| /* |
| * 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 intializations 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 kmem_cache_t 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 semaphore 'cache_chain_sem'. |
| * 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/config.h> |
| #include <linux/slab.h> |
| #include <linux/mm.h> |
| #include <linux/swap.h> |
| #include <linux/cache.h> |
| #include <linux/interrupt.h> |
| #include <linux/init.h> |
| #include <linux/compiler.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/nodemask.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/cacheflush.h> |
| #include <asm/tlbflush.h> |
| #include <asm/page.h> |
| |
| /* |
| * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL, |
| * 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 *) |
| |
| #ifndef cache_line_size |
| #define cache_line_size() L1_CACHE_BYTES |
| #endif |
| |
| #ifndef ARCH_KMALLOC_MINALIGN |
| /* |
| * Enforce a minimum alignment for the kmalloc caches. |
| * Usually, the kmalloc caches are cache_line_size() aligned, except when |
| * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned. |
| * Some archs want to perform DMA into kmalloc caches and need a guaranteed |
| * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that. |
| * Note that this flag disables some debug features. |
| */ |
| #define ARCH_KMALLOC_MINALIGN 0 |
| #endif |
| |
| #ifndef ARCH_SLAB_MINALIGN |
| /* |
| * Enforce a minimum alignment for all caches. |
| * Intended for archs that get misalignment faults even for BYTES_PER_WORD |
| * aligned buffers. Includes ARCH_KMALLOC_MINALIGN. |
| * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables |
| * some debug features. |
| */ |
| #define ARCH_SLAB_MINALIGN 0 |
| #endif |
| |
| #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_DEBUG_INITIAL | SLAB_RED_ZONE | \ |
| SLAB_POISON | SLAB_HWCACHE_ALIGN | \ |
| SLAB_NO_REAP | SLAB_CACHE_DMA | \ |
| SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \ |
| SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
| SLAB_DESTROY_BY_RCU) |
| #else |
| # define CREATE_MASK (SLAB_HWCACHE_ALIGN | SLAB_NO_REAP | \ |
| SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \ |
| SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
| SLAB_DESTROY_BY_RCU) |
| #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 SLAB_LIMIT (((kmem_bufctl_t)(~0U))-2) |
| |
| /* Max number of objs-per-slab for caches which use off-slab slabs. |
| * Needed to avoid a possible looping condition in cache_grow(). |
| */ |
| static unsigned long offslab_limit; |
| |
| /* |
| * 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 { |
| 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_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. |
| * |
| * We assume struct slab_rcu can overlay struct slab when destroying. |
| */ |
| struct slab_rcu { |
| struct rcu_head head; |
| kmem_cache_t *cachep; |
| void *addr; |
| }; |
| |
| /* |
| * 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[0]; /* |
| * Must have this definition in here for the proper |
| * alignment of array_cache. Also simplifies accessing |
| * the entries. |
| * [0] is for gcc 2.95. It should really be []. |
| */ |
| }; |
| |
| /* 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 long next_reap; |
| int free_touched; |
| unsigned int free_limit; |
| spinlock_t list_lock; |
| struct array_cache *shared; /* shared per node */ |
| struct array_cache **alien; /* on other nodes */ |
| }; |
| |
| /* |
| * Need this for bootstrapping a per node allocator. |
| */ |
| #define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1) |
| struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; |
| #define CACHE_CACHE 0 |
| #define SIZE_AC 1 |
| #define SIZE_L3 (1 + MAX_NUMNODES) |
| |
| /* |
| * 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) |
| { |
| 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 |
| { |
| extern void __bad_size(void); |
| __bad_size(); |
| } |
| } else |
| BUG(); |
| return 0; |
| } |
| |
| #define INDEX_AC index_of(sizeof(struct arraycache_init)) |
| #define INDEX_L3 index_of(sizeof(struct kmem_list3)) |
| |
| static inline 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; |
| 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) |
| |
| /* |
| * kmem_cache_t |
| * |
| * manages a cache. |
| */ |
| |
| struct kmem_cache { |
| /* 1) per-cpu data, touched during every alloc/free */ |
| struct array_cache *array[NR_CPUS]; |
| unsigned int batchcount; |
| unsigned int limit; |
| unsigned int shared; |
| unsigned int objsize; |
| /* 2) touched by every alloc & free from the backend */ |
| struct kmem_list3 *nodelists[MAX_NUMNODES]; |
| unsigned int flags; /* constant flags */ |
| unsigned int num; /* # of objs per slab */ |
| spinlock_t spinlock; |
| |
| /* 3) cache_grow/shrink */ |
| /* order of pgs per slab (2^n) */ |
| unsigned int gfporder; |
| |
| /* force GFP flags, e.g. GFP_DMA */ |
| gfp_t gfpflags; |
| |
| size_t colour; /* cache colouring range */ |
| unsigned int colour_off; /* colour offset */ |
| unsigned int colour_next; /* cache colouring */ |
| kmem_cache_t *slabp_cache; |
| unsigned int slab_size; |
| unsigned int dflags; /* dynamic flags */ |
| |
| /* constructor func */ |
| void (*ctor)(void *, kmem_cache_t *, unsigned long); |
| |
| /* de-constructor func */ |
| void (*dtor)(void *, kmem_cache_t *, unsigned long); |
| |
| /* 4) cache creation/removal */ |
| const char *name; |
| struct list_head next; |
| |
| /* 5) statistics */ |
| #if STATS |
| unsigned long num_active; |
| unsigned long num_allocations; |
| unsigned long high_mark; |
| unsigned long grown; |
| unsigned long reaped; |
| unsigned long errors; |
| unsigned long max_freeable; |
| unsigned long node_allocs; |
| unsigned long node_frees; |
| atomic_t allochit; |
| atomic_t allocmiss; |
| atomic_t freehit; |
| atomic_t freemiss; |
| #endif |
| #if DEBUG |
| int dbghead; |
| int reallen; |
| #endif |
| }; |
| |
| #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_INC_REAPED(x) ((x)->reaped++) |
| #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_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_INC_REAPED(x) do { } 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_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 |
| /* Magic nums for obj red zoning. |
| * Placed in the first word before and the first word after an obj. |
| */ |
| #define RED_INACTIVE 0x5A2CF071UL /* when obj is inactive */ |
| #define RED_ACTIVE 0x170FC2A5UL /* when obj is active */ |
| |
| /* ...and for poisoning */ |
| #define POISON_INUSE 0x5a /* for use-uninitialised poisoning */ |
| #define POISON_FREE 0x6b /* for use-after-free poisoning */ |
| #define POISON_END 0xa5 /* end-byte of poisoning */ |
| |
| /* memory layout of objects: |
| * 0 : objp |
| * 0 .. cachep->dbghead - 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->dbghead - BYTES_PER_WORD .. cachep->dbghead - 1: |
| * redzone word. |
| * cachep->dbghead: The real object. |
| * cachep->objsize - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
| * cachep->objsize - 1* BYTES_PER_WORD: last caller address [BYTES_PER_WORD long] |
| */ |
| static int obj_dbghead(kmem_cache_t *cachep) |
| { |
| return cachep->dbghead; |
| } |
| |
| static int obj_reallen(kmem_cache_t *cachep) |
| { |
| return cachep->reallen; |
| } |
| |
| static unsigned long *dbg_redzone1(kmem_cache_t *cachep, void *objp) |
| { |
| BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
| return (unsigned long*) (objp+obj_dbghead(cachep)-BYTES_PER_WORD); |
| } |
| |
| static unsigned long *dbg_redzone2(kmem_cache_t *cachep, void *objp) |
| { |
| BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
| if (cachep->flags & SLAB_STORE_USER) |
| return (unsigned long*) (objp+cachep->objsize-2*BYTES_PER_WORD); |
| return (unsigned long*) (objp+cachep->objsize-BYTES_PER_WORD); |
| } |
| |
| static void **dbg_userword(kmem_cache_t *cachep, void *objp) |
| { |
| BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
| return (void**)(objp+cachep->objsize-BYTES_PER_WORD); |
| } |
| |
| #else |
| |
| #define obj_dbghead(x) 0 |
| #define obj_reallen(cachep) (cachep->objsize) |
| #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;}) |
| #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;}) |
| #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
| |
| #endif |
| |
| /* |
| * Maximum size of an obj (in 2^order pages) |
| * and absolute limit for the gfp order. |
| */ |
| #if defined(CONFIG_LARGE_ALLOCS) |
| #define MAX_OBJ_ORDER 13 /* up to 32Mb */ |
| #define MAX_GFP_ORDER 13 /* up to 32Mb */ |
| #elif defined(CONFIG_MMU) |
| #define MAX_OBJ_ORDER 5 /* 32 pages */ |
| #define MAX_GFP_ORDER 5 /* 32 pages */ |
| #else |
| #define MAX_OBJ_ORDER 8 /* up to 1Mb */ |
| #define MAX_GFP_ORDER 8 /* up to 1Mb */ |
| #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 |
| * global 'mem_map'. 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) |
| { |
| 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) |
| { |
| return (struct slab *)page->lru.prev; |
| } |
| |
| /* 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 kmem_cache_t cache_cache = { |
| .batchcount = 1, |
| .limit = BOOT_CPUCACHE_ENTRIES, |
| .shared = 1, |
| .objsize = sizeof(kmem_cache_t), |
| .flags = SLAB_NO_REAP, |
| .spinlock = SPIN_LOCK_UNLOCKED, |
| .name = "kmem_cache", |
| #if DEBUG |
| .reallen = sizeof(kmem_cache_t), |
| #endif |
| }; |
| |
| /* Guard access to the cache-chain. */ |
| static struct semaphore cache_chain_sem; |
| static struct list_head cache_chain; |
| |
| /* |
| * vm_enough_memory() looks at this to determine how many |
| * slab-allocated pages are possibly freeable under pressure |
| * |
| * SLAB_RECLAIM_ACCOUNT turns this on per-slab |
| */ |
| atomic_t slab_reclaim_pages; |
| |
| /* |
| * chicken and egg problem: delay the per-cpu array allocation |
| * until the general caches are up. |
| */ |
| static enum { |
| NONE, |
| PARTIAL_AC, |
| PARTIAL_L3, |
| FULL |
| } g_cpucache_up; |
| |
| static DEFINE_PER_CPU(struct work_struct, reap_work); |
| |
| static void free_block(kmem_cache_t* cachep, void** objpp, int len, int node); |
| static void enable_cpucache (kmem_cache_t *cachep); |
| static void cache_reap (void *unused); |
| static int __node_shrink(kmem_cache_t *cachep, int node); |
| |
| static inline struct array_cache *ac_data(kmem_cache_t *cachep) |
| { |
| return cachep->array[smp_processor_id()]; |
| } |
| |
| static inline kmem_cache_t *__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 |
| 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. |
| */ |
| if (unlikely(gfpflags & GFP_DMA)) |
| return csizep->cs_dmacachep; |
| return csizep->cs_cachep; |
| } |
| |
| kmem_cache_t *kmem_find_general_cachep(size_t size, gfp_t gfpflags) |
| { |
| return __find_general_cachep(size, gfpflags); |
| } |
| EXPORT_SYMBOL(kmem_find_general_cachep); |
| |
| /* Cal the num objs, wastage, and bytes left over for a given slab size. */ |
| static void cache_estimate(unsigned long gfporder, size_t size, size_t align, |
| int flags, size_t *left_over, unsigned int *num) |
| { |
| int i; |
| size_t wastage = PAGE_SIZE<<gfporder; |
| size_t extra = 0; |
| size_t base = 0; |
| |
| if (!(flags & CFLGS_OFF_SLAB)) { |
| base = sizeof(struct slab); |
| extra = sizeof(kmem_bufctl_t); |
| } |
| i = 0; |
| while (i*size + ALIGN(base+i*extra, align) <= wastage) |
| i++; |
| if (i > 0) |
| i--; |
| |
| if (i > SLAB_LIMIT) |
| i = SLAB_LIMIT; |
| |
| *num = i; |
| wastage -= i*size; |
| wastage -= ALIGN(base+i*extra, align); |
| *left_over = wastage; |
| } |
| |
| #define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg) |
| |
| static void __slab_error(const char *function, kmem_cache_t *cachep, char *msg) |
| { |
| printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", |
| function, cachep->name, msg); |
| dump_stack(); |
| } |
| |
| /* |
| * 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 __devinit start_cpu_timer(int cpu) |
| { |
| struct work_struct *reap_work = &per_cpu(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->func == NULL) { |
| INIT_WORK(reap_work, cache_reap, NULL); |
| schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu); |
| } |
| } |
| |
| static struct array_cache *alloc_arraycache(int node, int entries, |
| int batchcount) |
| { |
| int memsize = sizeof(void*)*entries+sizeof(struct array_cache); |
| struct array_cache *nc = NULL; |
| |
| nc = kmalloc_node(memsize, GFP_KERNEL, node); |
| if (nc) { |
| nc->avail = 0; |
| nc->limit = entries; |
| nc->batchcount = batchcount; |
| nc->touched = 0; |
| spin_lock_init(&nc->lock); |
| } |
| return nc; |
| } |
| |
| #ifdef CONFIG_NUMA |
| static inline struct array_cache **alloc_alien_cache(int node, int limit) |
| { |
| struct array_cache **ac_ptr; |
| int memsize = sizeof(void*)*MAX_NUMNODES; |
| int i; |
| |
| if (limit > 1) |
| limit = 12; |
| ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node); |
| if (ac_ptr) { |
| for_each_node(i) { |
| if (i == node || !node_online(i)) { |
| ac_ptr[i] = NULL; |
| continue; |
| } |
| ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d); |
| if (!ac_ptr[i]) { |
| for (i--; i <=0; i--) |
| kfree(ac_ptr[i]); |
| kfree(ac_ptr); |
| return NULL; |
| } |
| } |
| } |
| return ac_ptr; |
| } |
| |
| static inline 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 inline void __drain_alien_cache(kmem_cache_t *cachep, struct array_cache *ac, int node) |
| { |
| struct kmem_list3 *rl3 = cachep->nodelists[node]; |
| |
| if (ac->avail) { |
| spin_lock(&rl3->list_lock); |
| free_block(cachep, ac->entry, ac->avail, node); |
| ac->avail = 0; |
| spin_unlock(&rl3->list_lock); |
| } |
| } |
| |
| static void drain_alien_cache(kmem_cache_t *cachep, struct kmem_list3 *l3) |
| { |
| int i=0; |
| struct array_cache *ac; |
| unsigned long flags; |
| |
| for_each_online_node(i) { |
| ac = l3->alien[i]; |
| if (ac) { |
| spin_lock_irqsave(&ac->lock, flags); |
| __drain_alien_cache(cachep, ac, i); |
| spin_unlock_irqrestore(&ac->lock, flags); |
| } |
| } |
| } |
| #else |
| #define alloc_alien_cache(node, limit) do { } while (0) |
| #define free_alien_cache(ac_ptr) do { } while (0) |
| #define drain_alien_cache(cachep, l3) do { } while (0) |
| #endif |
| |
| static int __devinit cpuup_callback(struct notifier_block *nfb, |
| unsigned long action, void *hcpu) |
| { |
| long cpu = (long)hcpu; |
| kmem_cache_t* cachep; |
| struct kmem_list3 *l3 = NULL; |
| int node = cpu_to_node(cpu); |
| int memsize = sizeof(struct kmem_list3); |
| struct array_cache *nc = NULL; |
| |
| switch (action) { |
| case CPU_UP_PREPARE: |
| down(&cache_chain_sem); |
| /* 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 |
| */ |
| |
| list_for_each_entry(cachep, &cache_chain, next) { |
| /* setup 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]) { |
| if (!(l3 = kmalloc_node(memsize, |
| GFP_KERNEL, node))) |
| goto bad; |
| kmem_list3_init(l3); |
| l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
| ((unsigned long)cachep)%REAPTIMEOUT_LIST3; |
| |
| 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); |
| } |
| |
| /* Now we can go ahead with allocating the shared array's |
| & array cache's */ |
| list_for_each_entry(cachep, &cache_chain, next) { |
| nc = alloc_arraycache(node, cachep->limit, |
| cachep->batchcount); |
| if (!nc) |
| goto bad; |
| cachep->array[cpu] = nc; |
| |
| l3 = cachep->nodelists[node]; |
| BUG_ON(!l3); |
| if (!l3->shared) { |
| if (!(nc = alloc_arraycache(node, |
| cachep->shared*cachep->batchcount, |
| 0xbaadf00d))) |
| goto bad; |
| |
| /* we are serialised from CPU_DEAD or |
| CPU_UP_CANCELLED by the cpucontrol lock */ |
| l3->shared = nc; |
| } |
| } |
| up(&cache_chain_sem); |
| break; |
| case CPU_ONLINE: |
| start_cpu_timer(cpu); |
| break; |
| #ifdef CONFIG_HOTPLUG_CPU |
| case CPU_DEAD: |
| /* fall thru */ |
| case CPU_UP_CANCELED: |
| down(&cache_chain_sem); |
| |
| list_for_each_entry(cachep, &cache_chain, next) { |
| struct array_cache *nc; |
| cpumask_t mask; |
| |
| mask = node_to_cpumask(node); |
| spin_lock_irq(&cachep->spinlock); |
| /* cpu is dead; no one can alloc from it. */ |
| nc = cachep->array[cpu]; |
| cachep->array[cpu] = NULL; |
| l3 = cachep->nodelists[node]; |
| |
| if (!l3) |
| goto unlock_cache; |
| |
| spin_lock(&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 (!cpus_empty(mask)) { |
| spin_unlock(&l3->list_lock); |
| goto unlock_cache; |
| } |
| |
| if (l3->shared) { |
| free_block(cachep, l3->shared->entry, |
| l3->shared->avail, node); |
| kfree(l3->shared); |
| l3->shared = NULL; |
| } |
| if (l3->alien) { |
| drain_alien_cache(cachep, l3); |
| free_alien_cache(l3->alien); |
| l3->alien = NULL; |
| } |
| |
| /* free slabs belonging to this node */ |
| if (__node_shrink(cachep, node)) { |
| cachep->nodelists[node] = NULL; |
| spin_unlock(&l3->list_lock); |
| kfree(l3); |
| } else { |
| spin_unlock(&l3->list_lock); |
| } |
| unlock_cache: |
| spin_unlock_irq(&cachep->spinlock); |
| kfree(nc); |
| } |
| up(&cache_chain_sem); |
| break; |
| #endif |
| } |
| return NOTIFY_OK; |
| bad: |
| up(&cache_chain_sem); |
| return NOTIFY_BAD; |
| } |
| |
| static struct notifier_block cpucache_notifier = { &cpuup_callback, NULL, 0 }; |
| |
| /* |
| * swap the static kmem_list3 with kmalloced memory |
| */ |
| static void init_list(kmem_cache_t *cachep, struct kmem_list3 *list, |
| int nodeid) |
| { |
| struct kmem_list3 *ptr; |
| |
| BUG_ON(cachep->nodelists[nodeid] != list); |
| ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid); |
| BUG_ON(!ptr); |
| |
| local_irq_disable(); |
| memcpy(ptr, list, sizeof(struct kmem_list3)); |
| MAKE_ALL_LISTS(cachep, ptr, nodeid); |
| cachep->nodelists[nodeid] = ptr; |
| local_irq_enable(); |
| } |
| |
| /* Initialisation. |
| * Called after the gfp() functions have been enabled, and before smp_init(). |
| */ |
| void __init kmem_cache_init(void) |
| { |
| size_t left_over; |
| struct cache_sizes *sizes; |
| struct cache_names *names; |
| int i; |
| |
| for (i = 0; i < NUM_INIT_LISTS; i++) { |
| kmem_list3_init(&initkmem_list3[i]); |
| if (i < MAX_NUMNODES) |
| cache_cache.nodelists[i] = NULL; |
| } |
| |
| /* |
| * Fragmentation resistance on low memory - only use bigger |
| * page orders on machines with more than 32MB of memory. |
| */ |
| if (num_physpages > (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 kmem_cache_t |
| * 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 kmem_cache_t 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. |
| */ |
| |
| /* 1) create the cache_cache */ |
| init_MUTEX(&cache_chain_sem); |
| 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[numa_node_id()] = &initkmem_list3[CACHE_CACHE]; |
| |
| cache_cache.objsize = ALIGN(cache_cache.objsize, cache_line_size()); |
| |
| cache_estimate(0, cache_cache.objsize, cache_line_size(), 0, |
| &left_over, &cache_cache.num); |
| if (!cache_cache.num) |
| BUG(); |
| |
| cache_cache.colour = left_over/cache_cache.colour_off; |
| cache_cache.colour_next = 0; |
| 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, 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, NULL); |
| |
| 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, NULL); |
| |
| /* Inc off-slab bufctl limit until the ceiling is hit. */ |
| if (!(OFF_SLAB(sizes->cs_cachep))) { |
| offslab_limit = sizes->cs_size-sizeof(struct slab); |
| offslab_limit /= sizeof(kmem_bufctl_t); |
| } |
| |
| sizes->cs_dmacachep = kmem_cache_create(names->name_dma, |
| sizes->cs_size, ARCH_KMALLOC_MINALIGN, |
| (ARCH_KMALLOC_FLAGS | SLAB_CACHE_DMA | SLAB_PANIC), |
| NULL, NULL); |
| |
| sizes++; |
| names++; |
| } |
| /* 4) Replace the bootstrap head arrays */ |
| { |
| void * ptr; |
| |
| ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); |
| |
| local_irq_disable(); |
| BUG_ON(ac_data(&cache_cache) != &initarray_cache.cache); |
| memcpy(ptr, ac_data(&cache_cache), |
| sizeof(struct arraycache_init)); |
| cache_cache.array[smp_processor_id()] = ptr; |
| local_irq_enable(); |
| |
| ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); |
| |
| local_irq_disable(); |
| BUG_ON(ac_data(malloc_sizes[INDEX_AC].cs_cachep) |
| != &initarray_generic.cache); |
| memcpy(ptr, ac_data(malloc_sizes[INDEX_AC].cs_cachep), |
| sizeof(struct arraycache_init)); |
| malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = |
| ptr; |
| local_irq_enable(); |
| } |
| /* 5) Replace the bootstrap kmem_list3's */ |
| { |
| int node; |
| /* Replace the static kmem_list3 structures for the boot cpu */ |
| init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], |
| numa_node_id()); |
| |
| for_each_online_node(node) { |
| init_list(malloc_sizes[INDEX_AC].cs_cachep, |
| &initkmem_list3[SIZE_AC+node], node); |
| |
| if (INDEX_AC != INDEX_L3) { |
| init_list(malloc_sizes[INDEX_L3].cs_cachep, |
| &initkmem_list3[SIZE_L3+node], |
| node); |
| } |
| } |
| } |
| |
| /* 6) resize the head arrays to their final sizes */ |
| { |
| kmem_cache_t *cachep; |
| down(&cache_chain_sem); |
| list_for_each_entry(cachep, &cache_chain, next) |
| enable_cpucache(cachep); |
| up(&cache_chain_sem); |
| } |
| |
| /* Done! */ |
| g_cpucache_up = FULL; |
| |
| /* Register a cpu startup notifier callback |
| * that initializes ac_data for all new cpus |
| */ |
| register_cpu_notifier(&cpucache_notifier); |
| |
| /* 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 gfp. |
| */ |
| 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(kmem_cache_t *cachep, gfp_t flags, int nodeid) |
| { |
| struct page *page; |
| void *addr; |
| int i; |
| |
| flags |= cachep->gfpflags; |
| page = alloc_pages_node(nodeid, flags, cachep->gfporder); |
| if (!page) |
| return NULL; |
| addr = page_address(page); |
| |
| i = (1 << cachep->gfporder); |
| if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
| atomic_add(i, &slab_reclaim_pages); |
| add_page_state(nr_slab, i); |
| while (i--) { |
| SetPageSlab(page); |
| page++; |
| } |
| return addr; |
| } |
| |
| /* |
| * Interface to system's page release. |
| */ |
| static void kmem_freepages(kmem_cache_t *cachep, void *addr) |
| { |
| unsigned long i = (1<<cachep->gfporder); |
| struct page *page = virt_to_page(addr); |
| const unsigned long nr_freed = i; |
| |
| while (i--) { |
| if (!TestClearPageSlab(page)) |
| BUG(); |
| page++; |
| } |
| sub_page_state(nr_slab, nr_freed); |
| if (current->reclaim_state) |
| current->reclaim_state->reclaimed_slab += nr_freed; |
| free_pages((unsigned long)addr, cachep->gfporder); |
| if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
| atomic_sub(1<<cachep->gfporder, &slab_reclaim_pages); |
| } |
| |
| static void kmem_rcu_free(struct rcu_head *head) |
| { |
| struct slab_rcu *slab_rcu = (struct slab_rcu *) head; |
| kmem_cache_t *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(kmem_cache_t *cachep, unsigned long *addr, |
| unsigned long caller) |
| { |
| int size = obj_reallen(cachep); |
| |
| addr = (unsigned long *)&((char*)addr)[obj_dbghead(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(kmem_cache_t *cachep, void *addr, unsigned char val) |
| { |
| int size = obj_reallen(cachep); |
| addr = &((char*)addr)[obj_dbghead(cachep)]; |
| |
| memset(addr, val, size); |
| *(unsigned char *)(addr+size-1) = POISON_END; |
| } |
| |
| static void dump_line(char *data, int offset, int limit) |
| { |
| int i; |
| printk(KERN_ERR "%03x:", offset); |
| for (i=0;i<limit;i++) { |
| printk(" %02x", (unsigned char)data[offset+i]); |
| } |
| printk("\n"); |
| } |
| #endif |
| |
| #if DEBUG |
| |
| static void print_objinfo(kmem_cache_t *cachep, void *objp, int lines) |
| { |
| int i, size; |
| char *realobj; |
| |
| if (cachep->flags & SLAB_RED_ZONE) { |
| printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\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_dbghead(cachep); |
| size = obj_reallen(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(kmem_cache_t *cachep, void *objp) |
| { |
| char *realobj; |
| int size, i; |
| int lines = 0; |
| |
| realobj = (char*)objp+obj_dbghead(cachep); |
| size = obj_reallen(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: start=%p, len=%d\n", |
| 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 = page_get_slab(virt_to_page(objp)); |
| int objnr; |
| |
| objnr = (objp-slabp->s_mem)/cachep->objsize; |
| if (objnr) { |
| objp = slabp->s_mem+(objnr-1)*cachep->objsize; |
| realobj = (char*)objp+obj_dbghead(cachep); |
| printk(KERN_ERR "Prev obj: start=%p, len=%d\n", |
| realobj, size); |
| print_objinfo(cachep, objp, 2); |
| } |
| if (objnr+1 < cachep->num) { |
| objp = slabp->s_mem+(objnr+1)*cachep->objsize; |
| realobj = (char*)objp+obj_dbghead(cachep); |
| printk(KERN_ERR "Next obj: start=%p, len=%d\n", |
| realobj, size); |
| print_objinfo(cachep, objp, 2); |
| } |
| } |
| } |
| #endif |
| |
| /* 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 (kmem_cache_t *cachep, struct slab *slabp) |
| { |
| void *addr = slabp->s_mem - slabp->colouroff; |
| |
| #if DEBUG |
| int i; |
| for (i = 0; i < cachep->num; i++) { |
| void *objp = slabp->s_mem + cachep->objsize * i; |
| |
| if (cachep->flags & SLAB_POISON) { |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if ((cachep->objsize%PAGE_SIZE)==0 && OFF_SLAB(cachep)) |
| kernel_map_pages(virt_to_page(objp), cachep->objsize/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"); |
| } |
| if (cachep->dtor && !(cachep->flags & SLAB_POISON)) |
| (cachep->dtor)(objp+obj_dbghead(cachep), cachep, 0); |
| } |
| #else |
| if (cachep->dtor) { |
| int i; |
| for (i = 0; i < cachep->num; i++) { |
| void* objp = slabp->s_mem+cachep->objsize*i; |
| (cachep->dtor)(objp, cachep, 0); |
| } |
| } |
| #endif |
| |
| 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); |
| } |
| } |
| |
| /* For setting up all the kmem_list3s for cache whose objsize is same |
| as size of kmem_list3. */ |
| static inline void set_up_list3s(kmem_cache_t *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; |
| } |
| } |
| |
| /** |
| * 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. |
| * @dtor: A destructor 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 |
| * and the @dtor is run before the pages are handed back. |
| * |
| * @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_NO_REAP - Don't automatically reap this cache when we're under |
| * memory pressure. |
| * |
| * %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. |
| */ |
| kmem_cache_t * |
| kmem_cache_create (const char *name, size_t size, size_t align, |
| unsigned long flags, void (*ctor)(void*, kmem_cache_t *, unsigned long), |
| void (*dtor)(void*, kmem_cache_t *, unsigned long)) |
| { |
| size_t left_over, slab_size, ralign; |
| kmem_cache_t *cachep = NULL; |
| struct list_head *p; |
| |
| /* |
| * Sanity checks... these are all serious usage bugs. |
| */ |
| if ((!name) || |
| in_interrupt() || |
| (size < BYTES_PER_WORD) || |
| (size > (1<<MAX_OBJ_ORDER)*PAGE_SIZE) || |
| (dtor && !ctor)) { |
| printk(KERN_ERR "%s: Early error in slab %s\n", |
| __FUNCTION__, name); |
| BUG(); |
| } |
| |
| down(&cache_chain_sem); |
| |
| list_for_each(p, &cache_chain) { |
| kmem_cache_t *pc = list_entry(p, kmem_cache_t, next); |
| mm_segment_t old_fs = get_fs(); |
| 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. |
| */ |
| set_fs(KERNEL_DS); |
| res = __get_user(tmp, pc->name); |
| set_fs(old_fs); |
| if (res) { |
| printk("SLAB: cache with size %d has lost its name\n", |
| pc->objsize); |
| continue; |
| } |
| |
| if (!strcmp(pc->name,name)) { |
| printk("kmem_cache_create: duplicate cache %s\n", name); |
| dump_stack(); |
| goto oops; |
| } |
| } |
| |
| #if DEBUG |
| WARN_ON(strchr(name, ' ')); /* It confuses parsers */ |
| if ((flags & SLAB_DEBUG_INITIAL) && !ctor) { |
| /* No constructor, but inital state check requested */ |
| printk(KERN_ERR "%s: No con, but init state check " |
| "requested - %s\n", __FUNCTION__, name); |
| flags &= ~SLAB_DEBUG_INITIAL; |
| } |
| |
| #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+3*BYTES_PER_WORD))) |
| 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 |
| if (flags & SLAB_DESTROY_BY_RCU) |
| BUG_ON(dtor); |
| |
| /* |
| * Always checks flags, a caller might be expecting debug |
| * support which isn't available. |
| */ |
| if (flags & ~CREATE_MASK) |
| BUG(); |
| |
| /* 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 out 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; |
| } |
| /* 2) arch mandated alignment: disables debug if necessary */ |
| if (ralign < ARCH_SLAB_MINALIGN) { |
| ralign = ARCH_SLAB_MINALIGN; |
| if (ralign > BYTES_PER_WORD) |
| flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER); |
| } |
| /* 3) caller mandated alignment: disables debug if necessary */ |
| if (ralign < align) { |
| ralign = align; |
| if (ralign > BYTES_PER_WORD) |
| flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER); |
| } |
| /* 4) Store it. Note that the debug code below can reduce |
| * the alignment to BYTES_PER_WORD. |
| */ |
| align = ralign; |
| |
| /* Get cache's description obj. */ |
| cachep = (kmem_cache_t *) kmem_cache_alloc(&cache_cache, SLAB_KERNEL); |
| if (!cachep) |
| goto oops; |
| memset(cachep, 0, sizeof(kmem_cache_t)); |
| |
| #if DEBUG |
| cachep->reallen = size; |
| |
| if (flags & SLAB_RED_ZONE) { |
| /* redzoning only works with word aligned caches */ |
| align = BYTES_PER_WORD; |
| |
| /* add space for red zone words */ |
| cachep->dbghead += BYTES_PER_WORD; |
| size += 2*BYTES_PER_WORD; |
| } |
| if (flags & SLAB_STORE_USER) { |
| /* user store requires word alignment and |
| * one word storage behind the end of the real |
| * object. |
| */ |
| align = BYTES_PER_WORD; |
| size += BYTES_PER_WORD; |
| } |
| #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) |
| if (size >= malloc_sizes[INDEX_L3+1].cs_size && cachep->reallen > cache_line_size() && size < PAGE_SIZE) { |
| cachep->dbghead += PAGE_SIZE - size; |
| size = PAGE_SIZE; |
| } |
| #endif |
| #endif |
| |
| /* Determine if the slab management is 'on' or 'off' slab. */ |
| if (size >= (PAGE_SIZE>>3)) |
| /* |
| * 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); |
| |
| if ((flags & SLAB_RECLAIM_ACCOUNT) && size <= PAGE_SIZE) { |
| /* |
| * 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. |
| */ |
| cachep->gfporder = 0; |
| cache_estimate(cachep->gfporder, size, align, flags, |
| &left_over, &cachep->num); |
| } else { |
| /* |
| * Calculate size (in pages) of slabs, and the num of objs per |
| * slab. This could be made much more intelligent. For now, |
| * try to avoid using high page-orders for slabs. When the |
| * gfp() funcs are more friendly towards high-order requests, |
| * this should be changed. |
| */ |
| do { |
| unsigned int break_flag = 0; |
| cal_wastage: |
| cache_estimate(cachep->gfporder, size, align, flags, |
| &left_over, &cachep->num); |
| if (break_flag) |
| break; |
| if (cachep->gfporder >= MAX_GFP_ORDER) |
| break; |
| if (!cachep->num) |
| goto next; |
| if (flags & CFLGS_OFF_SLAB && |
| cachep->num > offslab_limit) { |
| /* This num of objs will cause problems. */ |
| cachep->gfporder--; |
| break_flag++; |
| goto cal_wastage; |
| } |
| |
| /* |
| * Large num of objs is good, but v. large slabs are |
| * currently bad for the gfp()s. |
| */ |
| if (cachep->gfporder >= slab_break_gfp_order) |
| break; |
| |
| if ((left_over*8) <= (PAGE_SIZE<<cachep->gfporder)) |
| break; /* Acceptable internal fragmentation. */ |
| next: |
| cachep->gfporder++; |
| } while (1); |
| } |
| |
| if (!cachep->num) { |
| printk("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); |
| } |
| |
| 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 (flags & SLAB_CACHE_DMA) |
| cachep->gfpflags |= GFP_DMA; |
| spin_lock_init(&cachep->spinlock); |
| cachep->objsize = size; |
| |
| if (flags & CFLGS_OFF_SLAB) |
| cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); |
| cachep->ctor = ctor; |
| cachep->dtor = dtor; |
| cachep->name = name; |
| |
| /* Don't let CPUs to come and go */ |
| lock_cpu_hotplug(); |
| |
| if (g_cpucache_up == FULL) { |
| enable_cpucache(cachep); |
| } else { |
| 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_KERNEL); |
| |
| 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_KERNEL, node); |
| BUG_ON(!cachep->nodelists[node]); |
| kmem_list3_init(cachep->nodelists[node]); |
| } |
| } |
| } |
| cachep->nodelists[numa_node_id()]->next_reap = |
| jiffies + REAPTIMEOUT_LIST3 + |
| ((unsigned long)cachep)%REAPTIMEOUT_LIST3; |
| |
| BUG_ON(!ac_data(cachep)); |
| ac_data(cachep)->avail = 0; |
| ac_data(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
| ac_data(cachep)->batchcount = 1; |
| ac_data(cachep)->touched = 0; |
| cachep->batchcount = 1; |
| cachep->limit = BOOT_CPUCACHE_ENTRIES; |
| } |
| |
| /* cache setup completed, link it into the list */ |
| list_add(&cachep->next, &cache_chain); |
| unlock_cpu_hotplug(); |
| oops: |
| if (!cachep && (flags & SLAB_PANIC)) |
| panic("kmem_cache_create(): failed to create slab `%s'\n", |
| name); |
| up(&cache_chain_sem); |
| 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(kmem_cache_t *cachep) |
| { |
| #ifdef CONFIG_SMP |
| check_irq_off(); |
| assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock); |
| #endif |
| } |
| |
| static inline void check_spinlock_acquired_node(kmem_cache_t *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 |
| |
| /* |
| * Waits for all CPUs to execute func(). |
| */ |
| static void smp_call_function_all_cpus(void (*func) (void *arg), void *arg) |
| { |
| check_irq_on(); |
| preempt_disable(); |
| |
| local_irq_disable(); |
| func(arg); |
| local_irq_enable(); |
| |
| if (smp_call_function(func, arg, 1, 1)) |
| BUG(); |
| |
| preempt_enable(); |
| } |
| |
| static void drain_array_locked(kmem_cache_t* cachep, |
| struct array_cache *ac, int force, int node); |
| |
| static void do_drain(void *arg) |
| { |
| kmem_cache_t *cachep = (kmem_cache_t*)arg; |
| struct array_cache *ac; |
| int node = numa_node_id(); |
| |
| check_irq_off(); |
| ac = ac_data(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(kmem_cache_t *cachep) |
| { |
| struct kmem_list3 *l3; |
| int node; |
| |
| smp_call_function_all_cpus(do_drain, cachep); |
| check_irq_on(); |
| spin_lock_irq(&cachep->spinlock); |
| for_each_online_node(node) { |
| l3 = cachep->nodelists[node]; |
| if (l3) { |
| spin_lock(&l3->list_lock); |
| drain_array_locked(cachep, l3->shared, 1, node); |
| spin_unlock(&l3->list_lock); |
| if (l3->alien) |
| drain_alien_cache(cachep, l3); |
| } |
| } |
| spin_unlock_irq(&cachep->spinlock); |
| } |
| |
| static int __node_shrink(kmem_cache_t *cachep, int node) |
| { |
| struct slab *slabp; |
| struct kmem_list3 *l3 = cachep->nodelists[node]; |
| int ret; |
| |
| for (;;) { |
| struct list_head *p; |
| |
| p = l3->slabs_free.prev; |
| if (p == &l3->slabs_free) |
| break; |
| |
| slabp = list_entry(l3->slabs_free.prev, struct slab, list); |
| #if DEBUG |
| if (slabp->inuse) |
| BUG(); |
| #endif |
| list_del(&slabp->list); |
| |
| l3->free_objects -= cachep->num; |
| spin_unlock_irq(&l3->list_lock); |
| slab_destroy(cachep, slabp); |
| spin_lock_irq(&l3->list_lock); |
| } |
| ret = !list_empty(&l3->slabs_full) || |
| !list_empty(&l3->slabs_partial); |
| return ret; |
| } |
| |
| static int __cache_shrink(kmem_cache_t *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) { |
| spin_lock_irq(&l3->list_lock); |
| ret += __node_shrink(cachep, i); |
| spin_unlock_irq(&l3->list_lock); |
| } |
| } |
| 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(kmem_cache_t *cachep) |
| { |
| if (!cachep || in_interrupt()) |
| BUG(); |
| |
| return __cache_shrink(cachep); |
| } |
| EXPORT_SYMBOL(kmem_cache_shrink); |
| |
| /** |
| * kmem_cache_destroy - delete a cache |
| * @cachep: the cache to destroy |
| * |
| * Remove a kmem_cache_t object from the slab cache. |
| * Returns 0 on success. |
| * |
| * 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 noone will allocate memory from the cache |
| * during the kmem_cache_destroy(). |
| */ |
| int kmem_cache_destroy(kmem_cache_t * cachep) |
| { |
| int i; |
| struct kmem_list3 *l3; |
| |
| if (!cachep || in_interrupt()) |
| BUG(); |
| |
| /* Don't let CPUs to come and go */ |
| lock_cpu_hotplug(); |
| |
| /* Find the cache in the chain of caches. */ |
| down(&cache_chain_sem); |
| /* |
| * the chain is never empty, cache_cache is never destroyed |
| */ |
| list_del(&cachep->next); |
| up(&cache_chain_sem); |
| |
| if (__cache_shrink(cachep)) { |
| slab_error(cachep, "Can't free all objects"); |
| down(&cache_chain_sem); |
| list_add(&cachep->next,&cache_chain); |
| up(&cache_chain_sem); |
| unlock_cpu_hotplug(); |
| return 1; |
| } |
| |
| if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) |
| synchronize_rcu(); |
| |
| for_each_online_cpu(i) |
| kfree(cachep->array[i]); |
| |
| /* NUMA: free the list3 structures */ |
| for_each_online_node(i) { |
| if ((l3 = cachep->nodelists[i])) { |
| kfree(l3->shared); |
| free_alien_cache(l3->alien); |
| kfree(l3); |
| } |
| } |
| kmem_cache_free(&cache_cache, cachep); |
| |
| unlock_cpu_hotplug(); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(kmem_cache_destroy); |
| |
| /* Get the memory for a slab management obj. */ |
| static struct slab* alloc_slabmgmt(kmem_cache_t *cachep, void *objp, |
| int colour_off, gfp_t local_flags) |
| { |
| struct slab *slabp; |
| |
| if (OFF_SLAB(cachep)) { |
| /* Slab management obj is off-slab. */ |
| slabp = kmem_cache_alloc(cachep->slabp_cache, 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; |
| |
| return slabp; |
| } |
| |
| static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) |
| { |
| return (kmem_bufctl_t *)(slabp+1); |
| } |
| |
| static void cache_init_objs(kmem_cache_t *cachep, |
| struct slab *slabp, unsigned long ctor_flags) |
| { |
| int i; |
| |
| for (i = 0; i < cachep->num; i++) { |
| void *objp = slabp->s_mem+cachep->objsize*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_dbghead(cachep), cachep, ctor_flags); |
| |
| 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->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) |
| kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0); |
| #else |
| if (cachep->ctor) |
| cachep->ctor(objp, cachep, ctor_flags); |
| #endif |
| slab_bufctl(slabp)[i] = i+1; |
| } |
| slab_bufctl(slabp)[i-1] = BUFCTL_END; |
| slabp->free = 0; |
| } |
| |
| static void kmem_flagcheck(kmem_cache_t *cachep, gfp_t flags) |
| { |
| if (flags & SLAB_DMA) { |
| if (!(cachep->gfpflags & GFP_DMA)) |
| BUG(); |
| } else { |
| if (cachep->gfpflags & GFP_DMA) |
| BUG(); |
| } |
| } |
| |
| static void set_slab_attr(kmem_cache_t *cachep, struct slab *slabp, void *objp) |
| { |
| int i; |
| struct page *page; |
| |
| /* Nasty!!!!!! I hope this is OK. */ |
| i = 1 << cachep->gfporder; |
| page = virt_to_page(objp); |
| do { |
| page_set_cache(page, cachep); |
| page_set_slab(page, slabp); |
| page++; |
| } while (--i); |
| } |
| |
| /* |
| * 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(kmem_cache_t *cachep, gfp_t flags, int nodeid) |
| { |
| struct slab *slabp; |
| void *objp; |
| size_t offset; |
| gfp_t local_flags; |
| unsigned long ctor_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(). |
| */ |
| if (flags & ~(SLAB_DMA|SLAB_LEVEL_MASK|SLAB_NO_GROW)) |
| BUG(); |
| if (flags & SLAB_NO_GROW) |
| return 0; |
| |
| ctor_flags = SLAB_CTOR_CONSTRUCTOR; |
| local_flags = (flags & SLAB_LEVEL_MASK); |
| if (!(local_flags & __GFP_WAIT)) |
| /* |
| * Not allowed to sleep. Need to tell a constructor about |
| * this - it might need to know... |
| */ |
| ctor_flags |= SLAB_CTOR_ATOMIC; |
| |
| /* About to mess with non-constant members - lock. */ |
| check_irq_off(); |
| spin_lock(&cachep->spinlock); |
| |
| /* Get colour for the slab, and cal the next value. */ |
| offset = cachep->colour_next; |
| cachep->colour_next++; |
| if (cachep->colour_next >= cachep->colour) |
| cachep->colour_next = 0; |
| offset *= cachep->colour_off; |
| |
| spin_unlock(&cachep->spinlock); |
| |
| check_irq_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 = kmem_getpages(cachep, flags, nodeid))) |
| goto failed; |
| |
| /* Get slab management. */ |
| if (!(slabp = alloc_slabmgmt(cachep, objp, offset, local_flags))) |
| goto opps1; |
| |
| slabp->nodeid = nodeid; |
| set_slab_attr(cachep, slabp, objp); |
| |
| cache_init_objs(cachep, slabp, ctor_flags); |
| |
| if (local_flags & __GFP_WAIT) |
| local_irq_disable(); |
| check_irq_off(); |
| l3 = cachep->nodelists[nodeid]; |
| 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 |
| * - destructor calls, for caches with POISON+dtor |
| */ |
| static void kfree_debugcheck(const void *objp) |
| { |
| struct page *page; |
| |
| if (!virt_addr_valid(objp)) { |
| printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", |
| (unsigned long)objp); |
| BUG(); |
| } |
| page = virt_to_page(objp); |
| if (!PageSlab(page)) { |
| printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n", (unsigned long)objp); |
| BUG(); |
| } |
| } |
| |
| static void *cache_free_debugcheck(kmem_cache_t *cachep, void *objp, |
| void *caller) |
| { |
| struct page *page; |
| unsigned int objnr; |
| struct slab *slabp; |
| |
| objp -= obj_dbghead(cachep); |
| kfree_debugcheck(objp); |
| page = virt_to_page(objp); |
| |
| if (page_get_cache(page) != cachep) { |
| printk(KERN_ERR "mismatch in kmem_cache_free: expected cache %p, got %p\n", |
| page_get_cache(page),cachep); |
| printk(KERN_ERR "%p is %s.\n", cachep, cachep->name); |
| printk(KERN_ERR "%p is %s.\n", page_get_cache(page), page_get_cache(page)->name); |
| WARN_ON(1); |
| } |
| slabp = page_get_slab(page); |
| |
| if (cachep->flags & SLAB_RED_ZONE) { |
| if (*dbg_redzone1(cachep, objp) != RED_ACTIVE || *dbg_redzone2(cachep, objp) != RED_ACTIVE) { |
| slab_error(cachep, "double free, or memory outside" |
| " object was overwritten"); |
| printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n", |
| objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(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 = (objp-slabp->s_mem)/cachep->objsize; |
| |
| BUG_ON(objnr >= cachep->num); |
| BUG_ON(objp != slabp->s_mem + objnr*cachep->objsize); |
| |
| if (cachep->flags & SLAB_DEBUG_INITIAL) { |
| /* Need to call the slab's constructor so the |
| * caller can perform a verify of its state (debugging). |
| * Called without the cache-lock held. |
| */ |
| cachep->ctor(objp+obj_dbghead(cachep), |
| cachep, SLAB_CTOR_CONSTRUCTOR|SLAB_CTOR_VERIFY); |
| } |
| if (cachep->flags & SLAB_POISON && cachep->dtor) { |
| /* we want to cache poison the object, |
| * call the destruction callback |
| */ |
| cachep->dtor(objp+obj_dbghead(cachep), cachep, 0); |
| } |
| if (cachep->flags & SLAB_POISON) { |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) { |
| store_stackinfo(cachep, objp, (unsigned long)caller); |
| kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0); |
| } else { |
| poison_obj(cachep, objp, POISON_FREE); |
| } |
| #else |
| poison_obj(cachep, objp, POISON_FREE); |
| #endif |
| } |
| return objp; |
| } |
| |
| static void check_slabp(kmem_cache_t *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(kmem_cache_t *cachep, gfp_t flags) |
| { |
| int batchcount; |
| struct kmem_list3 *l3; |
| struct array_cache *ac; |
| |
| check_irq_off(); |
| ac = ac_data(cachep); |
| retry: |
| 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[numa_node_id()]; |
| |
| BUG_ON(ac->avail > 0 || !l3); |
| spin_lock(&l3->list_lock); |
| |
| if (l3->shared) { |
| struct array_cache *shared_array = l3->shared; |
| if (shared_array->avail) { |
| if (batchcount > shared_array->avail) |
| batchcount = shared_array->avail; |
| shared_array->avail -= batchcount; |
| ac->avail = batchcount; |
| memcpy(ac->entry, |
| &(shared_array->entry[shared_array->avail]), |
| sizeof(void*)*batchcount); |
| shared_array->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); |
| while (slabp->inuse < cachep->num && batchcount--) { |
| kmem_bufctl_t next; |
| STATS_INC_ALLOCED(cachep); |
| STATS_INC_ACTIVE(cachep); |
| STATS_SET_HIGH(cachep); |
| |
| /* get obj pointer */ |
| ac->entry[ac->avail++] = slabp->s_mem + |
| slabp->free*cachep->objsize; |
| |
| slabp->inuse++; |
| next = slab_bufctl(slabp)[slabp->free]; |
| #if DEBUG |
| slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; |
| WARN_ON(numa_node_id() != slabp->nodeid); |
| #endif |
| slabp->free = next; |
| } |
| 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, numa_node_id()); |
| |
| // cache_grow can reenable interrupts, then ac could change. |
| ac = ac_data(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(kmem_cache_t *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(kmem_cache_t *cachep, |
| gfp_t flags, void *objp, void *caller) |
| { |
| if (!objp) |
| return objp; |
| if (cachep->flags & SLAB_POISON) { |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) |
| kernel_map_pages(virt_to_page(objp), cachep->objsize/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%lx, redzone 2: 0x%lx.\n", |
| objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp)); |
| } |
| *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
| *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
| } |
| objp += obj_dbghead(cachep); |
| if (cachep->ctor && cachep->flags & SLAB_POISON) { |
| unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR; |
| |
| if (!(flags & __GFP_WAIT)) |
| ctor_flags |= SLAB_CTOR_ATOMIC; |
| |
| cachep->ctor(objp, cachep, ctor_flags); |
| } |
| return objp; |
| } |
| #else |
| #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
| #endif |
| |
| static inline void *____cache_alloc(kmem_cache_t *cachep, gfp_t flags) |
| { |
| void* objp; |
| struct array_cache *ac; |
| |
| check_irq_off(); |
| ac = ac_data(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); |
| } |
| return objp; |
| } |
| |
| static inline void *__cache_alloc(kmem_cache_t *cachep, gfp_t flags) |
| { |
| unsigned long save_flags; |
| void* objp; |
| |
| cache_alloc_debugcheck_before(cachep, flags); |
| |
| local_irq_save(save_flags); |
| objp = ____cache_alloc(cachep, flags); |
| local_irq_restore(save_flags); |
| objp = cache_alloc_debugcheck_after(cachep, flags, objp, |
| __builtin_return_address(0)); |
| prefetchw(objp); |
| return objp; |
| } |
| |
| #ifdef CONFIG_NUMA |
| /* |
| * A interface to enable slab creation on nodeid |
| */ |
| static void *__cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int nodeid) |
| { |
| struct list_head *entry; |
| struct slab *slabp; |
| struct kmem_list3 *l3; |
| void *obj; |
| kmem_bufctl_t next; |
| int x; |
| |
| l3 = cachep->nodelists[nodeid]; |
| BUG_ON(!l3); |
| |
| retry: |
| 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); |
| |
| /* get obj pointer */ |
| obj = slabp->s_mem + slabp->free*cachep->objsize; |
| slabp->inuse++; |
| next = slab_bufctl(slabp)[slabp->free]; |
| #if DEBUG |
| slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; |
| #endif |
| slabp->free = next; |
| 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, nodeid); |
| |
| if (!x) |
| return NULL; |
| |
| goto retry; |
| done: |
| return obj; |
| } |
| #endif |
| |
| /* |
| * Caller needs to acquire correct kmem_list's list_lock |
| */ |
| static void free_block(kmem_cache_t *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; |
| unsigned int objnr; |
| |
| slabp = page_get_slab(virt_to_page(objp)); |
| l3 = cachep->nodelists[node]; |
| list_del(&slabp->list); |
| objnr = (objp - slabp->s_mem) / cachep->objsize; |
| check_spinlock_acquired_node(cachep, node); |
| check_slabp(cachep, slabp); |
| |
| #if DEBUG |
| /* Verify that the slab belongs to the intended node */ |
| WARN_ON(slabp->nodeid != node); |
| |
| if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) { |
| 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; |
| STATS_DEC_ACTIVE(cachep); |
| slabp->inuse--; |
| 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; |
| 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(kmem_cache_t *cachep, struct array_cache *ac) |
| { |
| int batchcount; |
| struct kmem_list3 *l3; |
| int node = numa_node_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); |
| } |
| |
| |
| /* |
| * __cache_free |
| * 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(kmem_cache_t *cachep, void *objp) |
| { |
| struct array_cache *ac = ac_data(cachep); |
| |
| check_irq_off(); |
| objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); |
| |
| /* Make sure we are not freeing a object from another |
| * node to the array cache on this cpu. |
| */ |
| #ifdef CONFIG_NUMA |
| { |
| struct slab *slabp; |
| slabp = page_get_slab(virt_to_page(objp)); |
| if (unlikely(slabp->nodeid != numa_node_id())) { |
| struct array_cache *alien = NULL; |
| int nodeid = slabp->nodeid; |
| struct kmem_list3 *l3 = cachep->nodelists[numa_node_id()]; |
| |
| STATS_INC_NODEFREES(cachep); |
| if (l3->alien && l3->alien[nodeid]) { |
| alien = l3->alien[nodeid]; |
| spin_lock(&alien->lock); |
| if (unlikely(alien->avail == alien->limit)) |
| __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; |
| } |
| } |
| #endif |
| 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(kmem_cache_t *cachep, gfp_t flags) |
| { |
| return __cache_alloc(cachep, flags); |
| } |
| EXPORT_SYMBOL(kmem_cache_alloc); |
| |
| /** |
| * kmem_ptr_validate - check if an untrusted pointer might |
| * be a slab entry. |
| * @cachep: the cache we're checking against |
| * @ptr: pointer to validate |
| * |
| * This verifies that the untrusted pointer looks sane: |
| * it is _not_ a guarantee that the pointer is actually |
| * part of the slab cache in question, but it at least |
| * validates that the pointer can be dereferenced and |
| * looks half-way sane. |
| * |
| * Currently only used for dentry validation. |
| */ |
| int fastcall kmem_ptr_validate(kmem_cache_t *cachep, void *ptr) |
| { |
| unsigned long addr = (unsigned long) ptr; |
| unsigned long min_addr = PAGE_OFFSET; |
| unsigned long align_mask = BYTES_PER_WORD-1; |
| unsigned long size = cachep->objsize; |
| struct page *page; |
| |
| if (unlikely(addr < min_addr)) |
| goto out; |
| if (unlikely(addr > (unsigned long)high_memory - size)) |
| goto out; |
| if (unlikely(addr & align_mask)) |
| goto out; |
| if (unlikely(!kern_addr_valid(addr))) |
| goto out; |
| if (unlikely(!kern_addr_valid(addr + size - 1))) |
| goto out; |
| page = virt_to_page(ptr); |
| if (unlikely(!PageSlab(page))) |
| goto out; |
| if (unlikely(page_get_cache(page) != cachep)) |
| goto out; |
| return 1; |
| out: |
| return 0; |
| } |
| |
| #ifdef CONFIG_NUMA |
| /** |
| * kmem_cache_alloc_node - Allocate an object on the specified node |
| * @cachep: The cache to allocate from. |
| * @flags: See kmalloc(). |
| * @nodeid: node number of the target node. |
| * |
| * Identical to kmem_cache_alloc, except that this function is slow |
| * and can sleep. And it will allocate memory on the given node, which |
| * can improve the performance for cpu bound structures. |
| * New and improved: it will now make sure that the object gets |
| * put on the correct node list so that there is no false sharing. |
| */ |
| void *kmem_cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int nodeid) |
| { |
| unsigned long save_flags; |
| void *ptr; |
| |
| if (nodeid == -1) |
| return __cache_alloc(cachep, flags); |
| |
| if (unlikely(!cachep->nodelists[nodeid])) { |
| /* Fall back to __cache_alloc if we run into trouble */ |
| printk(KERN_WARNING "slab: not allocating in inactive node %d for cache %s\n", nodeid, cachep->name); |
| return __cache_alloc(cachep,flags); |
| } |
| |
| cache_alloc_debugcheck_before(cachep, flags); |
| local_irq_save(save_flags); |
| if (nodeid == numa_node_id()) |
| ptr = ____cache_alloc(cachep, flags); |
| else |
| ptr = __cache_alloc_node(cachep, flags, nodeid); |
| local_irq_restore(save_flags); |
| ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, __builtin_return_address(0)); |
| |
| return ptr; |
| } |
| EXPORT_SYMBOL(kmem_cache_alloc_node); |
| |
| void *kmalloc_node(size_t size, gfp_t flags, int node) |
| { |
| kmem_cache_t *cachep; |
| |
| cachep = kmem_find_general_cachep(size, flags); |
| if (unlikely(cachep == NULL)) |
| return NULL; |
| return kmem_cache_alloc_node(cachep, flags, node); |
| } |
| EXPORT_SYMBOL(kmalloc_node); |
| #endif |
| |
| /** |
| * kmalloc - allocate memory |
| * @size: how many bytes of memory are required. |
| * @flags: the type of memory to allocate. |
| * |
| * kmalloc is the normal method of allocating memory |
| * in the kernel. |
| * |
| * The @flags argument may be one of: |
| * |
| * %GFP_USER - Allocate memory on behalf of user. May sleep. |
| * |
| * %GFP_KERNEL - Allocate normal kernel ram. May sleep. |
| * |
| * %GFP_ATOMIC - Allocation will not sleep. Use inside interrupt handlers. |
| * |
| * Additionally, the %GFP_DMA flag may be set to indicate the memory |
| * must be suitable for DMA. This can mean different things on different |
| * platforms. For example, on i386, it means that the memory must come |
| * from the first 16MB. |
| */ |
| void *__kmalloc(size_t size, gfp_t flags) |
| { |
| kmem_cache_t *cachep; |
| |
| /* 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(cachep == NULL)) |
| return NULL; |
| return __cache_alloc(cachep, flags); |
| } |
| EXPORT_SYMBOL(__kmalloc); |
| |
| #ifdef CONFIG_SMP |
| /** |
| * __alloc_percpu - allocate one copy of the object for every present |
| * cpu in the system, zeroing them. |
| * Objects should be dereferenced using the per_cpu_ptr macro only. |
| * |
| * @size: how many bytes of memory are required. |
| * @align: the alignment, which can't be greater than SMP_CACHE_BYTES. |
| */ |
| void *__alloc_percpu(size_t size, size_t align) |
| { |
| int i; |
| struct percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL); |
| |
| if (!pdata) |
| return NULL; |
| |
| /* |
| * Cannot use for_each_online_cpu since a cpu may come online |
| * and we have no way of figuring out how to fix the array |
| * that we have allocated then.... |
| */ |
| for_each_cpu(i) { |
| int node = cpu_to_node(i); |
| |
| if (node_online(node)) |
| pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node); |
| else |
| pdata->ptrs[i] = kmalloc(size, GFP_KERNEL); |
| |
| if (!pdata->ptrs[i]) |
| goto unwind_oom; |
| memset(pdata->ptrs[i], 0, size); |
| } |
| |
| /* Catch derefs w/o wrappers */ |
| return (void *) (~(unsigned long) pdata); |
| |
| unwind_oom: |
| while (--i >= 0) { |
| if (!cpu_possible(i)) |
| continue; |
| kfree(pdata->ptrs[i]); |
| } |
| kfree(pdata); |
| return NULL; |
| } |
| EXPORT_SYMBOL(__alloc_percpu); |
| #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(kmem_cache_t *cachep, void *objp) |
| { |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| __cache_free(cachep, objp); |
| local_irq_restore(flags); |
| } |
| EXPORT_SYMBOL(kmem_cache_free); |
| |
| /** |
| * kzalloc - allocate memory. The memory is set to zero. |
| * @size: how many bytes of memory are required. |
| * @flags: the type of memory to allocate. |
| */ |
| void *kzalloc(size_t size, gfp_t flags) |
| { |
| void *ret = kmalloc(size, flags); |
| if (ret) |
| memset(ret, 0, size); |
| return ret; |
| } |
| EXPORT_SYMBOL(kzalloc); |
| |
| /** |
| * 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) |
| { |
| kmem_cache_t *c; |
| unsigned long flags; |
| |
| if (unlikely(!objp)) |
| return; |
| local_irq_save(flags); |
| kfree_debugcheck(objp); |
| c = page_get_cache(virt_to_page(objp)); |
| __cache_free(c, (void*)objp); |
| local_irq_restore(flags); |
| } |
| EXPORT_SYMBOL(kfree); |
| |
| #ifdef CONFIG_SMP |
| /** |
| * free_percpu - free previously allocated percpu memory |
| * @objp: pointer returned by alloc_percpu. |
| * |
| * Don't free memory not originally allocated by alloc_percpu() |
| * The complemented objp is to check for that. |
| */ |
| void |
| free_percpu(const void *objp) |
| { |
| int i; |
| struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp); |
| |
| /* |
| * We allocate for all cpus so we cannot use for online cpu here. |
| */ |
| for_each_cpu(i) |
| kfree(p->ptrs[i]); |
| kfree(p); |
| } |
| EXPORT_SYMBOL(free_percpu); |
| #endif |
| |
| unsigned int kmem_cache_size(kmem_cache_t *cachep) |
| { |
| return obj_reallen(cachep); |
| } |
| EXPORT_SYMBOL(kmem_cache_size); |
| |
| const char *kmem_cache_name(kmem_cache_t *cachep) |
| { |
| return cachep->name; |
| } |
| EXPORT_SYMBOL_GPL(kmem_cache_name); |
| |
| /* |
| * This initializes kmem_list3 for all nodes. |
| */ |
| static int alloc_kmemlist(kmem_cache_t *cachep) |
| { |
| int node; |
| struct kmem_list3 *l3; |
| int err = 0; |
| |
| for_each_online_node(node) { |
| struct array_cache *nc = NULL, *new; |
| struct array_cache **new_alien = NULL; |
| #ifdef CONFIG_NUMA |
| if (!(new_alien = alloc_alien_cache(node, cachep->limit))) |
| goto fail; |
| #endif |
| if (!(new = alloc_arraycache(node, (cachep->shared* |
| cachep->batchcount), 0xbaadf00d))) |
| goto fail; |
| if ((l3 = cachep->nodelists[node])) { |
| |
| spin_lock_irq(&l3->list_lock); |
| |
| if ((nc = cachep->nodelists[node]->shared)) |
| free_block(cachep, nc->entry, |
| nc->avail, node); |
| |
| l3->shared = new; |
| if (!cachep->nodelists[node]->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(nc); |
| free_alien_cache(new_alien); |
| continue; |
| } |
| if (!(l3 = kmalloc_node(sizeof(struct kmem_list3), |
| GFP_KERNEL, node))) |
| goto fail; |
| |
| kmem_list3_init(l3); |
| l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
| ((unsigned long)cachep)%REAPTIMEOUT_LIST3; |
| l3->shared = new; |
| l3->alien = new_alien; |
| l3->free_limit = (1 + nr_cpus_node(node))* |
| cachep->batchcount + cachep->num; |
| cachep->nodelists[node] = l3; |
| } |
| return err; |
| fail: |
| err = -ENOMEM; |
| return err; |
| } |
| |
| struct ccupdate_struct { |
| kmem_cache_t *cachep; |
| struct array_cache *new[NR_CPUS]; |
| }; |
| |
| static void do_ccupdate_local(void *info) |
| { |
| struct ccupdate_struct *new = (struct ccupdate_struct *)info; |
| struct array_cache *old; |
| |
| check_irq_off(); |
| old = ac_data(new->cachep); |
| |
| new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; |
| new->new[smp_processor_id()] = old; |
| } |
| |
| |
| static int do_tune_cpucache(kmem_cache_t *cachep, int limit, int batchcount, |
| int shared) |
| { |
|