slab.c 109.6 KB
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/*
 * 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.
 *
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 * The c_cpuarray may not be read with enabled local interrupts -
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 * it's changed with a smp_call_function().
 *
 * SMP synchronization:
 *  constructors and destructors are called without any locking.
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 *  Several members in struct kmem_cache and struct slab never change, they
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 *	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
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 *	The global cache-chain is protected by the mutex 'cache_chain_mutex'.
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 *	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.
 *
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 * 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.
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 */

#include	<linux/config.h>
#include	<linux/slab.h>
#include	<linux/mm.h>
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#include	<linux/poison.h>
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#include	<linux/swap.h>
#include	<linux/cache.h>
#include	<linux/interrupt.h>
#include	<linux/init.h>
#include	<linux/compiler.h>
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#include	<linux/cpuset.h>
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#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>
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#include	<linux/string.h>
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#include	<linux/nodemask.h>
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#include	<linux/mempolicy.h>
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#include	<linux/mutex.h>
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#include	<linux/rtmutex.h>
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#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 | \
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			 SLAB_CACHE_DMA | \
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			 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
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			 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
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#else
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# define CREATE_MASK	(SLAB_HWCACHE_ALIGN | \
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			 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
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			 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
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#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.
 */

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typedef unsigned int kmem_bufctl_t;
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#define BUFCTL_END	(((kmem_bufctl_t)(~0U))-0)
#define BUFCTL_FREE	(((kmem_bufctl_t)(~0U))-1)
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#define	BUFCTL_ACTIVE	(((kmem_bufctl_t)(~0U))-2)
#define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-3)
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/*
 * 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 {
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	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;
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};

/*
 * 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 {
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	struct rcu_head head;
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	struct kmem_cache *cachep;
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	void *addr;
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};

/*
 * 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;
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	spinlock_t lock;
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	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 [].
			 */
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};

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/*
 * bootstrap: The caches do not work without cpuarrays anymore, but the
 * cpuarrays are allocated from the generic caches...
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 */
#define BOOT_CPUCACHE_ENTRIES	1
struct arraycache_init {
	struct array_cache cache;
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	void *entries[BOOT_CPUCACHE_ENTRIES];
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};

/*
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 * The slab lists for all objects.
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 */
struct kmem_list3 {
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	struct list_head slabs_partial;	/* partial list first, better asm code */
	struct list_head slabs_full;
	struct list_head slabs_free;
	unsigned long free_objects;
	unsigned int free_limit;
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	unsigned int colour_next;	/* Per-node cache coloring */
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	spinlock_t list_lock;
	struct array_cache *shared;	/* shared per node */
	struct array_cache **alien;	/* on other nodes */
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	unsigned long next_reap;	/* updated without locking */
	int free_touched;		/* updated without locking */
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};

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/*
 * 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)

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static int drain_freelist(struct kmem_cache *cache,
			struct kmem_list3 *l3, int tofree);
static void free_block(struct kmem_cache *cachep, void **objpp, int len,
			int node);
static void enable_cpucache(struct kmem_cache *cachep);
static void cache_reap(void *unused);

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/*
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 * 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.
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 */
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static __always_inline int index_of(const size_t size)
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{
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	extern void __bad_size(void);

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	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
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		__bad_size();
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	} else
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		__bad_size();
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	return 0;
}

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static int slab_early_init = 1;

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#define INDEX_AC index_of(sizeof(struct arraycache_init))
#define INDEX_L3 index_of(sizeof(struct kmem_list3))
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static void kmem_list3_init(struct kmem_list3 *parent)
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{
	INIT_LIST_HEAD(&parent->slabs_full);
	INIT_LIST_HEAD(&parent->slabs_partial);
	INIT_LIST_HEAD(&parent->slabs_free);
	parent->shared = NULL;
	parent->alien = NULL;
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	parent->colour_next = 0;
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	spin_lock_init(&parent->list_lock);
	parent->free_objects = 0;
	parent->free_touched = 0;
}

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#define MAKE_LIST(cachep, listp, slab, nodeid)				\
	do {								\
		INIT_LIST_HEAD(listp);					\
		list_splice(&(cachep->nodelists[nodeid]->slab), listp);	\
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	} while (0)

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#define	MAKE_ALL_LISTS(cachep, ptr, nodeid)				\
	do {								\
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	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)
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/*
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 * struct kmem_cache
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 *
 * manages a cache.
 */
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struct kmem_cache {
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/* 1) per-cpu data, touched during every alloc/free */
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	struct array_cache *array[NR_CPUS];
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/* 2) Cache tunables. Protected by cache_chain_mutex */
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	unsigned int batchcount;
	unsigned int limit;
	unsigned int shared;
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	unsigned int buffer_size;
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/* 3) touched by every alloc & free from the backend */
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	struct kmem_list3 *nodelists[MAX_NUMNODES];
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	unsigned int flags;		/* constant flags */
	unsigned int num;		/* # of objs per slab */
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/* 4) cache_grow/shrink */
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	/* order of pgs per slab (2^n) */
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	unsigned int gfporder;
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	/* force GFP flags, e.g. GFP_DMA */
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	gfp_t gfpflags;
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	size_t colour;			/* cache colouring range */
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	unsigned int colour_off;	/* colour offset */
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	struct kmem_cache *slabp_cache;
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	unsigned int slab_size;
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	unsigned int dflags;		/* dynamic flags */
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	/* constructor func */
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	void (*ctor) (void *, struct kmem_cache *, unsigned long);
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	/* de-constructor func */
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	void (*dtor) (void *, struct kmem_cache *, unsigned long);
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/* 5) cache creation/removal */
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	const char *name;
	struct list_head next;
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/* 6) statistics */
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#if STATS
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	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;
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	unsigned long node_overflow;
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	atomic_t allochit;
	atomic_t allocmiss;
	atomic_t freehit;
	atomic_t freemiss;
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#endif
#if DEBUG
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	/*
	 * If debugging is enabled, then the allocator can add additional
	 * fields and/or padding to every object. buffer_size contains the total
	 * object size including these internal fields, the following two
	 * variables contain the offset to the user object and its size.
	 */
	int obj_offset;
	int obj_size;
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#endif
};

#define CFLGS_OFF_SLAB		(0x80000000UL)
#define	OFF_SLAB(x)	((x)->flags & CFLGS_OFF_SLAB)

#define BATCHREFILL_LIMIT	16
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/*
 * Optimization question: fewer reaps means less probability for unnessary
 * cpucache drain/refill cycles.
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 *
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 * OTOH the cpuarrays can contain lots of objects,
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 * 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++)
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#define	STATS_ADD_REAPED(x,y)	((x)->reaped += (y))
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#define	STATS_SET_HIGH(x)						\
	do {								\
		if ((x)->num_active > (x)->high_mark)			\
			(x)->high_mark = (x)->num_active;		\
	} while (0)
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#define	STATS_INC_ERR(x)	((x)->errors++)
#define	STATS_INC_NODEALLOCS(x)	((x)->node_allocs++)
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#define	STATS_INC_NODEFREES(x)	((x)->node_frees++)
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#define STATS_INC_ACOVERFLOW(x)   ((x)->node_overflow++)
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#define	STATS_SET_FREEABLE(x, i)					\
	do {								\
		if ((x)->max_freeable < i)				\
			(x)->max_freeable = i;				\
	} while (0)
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#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)
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#define	STATS_ADD_REAPED(x,y)	do { } while (0)
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#define	STATS_SET_HIGH(x)	do { } while (0)
#define	STATS_INC_ERR(x)	do { } while (0)
#define	STATS_INC_NODEALLOCS(x)	do { } while (0)
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#define	STATS_INC_NODEFREES(x)	do { } while (0)
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#define STATS_INC_ACOVERFLOW(x)   do { } while (0)
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#define	STATS_SET_FREEABLE(x, i) do { } while (0)
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#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

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/*
 * memory layout of objects:
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 * 0		: objp
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 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
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 * 		the end of an object is aligned with the end of the real
 * 		allocation. Catches writes behind the end of the allocation.
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 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
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 * 		redzone word.
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 * cachep->obj_offset: The real object.
 * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
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 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
 *					[BYTES_PER_WORD long]
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 */
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static int obj_offset(struct kmem_cache *cachep)
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{
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	return cachep->obj_offset;
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}

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static int obj_size(struct kmem_cache *cachep)
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{
525
	return cachep->obj_size;
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}

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static unsigned long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
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	return (unsigned long*) (objp+obj_offset(cachep)-BYTES_PER_WORD);
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}

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static unsigned long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
	if (cachep->flags & SLAB_STORE_USER)
538
		return (unsigned long *)(objp + cachep->buffer_size -
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					 2 * BYTES_PER_WORD);
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	return (unsigned long *)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

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static void **dbg_userword(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
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	return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

#else

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#define obj_offset(x)			0
#define obj_size(cachep)		(cachep->buffer_size)
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#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

/*
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 * Maximum size of an obj (in 2^order pages) and absolute limit for the gfp
 * order.
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 */
#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;

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/*
 * Functions for storing/retrieving the cachep and or slab from the page
 * allocator.  These are used to find the slab an obj belongs to.  With kfree(),
 * these are used to find the cache which an obj belongs to.
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 */
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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)
{
593 594
	if (unlikely(PageCompound(page)))
		page = (struct page *)page_private(page);
595
	BUG_ON(!PageSlab(page));
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	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)
{
606 607
	if (unlikely(PageCompound(page)))
		page = (struct page *)page_private(page);
608
	BUG_ON(!PageSlab(page));
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	return (struct slab *)page->lru.prev;
}
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static inline struct kmem_cache *virt_to_cache(const void *obj)
{
	struct page *page = virt_to_page(obj);
	return page_get_cache(page);
}

static inline struct slab *virt_to_slab(const void *obj)
{
	struct page *page = virt_to_page(obj);
	return page_get_slab(page);
}

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static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
				 unsigned int idx)
{
	return slab->s_mem + cache->buffer_size * idx;
}

static inline unsigned int obj_to_index(struct kmem_cache *cache,
					struct slab *slab, void *obj)
{
	return (unsigned)(obj - slab->s_mem) / cache->buffer_size;
}

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/*
 * These are the default caches for kmalloc. Custom caches can have other sizes.
 */
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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>
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	{NULL,}
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#undef CACHE
};

static struct arraycache_init initarray_cache __initdata =
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    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
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static struct arraycache_init initarray_generic =
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    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
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/* internal cache of cache description objs */
666
static struct kmem_cache cache_cache = {
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	.batchcount = 1,
	.limit = BOOT_CPUCACHE_ENTRIES,
	.shared = 1,
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	.buffer_size = sizeof(struct kmem_cache),
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	.name = "kmem_cache",
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#if DEBUG
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	.obj_size = sizeof(struct kmem_cache),
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#endif
};

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#ifdef CONFIG_LOCKDEP

/*
 * Slab sometimes uses the kmalloc slabs to store the slab headers
 * for other slabs "off slab".
 * The locking for this is tricky in that it nests within the locks
 * of all other slabs in a few places; to deal with this special
 * locking we put on-slab caches into a separate lock-class.
 */
static struct lock_class_key on_slab_key;

static inline void init_lock_keys(struct cache_sizes *s)
{
	int q;

	for (q = 0; q < MAX_NUMNODES; q++) {
		if (!s->cs_cachep->nodelists[q] || OFF_SLAB(s->cs_cachep))
			continue;
		lockdep_set_class(&s->cs_cachep->nodelists[q]->list_lock,
				  &on_slab_key);
	}
}

#else
static inline void init_lock_keys(struct cache_sizes *s)
{
}
#endif



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/* Guard access to the cache-chain. */
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static DEFINE_MUTEX(cache_chain_mutex);
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static struct list_head cache_chain;

/*
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 * vm_enough_memory() looks at this to determine how many slab-allocated pages
 * are possibly freeable under pressure
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 *
 * 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,
726 727
	PARTIAL_AC,
	PARTIAL_L3,
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	FULL
} g_cpucache_up;

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/*
 * used by boot code to determine if it can use slab based allocator
 */
int slab_is_available(void)
{
	return g_cpucache_up == FULL;
}

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static DEFINE_PER_CPU(struct work_struct, reap_work);

741
static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
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{
	return cachep->array[smp_processor_id()];
}

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static inline struct kmem_cache *__find_general_cachep(size_t size,
							gfp_t gfpflags)
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{
	struct cache_sizes *csizep = malloc_sizes;

#if DEBUG
	/* This happens if someone tries to call
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	 * kmem_cache_create(), or __kmalloc(), before
	 * the generic caches are initialized.
	 */
756
	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
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#endif
	while (size > csizep->cs_size)
		csizep++;

	/*
762
	 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
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	 * 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;
}

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static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
772 773 774 775
{
	return __find_general_cachep(size, gfpflags);
}

776
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
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{
778 779
	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
}
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/*
 * Calculate the number of objects and left-over bytes for a given buffer size.
 */
784 785 786 787 788 789 790
static void cache_estimate(unsigned long gfporder, size_t buffer_size,
			   size_t align, int flags, size_t *left_over,
			   unsigned int *num)
{
	int nr_objs;
	size_t mgmt_size;
	size_t slab_size = PAGE_SIZE << gfporder;
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	/*
	 * The slab management structure can be either off the slab or
	 * on it. For the latter case, the memory allocated for a
	 * slab is used for:
	 *
	 * - The struct slab
	 * - One kmem_bufctl_t for each object
	 * - Padding to respect alignment of @align
	 * - @buffer_size bytes for each object
	 *
	 * If the slab management structure is off the slab, then the
	 * alignment will already be calculated into the size. Because
	 * the slabs are all pages aligned, the objects will be at the
	 * correct alignment when allocated.
	 */
	if (flags & CFLGS_OFF_SLAB) {
		mgmt_size = 0;
		nr_objs = slab_size / buffer_size;

		if (nr_objs > SLAB_LIMIT)
			nr_objs = SLAB_LIMIT;
	} else {
		/*
		 * Ignore padding for the initial guess. The padding
		 * is at most @align-1 bytes, and @buffer_size is at
		 * least @align. In the worst case, this result will
		 * be one greater than the number of objects that fit
		 * into the memory allocation when taking the padding
		 * into account.
		 */
		nr_objs = (slab_size - sizeof(struct slab)) /
			  (buffer_size + sizeof(kmem_bufctl_t));

		/*
		 * This calculated number will be either the right
		 * amount, or one greater than what we want.
		 */
		if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size
		       > slab_size)
			nr_objs--;

		if (nr_objs > SLAB_LIMIT)
			nr_objs = SLAB_LIMIT;

		mgmt_size = slab_mgmt_size(nr_objs, align);
	}
	*num = nr_objs;
	*left_over = slab_size - nr_objs*buffer_size - mgmt_size;
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}

#define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)

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static void __slab_error(const char *function, struct kmem_cache *cachep,
			char *msg)
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{
	printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
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	       function, cachep->name, msg);
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	dump_stack();
}

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#ifdef CONFIG_NUMA
/*
 * Special reaping functions for NUMA systems called from cache_reap().
 * These take care of doing round robin flushing of alien caches (containing
 * objects freed on different nodes from which they were allocated) and the
 * flushing of remote pcps by calling drain_node_pages.
 */
static DEFINE_PER_CPU(unsigned long, reap_node);

static void init_reap_node(int cpu)
{
	int node;

	node = next_node(cpu_to_node(cpu), node_online_map);
	if (node == MAX_NUMNODES)
867
		node = first_node(node_online_map);
868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892

	__get_cpu_var(reap_node) = node;
}

static void next_reap_node(void)
{
	int node = __get_cpu_var(reap_node);

	/*
	 * Also drain per cpu pages on remote zones
	 */
	if (node != numa_node_id())
		drain_node_pages(node);

	node = next_node(node, node_online_map);
	if (unlikely(node >= MAX_NUMNODES))
		node = first_node(node_online_map);
	__get_cpu_var(reap_node) = node;
}

#else
#define init_reap_node(cpu) do { } while (0)
#define next_reap_node(void) do { } while (0)
#endif

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/*
 * 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) {
910
		init_reap_node(cpu);
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		INIT_WORK(reap_work, cache_reap, NULL);
		schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
	}
}

916
static struct array_cache *alloc_arraycache(int node, int entries,
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					    int batchcount)
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{
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	int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
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	struct array_cache *nc = NULL;

922
	nc = kmalloc_node(memsize, GFP_KERNEL, node);
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	if (nc) {
		nc->avail = 0;
		nc->limit = entries;
		nc->batchcount = batchcount;
		nc->touched = 0;
928
		spin_lock_init(&nc->lock);
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	}
	return nc;
}

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/*
 * Transfer objects in one arraycache to another.
 * Locking must be handled by the caller.
 *
 * Return the number of entries transferred.
 */
static int transfer_objects(struct array_cache *to,
		struct array_cache *from, unsigned int max)
{
	/* Figure out how many entries to transfer */
	int nr = min(min(from->avail, max), to->limit - to->avail);

	if (!nr)
		return 0;

	memcpy(to->entry + to->avail, from->entry + from->avail -nr,
			sizeof(void *) *nr);

	from->avail -= nr;
	to->avail += nr;
	to->touched = 1;
	return nr;
}

957
#ifdef CONFIG_NUMA
958
static void *__cache_alloc_node(struct kmem_cache *, gfp_t, int);
959
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
960

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static struct array_cache **alloc_alien_cache(int node, int limit)
962 963
{
	struct array_cache **ac_ptr;
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	int memsize = sizeof(void *) * MAX_NUMNODES;
965 966 967 968 969 970 971 972 973 974 975 976 977
	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]) {
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				for (i--; i <= 0; i--)
979 980 981 982 983 984 985 986 987
					kfree(ac_ptr[i]);
				kfree(ac_ptr);
				return NULL;
			}
		}
	}
	return ac_ptr;
}

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static void free_alien_cache(struct array_cache **ac_ptr)
989 990 991 992 993 994
{
	int i;

	if (!ac_ptr)
		return;
	for_each_node(i)
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	    kfree(ac_ptr[i]);
996 997 998
	kfree(ac_ptr);
}

999
static void __drain_alien_cache(struct kmem_cache *cachep,
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				struct array_cache *ac, int node)
1001 1002 1003 1004 1005
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
1006 1007 1008 1009 1010
		/*
		 * Stuff objects into the remote nodes shared array first.
		 * That way we could avoid the overhead of putting the objects
		 * into the free lists and getting them back later.
		 */
1011 1012
		if (rl3->shared)
			transfer_objects(rl3->shared, ac, ac->limit);
1013

1014
		free_block(cachep, ac->entry, ac->avail, node);
1015 1016 1017 1018 1019
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

1020 1021 1022 1023 1024 1025 1026 1027 1028
/*
 * Called from cache_reap() to regularly drain alien caches round robin.
 */
static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
{
	int node = __get_cpu_var(reap_node);

	if (l3->alien) {
		struct array_cache *ac = l3->alien[node];
1029 1030

		if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
1031 1032 1033 1034 1035 1036
			__drain_alien_cache(cachep, ac, node);
			spin_unlock_irq(&ac->lock);
		}
	}
}

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static void drain_alien_cache(struct kmem_cache *cachep,
				struct array_cache **alien)
1039
{
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	int i = 0;
1041 1042 1043 1044
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
1045
		ac = alien[i];
1046 1047 1048 1049 1050 1051 1052
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
1053

1054
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071
{
	struct slab *slabp = virt_to_slab(objp);
	int nodeid = slabp->nodeid;
	struct kmem_list3 *l3;
	struct array_cache *alien = NULL;

	/*
	 * Make sure we are not freeing a object from another node to the array
	 * cache on this cpu.
	 */
	if (likely(slabp->nodeid == numa_node_id()))
		return 0;

	l3 = cachep->nodelists[numa_node_id()];
	STATS_INC_NODEFREES(cachep);
	if (l3->alien && l3->alien[nodeid]) {
		alien = l3->alien[nodeid];
1072
		spin_lock(&alien->lock);
1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086
		if (unlikely(alien->avail == alien->limit)) {
			STATS_INC_ACOVERFLOW(cachep);
			__drain_alien_cache(cachep, alien, nodeid);
		}
		alien->entry[alien->avail++] = objp;
		spin_unlock(&alien->lock);
	} else {
		spin_lock(&(cachep->nodelists[nodeid])->list_lock);
		free_block(cachep, &objp, 1, nodeid);
		spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
	}
	return 1;
}

1087
#else
1088

1089
#define drain_alien_cache(cachep, alien) do { } while (0)
1090
#define reap_alien(cachep, l3) do { } while (0)
1091

1092 1093 1094 1095 1096
static inline struct array_cache **alloc_alien_cache(int node, int limit)
{
	return (struct array_cache **) 0x01020304ul;
}

1097 1098 1099
static inline void free_alien_cache(struct array_cache **ac_ptr)
{
}
1100

1101
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1102 1103 1104 1105
{
	return 0;
}

1106 1107
#endif

1108
static int __cpuinit cpuup_callback(struct notifier_block *nfb,
P
Pekka Enberg 已提交
1109
				    unsigned long action, void *hcpu)
L
Linus Torvalds 已提交
1110 1111
{
	long cpu = (long)hcpu;
1112
	struct kmem_cache *cachep;
1113 1114 1115
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
	int memsize = sizeof(struct kmem_list3);
L
Linus Torvalds 已提交
1116 1117 1118

	switch (action) {
	case CPU_UP_PREPARE:
I
Ingo Molnar 已提交
1119
		mutex_lock(&cache_chain_mutex);
A
Andrew Morton 已提交
1120 1121
		/*
		 * We need to do this right in the beginning since
1122 1123 1124 1125 1126
		 * 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
		 */

L
Linus Torvalds 已提交
1127
		list_for_each_entry(cachep, &cache_chain, next) {
A
Andrew Morton 已提交
1128 1129
			/*
			 * Set up the size64 kmemlist for cpu before we can
1130 1131 1132 1133
			 * begin anything. Make sure some other cpu on this
			 * node has not already allocated this
			 */
			if (!cachep->nodelists[node]) {
A
Andrew Morton 已提交
1134 1135
				l3 = kmalloc_node(memsize, GFP_KERNEL, node);
				if (!l3)
1136 1137 1138
					goto bad;
				kmem_list3_init(l3);
				l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
P
Pekka Enberg 已提交
1139
				    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1140

1141 1142 1143 1144 1145
				/*
				 * The l3s don't come and go as CPUs come and
				 * go.  cache_chain_mutex is sufficient
				 * protection here.
				 */
1146 1147
				cachep->nodelists[node] = l3;
			}
L
Linus Torvalds 已提交
1148

1149 1150
			spin_lock_irq(&cachep->nodelists[node]->list_lock);
			cachep->nodelists[node]->free_limit =
A
Andrew Morton 已提交
1151 1152
				(1 + nr_cpus_node(node)) *
				cachep->batchcount + cachep->num;
1153 1154 1155
			spin_unlock_irq(&cachep->nodelists[node]->list_lock);
		}

A
Andrew Morton 已提交
1156 1157 1158 1159
		/*
		 * Now we can go ahead with allocating the shared arrays and
		 * array caches
		 */
1160
		list_for_each_entry(cachep, &cache_chain, next) {
1161
			struct array_cache *nc;
1162 1163
			struct array_cache *shared;
			struct array_cache **alien;
1164

1165
			nc = alloc_arraycache(node, cachep->limit,
1166
						cachep->batchcount);
L
Linus Torvalds 已提交
1167 1168
			if (!nc)
				goto bad;
1169 1170 1171 1172 1173
			shared = alloc_arraycache(node,
					cachep->shared * cachep->batchcount,
					0xbaadf00d);
			if (!shared)
				goto bad;
1174

1175 1176 1177
			alien = alloc_alien_cache(node, cachep->limit);
			if (!alien)
				goto bad;
L
Linus Torvalds 已提交
1178
			cachep->array[cpu] = nc;
1179 1180 1181
			l3 = cachep->nodelists[node];
			BUG_ON(!l3);

1182 1183 1184 1185 1186 1187 1188 1189
			spin_lock_irq(&l3->list_lock);
			if (!l3->shared) {
				/*
				 * We are serialised from CPU_DEAD or
				 * CPU_UP_CANCELLED by the cpucontrol lock
				 */
				l3->shared = shared;
				shared = NULL;
1190
			}
1191 1192 1193 1194 1195 1196 1197 1198 1199
#ifdef CONFIG_NUMA
			if (!l3->alien) {
				l3->alien = alien;
				alien = NULL;
			}
#endif
			spin_unlock_irq(&l3->list_lock);
			kfree(shared);
			free_alien_cache(alien);
L
Linus Torvalds 已提交
1200
		}
I
Ingo Molnar 已提交
1201
		mutex_unlock(&cache_chain_mutex);
L
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1202 1203 1204 1205 1206 1207
		break;
	case CPU_ONLINE:
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
	case CPU_DEAD:
1208 1209 1210 1211 1212 1213 1214 1215
		/*
		 * Even if all the cpus of a node are down, we don't free the
		 * kmem_list3 of any cache. This to avoid a race between
		 * cpu_down, and a kmalloc allocation from another cpu for
		 * memory from the node of the cpu going down.  The list3
		 * structure is usually allocated from kmem_cache_create() and
		 * gets destroyed at kmem_cache_destroy().
		 */
L
Linus Torvalds 已提交
1216 1217
		/* fall thru */
	case CPU_UP_CANCELED:
I
Ingo Molnar 已提交
1218
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1219 1220
		list_for_each_entry(cachep, &cache_chain, next) {
			struct array_cache *nc;
1221 1222
			struct array_cache *shared;
			struct array_cache **alien;
1223
			cpumask_t mask;
L
Linus Torvalds 已提交
1224

1225
			mask = node_to_cpumask(node);
L
Linus Torvalds 已提交
1226 1227 1228
			/* cpu is dead; no one can alloc from it. */
			nc = cachep->array[cpu];
			cachep->array[cpu] = NULL;
1229 1230 1231
			l3 = cachep->nodelists[node];

			if (!l3)
1232
				goto free_array_cache;
1233

1234
			spin_lock_irq(&l3->list_lock);
1235 1236 1237 1238

			/* Free limit for this kmem_list3 */
			l3->free_limit -= cachep->batchcount;
			if (nc)
1239
				free_block(cachep, nc->entry, nc->avail, node);
1240 1241

			if (!cpus_empty(mask)) {
1242
				spin_unlock_irq(&l3->list_lock);
1243
				goto free_array_cache;
P
Pekka Enberg 已提交
1244
			}
1245

1246 1247
			shared = l3->shared;
			if (shared) {
1248
				free_block(cachep, l3->shared->entry,
P
Pekka Enberg 已提交
1249
					   l3->shared->avail, node);
1250 1251 1252
				l3->shared = NULL;
			}

1253 1254 1255 1256 1257 1258 1259 1260 1261
			alien = l3->alien;
			l3->alien = NULL;

			spin_unlock_irq(&l3->list_lock);

			kfree(shared);
			if (alien) {
				drain_alien_cache(cachep, alien);
				free_alien_cache(alien);
1262
			}
1263
free_array_cache:
L
Linus Torvalds 已提交
1264 1265
			kfree(nc);
		}
1266 1267 1268 1269 1270 1271 1272 1273 1274
		/*
		 * In the previous loop, all the objects were freed to
		 * the respective cache's slabs,  now we can go ahead and
		 * shrink each nodelist to its limit.
		 */
		list_for_each_entry(cachep, &cache_chain, next) {
			l3 = cachep->nodelists[node];
			if (!l3)
				continue;
1275
			drain_freelist(cachep, l3, l3->free_objects);
1276
		}
I
Ingo Molnar 已提交
1277
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1278 1279 1280 1281
		break;
#endif
	}
	return NOTIFY_OK;
A
Andrew Morton 已提交
1282
bad:
I
Ingo Molnar 已提交
1283
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1284 1285 1286
	return NOTIFY_BAD;
}

1287 1288 1289
static struct notifier_block __cpuinitdata cpucache_notifier = {
	&cpuup_callback, NULL, 0
};
L
Linus Torvalds 已提交
1290

1291 1292 1293
/*
 * swap the static kmem_list3 with kmalloced memory
 */
A
Andrew Morton 已提交
1294 1295
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
			int nodeid)
1296 1297 1298 1299 1300 1301 1302 1303 1304
{
	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));
1305 1306 1307 1308 1309
	/*
	 * Do not assume that spinlocks can be initialized via memcpy:
	 */
	spin_lock_init(&ptr->list_lock);

1310 1311 1312 1313 1314
	MAKE_ALL_LISTS(cachep, ptr, nodeid);
	cachep->nodelists[nodeid] = ptr;
	local_irq_enable();
}

A
Andrew Morton 已提交
1315 1316 1317
/*
 * Initialisation.  Called after the page allocator have been initialised and
 * before smp_init().
L
Linus Torvalds 已提交
1318 1319 1320 1321 1322 1323
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1324
	int i;
1325
	int order;
1326 1327 1328 1329 1330 1331

	for (i = 0; i < NUM_INIT_LISTS; i++) {
		kmem_list3_init(&initkmem_list3[i]);
		if (i < MAX_NUMNODES)
			cache_cache.nodelists[i] = NULL;
	}
L
Linus Torvalds 已提交
1332 1333 1334 1335 1336 1337 1338 1339 1340 1341

	/*
	 * 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:
A
Andrew Morton 已提交
1342 1343 1344
	 * 1) initialize the cache_cache cache: it contains the struct
	 *    kmem_cache structures of all caches, except cache_cache itself:
	 *    cache_cache is statically allocated.
1345 1346 1347
	 *    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.
L
Linus Torvalds 已提交
1348
	 * 2) Create the first kmalloc cache.
1349
	 *    The struct kmem_cache for the new cache is allocated normally.
1350 1351 1352
	 *    An __init data area is used for the head array.
	 * 3) Create the remaining kmalloc caches, with minimally sized
	 *    head arrays.
L
Linus Torvalds 已提交
1353 1354
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1355 1356 1357
	 * 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.
L
Linus Torvalds 已提交
1358 1359 1360 1361 1362 1363 1364
	 */

	/* 1) create the cache_cache */
	INIT_LIST_HEAD(&cache_chain);
	list_add(&cache_cache.next, &cache_chain);
	cache_cache.colour_off = cache_line_size();
	cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
1365
	cache_cache.nodelists[numa_node_id()] = &initkmem_list3[CACHE_CACHE];
L
Linus Torvalds 已提交
1366

A
Andrew Morton 已提交
1367 1368
	cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
					cache_line_size());
L
Linus Torvalds 已提交
1369

1370 1371 1372 1373 1374 1375
	for (order = 0; order < MAX_ORDER; order++) {
		cache_estimate(order, cache_cache.buffer_size,
			cache_line_size(), 0, &left_over, &cache_cache.num);
		if (cache_cache.num)
			break;
	}
1376
	BUG_ON(!cache_cache.num);
1377
	cache_cache.gfporder = order;
P
Pekka Enberg 已提交
1378 1379 1380
	cache_cache.colour = left_over / cache_cache.colour_off;
	cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
				      sizeof(struct slab), cache_line_size());
L
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1381 1382 1383 1384 1385

	/* 2+3) create the kmalloc caches */
	sizes = malloc_sizes;
	names = cache_names;

A
Andrew Morton 已提交
1386 1387 1388 1389
	/*
	 * Initialize the caches that provide memory for the array cache and the
	 * kmem_list3 structures first.  Without this, further allocations will
	 * bug.
1390 1391 1392
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
A
Andrew Morton 已提交
1393 1394 1395 1396
					sizes[INDEX_AC].cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
1397

A
Andrew Morton 已提交
1398
	if (INDEX_AC != INDEX_L3) {
1399
		sizes[INDEX_L3].cs_cachep =
A
Andrew Morton 已提交
1400 1401 1402 1403 1404 1405
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size,
				ARCH_KMALLOC_MINALIGN,
				ARCH_KMALLOC_FLAGS|SLAB_PANIC,
				NULL, NULL);
	}
1406

1407 1408
	slab_early_init = 0;

L
Linus Torvalds 已提交
1409
	while (sizes->cs_size != ULONG_MAX) {
1410 1411
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1412 1413 1414
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1415 1416
		 * allow tighter packing of the smaller caches.
		 */
A
Andrew Morton 已提交
1417
		if (!sizes->cs_cachep) {
1418
			sizes->cs_cachep = kmem_cache_create(names->name,
A
Andrew Morton 已提交
1419 1420 1421 1422 1423
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
		}
1424
		init_lock_keys(sizes);
L
Linus Torvalds 已提交
1425 1426

		sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
A
Andrew Morton 已提交
1427 1428 1429 1430 1431
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
						SLAB_PANIC,
					NULL, NULL);
L
Linus Torvalds 已提交
1432 1433 1434 1435 1436
		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
1437
		struct array_cache *ptr;
1438

L
Linus Torvalds 已提交
1439
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1440

L
Linus Torvalds 已提交
1441
		local_irq_disable();
1442 1443
		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
		memcpy(ptr, cpu_cache_get(&cache_cache),
P
Pekka Enberg 已提交
1444
		       sizeof(struct arraycache_init));
1445 1446 1447 1448 1449
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

L
Linus Torvalds 已提交
1450 1451
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1452

L
Linus Torvalds 已提交
1453
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1454

L
Linus Torvalds 已提交
1455
		local_irq_disable();
1456
		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
P
Pekka Enberg 已提交
1457
		       != &initarray_generic.cache);
1458
		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
P
Pekka Enberg 已提交
1459
		       sizeof(struct arraycache_init));
1460 1461 1462 1463 1464
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

1465
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
P
Pekka Enberg 已提交
1466
		    ptr;
L
Linus Torvalds 已提交
1467 1468
		local_irq_enable();
	}
1469 1470 1471 1472 1473
	/* 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],
P
Pekka Enberg 已提交
1474
			  numa_node_id());
1475 1476 1477

		for_each_online_node(node) {
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
P
Pekka Enberg 已提交
1478
				  &initkmem_list3[SIZE_AC + node], node);
1479 1480 1481

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
P
Pekka Enberg 已提交
1482 1483
					  &initkmem_list3[SIZE_L3 + node],
					  node);
1484 1485 1486
			}
		}
	}
L
Linus Torvalds 已提交
1487

1488
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1489
	{
1490
		struct kmem_cache *cachep;
I
Ingo Molnar 已提交
1491
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1492
		list_for_each_entry(cachep, &cache_chain, next)
A
Andrew Morton 已提交
1493
			enable_cpucache(cachep);
I
Ingo Molnar 已提交
1494
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1495 1496 1497 1498 1499
	}

	/* Done! */
	g_cpucache_up = FULL;

A
Andrew Morton 已提交
1500 1501 1502
	/*
	 * Register a cpu startup notifier callback that initializes
	 * cpu_cache_get for all new cpus
L
Linus Torvalds 已提交
1503 1504 1505
	 */
	register_cpu_notifier(&cpucache_notifier);

A
Andrew Morton 已提交
1506 1507 1508
	/*
	 * The reap timers are started later, with a module init call: That part
	 * of the kernel is not yet operational.
L
Linus Torvalds 已提交
1509 1510 1511 1512 1513 1514 1515
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

A
Andrew Morton 已提交
1516 1517
	/*
	 * Register the timers that return unneeded pages to the page allocator
L
Linus Torvalds 已提交
1518
	 */
1519
	for_each_online_cpu(cpu)
A
Andrew Morton 已提交
1520
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531
	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.
 */
1532
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1533 1534
{
	struct page *page;
1535
	int nr_pages;
L
Linus Torvalds 已提交
1536 1537
	int i;

1538
#ifndef CONFIG_MMU
1539 1540 1541
	/*
	 * Nommu uses slab's for process anonymous memory allocations, and thus
	 * requires __GFP_COMP to properly refcount higher order allocations
1542
	 */
1543
	flags |= __GFP_COMP;
1544
#endif
1545 1546 1547
	flags |= cachep->gfpflags;

	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1548 1549 1550
	if (!page)
		return NULL;

1551
	nr_pages = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1552
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1553
		atomic_add(nr_pages, &slab_reclaim_pages);
1554
	add_zone_page_state(page_zone(page), NR_SLAB, nr_pages);
1555 1556 1557
	for (i = 0; i < nr_pages; i++)
		__SetPageSlab(page + i);
	return page_address(page);
L
Linus Torvalds 已提交
1558 1559 1560 1561 1562
}

/*
 * Interface to system's page release.
 */
1563
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
L
Linus Torvalds 已提交
1564
{
P
Pekka Enberg 已提交
1565
	unsigned long i = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1566 1567 1568
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

1569
	sub_zone_page_state(page_zone(page), NR_SLAB, nr_freed);
L
Linus Torvalds 已提交
1570
	while (i--) {
N
Nick Piggin 已提交
1571 1572
		BUG_ON(!PageSlab(page));
		__ClearPageSlab(page);
L
Linus Torvalds 已提交
1573 1574 1575 1576 1577
		page++;
	}
	if (current->reclaim_state)
		current->reclaim_state->reclaimed_slab += nr_freed;
	free_pages((unsigned long)addr, cachep->gfporder);
P
Pekka Enberg 已提交
1578 1579
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		atomic_sub(1 << cachep->gfporder, &slab_reclaim_pages);
L
Linus Torvalds 已提交
1580 1581 1582 1583
}

static void kmem_rcu_free(struct rcu_head *head)
{
P
Pekka Enberg 已提交
1584
	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1585
	struct kmem_cache *cachep = slab_rcu->cachep;
L
Linus Torvalds 已提交
1586 1587 1588 1589 1590 1591 1592 1593 1594

	kmem_freepages(cachep, slab_rcu->addr);
	if (OFF_SLAB(cachep))
		kmem_cache_free(cachep->slabp_cache, slab_rcu);
}

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
1595
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
P
Pekka Enberg 已提交
1596
			    unsigned long caller)
L
Linus Torvalds 已提交
1597
{
1598
	int size = obj_size(cachep);
L
Linus Torvalds 已提交
1599

1600
	addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1601

P
Pekka Enberg 已提交
1602
	if (size < 5 * sizeof(unsigned long))
L
Linus Torvalds 已提交
1603 1604
		return;

P
Pekka Enberg 已提交
1605 1606 1607 1608
	*addr++ = 0x12345678;
	*addr++ = caller;
	*addr++ = smp_processor_id();
	size -= 3 * sizeof(unsigned long);
L
Linus Torvalds 已提交
1609 1610 1611 1612 1613 1614 1615
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
P
Pekka Enberg 已提交
1616
				*addr++ = svalue;
L
Linus Torvalds 已提交
1617 1618 1619 1620 1621 1622 1623
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
P
Pekka Enberg 已提交
1624
	*addr++ = 0x87654321;
L
Linus Torvalds 已提交
1625 1626 1627
}
#endif

1628
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
L
Linus Torvalds 已提交
1629
{
1630 1631
	int size = obj_size(cachep);
	addr = &((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1632 1633

	memset(addr, val, size);
P
Pekka Enberg 已提交
1634
	*(unsigned char *)(addr + size - 1) = POISON_END;
L
Linus Torvalds 已提交
1635 1636 1637 1638 1639 1640
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
	printk(KERN_ERR "%03x:", offset);
A
Andrew Morton 已提交
1641
	for (i = 0; i < limit; i++)
P
Pekka Enberg 已提交
1642
		printk(" %02x", (unsigned char)data[offset + i]);
L
Linus Torvalds 已提交
1643 1644 1645 1646 1647 1648
	printk("\n");
}
#endif

#if DEBUG

1649
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
L
Linus Torvalds 已提交
1650 1651 1652 1653 1654 1655
{
	int i, size;
	char *realobj;

	if (cachep->flags & SLAB_RED_ZONE) {
		printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n",
A
Andrew Morton 已提交
1656 1657
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
1658 1659 1660 1661
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
A
Andrew Morton 已提交
1662
			*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1663
		print_symbol("(%s)",
A
Andrew Morton 已提交
1664
				(unsigned long)*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1665 1666
		printk("\n");
	}
1667 1668
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
P
Pekka Enberg 已提交
1669
	for (i = 0; i < size && lines; i += 16, lines--) {
L
Linus Torvalds 已提交
1670 1671
		int limit;
		limit = 16;
P
Pekka Enberg 已提交
1672 1673
		if (i + limit > size)
			limit = size - i;
L
Linus Torvalds 已提交
1674 1675 1676 1677
		dump_line(realobj, i, limit);
	}
}

1678
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
1679 1680 1681 1682 1683
{
	char *realobj;
	int size, i;
	int lines = 0;

1684 1685
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
L
Linus Torvalds 已提交
1686

P
Pekka Enberg 已提交
1687
	for (i = 0; i < size; i++) {
L
Linus Torvalds 已提交
1688
		char exp = POISON_FREE;
P
Pekka Enberg 已提交
1689
		if (i == size - 1)
L
Linus Torvalds 已提交
1690 1691 1692 1693 1694 1695
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
P
Pekka Enberg 已提交
1696
				printk(KERN_ERR
A
Andrew Morton 已提交
1697 1698
					"Slab corruption: start=%p, len=%d\n",
					realobj, size);
L
Linus Torvalds 已提交
1699 1700 1701
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
P
Pekka Enberg 已提交
1702
			i = (i / 16) * 16;
L
Linus Torvalds 已提交
1703
			limit = 16;
P
Pekka Enberg 已提交
1704 1705
			if (i + limit > size)
				limit = size - i;
L
Linus Torvalds 已提交
1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717
			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:
		 */
1718
		struct slab *slabp = virt_to_slab(objp);
1719
		unsigned int objnr;
L
Linus Torvalds 已提交
1720

1721
		objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
1722
		if (objnr) {
1723
			objp = index_to_obj(cachep, slabp, objnr - 1);
1724
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1725
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1726
			       realobj, size);
L
Linus Torvalds 已提交
1727 1728
			print_objinfo(cachep, objp, 2);
		}
P
Pekka Enberg 已提交
1729
		if (objnr + 1 < cachep->num) {
1730
			objp = index_to_obj(cachep, slabp, objnr + 1);
1731
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1732
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1733
			       realobj, size);
L
Linus Torvalds 已提交
1734 1735 1736 1737 1738 1739
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

1740 1741
#if DEBUG
/**
1742 1743 1744 1745 1746 1747
 * slab_destroy_objs - destroy a slab and its objects
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
 * Call the registered destructor for each object in a slab that is being
 * destroyed.
L
Linus Torvalds 已提交
1748
 */
1749
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
1750 1751 1752
{
	int i;
	for (i = 0; i < cachep->num; i++) {
1753
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
1754 1755 1756

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
1757 1758
			if (cachep->buffer_size % PAGE_SIZE == 0 &&
					OFF_SLAB(cachep))
P
Pekka Enberg 已提交
1759
				kernel_map_pages(virt_to_page(objp),
A
Andrew Morton 已提交
1760
					cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
1761 1762 1763 1764 1765 1766 1767 1768 1769
			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 "
P
Pekka Enberg 已提交
1770
					   "was overwritten");
L
Linus Torvalds 已提交
1771 1772
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
P
Pekka Enberg 已提交
1773
					   "was overwritten");
L
Linus Torvalds 已提交
1774 1775
		}
		if (cachep->dtor && !(cachep->flags & SLAB_POISON))
1776
			(cachep->dtor) (objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
1777
	}
1778
}
L
Linus Torvalds 已提交
1779
#else
1780
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
1781
{
L
Linus Torvalds 已提交
1782 1783 1784
	if (cachep->dtor) {
		int i;
		for (i = 0; i < cachep->num; i++) {
1785
			void *objp = index_to_obj(cachep, slabp, i);
P
Pekka Enberg 已提交
1786
			(cachep->dtor) (objp, cachep, 0);
L
Linus Torvalds 已提交
1787 1788
		}
	}
1789
}
L
Linus Torvalds 已提交
1790 1791
#endif

1792 1793 1794 1795 1796
/**
 * slab_destroy - destroy and release all objects in a slab
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
1797
 * Destroy all the objs in a slab, and release the mem back to the system.
A
Andrew Morton 已提交
1798 1799
 * Before calling the slab must have been unlinked from the cache.  The
 * cache-lock is not held/needed.
1800
 */
1801
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1802 1803 1804 1805
{
	void *addr = slabp->s_mem - slabp->colouroff;

	slab_destroy_objs(cachep, slabp);
L
Linus Torvalds 已提交
1806 1807 1808
	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

P
Pekka Enberg 已提交
1809
		slab_rcu = (struct slab_rcu *)slabp;
L
Linus Torvalds 已提交
1810 1811 1812 1813 1814
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
1815 1816
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
L
Linus Torvalds 已提交
1817 1818 1819
	}
}

A
Andrew Morton 已提交
1820 1821 1822 1823
/*
 * For setting up all the kmem_list3s for cache whose buffer_size is same as
 * size of kmem_list3.
 */
1824
static void set_up_list3s(struct kmem_cache *cachep, int index)
1825 1826 1827 1828
{
	int node;

	for_each_online_node(node) {
P
Pekka Enberg 已提交
1829
		cachep->nodelists[node] = &initkmem_list3[index + node];
1830
		cachep->nodelists[node]->next_reap = jiffies +
P
Pekka Enberg 已提交
1831 1832
		    REAPTIMEOUT_LIST3 +
		    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1833 1834 1835
	}
}

1836
/**
1837 1838 1839 1840 1841 1842 1843
 * calculate_slab_order - calculate size (page order) of slabs
 * @cachep: pointer to the cache that is being created
 * @size: size of objects to be created in this cache.
 * @align: required alignment for the objects.
 * @flags: slab allocation flags
 *
 * Also calculates the number of objects per slab.
1844 1845 1846 1847 1848
 *
 * This could be made much more intelligent.  For now, try to avoid using
 * high order pages for slabs.  When the gfp() functions are more friendly
 * towards high-order requests, this should be changed.
 */
A
Andrew Morton 已提交
1849
static size_t calculate_slab_order(struct kmem_cache *cachep,
R
Randy Dunlap 已提交
1850
			size_t size, size_t align, unsigned long flags)
1851
{
1852
	unsigned long offslab_limit;
1853
	size_t left_over = 0;
1854
	int gfporder;
1855

A
Andrew Morton 已提交
1856
	for (gfporder = 0; gfporder <= MAX_GFP_ORDER; gfporder++) {
1857 1858 1859
		unsigned int num;
		size_t remainder;

1860
		cache_estimate(gfporder, size, align, flags, &remainder, &num);
1861 1862
		if (!num)
			continue;
1863

1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875
		if (flags & CFLGS_OFF_SLAB) {
			/*
			 * Max number of objs-per-slab for caches which
			 * use off-slab slabs. Needed to avoid a possible
			 * looping condition in cache_grow().
			 */
			offslab_limit = size - sizeof(struct slab);
			offslab_limit /= sizeof(kmem_bufctl_t);

 			if (num > offslab_limit)
				break;
		}
1876

1877
		/* Found something acceptable - save it away */
1878
		cachep->num = num;
1879
		cachep->gfporder = gfporder;
1880 1881
		left_over = remainder;

1882 1883 1884 1885 1886 1887 1888 1889
		/*
		 * A VFS-reclaimable slab tends to have most allocations
		 * as GFP_NOFS and we really don't want to have to be allocating
		 * higher-order pages when we are unable to shrink dcache.
		 */
		if (flags & SLAB_RECLAIM_ACCOUNT)
			break;

1890 1891 1892 1893
		/*
		 * Large number of objects is good, but very large slabs are
		 * currently bad for the gfp()s.
		 */
1894
		if (gfporder >= slab_break_gfp_order)
1895 1896
			break;

1897 1898 1899
		/*
		 * Acceptable internal fragmentation?
		 */
A
Andrew Morton 已提交
1900
		if (left_over * 8 <= (PAGE_SIZE << gfporder))
1901 1902 1903 1904 1905
			break;
	}
	return left_over;
}

1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
static void setup_cpu_cache(struct kmem_cache *cachep)
{
	if (g_cpucache_up == FULL) {
		enable_cpucache(cachep);
		return;
	}
	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;

	cpu_cache_get(cachep)->avail = 0;
	cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
	cpu_cache_get(cachep)->batchcount = 1;
	cpu_cache_get(cachep)->touched = 0;
	cachep->batchcount = 1;
	cachep->limit = BOOT_CPUCACHE_ENTRIES;
}

L
Linus Torvalds 已提交
1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974
/**
 * 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
A
Andrew Morton 已提交
1975 1976
 * the module calling this has to destroy the cache before getting unloaded.
 *
L
Linus Torvalds 已提交
1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988
 * The flags are
 *
 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
 * to catch references to uninitialised memory.
 *
 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
 * for buffer overruns.
 *
 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
 * cacheline.  This can be beneficial if you're counting cycles as closely
 * as davem.
 */
1989
struct kmem_cache *
L
Linus Torvalds 已提交
1990
kmem_cache_create (const char *name, size_t size, size_t align,
A
Andrew Morton 已提交
1991 1992
	unsigned long flags,
	void (*ctor)(void*, struct kmem_cache *, unsigned long),
1993
	void (*dtor)(void*, struct kmem_cache *, unsigned long))
L
Linus Torvalds 已提交
1994 1995
{
	size_t left_over, slab_size, ralign;
1996
	struct kmem_cache *cachep = NULL, *pc;
L
Linus Torvalds 已提交
1997 1998 1999 2000

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
A
Andrew Morton 已提交
2001
	if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
P
Pekka Enberg 已提交
2002
	    (size > (1 << MAX_OBJ_ORDER) * PAGE_SIZE) || (dtor && !ctor)) {
A
Andrew Morton 已提交
2003 2004
		printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
				name);
P
Pekka Enberg 已提交
2005 2006
		BUG();
	}
L
Linus Torvalds 已提交
2007

2008 2009 2010 2011 2012 2013
	/*
	 * Prevent CPUs from coming and going.
	 * lock_cpu_hotplug() nests outside cache_chain_mutex
	 */
	lock_cpu_hotplug();

I
Ingo Molnar 已提交
2014
	mutex_lock(&cache_chain_mutex);
2015

2016
	list_for_each_entry(pc, &cache_chain, next) {
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
		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",
2031
			       pc->buffer_size);
2032 2033 2034
			continue;
		}

P
Pekka Enberg 已提交
2035
		if (!strcmp(pc->name, name)) {
2036 2037 2038 2039 2040 2041
			printk("kmem_cache_create: duplicate cache %s\n", name);
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
2042 2043 2044 2045 2046
#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 "
P
Pekka Enberg 已提交
2047
		       "requested - %s\n", __FUNCTION__, name);
L
Linus Torvalds 已提交
2048 2049 2050 2051 2052 2053 2054 2055 2056
		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.
	 */
A
Andrew Morton 已提交
2057
	if (size < 4096 || fls(size - 1) == fls(size-1 + 3 * BYTES_PER_WORD))
P
Pekka Enberg 已提交
2058
		flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
L
Linus Torvalds 已提交
2059 2060 2061 2062 2063 2064 2065 2066 2067 2068
	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);

	/*
A
Andrew Morton 已提交
2069 2070
	 * Always checks flags, a caller might be expecting debug support which
	 * isn't available.
L
Linus Torvalds 已提交
2071
	 */
2072
	BUG_ON(flags & ~CREATE_MASK);
L
Linus Torvalds 已提交
2073

A
Andrew Morton 已提交
2074 2075
	/*
	 * Check that size is in terms of words.  This is needed to avoid
L
Linus Torvalds 已提交
2076 2077 2078
	 * unaligned accesses for some archs when redzoning is used, and makes
	 * sure any on-slab bufctl's are also correctly aligned.
	 */
P
Pekka Enberg 已提交
2079 2080 2081
	if (size & (BYTES_PER_WORD - 1)) {
		size += (BYTES_PER_WORD - 1);
		size &= ~(BYTES_PER_WORD - 1);
L
Linus Torvalds 已提交
2082 2083
	}

A
Andrew Morton 已提交
2084 2085
	/* calculate the final buffer alignment: */

L
Linus Torvalds 已提交
2086 2087
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
A
Andrew Morton 已提交
2088 2089 2090 2091
		/*
		 * Default alignment: as specified by the arch code.  Except if
		 * an object is really small, then squeeze multiple objects into
		 * one cacheline.
L
Linus Torvalds 已提交
2092 2093
		 */
		ralign = cache_line_size();
P
Pekka Enberg 已提交
2094
		while (size <= ralign / 2)
L
Linus Torvalds 已提交
2095 2096 2097 2098 2099 2100 2101 2102
			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)
P
Pekka Enberg 已提交
2103
			flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
L
Linus Torvalds 已提交
2104 2105 2106 2107 2108
	}
	/* 3) caller mandated alignment: disables debug if necessary */
	if (ralign < align) {
		ralign = align;
		if (ralign > BYTES_PER_WORD)
P
Pekka Enberg 已提交
2109
			flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
L
Linus Torvalds 已提交
2110
	}
A
Andrew Morton 已提交
2111 2112
	/*
	 * 4) Store it. Note that the debug code below can reduce
L
Linus Torvalds 已提交
2113 2114 2115 2116 2117
	 *    the alignment to BYTES_PER_WORD.
	 */
	align = ralign;

	/* Get cache's description obj. */
P
Pekka Enberg 已提交
2118
	cachep = kmem_cache_zalloc(&cache_cache, SLAB_KERNEL);
L
Linus Torvalds 已提交
2119
	if (!cachep)
2120
		goto oops;
L
Linus Torvalds 已提交
2121 2122

#if DEBUG
2123
	cachep->obj_size = size;
L
Linus Torvalds 已提交
2124 2125 2126 2127 2128 2129

	if (flags & SLAB_RED_ZONE) {
		/* redzoning only works with word aligned caches */
		align = BYTES_PER_WORD;

		/* add space for red zone words */
2130
		cachep->obj_offset += BYTES_PER_WORD;
P
Pekka Enberg 已提交
2131
		size += 2 * BYTES_PER_WORD;
L
Linus Torvalds 已提交
2132 2133 2134 2135 2136 2137 2138 2139 2140 2141
	}
	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)
P
Pekka Enberg 已提交
2142
	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2143 2144
	    && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
		cachep->obj_offset += PAGE_SIZE - size;
L
Linus Torvalds 已提交
2145 2146 2147 2148 2149
		size = PAGE_SIZE;
	}
#endif
#endif

2150 2151 2152 2153 2154 2155
	/*
	 * Determine if the slab management is 'on' or 'off' slab.
	 * (bootstrapping cannot cope with offslab caches so don't do
	 * it too early on.)
	 */
	if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init)
L
Linus Torvalds 已提交
2156 2157 2158 2159 2160 2161 2162 2163
		/*
		 * 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);

2164
	left_over = calculate_slab_order(cachep, size, align, flags);
L
Linus Torvalds 已提交
2165 2166 2167 2168 2169

	if (!cachep->num) {
		printk("kmem_cache_create: couldn't create cache %s.\n", name);
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
2170
		goto oops;
L
Linus Torvalds 已提交
2171
	}
P
Pekka Enberg 已提交
2172 2173
	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
			  + sizeof(struct slab), align);
L
Linus Torvalds 已提交
2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185

	/*
	 * 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 */
P
Pekka Enberg 已提交
2186 2187
		slab_size =
		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
L
Linus Torvalds 已提交
2188 2189 2190 2191 2192 2193
	}

	cachep->colour_off = cache_line_size();
	/* Offset must be a multiple of the alignment. */
	if (cachep->colour_off < align)
		cachep->colour_off = align;
P
Pekka Enberg 已提交
2194
	cachep->colour = left_over / cachep->colour_off;
L
Linus Torvalds 已提交
2195 2196 2197 2198 2199
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
	if (flags & SLAB_CACHE_DMA)
		cachep->gfpflags |= GFP_DMA;
2200
	cachep->buffer_size = size;
L
Linus Torvalds 已提交
2201 2202

	if (flags & CFLGS_OFF_SLAB)
2203
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
L
Linus Torvalds 已提交
2204 2205 2206 2207 2208
	cachep->ctor = ctor;
	cachep->dtor = dtor;
	cachep->name = name;


2209
	setup_cpu_cache(cachep);
L
Linus Torvalds 已提交
2210 2211 2212

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
A
Andrew Morton 已提交
2213
oops:
L
Linus Torvalds 已提交
2214 2215
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
P
Pekka Enberg 已提交
2216
		      name);
I
Ingo Molnar 已提交
2217
	mutex_unlock(&cache_chain_mutex);
2218
	unlock_cpu_hotplug();
L
Linus Torvalds 已提交
2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233
	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());
}

2234
static void check_spinlock_acquired(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2235 2236 2237
{
#ifdef CONFIG_SMP
	check_irq_off();
2238
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
2239 2240
#endif
}
2241

2242
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2243 2244 2245 2246 2247 2248 2249
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
2250 2251 2252 2253
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
2254
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
2255 2256
#endif

2257 2258 2259 2260
static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
			struct array_cache *ac,
			int force, int node);

L
Linus Torvalds 已提交
2261 2262
static void do_drain(void *arg)
{
A
Andrew Morton 已提交
2263
	struct kmem_cache *cachep = arg;
L
Linus Torvalds 已提交
2264
	struct array_cache *ac;
2265
	int node = numa_node_id();
L
Linus Torvalds 已提交
2266 2267

	check_irq_off();
2268
	ac = cpu_cache_get(cachep);
2269 2270 2271
	spin_lock(&cachep->nodelists[node]->list_lock);
	free_block(cachep, ac->entry, ac->avail, node);
	spin_unlock(&cachep->nodelists[node]->list_lock);
L
Linus Torvalds 已提交
2272 2273 2274
	ac->avail = 0;
}

2275
static void drain_cpu_caches(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2276
{
2277 2278 2279
	struct kmem_list3 *l3;
	int node;

A
Andrew Morton 已提交
2280
	on_each_cpu(do_drain, cachep, 1, 1);
L
Linus Torvalds 已提交
2281
	check_irq_on();
P
Pekka Enberg 已提交
2282
	for_each_online_node(node) {
2283
		l3 = cachep->nodelists[node];
2284 2285 2286 2287 2288 2289 2290
		if (l3 && l3->alien)
			drain_alien_cache(cachep, l3->alien);
	}

	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (l3)
2291
			drain_array(cachep, l3, l3->shared, 1, node);
2292
	}
L
Linus Torvalds 已提交
2293 2294
}

2295 2296 2297 2298 2299 2300 2301 2302
/*
 * Remove slabs from the list of free slabs.
 * Specify the number of slabs to drain in tofree.
 *
 * Returns the actual number of slabs released.
 */
static int drain_freelist(struct kmem_cache *cache,
			struct kmem_list3 *l3, int tofree)
L
Linus Torvalds 已提交
2303
{
2304 2305
	struct list_head *p;
	int nr_freed;
L
Linus Torvalds 已提交
2306 2307
	struct slab *slabp;

2308 2309
	nr_freed = 0;
	while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
L
Linus Torvalds 已提交
2310

2311
		spin_lock_irq(&l3->list_lock);
2312
		p = l3->slabs_free.prev;
2313 2314 2315 2316
		if (p == &l3->slabs_free) {
			spin_unlock_irq(&l3->list_lock);
			goto out;
		}
L
Linus Torvalds 已提交
2317

2318
		slabp = list_entry(p, struct slab, list);
L
Linus Torvalds 已提交
2319
#if DEBUG
2320
		BUG_ON(slabp->inuse);
L
Linus Torvalds 已提交
2321 2322
#endif
		list_del(&slabp->list);
2323 2324 2325 2326 2327
		/*
		 * Safe to drop the lock. The slab is no longer linked
		 * to the cache.
		 */
		l3->free_objects -= cache->num;
2328
		spin_unlock_irq(&l3->list_lock);
2329 2330
		slab_destroy(cache, slabp);
		nr_freed++;
L
Linus Torvalds 已提交
2331
	}
2332 2333
out:
	return nr_freed;
L
Linus Torvalds 已提交
2334 2335
}

2336
static int __cache_shrink(struct kmem_cache *cachep)
2337 2338 2339 2340 2341 2342 2343 2344 2345
{
	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];
2346 2347 2348 2349 2350 2351 2352
		if (!l3)
			continue;

		drain_freelist(cachep, l3, l3->free_objects);

		ret += !list_empty(&l3->slabs_full) ||
			!list_empty(&l3->slabs_partial);
2353 2354 2355 2356
	}
	return (ret ? 1 : 0);
}

L
Linus Torvalds 已提交
2357 2358 2359 2360 2361 2362 2363
/**
 * 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.
 */
2364
int kmem_cache_shrink(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2365
{
2366
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2367 2368 2369 2370 2371 2372 2373 2374 2375

	return __cache_shrink(cachep);
}
EXPORT_SYMBOL(kmem_cache_shrink);

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
2376
 * Remove a struct kmem_cache object from the slab cache.
L
Linus Torvalds 已提交
2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388
 * 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().
 */
2389
int kmem_cache_destroy(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2390 2391
{
	int i;
2392
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2393

2394
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2395 2396 2397 2398 2399

	/* Don't let CPUs to come and go */
	lock_cpu_hotplug();

	/* Find the cache in the chain of caches. */
I
Ingo Molnar 已提交
2400
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2401 2402 2403 2404
	/*
	 * the chain is never empty, cache_cache is never destroyed
	 */
	list_del(&cachep->next);
I
Ingo Molnar 已提交
2405
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2406 2407 2408

	if (__cache_shrink(cachep)) {
		slab_error(cachep, "Can't free all objects");
I
Ingo Molnar 已提交
2409
		mutex_lock(&cache_chain_mutex);
P
Pekka Enberg 已提交
2410
		list_add(&cachep->next, &cache_chain);
I
Ingo Molnar 已提交
2411
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2412 2413 2414 2415 2416
		unlock_cpu_hotplug();
		return 1;
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2417
		synchronize_rcu();
L
Linus Torvalds 已提交
2418

2419
	for_each_online_cpu(i)
P
Pekka Enberg 已提交
2420
	    kfree(cachep->array[i]);
L
Linus Torvalds 已提交
2421 2422

	/* NUMA: free the list3 structures */
2423
	for_each_online_node(i) {
A
Andrew Morton 已提交
2424 2425
		l3 = cachep->nodelists[i];
		if (l3) {
2426 2427 2428 2429 2430
			kfree(l3->shared);
			free_alien_cache(l3->alien);
			kfree(l3);
		}
	}
L
Linus Torvalds 已提交
2431 2432 2433 2434 2435 2436 2437
	kmem_cache_free(&cache_cache, cachep);
	unlock_cpu_hotplug();
	return 0;
}
EXPORT_SYMBOL(kmem_cache_destroy);

/* Get the memory for a slab management obj. */
2438
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
2439 2440
				   int colour_off, gfp_t local_flags,
				   int nodeid)
L
Linus Torvalds 已提交
2441 2442
{
	struct slab *slabp;
P
Pekka Enberg 已提交
2443

L
Linus Torvalds 已提交
2444 2445
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
2446 2447
		slabp = kmem_cache_alloc_node(cachep->slabp_cache,
					      local_flags, nodeid);
L
Linus Torvalds 已提交
2448 2449 2450
		if (!slabp)
			return NULL;
	} else {
P
Pekka Enberg 已提交
2451
		slabp = objp + colour_off;
L
Linus Torvalds 已提交
2452 2453 2454 2455
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
P
Pekka Enberg 已提交
2456
	slabp->s_mem = objp + colour_off;
2457
	slabp->nodeid = nodeid;
L
Linus Torvalds 已提交
2458 2459 2460 2461 2462
	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
P
Pekka Enberg 已提交
2463
	return (kmem_bufctl_t *) (slabp + 1);
L
Linus Torvalds 已提交
2464 2465
}

2466
static void cache_init_objs(struct kmem_cache *cachep,
P
Pekka Enberg 已提交
2467
			    struct slab *slabp, unsigned long ctor_flags)
L
Linus Torvalds 已提交
2468 2469 2470 2471
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2472
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484
#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;
		}
		/*
A
Andrew Morton 已提交
2485 2486 2487
		 * Constructors are not allowed to allocate memory from the same
		 * cache which they are a constructor for.  Otherwise, deadlock.
		 * They must also be threaded.
L
Linus Torvalds 已提交
2488 2489
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2490
			cachep->ctor(objp + obj_offset(cachep), cachep,
P
Pekka Enberg 已提交
2491
				     ctor_flags);
L
Linus Torvalds 已提交
2492 2493 2494 2495

		if (cachep->flags & SLAB_RED_ZONE) {
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2496
					   " end of an object");
L
Linus Torvalds 已提交
2497 2498
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2499
					   " start of an object");
L
Linus Torvalds 已提交
2500
		}
A
Andrew Morton 已提交
2501 2502
		if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
			    OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
P
Pekka Enberg 已提交
2503
			kernel_map_pages(virt_to_page(objp),
2504
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2505 2506 2507 2508
#else
		if (cachep->ctor)
			cachep->ctor(objp, cachep, ctor_flags);
#endif
P
Pekka Enberg 已提交
2509
		slab_bufctl(slabp)[i] = i + 1;
L
Linus Torvalds 已提交
2510
	}
P
Pekka Enberg 已提交
2511
	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
L
Linus Torvalds 已提交
2512 2513 2514
	slabp->free = 0;
}

2515
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2516
{
A
Andrew Morton 已提交
2517 2518 2519 2520
	if (flags & SLAB_DMA)
		BUG_ON(!(cachep->gfpflags & GFP_DMA));
	else
		BUG_ON(cachep->gfpflags & GFP_DMA);
L
Linus Torvalds 已提交
2521 2522
}

A
Andrew Morton 已提交
2523 2524
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
				int nodeid)
2525
{
2526
	void *objp = index_to_obj(cachep, slabp, slabp->free);
2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539
	kmem_bufctl_t next;

	slabp->inuse++;
	next = slab_bufctl(slabp)[slabp->free];
#if DEBUG
	slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
	WARN_ON(slabp->nodeid != nodeid);
#endif
	slabp->free = next;

	return objp;
}

A
Andrew Morton 已提交
2540 2541
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
				void *objp, int nodeid)
2542
{
2543
	unsigned int objnr = obj_to_index(cachep, slabp, objp);
2544 2545 2546 2547 2548

#if DEBUG
	/* Verify that the slab belongs to the intended node */
	WARN_ON(slabp->nodeid != nodeid);

2549
	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
2550
		printk(KERN_ERR "slab: double free detected in cache "
A
Andrew Morton 已提交
2551
				"'%s', objp %p\n", cachep->name, objp);
2552 2553 2554 2555 2556 2557 2558 2559
		BUG();
	}
#endif
	slab_bufctl(slabp)[objnr] = slabp->free;
	slabp->free = objnr;
	slabp->inuse--;
}

2560 2561 2562 2563 2564 2565 2566
/*
 * Map pages beginning at addr to the given cache and slab. This is required
 * for the slab allocator to be able to lookup the cache and slab of a
 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
 */
static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
			   void *addr)
L
Linus Torvalds 已提交
2567
{
2568
	int nr_pages;
L
Linus Torvalds 已提交
2569 2570
	struct page *page;

2571
	page = virt_to_page(addr);
2572

2573
	nr_pages = 1;
2574
	if (likely(!PageCompound(page)))
2575 2576
		nr_pages <<= cache->gfporder;

L
Linus Torvalds 已提交
2577
	do {
2578 2579
		page_set_cache(page, cache);
		page_set_slab(page, slab);
L
Linus Torvalds 已提交
2580
		page++;
2581
	} while (--nr_pages);
L
Linus Torvalds 已提交
2582 2583 2584 2585 2586 2587
}

/*
 * 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.
 */
2588
static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
2589
{
P
Pekka Enberg 已提交
2590 2591 2592 2593 2594
	struct slab *slabp;
	void *objp;
	size_t offset;
	gfp_t local_flags;
	unsigned long ctor_flags;
2595
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2596

A
Andrew Morton 已提交
2597 2598 2599
	/*
	 * Be lazy and only check for valid flags here,  keeping it out of the
	 * critical path in kmem_cache_alloc().
L
Linus Torvalds 已提交
2600
	 */
2601
	BUG_ON(flags & ~(SLAB_DMA | SLAB_LEVEL_MASK | SLAB_NO_GROW));
L
Linus Torvalds 已提交
2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613
	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;

2614
	/* Take the l3 list lock to change the colour_next on this node */
L
Linus Torvalds 已提交
2615
	check_irq_off();
2616 2617
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2618 2619

	/* Get colour for the slab, and cal the next value. */
2620 2621 2622 2623 2624
	offset = l3->colour_next;
	l3->colour_next++;
	if (l3->colour_next >= cachep->colour)
		l3->colour_next = 0;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2625

2626
	offset *= cachep->colour_off;
L
Linus Torvalds 已提交
2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638

	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);

A
Andrew Morton 已提交
2639 2640 2641
	/*
	 * Get mem for the objs.  Attempt to allocate a physical page from
	 * 'nodeid'.
2642
	 */
A
Andrew Morton 已提交
2643 2644
	objp = kmem_getpages(cachep, flags, nodeid);
	if (!objp)
L
Linus Torvalds 已提交
2645 2646 2647
		goto failed;

	/* Get slab management. */
2648
	slabp = alloc_slabmgmt(cachep, objp, offset, local_flags, nodeid);
A
Andrew Morton 已提交
2649
	if (!slabp)
L
Linus Torvalds 已提交
2650 2651
		goto opps1;

2652
	slabp->nodeid = nodeid;
2653
	slab_map_pages(cachep, slabp, objp);
L
Linus Torvalds 已提交
2654 2655 2656 2657 2658 2659

	cache_init_objs(cachep, slabp, ctor_flags);

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2660
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2661 2662

	/* Make slab active. */
2663
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2664
	STATS_INC_GROWN(cachep);
2665 2666
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2667
	return 1;
A
Andrew Morton 已提交
2668
opps1:
L
Linus Torvalds 已提交
2669
	kmem_freepages(cachep, objp);
A
Andrew Morton 已提交
2670
failed:
L
Linus Torvalds 已提交
2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689
	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",
P
Pekka Enberg 已提交
2690 2691
		       (unsigned long)objp);
		BUG();
L
Linus Torvalds 已提交
2692 2693 2694
	}
	page = virt_to_page(objp);
	if (!PageSlab(page)) {
P
Pekka Enberg 已提交
2695 2696
		printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n",
		       (unsigned long)objp);
L
Linus Torvalds 已提交
2697 2698 2699 2700
		BUG();
	}
}

2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722
static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
{
	unsigned long redzone1, redzone2;

	redzone1 = *dbg_redzone1(cache, obj);
	redzone2 = *dbg_redzone2(cache, obj);

	/*
	 * Redzone is ok.
	 */
	if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
		return;

	if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
		slab_error(cache, "double free detected");
	else
		slab_error(cache, "memory outside object was overwritten");

	printk(KERN_ERR "%p: redzone 1:0x%lx, redzone 2:0x%lx.\n",
			obj, redzone1, redzone2);
}

2723
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2724
				   void *caller)
L
Linus Torvalds 已提交
2725 2726 2727 2728 2729
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

2730
	objp -= obj_offset(cachep);
L
Linus Torvalds 已提交
2731 2732 2733
	kfree_debugcheck(objp);
	page = virt_to_page(objp);

2734
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2735 2736

	if (cachep->flags & SLAB_RED_ZONE) {
2737
		verify_redzone_free(cachep, objp);
L
Linus Torvalds 已提交
2738 2739 2740 2741 2742 2743
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

2744
	objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
2745 2746

	BUG_ON(objnr >= cachep->num);
2747
	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
L
Linus Torvalds 已提交
2748 2749

	if (cachep->flags & SLAB_DEBUG_INITIAL) {
A
Andrew Morton 已提交
2750 2751 2752 2753
		/*
		 * Need to call the slab's constructor so the caller can
		 * perform a verify of its state (debugging).  Called without
		 * the cache-lock held.
L
Linus Torvalds 已提交
2754
		 */
2755
		cachep->ctor(objp + obj_offset(cachep),
P
Pekka Enberg 已提交
2756
			     cachep, SLAB_CTOR_CONSTRUCTOR | SLAB_CTOR_VERIFY);
L
Linus Torvalds 已提交
2757 2758 2759 2760 2761
	}
	if (cachep->flags & SLAB_POISON && cachep->dtor) {
		/* we want to cache poison the object,
		 * call the destruction callback
		 */
2762
		cachep->dtor(objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
2763
	}
2764 2765 2766
#ifdef CONFIG_DEBUG_SLAB_LEAK
	slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
#endif
L
Linus Torvalds 已提交
2767 2768
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
2769
		if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
L
Linus Torvalds 已提交
2770
			store_stackinfo(cachep, objp, (unsigned long)caller);
P
Pekka Enberg 已提交
2771
			kernel_map_pages(virt_to_page(objp),
2772
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2773 2774 2775 2776 2777 2778 2779 2780 2781 2782
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

2783
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
2784 2785 2786
{
	kmem_bufctl_t i;
	int entries = 0;
P
Pekka Enberg 已提交
2787

L
Linus Torvalds 已提交
2788 2789 2790 2791 2792 2793 2794
	/* 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) {
A
Andrew Morton 已提交
2795 2796 2797 2798
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);
P
Pekka Enberg 已提交
2799
		for (i = 0;
2800
		     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
P
Pekka Enberg 已提交
2801
		     i++) {
A
Andrew Morton 已提交
2802
			if (i % 16 == 0)
L
Linus Torvalds 已提交
2803
				printk("\n%03x:", i);
P
Pekka Enberg 已提交
2804
			printk(" %02x", ((unsigned char *)slabp)[i]);
L
Linus Torvalds 已提交
2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815
		}
		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

2816
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2817 2818 2819 2820 2821 2822
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;

	check_irq_off();
2823
	ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2824
retry:
L
Linus Torvalds 已提交
2825 2826
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
A
Andrew Morton 已提交
2827 2828 2829 2830
		/*
		 * If there was little recent activity on this cache, then
		 * perform only a partial refill.  Otherwise we could generate
		 * refill bouncing.
L
Linus Torvalds 已提交
2831 2832 2833
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
2834 2835 2836 2837
	l3 = cachep->nodelists[numa_node_id()];

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2838

2839 2840 2841 2842
	/* See if we can refill from the shared array */
	if (l3->shared && transfer_objects(ac, l3->shared, batchcount))
		goto alloc_done;

L
Linus Torvalds 已提交
2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862
	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--) {
			STATS_INC_ALLOCED(cachep);
			STATS_INC_ACTIVE(cachep);
			STATS_SET_HIGH(cachep);

2863 2864
			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
							    numa_node_id());
L
Linus Torvalds 已提交
2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875
		}
		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);
	}

A
Andrew Morton 已提交
2876
must_grow:
L
Linus Torvalds 已提交
2877
	l3->free_objects -= ac->avail;
A
Andrew Morton 已提交
2878
alloc_done:
2879
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2880 2881 2882

	if (unlikely(!ac->avail)) {
		int x;
2883 2884
		x = cache_grow(cachep, flags, numa_node_id());

A
Andrew Morton 已提交
2885
		/* cache_grow can reenable interrupts, then ac could change. */
2886
		ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2887
		if (!x && ac->avail == 0)	/* no objects in sight? abort */
L
Linus Torvalds 已提交
2888 2889
			return NULL;

A
Andrew Morton 已提交
2890
		if (!ac->avail)		/* objects refilled by interrupt? */
L
Linus Torvalds 已提交
2891 2892 2893
			goto retry;
	}
	ac->touched = 1;
2894
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
2895 2896
}

A
Andrew Morton 已提交
2897 2898
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
						gfp_t flags)
L
Linus Torvalds 已提交
2899 2900 2901 2902 2903 2904 2905 2906
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
A
Andrew Morton 已提交
2907 2908
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
				gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
2909
{
P
Pekka Enberg 已提交
2910
	if (!objp)
L
Linus Torvalds 已提交
2911
		return objp;
P
Pekka Enberg 已提交
2912
	if (cachep->flags & SLAB_POISON) {
L
Linus Torvalds 已提交
2913
#ifdef CONFIG_DEBUG_PAGEALLOC
2914
		if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
P
Pekka Enberg 已提交
2915
			kernel_map_pages(virt_to_page(objp),
2916
					 cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927
		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) {
A
Andrew Morton 已提交
2928 2929 2930 2931
		if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
				*dbg_redzone2(cachep, objp) != RED_INACTIVE) {
			slab_error(cachep, "double free, or memory outside"
						" object was overwritten");
P
Pekka Enberg 已提交
2932
			printk(KERN_ERR
A
Andrew Morton 已提交
2933 2934 2935
				"%p: redzone 1:0x%lx, redzone 2:0x%lx\n",
				objp, *dbg_redzone1(cachep, objp),
				*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
2936 2937 2938 2939
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
2940 2941 2942 2943 2944 2945 2946 2947 2948 2949
#ifdef CONFIG_DEBUG_SLAB_LEAK
	{
		struct slab *slabp;
		unsigned objnr;

		slabp = page_get_slab(virt_to_page(objp));
		objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
	}
#endif
2950
	objp += obj_offset(cachep);
L
Linus Torvalds 已提交
2951
	if (cachep->ctor && cachep->flags & SLAB_POISON) {
P
Pekka Enberg 已提交
2952
		unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
L
Linus Torvalds 已提交
2953 2954 2955 2956 2957

		if (!(flags & __GFP_WAIT))
			ctor_flags |= SLAB_CTOR_ATOMIC;

		cachep->ctor(objp, cachep, ctor_flags);
P
Pekka Enberg 已提交
2958
	}
L
Linus Torvalds 已提交
2959 2960 2961 2962 2963 2964
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

2965
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2966
{
P
Pekka Enberg 已提交
2967
	void *objp;
L
Linus Torvalds 已提交
2968 2969
	struct array_cache *ac;

2970
#ifdef CONFIG_NUMA
2971
	if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
2972 2973 2974
		objp = alternate_node_alloc(cachep, flags);
		if (objp != NULL)
			return objp;
2975 2976 2977
	}
#endif

2978
	check_irq_off();
2979
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
2980 2981 2982
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
2983
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
2984 2985 2986 2987
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
2988 2989 2990
	return objp;
}

A
Andrew Morton 已提交
2991 2992
static __always_inline void *__cache_alloc(struct kmem_cache *cachep,
						gfp_t flags, void *caller)
2993 2994
{
	unsigned long save_flags;
P
Pekka Enberg 已提交
2995
	void *objp;
2996 2997 2998 2999 3000

	cache_alloc_debugcheck_before(cachep, flags);

	local_irq_save(save_flags);
	objp = ____cache_alloc(cachep, flags);
L
Linus Torvalds 已提交
3001
	local_irq_restore(save_flags);
3002
	objp = cache_alloc_debugcheck_after(cachep, flags, objp,
3003
					    caller);
3004
	prefetchw(objp);
L
Linus Torvalds 已提交
3005 3006 3007
	return objp;
}

3008
#ifdef CONFIG_NUMA
3009
/*
3010
 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030
 *
 * If we are in_interrupt, then process context, including cpusets and
 * mempolicy, may not apply and should not be used for allocation policy.
 */
static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
{
	int nid_alloc, nid_here;

	if (in_interrupt())
		return NULL;
	nid_alloc = nid_here = numa_node_id();
	if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
		nid_alloc = cpuset_mem_spread_node();
	else if (current->mempolicy)
		nid_alloc = slab_node(current->mempolicy);
	if (nid_alloc != nid_here)
		return __cache_alloc_node(cachep, flags, nid_alloc);
	return NULL;
}

3031 3032
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
3033
 */
A
Andrew Morton 已提交
3034 3035
static void *__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
				int nodeid)
3036 3037
{
	struct list_head *entry;
P
Pekka Enberg 已提交
3038 3039 3040 3041 3042 3043 3044 3045
	struct slab *slabp;
	struct kmem_list3 *l3;
	void *obj;
	int x;

	l3 = cachep->nodelists[nodeid];
	BUG_ON(!l3);

A
Andrew Morton 已提交
3046
retry:
3047
	check_irq_off();
P
Pekka Enberg 已提交
3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066
	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);

3067
	obj = slab_get_obj(cachep, slabp, nodeid);
P
Pekka Enberg 已提交
3068 3069 3070 3071 3072
	check_slabp(cachep, slabp);
	l3->free_objects--;
	/* move slabp to correct slabp list: */
	list_del(&slabp->list);

A
Andrew Morton 已提交
3073
	if (slabp->free == BUFCTL_END)
P
Pekka Enberg 已提交
3074
		list_add(&slabp->list, &l3->slabs_full);
A
Andrew Morton 已提交
3075
	else
P
Pekka Enberg 已提交
3076
		list_add(&slabp->list, &l3->slabs_partial);
3077

P
Pekka Enberg 已提交
3078 3079
	spin_unlock(&l3->list_lock);
	goto done;
3080

A
Andrew Morton 已提交
3081
must_grow:
P
Pekka Enberg 已提交
3082 3083
	spin_unlock(&l3->list_lock);
	x = cache_grow(cachep, flags, nodeid);
L
Linus Torvalds 已提交
3084

P
Pekka Enberg 已提交
3085 3086
	if (!x)
		return NULL;
3087

P
Pekka Enberg 已提交
3088
	goto retry;
A
Andrew Morton 已提交
3089
done:
P
Pekka Enberg 已提交
3090
	return obj;
3091 3092 3093 3094 3095 3096
}
#endif

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
3097
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
P
Pekka Enberg 已提交
3098
		       int node)
L
Linus Torvalds 已提交
3099 3100
{
	int i;
3101
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3102 3103 3104 3105 3106

	for (i = 0; i < nr_objects; i++) {
		void *objp = objpp[i];
		struct slab *slabp;

3107
		slabp = virt_to_slab(objp);
3108
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
3109
		list_del(&slabp->list);
3110
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
3111
		check_slabp(cachep, slabp);
3112
		slab_put_obj(cachep, slabp, objp, node);
L
Linus Torvalds 已提交
3113
		STATS_DEC_ACTIVE(cachep);
3114
		l3->free_objects++;
L
Linus Torvalds 已提交
3115 3116 3117 3118
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
3119 3120
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
L
Linus Torvalds 已提交
3121 3122
				slab_destroy(cachep, slabp);
			} else {
3123
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
3124 3125 3126 3127 3128 3129
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
3130
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
3131 3132 3133 3134
		}
	}
}

3135
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
L
Linus Torvalds 已提交
3136 3137
{
	int batchcount;
3138
	struct kmem_list3 *l3;
3139
	int node = numa_node_id();
L
Linus Torvalds 已提交
3140 3141 3142 3143 3144 3145

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
3146
	l3 = cachep->nodelists[node];
3147
	spin_lock(&l3->list_lock);
3148 3149
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
P
Pekka Enberg 已提交
3150
		int max = shared_array->limit - shared_array->avail;
L
Linus Torvalds 已提交
3151 3152 3153
		if (max) {
			if (batchcount > max)
				batchcount = max;
3154
			memcpy(&(shared_array->entry[shared_array->avail]),
P
Pekka Enberg 已提交
3155
			       ac->entry, sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
3156 3157 3158 3159 3160
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

3161
	free_block(cachep, ac->entry, batchcount, node);
A
Andrew Morton 已提交
3162
free_done:
L
Linus Torvalds 已提交
3163 3164 3165 3166 3167
#if STATS
	{
		int i = 0;
		struct list_head *p;

3168 3169
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180
			struct slab *slabp;

			slabp = list_entry(p, struct slab, list);
			BUG_ON(slabp->inuse);

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
3181
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3182
	ac->avail -= batchcount;
A
Andrew Morton 已提交
3183
	memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
L
Linus Torvalds 已提交
3184 3185 3186
}

/*
A
Andrew Morton 已提交
3187 3188
 * 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.
L
Linus Torvalds 已提交
3189
 */
3190
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3191
{
3192
	struct array_cache *ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3193 3194 3195 3196

	check_irq_off();
	objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));

3197
	if (cache_free_alien(cachep, objp))
3198 3199
		return;

L
Linus Torvalds 已提交
3200 3201
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
3202
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3203 3204 3205 3206
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
3207
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218
	}
}

/**
 * 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.
 */
3219
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3220
{
3221
	return __cache_alloc(cachep, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3222 3223 3224
}
EXPORT_SYMBOL(kmem_cache_alloc);

3225
/**
3226
 * kmem_cache_zalloc - Allocate an object. The memory is set to zero.
3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241
 * @cache: The cache to allocate from.
 * @flags: See kmalloc().
 *
 * Allocate an object from this cache and set the allocated memory to zero.
 * The flags are only relevant if the cache has no available objects.
 */
void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags)
{
	void *ret = __cache_alloc(cache, flags, __builtin_return_address(0));
	if (ret)
		memset(ret, 0, obj_size(cache));
	return ret;
}
EXPORT_SYMBOL(kmem_cache_zalloc);

L
Linus Torvalds 已提交
3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255
/**
 * 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.
 */
3256
int fastcall kmem_ptr_validate(struct kmem_cache *cachep, void *ptr)
L
Linus Torvalds 已提交
3257
{
P
Pekka Enberg 已提交
3258
	unsigned long addr = (unsigned long)ptr;
L
Linus Torvalds 已提交
3259
	unsigned long min_addr = PAGE_OFFSET;
P
Pekka Enberg 已提交
3260
	unsigned long align_mask = BYTES_PER_WORD - 1;
3261
	unsigned long size = cachep->buffer_size;
L
Linus Torvalds 已提交
3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276
	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;
3277
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
3278 3279
		goto out;
	return 1;
A
Andrew Morton 已提交
3280
out:
L
Linus Torvalds 已提交
3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293
	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.
3294 3295
 * 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.
L
Linus Torvalds 已提交
3296
 */
3297
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
3298
{
3299 3300
	unsigned long save_flags;
	void *ptr;
L
Linus Torvalds 已提交
3301

3302 3303
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
3304 3305

	if (nodeid == -1 || nodeid == numa_node_id() ||
A
Andrew Morton 已提交
3306
			!cachep->nodelists[nodeid])
3307 3308 3309
		ptr = ____cache_alloc(cachep, flags);
	else
		ptr = __cache_alloc_node(cachep, flags, nodeid);
3310
	local_irq_restore(save_flags);
3311 3312 3313

	ptr = cache_alloc_debugcheck_after(cachep, flags, ptr,
					   __builtin_return_address(0));
L
Linus Torvalds 已提交
3314

3315
	return ptr;
L
Linus Torvalds 已提交
3316 3317 3318
}
EXPORT_SYMBOL(kmem_cache_alloc_node);

A
Al Viro 已提交
3319
void *kmalloc_node(size_t size, gfp_t flags, int node)
3320
{
3321
	struct kmem_cache *cachep;
3322 3323 3324 3325 3326 3327 3328

	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);
L
Linus Torvalds 已提交
3329 3330 3331
#endif

/**
3332
 * __do_kmalloc - allocate memory
L
Linus Torvalds 已提交
3333
 * @size: how many bytes of memory are required.
3334
 * @flags: the type of memory to allocate (see kmalloc).
3335
 * @caller: function caller for debug tracking of the caller
L
Linus Torvalds 已提交
3336
 */
3337 3338
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
					  void *caller)
L
Linus Torvalds 已提交
3339
{
3340
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3341

3342 3343 3344 3345 3346 3347
	/* 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);
3348 3349
	if (unlikely(cachep == NULL))
		return NULL;
3350 3351 3352 3353 3354 3355
	return __cache_alloc(cachep, flags, caller);
}


void *__kmalloc(size_t size, gfp_t flags)
{
3356
#ifndef CONFIG_DEBUG_SLAB
3357
	return __do_kmalloc(size, flags, NULL);
3358 3359 3360
#else
	return __do_kmalloc(size, flags, __builtin_return_address(0));
#endif
L
Linus Torvalds 已提交
3361 3362 3363
}
EXPORT_SYMBOL(__kmalloc);

3364
#ifdef CONFIG_DEBUG_SLAB
3365 3366 3367 3368 3369 3370 3371
void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
{
	return __do_kmalloc(size, flags, caller);
}
EXPORT_SYMBOL(__kmalloc_track_caller);
#endif

L
Linus Torvalds 已提交
3372 3373
#ifdef CONFIG_SMP
/**
3374 3375 3376
 * percpu_depopulate - depopulate per-cpu data for given cpu
 * @__pdata: per-cpu data to depopulate
 * @cpu: depopulate per-cpu data for this cpu
L
Linus Torvalds 已提交
3377
 *
3378 3379
 * Depopulating per-cpu data for a cpu going offline would be a typical
 * use case. You need to register a cpu hotplug handler for that purpose.
L
Linus Torvalds 已提交
3380
 */
3381
void percpu_depopulate(void *__pdata, int cpu)
L
Linus Torvalds 已提交
3382
{
3383 3384 3385 3386 3387 3388 3389
	struct percpu_data *pdata = __percpu_disguise(__pdata);
	if (pdata->ptrs[cpu]) {
		kfree(pdata->ptrs[cpu]);
		pdata->ptrs[cpu] = NULL;
	}
}
EXPORT_SYMBOL_GPL(percpu_depopulate);
L
Linus Torvalds 已提交
3390

3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402
/**
 * percpu_depopulate_mask - depopulate per-cpu data for some cpu's
 * @__pdata: per-cpu data to depopulate
 * @mask: depopulate per-cpu data for cpu's selected through mask bits
 */
void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask)
{
	int cpu;
	for_each_cpu_mask(cpu, *mask)
		percpu_depopulate(__pdata, cpu);
}
EXPORT_SYMBOL_GPL(__percpu_depopulate_mask);
L
Linus Torvalds 已提交
3403

3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418
/**
 * percpu_populate - populate per-cpu data for given cpu
 * @__pdata: per-cpu data to populate further
 * @size: size of per-cpu object
 * @gfp: may sleep or not etc.
 * @cpu: populate per-data for this cpu
 *
 * Populating per-cpu data for a cpu coming online would be a typical
 * use case. You need to register a cpu hotplug handler for that purpose.
 * Per-cpu object is populated with zeroed buffer.
 */
void *percpu_populate(void *__pdata, size_t size, gfp_t gfp, int cpu)
{
	struct percpu_data *pdata = __percpu_disguise(__pdata);
	int node = cpu_to_node(cpu);
3419

3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430
	BUG_ON(pdata->ptrs[cpu]);
	if (node_online(node)) {
		/* FIXME: kzalloc_node(size, gfp, node) */
		pdata->ptrs[cpu] = kmalloc_node(size, gfp, node);
		if (pdata->ptrs[cpu])
			memset(pdata->ptrs[cpu], 0, size);
	} else
		pdata->ptrs[cpu] = kzalloc(size, gfp);
	return pdata->ptrs[cpu];
}
EXPORT_SYMBOL_GPL(percpu_populate);
L
Linus Torvalds 已提交
3431

3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445
/**
 * percpu_populate_mask - populate per-cpu data for more cpu's
 * @__pdata: per-cpu data to populate further
 * @size: size of per-cpu object
 * @gfp: may sleep or not etc.
 * @mask: populate per-cpu data for cpu's selected through mask bits
 *
 * Per-cpu objects are populated with zeroed buffers.
 */
int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
			   cpumask_t *mask)
{
	cpumask_t populated = CPU_MASK_NONE;
	int cpu;
L
Linus Torvalds 已提交
3446

3447 3448 3449 3450 3451 3452 3453 3454 3455
	for_each_cpu_mask(cpu, *mask)
		if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
			__percpu_depopulate_mask(__pdata, &populated);
			return -ENOMEM;
		} else
			cpu_set(cpu, populated);
	return 0;
}
EXPORT_SYMBOL_GPL(__percpu_populate_mask);
L
Linus Torvalds 已提交
3456

3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475
/**
 * percpu_alloc_mask - initial setup of per-cpu data
 * @size: size of per-cpu object
 * @gfp: may sleep or not etc.
 * @mask: populate per-data for cpu's selected through mask bits
 *
 * Populating per-cpu data for all online cpu's would be a typical use case,
 * which is simplified by the percpu_alloc() wrapper.
 * Per-cpu objects are populated with zeroed buffers.
 */
void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
{
	void *pdata = kzalloc(sizeof(struct percpu_data), gfp);
	void *__pdata = __percpu_disguise(pdata);

	if (unlikely(!pdata))
		return NULL;
	if (likely(!__percpu_populate_mask(__pdata, size, gfp, mask)))
		return __pdata;
L
Linus Torvalds 已提交
3476 3477 3478
	kfree(pdata);
	return NULL;
}
3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494
EXPORT_SYMBOL_GPL(__percpu_alloc_mask);

/**
 * percpu_free - final cleanup of per-cpu data
 * @__pdata: object to clean up
 *
 * We simply clean up any per-cpu object left. No need for the client to
 * track and specify through a bis mask which per-cpu objects are to free.
 */
void percpu_free(void *__pdata)
{
	__percpu_depopulate_mask(__pdata, &cpu_possible_map);
	kfree(__percpu_disguise(__pdata));
}
EXPORT_SYMBOL_GPL(percpu_free);
#endif	/* CONFIG_SMP */
L
Linus Torvalds 已提交
3495 3496 3497 3498 3499 3500 3501 3502 3503

/**
 * 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.
 */
3504
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3505 3506 3507
{
	unsigned long flags;

3508 3509
	BUG_ON(virt_to_cache(objp) != cachep);

L
Linus Torvalds 已提交
3510
	local_irq_save(flags);
3511
	__cache_free(cachep, objp);
L
Linus Torvalds 已提交
3512 3513 3514 3515 3516 3517 3518 3519
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kmem_cache_free);

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3520 3521
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3522 3523 3524 3525 3526
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
3527
	struct kmem_cache *c;
L
Linus Torvalds 已提交
3528 3529 3530 3531 3532 3533
	unsigned long flags;

	if (unlikely(!objp))
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3534
	c = virt_to_cache(objp);
3535
	debug_check_no_locks_freed(objp, obj_size(c));
3536
	__cache_free(c, (void *)objp);
L
Linus Torvalds 已提交
3537 3538 3539 3540
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

3541
unsigned int kmem_cache_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3542
{
3543
	return obj_size(cachep);
L
Linus Torvalds 已提交
3544 3545 3546
}
EXPORT_SYMBOL(kmem_cache_size);

3547
const char *kmem_cache_name(struct kmem_cache *cachep)
3548 3549 3550 3551 3552
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3553
/*
3554
 * This initializes kmem_list3 or resizes varioius caches for all nodes.
3555
 */
3556
static int alloc_kmemlist(struct kmem_cache *cachep)
3557 3558 3559
{
	int node;
	struct kmem_list3 *l3;
3560 3561
	struct array_cache *new_shared;
	struct array_cache **new_alien;
3562 3563

	for_each_online_node(node) {
3564

A
Andrew Morton 已提交
3565 3566
		new_alien = alloc_alien_cache(node, cachep->limit);
		if (!new_alien)
3567
			goto fail;
3568

3569 3570
		new_shared = alloc_arraycache(node,
				cachep->shared*cachep->batchcount,
A
Andrew Morton 已提交
3571
					0xbaadf00d);
3572 3573
		if (!new_shared) {
			free_alien_cache(new_alien);
3574
			goto fail;
3575
		}
3576

A
Andrew Morton 已提交
3577 3578
		l3 = cachep->nodelists[node];
		if (l3) {
3579 3580
			struct array_cache *shared = l3->shared;

3581 3582
			spin_lock_irq(&l3->list_lock);

3583
			if (shared)
3584 3585
				free_block(cachep, shared->entry,
						shared->avail, node);
3586

3587 3588
			l3->shared = new_shared;
			if (!l3->alien) {
3589 3590 3591
				l3->alien = new_alien;
				new_alien = NULL;
			}
P
Pekka Enberg 已提交
3592
			l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3593
					cachep->batchcount + cachep->num;
3594
			spin_unlock_irq(&l3->list_lock);
3595
			kfree(shared);
3596 3597 3598
			free_alien_cache(new_alien);
			continue;
		}
A
Andrew Morton 已提交
3599
		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
3600 3601 3602
		if (!l3) {
			free_alien_cache(new_alien);
			kfree(new_shared);
3603
			goto fail;
3604
		}
3605 3606 3607

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
A
Andrew Morton 已提交
3608
				((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3609
		l3->shared = new_shared;
3610
		l3->alien = new_alien;
P
Pekka Enberg 已提交
3611
		l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3612
					cachep->batchcount + cachep->num;
3613 3614
		cachep->nodelists[node] = l3;
	}
3615
	return 0;
3616

A
Andrew Morton 已提交
3617
fail:
3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632
	if (!cachep->next.next) {
		/* Cache is not active yet. Roll back what we did */
		node--;
		while (node >= 0) {
			if (cachep->nodelists[node]) {
				l3 = cachep->nodelists[node];

				kfree(l3->shared);
				free_alien_cache(l3->alien);
				kfree(l3);
				cachep->nodelists[node] = NULL;
			}
			node--;
		}
	}
3633
	return -ENOMEM;
3634 3635
}

L
Linus Torvalds 已提交
3636
struct ccupdate_struct {
3637
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3638 3639 3640 3641 3642
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
A
Andrew Morton 已提交
3643
	struct ccupdate_struct *new = info;
L
Linus Torvalds 已提交
3644 3645 3646
	struct array_cache *old;

	check_irq_off();
3647
	old = cpu_cache_get(new->cachep);
3648

L
Linus Torvalds 已提交
3649 3650 3651 3652
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}

3653
/* Always called with the cache_chain_mutex held */
A
Andrew Morton 已提交
3654 3655
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
				int batchcount, int shared)
L
Linus Torvalds 已提交
3656 3657
{
	struct ccupdate_struct new;
3658
	int i, err;
L
Linus Torvalds 已提交
3659

P
Pekka Enberg 已提交
3660
	memset(&new.new, 0, sizeof(new.new));
3661
	for_each_online_cpu(i) {
A
Andrew Morton 已提交
3662 3663
		new.new[i] = alloc_arraycache(cpu_to_node(i), limit,
						batchcount);
3664
		if (!new.new[i]) {
P
Pekka Enberg 已提交
3665 3666
			for (i--; i >= 0; i--)
				kfree(new.new[i]);
3667
			return -ENOMEM;
L
Linus Torvalds 已提交
3668 3669 3670 3671
		}
	}
	new.cachep = cachep;

A
Andrew Morton 已提交
3672
	on_each_cpu(do_ccupdate_local, (void *)&new, 1, 1);
3673

L
Linus Torvalds 已提交
3674 3675 3676
	check_irq_on();
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3677
	cachep->shared = shared;
L
Linus Torvalds 已提交
3678

3679
	for_each_online_cpu(i) {
L
Linus Torvalds 已提交
3680 3681 3682
		struct array_cache *ccold = new.new[i];
		if (!ccold)
			continue;
3683
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3684
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3685
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3686 3687 3688
		kfree(ccold);
	}

3689 3690 3691
	err = alloc_kmemlist(cachep);
	if (err) {
		printk(KERN_ERR "alloc_kmemlist failed for %s, error %d.\n",
P
Pekka Enberg 已提交
3692
		       cachep->name, -err);
3693
		BUG();
L
Linus Torvalds 已提交
3694 3695 3696 3697
	}
	return 0;
}

3698
/* Called with cache_chain_mutex held always */
3699
static void enable_cpucache(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3700 3701 3702 3703
{
	int err;
	int limit, shared;

A
Andrew Morton 已提交
3704 3705
	/*
	 * The head array serves three purposes:
L
Linus Torvalds 已提交
3706 3707
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
A
Andrew Morton 已提交
3708
	 * - reduce the number of linked list operations on the slab and
L
Linus Torvalds 已提交
3709 3710 3711 3712
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
3713
	if (cachep->buffer_size > 131072)
L
Linus Torvalds 已提交
3714
		limit = 1;
3715
	else if (cachep->buffer_size > PAGE_SIZE)
L
Linus Torvalds 已提交
3716
		limit = 8;
3717
	else if (cachep->buffer_size > 1024)
L
Linus Torvalds 已提交
3718
		limit = 24;
3719
	else if (cachep->buffer_size > 256)
L
Linus Torvalds 已提交
3720 3721 3722 3723
		limit = 54;
	else
		limit = 120;

A
Andrew Morton 已提交
3724 3725
	/*
	 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
L
Linus Torvalds 已提交
3726 3727 3728 3729 3730 3731 3732 3733 3734
	 * allocation behaviour: Most allocs on one cpu, most free operations
	 * on another cpu. For these cases, an efficient object passing between
	 * cpus is necessary. This is provided by a shared array. The array
	 * replaces Bonwick's magazine layer.
	 * On uniprocessor, it's functionally equivalent (but less efficient)
	 * to a larger limit. Thus disabled by default.
	 */
	shared = 0;
#ifdef CONFIG_SMP
3735
	if (cachep->buffer_size <= PAGE_SIZE)
L
Linus Torvalds 已提交
3736 3737 3738 3739
		shared = 8;
#endif

#if DEBUG
A
Andrew Morton 已提交
3740 3741 3742
	/*
	 * With debugging enabled, large batchcount lead to excessively long
	 * periods with disabled local interrupts. Limit the batchcount
L
Linus Torvalds 已提交
3743 3744 3745 3746
	 */
	if (limit > 32)
		limit = 32;
#endif
P
Pekka Enberg 已提交
3747
	err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
L
Linus Torvalds 已提交
3748 3749
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
P
Pekka Enberg 已提交
3750
		       cachep->name, -err);
L
Linus Torvalds 已提交
3751 3752
}

3753 3754
/*
 * Drain an array if it contains any elements taking the l3 lock only if
3755 3756
 * necessary. Note that the l3 listlock also protects the array_cache
 * if drain_array() is used on the shared array.
3757 3758 3759
 */
void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
			 struct array_cache *ac, int force, int node)
L
Linus Torvalds 已提交
3760 3761 3762
{
	int tofree;

3763 3764
	if (!ac || !ac->avail)
		return;
L
Linus Torvalds 已提交
3765 3766
	if (ac->touched && !force) {
		ac->touched = 0;
3767
	} else {
3768
		spin_lock_irq(&l3->list_lock);
3769 3770 3771 3772 3773 3774 3775 3776 3777
		if (ac->avail) {
			tofree = force ? ac->avail : (ac->limit + 4) / 5;
			if (tofree > ac->avail)
				tofree = (ac->avail + 1) / 2;
			free_block(cachep, ac->entry, tofree, node);
			ac->avail -= tofree;
			memmove(ac->entry, &(ac->entry[tofree]),
				sizeof(void *) * ac->avail);
		}
3778
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3779 3780 3781 3782 3783
	}
}

/**
 * cache_reap - Reclaim memory from caches.
3784
 * @unused: unused parameter
L
Linus Torvalds 已提交
3785 3786 3787 3788 3789 3790
 *
 * Called from workqueue/eventd every few seconds.
 * Purpose:
 * - clear the per-cpu caches for this CPU.
 * - return freeable pages to the main free memory pool.
 *
A
Andrew Morton 已提交
3791 3792
 * If we cannot acquire the cache chain mutex then just give up - we'll try
 * again on the next iteration.
L
Linus Torvalds 已提交
3793 3794 3795
 */
static void cache_reap(void *unused)
{
3796
	struct kmem_cache *searchp;
3797
	struct kmem_list3 *l3;
3798
	int node = numa_node_id();
L
Linus Torvalds 已提交
3799

I
Ingo Molnar 已提交
3800
	if (!mutex_trylock(&cache_chain_mutex)) {
L
Linus Torvalds 已提交
3801
		/* Give up. Setup the next iteration. */
P
Pekka Enberg 已提交
3802 3803
		schedule_delayed_work(&__get_cpu_var(reap_work),
				      REAPTIMEOUT_CPUC);
L
Linus Torvalds 已提交
3804 3805 3806
		return;
	}

3807
	list_for_each_entry(searchp, &cache_chain, next) {
L
Linus Torvalds 已提交
3808 3809
		check_irq_on();

3810 3811 3812 3813 3814
		/*
		 * We only take the l3 lock if absolutely necessary and we
		 * have established with reasonable certainty that
		 * we can do some work if the lock was obtained.
		 */
3815
		l3 = searchp->nodelists[node];
3816

3817
		reap_alien(searchp, l3);
L
Linus Torvalds 已提交
3818

3819
		drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
L
Linus Torvalds 已提交
3820

3821 3822 3823 3824
		/*
		 * These are racy checks but it does not matter
		 * if we skip one check or scan twice.
		 */
3825
		if (time_after(l3->next_reap, jiffies))
3826
			goto next;
L
Linus Torvalds 已提交
3827

3828
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
3829

3830
		drain_array(searchp, l3, l3->shared, 0, node);
L
Linus Torvalds 已提交
3831

3832
		if (l3->free_touched)
3833
			l3->free_touched = 0;
3834 3835
		else {
			int freed;
L
Linus Torvalds 已提交
3836

3837 3838 3839 3840
			freed = drain_freelist(searchp, l3, (l3->free_limit +
				5 * searchp->num - 1) / (5 * searchp->num));
			STATS_ADD_REAPED(searchp, freed);
		}
3841
next:
L
Linus Torvalds 已提交
3842 3843 3844
		cond_resched();
	}
	check_irq_on();
I
Ingo Molnar 已提交
3845
	mutex_unlock(&cache_chain_mutex);
3846
	next_reap_node();
3847
	refresh_cpu_vm_stats(smp_processor_id());
A
Andrew Morton 已提交
3848
	/* Set up the next iteration */
3849
	schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
L
Linus Torvalds 已提交
3850 3851 3852 3853
}

#ifdef CONFIG_PROC_FS

3854
static void print_slabinfo_header(struct seq_file *m)
L
Linus Torvalds 已提交
3855
{
3856 3857 3858 3859
	/*
	 * Output format version, so at least we can change it
	 * without _too_ many complaints.
	 */
L
Linus Torvalds 已提交
3860
#if STATS
3861
	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
L
Linus Torvalds 已提交
3862
#else
3863
	seq_puts(m, "slabinfo - version: 2.1\n");
L
Linus Torvalds 已提交
3864
#endif
3865 3866 3867 3868
	seq_puts(m, "# name            <active_objs> <num_objs> <objsize> "
		 "<objperslab> <pagesperslab>");
	seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
	seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
L
Linus Torvalds 已提交
3869
#if STATS
3870
	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
3871
		 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
3872
	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
L
Linus Torvalds 已提交
3873
#endif
3874 3875 3876 3877 3878 3879 3880 3881
	seq_putc(m, '\n');
}

static void *s_start(struct seq_file *m, loff_t *pos)
{
	loff_t n = *pos;
	struct list_head *p;

I
Ingo Molnar 已提交
3882
	mutex_lock(&cache_chain_mutex);
3883 3884
	if (!n)
		print_slabinfo_header(m);
L
Linus Torvalds 已提交
3885 3886 3887 3888 3889 3890
	p = cache_chain.next;
	while (n--) {
		p = p->next;
		if (p == &cache_chain)
			return NULL;
	}
3891
	return list_entry(p, struct kmem_cache, next);
L
Linus Torvalds 已提交
3892 3893 3894 3895
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
3896
	struct kmem_cache *cachep = p;
L
Linus Torvalds 已提交
3897
	++*pos;
A
Andrew Morton 已提交
3898 3899
	return cachep->next.next == &cache_chain ?
		NULL : list_entry(cachep->next.next, struct kmem_cache, next);
L
Linus Torvalds 已提交
3900 3901 3902 3903
}

static void s_stop(struct seq_file *m, void *p)
{
I
Ingo Molnar 已提交
3904
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
3905 3906 3907 3908
}

static int s_show(struct seq_file *m, void *p)
{
3909
	struct kmem_cache *cachep = p;
P
Pekka Enberg 已提交
3910 3911 3912 3913 3914
	struct slab *slabp;
	unsigned long active_objs;
	unsigned long num_objs;
	unsigned long active_slabs = 0;
	unsigned long num_slabs, free_objects = 0, shared_avail = 0;
3915
	const char *name;
L
Linus Torvalds 已提交
3916
	char *error = NULL;
3917 3918
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3919 3920 3921

	active_objs = 0;
	num_slabs = 0;
3922 3923 3924 3925 3926
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

3927 3928
		check_irq_on();
		spin_lock_irq(&l3->list_lock);
3929

3930
		list_for_each_entry(slabp, &l3->slabs_full, list) {
3931 3932 3933 3934 3935
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
3936
		list_for_each_entry(slabp, &l3->slabs_partial, list) {
3937 3938 3939 3940 3941 3942 3943
			if (slabp->inuse == cachep->num && !error)
				error = "slabs_partial inuse accounting error";
			if (!slabp->inuse && !error)
				error = "slabs_partial/inuse accounting error";
			active_objs += slabp->inuse;
			active_slabs++;
		}
3944
		list_for_each_entry(slabp, &l3->slabs_free, list) {
3945 3946 3947 3948 3949
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
3950 3951
		if (l3->shared)
			shared_avail += l3->shared->avail;
3952

3953
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3954
	}
P
Pekka Enberg 已提交
3955 3956
	num_slabs += active_slabs;
	num_objs = num_slabs * cachep->num;
3957
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
3958 3959
		error = "free_objects accounting error";

P
Pekka Enberg 已提交
3960
	name = cachep->name;
L
Linus Torvalds 已提交
3961 3962 3963 3964
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
3965
		   name, active_objs, num_objs, cachep->buffer_size,
P
Pekka Enberg 已提交
3966
		   cachep->num, (1 << cachep->gfporder));
L
Linus Torvalds 已提交
3967
	seq_printf(m, " : tunables %4u %4u %4u",
P
Pekka Enberg 已提交
3968
		   cachep->limit, cachep->batchcount, cachep->shared);
3969
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
P
Pekka Enberg 已提交
3970
		   active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
3971
#if STATS
P
Pekka Enberg 已提交
3972
	{			/* list3 stats */
L
Linus Torvalds 已提交
3973 3974 3975 3976 3977 3978 3979
		unsigned long high = cachep->high_mark;
		unsigned long allocs = cachep->num_allocations;
		unsigned long grown = cachep->grown;
		unsigned long reaped = cachep->reaped;
		unsigned long errors = cachep->errors;
		unsigned long max_freeable = cachep->max_freeable;
		unsigned long node_allocs = cachep->node_allocs;
3980
		unsigned long node_frees = cachep->node_frees;
3981
		unsigned long overflows = cachep->node_overflow;
L
Linus Torvalds 已提交
3982

3983
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
3984
				%4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
A
Andrew Morton 已提交
3985
				reaped, errors, max_freeable, node_allocs,
3986
				node_frees, overflows);
L
Linus Torvalds 已提交
3987 3988 3989 3990 3991 3992 3993 3994 3995
	}
	/* cpu stats */
	{
		unsigned long allochit = atomic_read(&cachep->allochit);
		unsigned long allocmiss = atomic_read(&cachep->allocmiss);
		unsigned long freehit = atomic_read(&cachep->freehit);
		unsigned long freemiss = atomic_read(&cachep->freemiss);

		seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
P
Pekka Enberg 已提交
3996
			   allochit, allocmiss, freehit, freemiss);
L
Linus Torvalds 已提交
3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017
	}
#endif
	seq_putc(m, '\n');
	return 0;
}

/*
 * slabinfo_op - iterator that generates /proc/slabinfo
 *
 * Output layout:
 * cache-name
 * num-active-objs
 * total-objs
 * object size
 * num-active-slabs
 * total-slabs
 * num-pages-per-slab
 * + further values on SMP and with statistics enabled
 */

struct seq_operations slabinfo_op = {
P
Pekka Enberg 已提交
4018 4019 4020 4021
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
L
Linus Torvalds 已提交
4022 4023 4024 4025 4026 4027 4028 4029 4030 4031
};

#define MAX_SLABINFO_WRITE 128
/**
 * slabinfo_write - Tuning for the slab allocator
 * @file: unused
 * @buffer: user buffer
 * @count: data length
 * @ppos: unused
 */
P
Pekka Enberg 已提交
4032 4033
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
		       size_t count, loff_t *ppos)
L
Linus Torvalds 已提交
4034
{
P
Pekka Enberg 已提交
4035
	char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
L
Linus Torvalds 已提交
4036
	int limit, batchcount, shared, res;
4037
	struct kmem_cache *cachep;
P
Pekka Enberg 已提交
4038

L
Linus Torvalds 已提交
4039 4040 4041 4042
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
P
Pekka Enberg 已提交
4043
	kbuf[MAX_SLABINFO_WRITE] = '\0';
L
Linus Torvalds 已提交
4044 4045 4046 4047 4048 4049 4050 4051 4052 4053

	tmp = strchr(kbuf, ' ');
	if (!tmp)
		return -EINVAL;
	*tmp = '\0';
	tmp++;
	if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
		return -EINVAL;

	/* Find the cache in the chain of caches. */
I
Ingo Molnar 已提交
4054
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4055
	res = -EINVAL;
4056
	list_for_each_entry(cachep, &cache_chain, next) {
L
Linus Torvalds 已提交
4057
		if (!strcmp(cachep->name, kbuf)) {
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			if (limit < 1 || batchcount < 1 ||
					batchcount > limit || shared < 0) {
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				res = 0;
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			} else {
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				res = do_tune_cpucache(cachep, limit,
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						       batchcount, shared);
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			}
			break;
		}
	}
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	mutex_unlock(&cache_chain_mutex);
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	if (res >= 0)
		res = count;
	return res;
}
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#ifdef CONFIG_DEBUG_SLAB_LEAK

static void *leaks_start(struct seq_file *m, loff_t *pos)
{
	loff_t n = *pos;
	struct list_head *p;

	mutex_lock(&cache_chain_mutex);
	p = cache_chain.next;
	while (n--) {
		p = p->next;
		if (p == &cache_chain)
			return NULL;
	}
	return list_entry(p, struct kmem_cache, next);
}

static inline int add_caller(unsigned long *n, unsigned long v)
{
	unsigned long *p;
	int l;
	if (!v)
		return 1;
	l = n[1];
	p = n + 2;
	while (l) {
		int i = l/2;
		unsigned long *q = p + 2 * i;
		if (*q == v) {
			q[1]++;
			return 1;
		}
		if (*q > v) {
			l = i;
		} else {
			p = q + 2;
			l -= i + 1;
		}
	}
	if (++n[1] == n[0])
		return 0;
	memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n));
	p[0] = v;
	p[1] = 1;
	return 1;
}

static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
{
	void *p;
	int i;
	if (n[0] == n[1])
		return;
	for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) {
		if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
			continue;
		if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
			return;
	}
}

static void show_symbol(struct seq_file *m, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
	char *modname;
	const char *name;
	unsigned long offset, size;
	char namebuf[KSYM_NAME_LEN+1];

	name = kallsyms_lookup(address, &size, &offset, &modname, namebuf);

	if (name) {
		seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
		if (modname)
			seq_printf(m, " [%s]", modname);
		return;
	}
#endif
	seq_printf(m, "%p", (void *)address);
}

static int leaks_show(struct seq_file *m, void *p)
{
	struct kmem_cache *cachep = p;
	struct slab *slabp;
	struct kmem_list3 *l3;
	const char *name;
	unsigned long *n = m->private;
	int node;
	int i;

	if (!(cachep->flags & SLAB_STORE_USER))
		return 0;
	if (!(cachep->flags & SLAB_RED_ZONE))
		return 0;

	/* OK, we can do it */

	n[1] = 0;

	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

		check_irq_on();
		spin_lock_irq(&l3->list_lock);

4182
		list_for_each_entry(slabp, &l3->slabs_full, list)
4183
			handle_slab(n, cachep, slabp);
4184
		list_for_each_entry(slabp, &l3->slabs_partial, list)
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			handle_slab(n, cachep, slabp);
		spin_unlock_irq(&l3->list_lock);
	}
	name = cachep->name;
	if (n[0] == n[1]) {
		/* Increase the buffer size */
		mutex_unlock(&cache_chain_mutex);
		m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
		if (!m->private) {
			/* Too bad, we are really out */
			m->private = n;
			mutex_lock(&cache_chain_mutex);
			return -ENOMEM;
		}
		*(unsigned long *)m->private = n[0] * 2;
		kfree(n);
		mutex_lock(&cache_chain_mutex);
		/* Now make sure this entry will be retried */
		m->count = m->size;
		return 0;
	}
	for (i = 0; i < n[1]; i++) {
		seq_printf(m, "%s: %lu ", name, n[2*i+3]);
		show_symbol(m, n[2*i+2]);
		seq_putc(m, '\n');
	}
	return 0;
}

struct seq_operations slabstats_op = {
	.start = leaks_start,
	.next = s_next,
	.stop = s_stop,
	.show = leaks_show,
};
#endif
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#endif

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/**
 * ksize - get the actual amount of memory allocated for a given object
 * @objp: Pointer to the object
 *
 * kmalloc may internally round up allocations and return more memory
 * than requested. ksize() can be used to determine the actual amount of
 * memory allocated. The caller may use this additional memory, even though
 * a smaller amount of memory was initially specified with the kmalloc call.
 * The caller must guarantee that objp points to a valid object previously
 * allocated with either kmalloc() or kmem_cache_alloc(). The object
 * must not be freed during the duration of the call.
 */
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unsigned int ksize(const void *objp)
{
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	if (unlikely(objp == NULL))
		return 0;
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4240
	return obj_size(virt_to_cache(objp));
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}