + if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) + rcu_barrier(); + + __kmem_cache_destroy(cachep); + mutex_unlock(&cache_chain_mutex); + put_online_cpus(); +} +EXPORT_SYMBOL(kmem_cache_destroy); + +/* + * Get the memory for a slab management obj. + * For a slab cache when the slab descriptor is off-slab, slab descriptors + * always come from malloc_sizes caches. The slab descriptor cannot + * come from the same cache which is getting created because, + * when we are searching for an appropriate cache for these + * descriptors in kmem_cache_create, we search through the malloc_sizes array. + * If we are creating a malloc_sizes cache here it would not be visible to + * kmem_find_general_cachep till the initialization is complete. + * Hence we cannot have slabp_cache same as the original cache. + */ +static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, + int colour_off, gfp_t local_flags, + int nodeid) +{ + struct slab *slabp; + + if (OFF_SLAB(cachep)) { + /* Slab management obj is off-slab. */ + slabp = kmem_cache_alloc_node(cachep->slabp_cache, + local_flags, nodeid); + /* + * If the first object in the slab is leaked (it's allocated + * but no one has a reference to it), we want to make sure + * kmemleak does not treat the ->s_mem pointer as a reference + * to the object. Otherwise we will not report the leak. + */ + kmemleak_scan_area(&slabp->list, sizeof(struct list_head), + local_flags); + if (!slabp) + return NULL; + } else { + slabp = objp + colour_off; + colour_off += cachep->slab_size; + } + slabp->inuse = 0; + slabp->colouroff = colour_off; + slabp->s_mem = objp + colour_off; + slabp->nodeid = nodeid; + slabp->free = 0; + return slabp; +} + +static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) +{ + return (kmem_bufctl_t *) (slabp + 1); +} + +static void cache_init_objs(struct kmem_cache *cachep, + struct slab *slabp) +{ + int i; + + for (i = 0; i < cachep->num; i++) { + void *objp = index_to_obj(cachep, slabp, 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->buffer_size % PAGE_SIZE) == 0 && + OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) + kernel_map_pages(virt_to_page(objp), + cachep->buffer_size / PAGE_SIZE, 0); +#else + if (cachep->ctor) + cachep->ctor(objp); +#endif + slab_bufctl(slabp)[i] = i + 1; + } + slab_bufctl(slabp)[i - 1] = BUFCTL_END; +} + +static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) +{ + if (CONFIG_ZONE_DMA_FLAG) { + if (flags & GFP_DMA) + BUG_ON(!(cachep->gfpflags & GFP_DMA)); + else + BUG_ON(cachep->gfpflags & GFP_DMA); + } +} + +static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, + int nodeid) +{ + void *objp = index_to_obj(cachep, slabp, slabp->free); + kmem_bufctl_t next; + + slabp->inuse++; + next = slab_bufctl(slabp)[slabp->free]; +#if DEBUG + slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; + WARN_ON(slabp->nodeid != nodeid); +#endif + slabp->free = next; + + return objp; +} + +static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, + void *objp, int nodeid) +{ + unsigned int objnr = obj_to_index(cachep, slabp, objp); + +#if DEBUG + /* Verify that the slab belongs to the intended node */ + WARN_ON(slabp->nodeid != nodeid); + + if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) { + printk(KERN_ERR "slab: double free detected in cache " + "'%s', objp %p\n", cachep->name, objp); + BUG(); + } +#endif + slab_bufctl(slabp)[objnr] = slabp->free; + slabp->free = objnr; + slabp->inuse--; +} + +/* + * 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 slab *slab, + void *addr) +{ + int nr_pages; + struct page *page; + + page = virt_to_page(addr); + + nr_pages = 1; + if (likely(!PageCompound(page))) + nr_pages <<= cache->gfporder; + + do { + page_set_cache(page, cache); + page_set_slab(page, slab); + page++; + } while (--nr_pages); +} + +/* + * 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, void *objp) +{ + struct slab *slabp; + size_t offset; + gfp_t local_flags; + struct kmem_list3 *l3; + + /* + * Be lazy and only check for valid flags here, keeping it out of the + * critical path in kmem_cache_alloc(). + */ + BUG_ON(flags & GFP_SLAB_BUG_MASK); + local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); + + /* Take the l3 list lock to change the colour_next on this node */ + check_irq_off(); + l3 = cachep->nodelists[nodeid]; + spin_lock(&l3->list_lock); + + /* Get colour for the slab, and cal the next value. */ + offset = l3->colour_next; + l3->colour_next++; + if (l3->colour_next >= cachep->colour) + l3->colour_next = 0; + spin_unlock(&l3->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 (!objp) + objp = kmem_getpages(cachep, local_flags, nodeid); + if (!objp) + goto failed; + + /* Get slab management. */ + slabp = alloc_slabmgmt(cachep, objp, offset, + local_flags & ~GFP_CONSTRAINT_MASK, nodeid); + if (!slabp) + goto opps1; + + slab_map_pages(cachep, slabp, objp); + + cache_init_objs(cachep, slabp); + + if (local_flags & __GFP_WAIT) + local_irq_disable(); + check_irq_off(); + spin_lock(&l3->list_lock); + + /* Make slab active. */ + list_add_tail(&slabp->list, &(l3->slabs_free)); + STATS_INC_GROWN(cachep); + l3->free_objects += cachep->num; + spin_unlock(&l3->list_lock); + return 1; +opps1: + kmem_freepages(cachep, objp); +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, + void *caller) +{ + struct page *page; + unsigned int objnr; + struct slab *slabp; + + BUG_ON(virt_to_cache(objp) != cachep); + + objp -= obj_offset(cachep); + kfree_debugcheck(objp); + page = virt_to_head_page(objp); + + slabp = page_get_slab(page); + + 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) = caller; + + objnr = obj_to_index(cachep, slabp, objp); + + BUG_ON(objnr >= cachep->num); + BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); + +#ifdef CONFIG_DEBUG_SLAB_LEAK + slab_bufctl(slabp)[objnr] = BUFCTL_FREE; +#endif + if (cachep->flags & SLAB_POISON) { +#ifdef CONFIG_DEBUG_PAGEALLOC + if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { + store_stackinfo(cachep, objp, (unsigned long)caller); + kernel_map_pages(virt_to_page(objp), + cachep->buffer_size / PAGE_SIZE, 0); + } else { + poison_obj(cachep, objp, POISON_FREE); + } +#else + poison_obj(cachep, objp, POISON_FREE); +#endif + } + return objp; +} + +static void check_slabp(struct kmem_cache *cachep, struct slab *slabp) +{ + kmem_bufctl_t i; + int entries = 0; + + /* Check slab's freelist to see if this obj is there. */ + for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { + entries++; + if (entries > cachep->num || i >= cachep->num) + goto bad; + } + if (entries != cachep->num - slabp->inuse) { +bad: + printk(KERN_ERR "slab: Internal list corruption detected in " + "cache '%s'(%d), slabp %p(%d). Hexdump:\n", + cachep->name, cachep->num, slabp, slabp->inuse); + for (i = 0; + i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t); + i++) { + if (i % 16 == 0) + printk("\n%03x:", i); + printk(" %02x", ((unsigned char *)slabp)[i]); + } + printk("\n"); + BUG(); + } +} +#else +#define kfree_debugcheck(x) do { } while(0) +#define cache_free_debugcheck(x,objp,z) (objp) +#define check_slabp(x,y) do { } while(0) +#endif + +static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags) +{ + int batchcount; + struct kmem_list3 *l3; + struct array_cache *ac; + int node; + +retry: + check_irq_off(); + node = numa_mem_id(); + 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; + } + l3 = cachep->nodelists[node]; + + BUG_ON(ac->avail > 0 || !l3); + spin_lock(&l3->list_lock); + + /* See if we can refill from the shared array */ + if (l3->shared && transfer_objects(ac, l3->shared, batchcount)) { + l3->shared->touched = 1; + goto alloc_done; + } + + while (batchcount > 0) { + struct list_head *entry; + struct slab *slabp; + /* Get slab alloc is to come from. */ + entry = l3->slabs_partial.next; + if (entry == &l3->slabs_partial) { + l3->free_touched = 1; + entry = l3->slabs_free.next; + if (entry == &l3->slabs_free) + goto must_grow; + } + + slabp = list_entry(entry, struct slab, list); + check_slabp(cachep, slabp); + 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(slabp->inuse >= cachep->num); + + while (slabp->inuse < cachep->num && batchcount--) { + STATS_INC_ALLOCED(cachep); + STATS_INC_ACTIVE(cachep); + STATS_SET_HIGH(cachep); + + ac->entry[ac->avail++] = slab_get_obj(cachep, slabp, + node); + } + check_slabp(cachep, slabp); + + /* move slabp to correct slabp list: */ + list_del(&slabp->list); + if (slabp->free == BUFCTL_END) + list_add(&slabp->list, &l3->slabs_full); + else + list_add(&slabp->list, &l3->slabs_partial); + } + +must_grow: + l3->free_objects -= ac->avail; +alloc_done: + spin_unlock(&l3->list_lock); + + if (unlikely(!ac->avail)) { + int x; + x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); + + /* cache_grow can reenable interrupts, then ac could change. */ + ac = cpu_cache_get(cachep); + if (!x && ac->avail == 0) /* no objects in sight? abort */ + return NULL; + + if (!ac->avail) /* objects refilled by interrupt? */ + goto retry; + } + ac->touched = 1; + return ac->entry[--ac->avail]; +} + +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, void *caller) +{ + if (!objp) + return objp; + if (cachep->flags & SLAB_POISON) { +#ifdef CONFIG_DEBUG_PAGEALLOC + if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) + kernel_map_pages(virt_to_page(objp), + cachep->buffer_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) = 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; + } +#ifdef CONFIG_DEBUG_SLAB_LEAK + { + struct slab *slabp; + unsigned objnr; + + slabp = page_get_slab(virt_to_head_page(objp)); + objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size; + slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE; + } +#endif + objp += obj_offset(cachep); + if (cachep->ctor && cachep->flags & SLAB_POISON) + cachep->ctor(objp); +#if ARCH_SLAB_MINALIGN + if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) { + printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", + objp, ARCH_SLAB_MINALIGN); + } +#endif + 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 (cachep == &cache_cache) + return false; + + return should_failslab(obj_size(cachep), flags, cachep->flags); +} + +static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) +{ + void *objp; + struct array_cache *ac; + + check_irq_off(); + + ac = cpu_cache_get(cachep); + if (likely(ac->avail)) { + STATS_INC_ALLOCHIT(cachep); + ac->touched = 1; + objp = ac->entry[--ac->avail]; + } else { + STATS_INC_ALLOCMISS(cachep); + objp = cache_alloc_refill(cachep, flags); + /* + * the 'ac' may be updated by cache_alloc_refill(), + * and kmemleak_erase() requires its correct value. + */ + ac = cpu_cache_get(cachep); + } + /* + * 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 PF_SPREAD_SLAB|PF_MEMPOLICY. + * + * 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(); + get_mems_allowed(); + if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) + nid_alloc = cpuset_slab_spread_node(); + else if (current->mempolicy) + nid_alloc = slab_node(current->mempolicy); + put_mems_allowed(); + 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 nodelists 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; + + if (flags & __GFP_THISNODE) + return NULL; + + get_mems_allowed(); + zonelist = node_zonelist(slab_node(current->mempolicy), flags); + local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); + +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_hardwall(zone, flags) && + cache->nodelists[nid] && + cache->nodelists[nid]->free_objects) { + obj = ____cache_alloc_node(cache, + flags | GFP_THISNODE, 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. + */ + if (local_flags & __GFP_WAIT) + local_irq_enable(); + kmem_flagcheck(cache, flags); + obj = kmem_getpages(cache, local_flags, numa_mem_id()); + if (local_flags & __GFP_WAIT) + local_irq_disable(); + if (obj) { + /* + * Insert into the appropriate per node queues + */ + nid = page_to_nid(virt_to_page(obj)); + if (cache_grow(cache, flags, nid, obj)) { + obj = ____cache_alloc_node(cache, + flags | GFP_THISNODE, 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; + } + } + } + put_mems_allowed(); + 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 slab *slabp; + struct kmem_list3 *l3; + void *obj; + int x; + + l3 = cachep->nodelists[nodeid]; + BUG_ON(!l3); + +retry: + check_irq_off(); + spin_lock(&l3->list_lock); + entry = l3->slabs_partial.next; + if (entry == &l3->slabs_partial) { + l3->free_touched = 1; + entry = l3->slabs_free.next; + if (entry == &l3->slabs_free) + goto must_grow; + } + + slabp = list_entry(entry, struct slab, list); + check_spinlock_acquired_node(cachep, nodeid); + check_slabp(cachep, slabp); + + STATS_INC_NODEALLOCS(cachep); + STATS_INC_ACTIVE(cachep); + STATS_SET_HIGH(cachep); + + BUG_ON(slabp->inuse == cachep->num); + + obj = slab_get_obj(cachep, slabp, nodeid); + check_slabp(cachep, slabp); + l3->free_objects--; + /* move slabp to correct slabp list: */ + list_del(&slabp->list); + + if (slabp->free == BUFCTL_END) + list_add(&slabp->list, &l3->slabs_full); + else + list_add(&slabp->list, &l3->slabs_partial); + + spin_unlock(&l3->list_lock); + goto done; + +must_grow: + spin_unlock(&l3->list_lock); + x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); + if (x) + goto retry; + + return fallback_alloc(cachep, flags); + +done: + return obj; +} + +/** + * 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. + * @caller: return address of caller, used for debug information + * + * 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. + */ +static __always_inline void * +__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, + void *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; + + cache_alloc_debugcheck_before(cachep, flags); + local_irq_save(save_flags); + + if (nodeid == -1) + nodeid = slab_node; + + if (unlikely(!cachep->nodelists[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, obj_size(cachep), 1, cachep->flags, + flags); + + if (likely(ptr)) + kmemcheck_slab_alloc(cachep, flags, ptr, obj_size(cachep)); + + if (unlikely((flags & __GFP_ZERO) && ptr)) + memset(ptr, 0, obj_size(cachep)); + + return ptr; +} + +static __always_inline void * +__do_cache_alloc(struct kmem_cache *cache, gfp_t flags) +{ + void *objp; + + if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { + 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 * +__cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) +{ + unsigned long save_flags; + void *objp; + + flags &= gfp_allowed_mask; + + lockdep_trace_alloc(flags); + + if (slab_should_failslab(cachep, flags)) + return NULL; + + 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, obj_size(cachep), 1, cachep->flags, + flags); + prefetchw(objp); + + if (likely(objp)) + kmemcheck_slab_alloc(cachep, flags, objp, obj_size(cachep)); + + if (unlikely((flags & __GFP_ZERO) && objp)) + memset(objp, 0, obj_size(cachep)); + + return objp; +} + +/* + * Caller needs to acquire correct kmem_list's list_lock + */ +static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, + int node) +{ + int i; + struct kmem_list3 *l3; + + for (i = 0; i < nr_objects; i++) { + void *objp = objpp[i]; + struct slab *slabp; + + slabp = virt_to_slab(objp); + l3 = cachep->nodelists[node]; + list_del(&slabp->list); + check_spinlock_acquired_node(cachep, node); + check_slabp(cachep, slabp); + slab_put_obj(cachep, slabp, objp, node); + STATS_DEC_ACTIVE(cachep); + l3->free_objects++; + check_slabp(cachep, slabp); + + /* fixup slab chains */ + if (slabp->inuse == 0) { + if (l3->free_objects > l3->free_limit) { + l3->free_objects -= cachep->num; + /* No need to drop any previously held + * lock here, even if we have a off-slab slab + * descriptor it is guaranteed to come from + * a different cache, refer to comments before + * alloc_slabmgmt. + */ + slab_destroy(cachep, slabp); + } else { + list_add(&slabp->list, &l3->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(&slabp->list, &l3->slabs_partial); + } + } +} + +static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) +{ + int batchcount; + struct kmem_list3 *l3; + int node = numa_mem_id(); + + batchcount = ac->batchcount; +#if DEBUG + BUG_ON(!batchcount || batchcount > ac->avail); +#endif + check_irq_off(); + l3 = cachep->nodelists[node]; + spin_lock(&l3->list_lock); + if (l3->shared) { + struct array_cache *shared_array = l3->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); +free_done: +#if STATS + { + int i = 0; + struct list_head *p; + + p = l3->slabs_free.next; + while (p != &(l3->slabs_free)) { + struct slab *slabp; + + slabp = list_entry(p, struct slab, list); + BUG_ON(slabp->inuse); + + i++; + p = p->next; + } + STATS_SET_FREEABLE(cachep, i); + } +#endif + spin_unlock(&l3->list_lock); + 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, + void *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, obj_size(cachep)); + + /* + * 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 (likely(ac->avail < ac->limit)) { + STATS_INC_FREEHIT(cachep); + ac->entry[ac->avail++] = objp; + return; + } else { + STATS_INC_FREEMISS(cachep); + cache_flusharray(cachep, ac); + ac->entry[ac->avail++] = 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 = __cache_alloc(cachep, flags, __builtin_return_address(0)); + + trace_kmem_cache_alloc(_RET_IP_, ret, + obj_size(cachep), cachep->buffer_size, flags); + + return ret; +} +EXPORT_SYMBOL(kmem_cache_alloc); + +#ifdef CONFIG_TRACING +void * +kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags) +{ + void *ret; + + ret = __cache_alloc(cachep, flags, __builtin_return_address(0)); + + trace_kmalloc(_RET_IP_, ret, + size, slab_buffer_size(cachep), flags); + return ret; +} +EXPORT_SYMBOL(kmem_cache_alloc_trace); +#endif + +#ifdef CONFIG_NUMA +void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) +{ + void *ret = __cache_alloc_node(cachep, flags, nodeid, + __builtin_return_address(0)); + + trace_kmem_cache_alloc_node(_RET_IP_, ret, + obj_size(cachep), cachep->buffer_size, + flags, nodeid); + + return ret; +} +EXPORT_SYMBOL(kmem_cache_alloc_node); + +#ifdef CONFIG_TRACING +void *kmem_cache_alloc_node_trace(size_t size, + struct kmem_cache *cachep, + gfp_t flags, + int nodeid) +{ + void *ret; + + ret = __cache_alloc_node(cachep, flags, nodeid, + __builtin_return_address(0)); + trace_kmalloc_node(_RET_IP_, ret, + size, slab_buffer_size(cachep), + 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, void *caller) +{ + struct kmem_cache *cachep; + + cachep = kmem_find_general_cachep(size, flags); + if (unlikely(ZERO_OR_NULL_PTR(cachep))) + return cachep; + return kmem_cache_alloc_node_trace(size, cachep, flags, node); +} + +#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) +void *__kmalloc_node(size_t size, gfp_t flags, int node) +{ + return __do_kmalloc_node(size, flags, node, + __builtin_return_address(0)); +} +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, (void *)caller); +} +EXPORT_SYMBOL(__kmalloc_node_track_caller); +#else +void *__kmalloc_node(size_t size, gfp_t flags, int node) +{ + return __do_kmalloc_node(size, flags, node, NULL); +} +EXPORT_SYMBOL(__kmalloc_node); +#endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */ +#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, + void *caller) +{ + struct kmem_cache *cachep; + void *ret; + + /* If you want to save a few bytes .text space: replace + * __ with kmem_. + * Then kmalloc uses the uninlined functions instead of the inline + * functions. + */ + cachep = __find_general_cachep(size, flags); + if (unlikely(ZERO_OR_NULL_PTR(cachep))) + return cachep; + ret = __cache_alloc(cachep, flags, caller); + + trace_kmalloc((unsigned long) caller, ret, + size, cachep->buffer_size, flags); + + return ret; +} + + +#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) +void *__kmalloc(size_t size, gfp_t flags) +{ + return __do_kmalloc(size, flags, __builtin_return_address(0)); +} +EXPORT_SYMBOL(__kmalloc); + +void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) +{ + return __do_kmalloc(size, flags, (void *)caller); +} +EXPORT_SYMBOL(__kmalloc_track_caller); + +#else +void *__kmalloc(size_t size, gfp_t flags) +{ + return __do_kmalloc(size, flags, NULL); +} +EXPORT_SYMBOL(__kmalloc); +#endif + +/** + * 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; + + local_irq_save(flags); + debug_check_no_locks_freed(objp, obj_size(cachep)); + if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) + debug_check_no_obj_freed(objp, obj_size(cachep)); + __cache_free(cachep, objp, __builtin_return_address(0)); + 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, obj_size(c)); + debug_check_no_obj_freed(objp, obj_size(c)); + __cache_free(c, (void *)objp, __builtin_return_address(0)); + local_irq_restore(flags); +} +EXPORT_SYMBOL(kfree); + +unsigned int kmem_cache_size(struct kmem_cache *cachep) +{ + return obj_size(cachep); +} +EXPORT_SYMBOL(kmem_cache_size); + +/* + * This initializes kmem_list3 or resizes various caches for all nodes. + */ +static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp) +{ + int node; + struct kmem_list3 *l3; + struct array_cache *new_shared; + struct array_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; + } + } + + l3 = cachep->nodelists[node]; + if (l3) { + struct array_cache *shared = l3->shared; + + spin_lock_irq(&l3->list_lock); + + if (shared) + free_block(cachep, shared->entry, + shared->avail, node); + + l3->shared = new_shared; + if (!l3->alien) { + l3->alien = new_alien; + new_alien = NULL; + } + l3->free_limit = (1 + nr_cpus_node(node)) * + cachep->batchcount + cachep->num; + spin_unlock_irq(&l3->list_lock); + kfree(shared); + free_alien_cache(new_alien); + continue; + } + l3 = kmalloc_node(sizeof(struct kmem_list3), gfp, node); + if (!l3) { + free_alien_cache(new_alien); + kfree(new_shared); + goto fail; + } + + kmem_list3_init(l3); + l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + + ((unsigned long)cachep) % REAPTIMEOUT_LIST3; + l3->shared = new_shared; + l3->alien = new_alien; + l3->free_limit = (1 + nr_cpus_node(node)) * + cachep->batchcount + cachep->num; + cachep->nodelists[node] = l3; + } + return 0; + +fail: + if (!cachep->next.next) { + /* Cache is not active yet. Roll back what we did */ + node--; + while (node >= 0) { + if (cachep->nodelists[node]) { + l3 = cachep->nodelists[node]; + + kfree(l3->shared); + free_alien_cache(l3->alien); + kfree(l3); + cachep->nodelists[node] = NULL; + } + node--; + } + } + return -ENOMEM; +} + +struct ccupdate_struct { + struct kmem_cache *cachep; + struct array_cache *new[NR_CPUS]; +}; + +static void do_ccupdate_local(void *info) +{ + struct ccupdate_struct *new = info; + struct array_cache *old; + + check_irq_off(); + old = cpu_cache_get(new->cachep); + + new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; + new->new[smp_processor_id()] = old; +} + +/* Always called with the cache_chain_mutex held */ +static int do_tune_cpucache(struct kmem_cache *cachep, int limit, + int batchcount, int shared, gfp_t gfp) +{ + struct ccupdate_struct *new; + int i; + + new = kzalloc(sizeof(*new), gfp); + if (!new) + return -ENOMEM; + + for_each_online_cpu(i) { + new->new[i] = alloc_arraycache(cpu_to_mem(i), limit, + batchcount, gfp); + if (!new->new[i]) { + for (i--; i >= 0; i--) + kfree(new->new[i]); + kfree(new); + return -ENOMEM; + } + } + new->cachep = cachep; + + on_each_cpu(do_ccupdate_local, (void *)new, 1); + + check_irq_on(); + cachep->batchcount = batchcount; + cachep->limit = limit; + cachep->shared = shared; + + for_each_online_cpu(i) { + struct array_cache *ccold = new->new[i]; + if (!ccold) + continue; + spin_lock_irq(&cachep->nodelists[cpu_to_mem(i)]->list_lock); + free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i)); + spin_unlock_irq(&cachep->nodelists[cpu_to_mem(i)]->list_lock); + kfree(ccold); + } + kfree(new); + return alloc_kmemlist(cachep, gfp); +} + +/* Called with cache_chain_mutex held always */ +static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) +{ + int err; + int limit, shared; + + /* + * 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->buffer_size > 131072) + limit = 1; + else if (cachep->buffer_size > PAGE_SIZE) + limit = 8; + else if (cachep->buffer_size > 1024) + limit = 24; + else if (cachep->buffer_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->buffer_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 + err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, 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 l3 lock only if + * necessary. Note that the l3 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_list3 *l3, + struct array_cache *ac, int force, int node) +{ + int tofree; + + if (!ac || !ac->avail) + return; + if (ac->touched && !force) { + ac->touched = 0; + } else { + spin_lock_irq(&l3->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); + ac->avail -= tofree; + memmove(ac->entry, &(ac->entry[tofree]), + sizeof(void *) * ac->avail); + } + spin_unlock_irq(&l3->list_lock); + } +} + +/** + * 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_list3 *l3; + int node = numa_mem_id(); + struct delayed_work *work = to_delayed_work(w); + + if (!mutex_trylock(&cache_chain_mutex)) + /* Give up. Setup the next iteration. */ + goto out; + + list_for_each_entry(searchp, &cache_chain, next) { + check_irq_on(); + + /* + * We only take the l3 lock if absolutely necessary and we + * have established with reasonable certainty that + * we can do some work if the lock was obtained. + */ + l3 = searchp->nodelists[node]; + + reap_alien(searchp, l3); + + drain_array(searchp, l3, 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(l3->next_reap, jiffies)) + goto next; + + l3->next_reap = jiffies + REAPTIMEOUT_LIST3; + + drain_array(searchp, l3, l3->shared, 0, node); + + if (l3->free_touched) + l3->free_touched = 0; + else { + int freed; + + freed = drain_freelist(searchp, l3, (l3->free_limit + + 5 * searchp->num - 1) / (5 * searchp->num)); + STATS_ADD_REAPED(searchp, freed); + } +next: + cond_resched(); + } + check_irq_on(); + mutex_unlock(&cache_chain_mutex); + next_reap_node(); +out: + /* Set up the next iteration */ + schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); +} + +#ifdef CONFIG_SLABINFO + +static void print_slabinfo_header(struct seq_file *m) +{ + /* + * Output format version, so at least we can change it + * without _too_ many complaints. + */ +#if STATS + seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); +#else + seq_puts(m, "slabinfo - version: 2.1\n"); +#endif + seq_puts(m, "# name <active_objs> <num_objs> <objsize> " + "<objperslab> <pagesperslab>"); + seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); + seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); +#if STATS + seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " + "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); + seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); +#endif + seq_putc(m, '\n'); +} + +static void *s_start(struct seq_file *m, loff_t *pos) +{ + loff_t n = *pos; + + mutex_lock(&cache_chain_mutex); + if (!n) + print_slabinfo_header(m); + + return seq_list_start(&cache_chain, *pos); +} + +static void *s_next(struct seq_file *m, void *p, loff_t *pos) +{ + return seq_list_next(p, &cache_chain, pos); +} + +static void s_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&cache_chain_mutex); +} + +static int s_show(struct seq_file *m, void *p) +{ + struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next); + struct slab *slabp; + 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_list3 *l3; + + active_objs = 0; + num_slabs = 0; + for_each_online_node(node) { + l3 = cachep->nodelists[node]; + if (!l3) + continue; + + check_irq_on(); + spin_lock_irq(&l3->list_lock); + + list_for_each_entry(slabp, &l3->slabs_full, list) { + if (slabp->inuse != cachep->num && !error) + error = "slabs_full accounting error"; + active_objs += cachep->num; + active_slabs++; + } + list_for_each_entry(slabp, &l3->slabs_partial, list) { + if (slabp->inuse == cachep->num && !error) + error = "slabs_partial inuse accounting error"; + if (!slabp->inuse && !error) + error = "slabs_partial/inuse accounting error"; + active_objs += slabp->inuse; + active_slabs++; + } + list_for_each_entry(slabp, &l3->slabs_free, list) { + if (slabp->inuse && !error) + error = "slabs_free/inuse accounting error"; + num_slabs++; + } + free_objects += l3->free_objects; + if (l3->shared) + shared_avail += l3->shared->avail; + + spin_unlock_irq(&l3->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); + + seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", + name, active_objs, num_objs, cachep->buffer_size, + cachep->num, (1 << cachep->gfporder)); + seq_printf(m, " : tunables %4u %4u %4u", + cachep->limit, cachep->batchcount, cachep->shared); + seq_printf(m, " : slabdata %6lu %6lu %6lu", + active_slabs, num_slabs, shared_avail); +#if STATS + { /* list3 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 + seq_putc(m, '\n'); + return 0; +} + +/* + * slabinfo_op - iterator that generates /proc/slabinfo + * + * Output layout: + * cache-name + * num-active-objs + * total-objs + * object size + * num-active-slabs + * total-slabs + * num-pages-per-slab + * + further values on SMP and with statistics enabled + */ + +static const struct seq_operations slabinfo_op = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +#define MAX_SLABINFO_WRITE 128 +/** + * slabinfo_write - Tuning for the slab allocator + * @file: unused + * @buffer: user buffer + * @count: data length + * @ppos: unused + */ +static 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(&cache_chain_mutex); + res = -EINVAL; + list_for_each_entry(cachep, &cache_chain, next) { + 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(&cache_chain_mutex); + if (res >= 0) + res = count; + return res; +} + +static int slabinfo_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &slabinfo_op); +} + +static const struct file_operations proc_slabinfo_operations = { + .open = slabinfo_open, + .read = seq_read, + .write = slabinfo_write, + .llseek = seq_lseek, + .release = seq_release, +}; + +#ifdef CONFIG_DEBUG_SLAB_LEAK + +static void *leaks_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&cache_chain_mutex); + return seq_list_start(&cache_chain, *pos); +} + +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 slab *s) +{ + void *p; + int i; + if (n[0] == n[1]) + return; + for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) { + if (slab_bufctl(s)[i] != BUFCTL_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, next); + struct slab *slabp; + struct kmem_list3 *l3; + const char *name; + unsigned long *n = 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 */ + + n[1] = 0; + + for_each_online_node(node) { + l3 = cachep->nodelists[node]; + if (!l3) + continue; + + check_irq_on(); + spin_lock_irq(&l3->list_lock); + + list_for_each_entry(slabp, &l3->slabs_full, list) + handle_slab(n, cachep, slabp); + list_for_each_entry(slabp, &l3->slabs_partial, list) + handle_slab(n, cachep, slabp); + spin_unlock_irq(&l3->list_lock); + } + name = cachep->name; + if (n[0] == n[1]) { + /* Increase the buffer size */ + mutex_unlock(&cache_chain_mutex); + m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL); + if (!m->private) { + /* Too bad, we are really out */ + m->private = n; + mutex_lock(&cache_chain_mutex); + return -ENOMEM; + } + *(unsigned long *)m->private = n[0] * 2; + kfree(n); + mutex_lock(&cache_chain_mutex); + /* Now make sure this entry will be retried */ + m->count = m->size; + return 0; + } + for (i = 0; i < n[1]; i++) { + seq_printf(m, "%s: %lu ", name, n[2*i+3]); + show_symbol(m, n[2*i+2]); + seq_putc(m, '\n'); + } + + return 0; +} + +static const struct seq_operations slabstats_op = { + .start = leaks_start, + .next = s_next, + .stop = s_stop, + .show = leaks_show, +}; + +static int slabstats_open(struct inode *inode, struct file *file) +{ + unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); + int ret = -ENOMEM; + if (n) { + ret = seq_open(file, &slabstats_op); + if (!ret) { + struct seq_file *m = file->private_data; + *n = PAGE_SIZE / (2 * sizeof(unsigned long)); + m->private = n; + n = NULL; + } + kfree(n); + } + return ret; +} + +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) +{ + proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations); +#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 obj_size(virt_to_cache(objp)); +} +EXPORT_SYMBOL(ksize); |