slab.c 116.6 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/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/uaccess.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/fault-inject.h>
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#include	<linux/rtmutex.h>
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#include	<linux/reciprocal_div.h>
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#include	<asm/cacheflush.h>
#include	<asm/tlbflush.h>
#include	<asm/page.h>

/*
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 * DEBUG	- 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
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 *		  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
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# define CREATE_MASK	(SLAB_RED_ZONE | \
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			 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
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			 SLAB_CACHE_DMA | \
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			 SLAB_STORE_USER | \
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			 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 | \
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			 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);
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static int enable_cpucache(struct kmem_cache *cachep);
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static void cache_reap(struct work_struct *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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	u32 reciprocal_buffer_size;
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/* 3) touched by every alloc & free from the backend */

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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
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	/*
	 * We put nodelists[] at the end of kmem_cache, because we want to size
	 * this array to nr_node_ids slots instead of MAX_NUMNODES
	 * (see kmem_cache_init())
	 * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache
	 * is statically defined, so we reserve the max number of nodes.
	 */
	struct kmem_list3 *nodelists[MAX_NUMNODES];
	/*
	 * Do not add fields after nodelists[]
	 */
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};

#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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 */
529
static int obj_offset(struct kmem_cache *cachep)
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{
531
	return cachep->obj_offset;
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}

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static int obj_size(struct kmem_cache *cachep)
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{
536
	return cachep->obj_size;
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}

539
static unsigned long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
542
	return (unsigned long*) (objp+obj_offset(cachep)-BYTES_PER_WORD);
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}

545
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)
549
		return (unsigned long *)(objp + cachep->buffer_size -
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					 2 * BYTES_PER_WORD);
551
	return (unsigned long *)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

554
static void **dbg_userword(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
557
	return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

#else

562 563
#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)
{
604
	page = compound_head(page);
605
	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)
{
616
	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)
{
622
	struct page *page = virt_to_head_page(obj);
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	return page_get_cache(page);
}

static inline struct slab *virt_to_slab(const void *obj)
{
628
	struct page *page = virt_to_head_page(obj);
629 630 631
	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;
}

638 639 640 641 642 643 644 645
/*
 * We want to avoid an expensive divide : (offset / cache->buffer_size)
 *   Using the fact that buffer_size is a constant for a particular cache,
 *   we can replace (offset / cache->buffer_size) by
 *   reciprocal_divide(offset, cache->reciprocal_buffer_size)
 */
static inline unsigned int obj_to_index(const struct kmem_cache *cache,
					const struct slab *slab, void *obj)
646
{
647 648
	u32 offset = (obj - slab->s_mem);
	return reciprocal_divide(offset, cache->reciprocal_buffer_size);
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}

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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 */
681
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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};

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#define BAD_ALIEN_MAGIC 0x01020304ul

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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.
699 700 701 702
 *
 * We set lock class for alien array caches which are up during init.
 * The lock annotation will be lost if all cpus of a node goes down and
 * then comes back up during hotplug
703
 */
704 705 706 707
static struct lock_class_key on_slab_l3_key;
static struct lock_class_key on_slab_alc_key;

static inline void init_lock_keys(void)
708 709 710

{
	int q;
711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737
	struct cache_sizes *s = malloc_sizes;

	while (s->cs_size != ULONG_MAX) {
		for_each_node(q) {
			struct array_cache **alc;
			int r;
			struct kmem_list3 *l3 = s->cs_cachep->nodelists[q];
			if (!l3 || OFF_SLAB(s->cs_cachep))
				continue;
			lockdep_set_class(&l3->list_lock, &on_slab_l3_key);
			alc = l3->alien;
			/*
			 * FIXME: This check for BAD_ALIEN_MAGIC
			 * should go away when common slab code is taught to
			 * work even without alien caches.
			 * Currently, non NUMA code returns BAD_ALIEN_MAGIC
			 * for alloc_alien_cache,
			 */
			if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC)
				continue;
			for_each_node(r) {
				if (alc[r])
					lockdep_set_class(&alc[r]->lock,
					     &on_slab_alc_key);
			}
		}
		s++;
738 739 740
	}
}
#else
741
static inline void init_lock_keys(void)
742 743 744 745
{
}
#endif

746 747 748 749
/*
 * 1. Guard access to the cache-chain.
 * 2. Protect sanity of cpu_online_map against cpu hotplug events
 */
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static DEFINE_MUTEX(cache_chain_mutex);
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static struct list_head cache_chain;

/*
 * chicken and egg problem: delay the per-cpu array allocation
 * until the general caches are up.
 */
static enum {
	NONE,
759 760
	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 delayed_work, reap_work);
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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.
	 */
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	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
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#endif
	while (size > csizep->cs_size)
		csizep++;

	/*
795
	 * 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.
	 */
799
#ifdef CONFIG_ZONE_DMA
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	if (unlikely(gfpflags & GFP_DMA))
		return csizep->cs_dmacachep;
802
#endif
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	return csizep->cs_cachep;
}

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

811
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
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{
813 814
	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.
 */
819 820 821 822 823 824 825
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();
}

887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902
/*
 * By default on NUMA we use alien caches to stage the freeing of
 * objects allocated from other nodes. This causes massive memory
 * inefficiencies when using fake NUMA setup to split memory into a
 * large number of small nodes, so it can be disabled on the command
 * line
  */

static int use_alien_caches __read_mostly = 1;
static int __init noaliencache_setup(char *s)
{
	use_alien_caches = 0;
	return 1;
}
__setup("noaliencache", noaliencache_setup);

903 904 905 906 907 908 909 910 911 912 913 914 915 916 917
#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)
918
		node = first_node(node_online_map);
919

920
	per_cpu(reap_node, cpu) = node;
921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943
}

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)
{
953
	struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
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	/*
	 * When this gets called from do_initcalls via cpucache_init(),
	 * init_workqueues() has already run, so keventd will be setup
	 * at that time.
	 */
960
	if (keventd_up() && reap_work->work.func == NULL) {
961
		init_reap_node(cpu);
962
		INIT_DELAYED_WORK(reap_work, cache_reap);
963 964
		schedule_delayed_work_on(cpu, reap_work,
					__round_jiffies_relative(HZ, cpu));
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	}
}

968
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;

974
	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;
980
		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;
}

1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
#ifndef CONFIG_NUMA

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

static inline struct array_cache **alloc_alien_cache(int node, int limit)
{
	return (struct array_cache **)BAD_ALIEN_MAGIC;
}

static inline void free_alien_cache(struct array_cache **ac_ptr)
{
}

static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
{
	return 0;
}

static inline void *alternate_node_alloc(struct kmem_cache *cachep,
		gfp_t flags)
{
	return NULL;
}

1034
static inline void *____cache_alloc_node(struct kmem_cache *cachep,
1035 1036 1037 1038 1039 1040 1041
		 gfp_t flags, int nodeid)
{
	return NULL;
}

#else	/* CONFIG_NUMA */

1042
static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
1043
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
1044

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static struct array_cache **alloc_alien_cache(int node, int limit)
1046 1047
{
	struct array_cache **ac_ptr;
1048
	int memsize = sizeof(void *) * nr_node_ids;
1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061
	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--)
1063 1064 1065 1066 1067 1068 1069 1070 1071
					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)
1073 1074 1075 1076 1077 1078
{
	int i;

	if (!ac_ptr)
		return;
	for_each_node(i)
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	    kfree(ac_ptr[i]);
1080 1081 1082
	kfree(ac_ptr);
}

1083
static void __drain_alien_cache(struct kmem_cache *cachep,
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				struct array_cache *ac, int node)
1085 1086 1087 1088 1089
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
1090 1091 1092 1093 1094
		/*
		 * 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.
		 */
1095 1096
		if (rl3->shared)
			transfer_objects(rl3->shared, ac, ac->limit);
1097

1098
		free_block(cachep, ac->entry, ac->avail, node);
1099 1100 1101 1102 1103
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

1104 1105 1106 1107 1108 1109 1110 1111 1112
/*
 * 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];
1113 1114

		if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
1115 1116 1117 1118 1119 1120
			__drain_alien_cache(cachep, ac, node);
			spin_unlock_irq(&ac->lock);
		}
	}
}

A
Andrew Morton 已提交
1121 1122
static void drain_alien_cache(struct kmem_cache *cachep,
				struct array_cache **alien)
1123
{
P
Pekka Enberg 已提交
1124
	int i = 0;
1125 1126 1127 1128
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
1129
		ac = alien[i];
1130 1131 1132 1133 1134 1135 1136
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
1137

1138
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1139 1140 1141 1142 1143
{
	struct slab *slabp = virt_to_slab(objp);
	int nodeid = slabp->nodeid;
	struct kmem_list3 *l3;
	struct array_cache *alien = NULL;
P
Pekka Enberg 已提交
1144 1145 1146
	int node;

	node = numa_node_id();
1147 1148 1149 1150 1151

	/*
	 * Make sure we are not freeing a object from another node to the array
	 * cache on this cpu.
	 */
1152
	if (likely(slabp->nodeid == node))
1153 1154
		return 0;

P
Pekka Enberg 已提交
1155
	l3 = cachep->nodelists[node];
1156 1157 1158
	STATS_INC_NODEFREES(cachep);
	if (l3->alien && l3->alien[nodeid]) {
		alien = l3->alien[nodeid];
1159
		spin_lock(&alien->lock);
1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172
		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;
}
1173 1174
#endif

1175
static int __cpuinit cpuup_callback(struct notifier_block *nfb,
P
Pekka Enberg 已提交
1176
				    unsigned long action, void *hcpu)
L
Linus Torvalds 已提交
1177 1178
{
	long cpu = (long)hcpu;
1179
	struct kmem_cache *cachep;
1180 1181 1182
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
	int memsize = sizeof(struct kmem_list3);
L
Linus Torvalds 已提交
1183 1184 1185

	switch (action) {
	case CPU_UP_PREPARE:
I
Ingo Molnar 已提交
1186
		mutex_lock(&cache_chain_mutex);
A
Andrew Morton 已提交
1187 1188
		/*
		 * We need to do this right in the beginning since
1189 1190 1191 1192 1193
		 * 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
1194
		list_for_each_entry(cachep, &cache_chain, next) {
A
Andrew Morton 已提交
1195 1196
			/*
			 * Set up the size64 kmemlist for cpu before we can
1197 1198 1199 1200
			 * 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
1201 1202
				l3 = kmalloc_node(memsize, GFP_KERNEL, node);
				if (!l3)
1203 1204 1205
					goto bad;
				kmem_list3_init(l3);
				l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
P
Pekka Enberg 已提交
1206
				    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1207

1208 1209 1210 1211 1212
				/*
				 * The l3s don't come and go as CPUs come and
				 * go.  cache_chain_mutex is sufficient
				 * protection here.
				 */
1213 1214
				cachep->nodelists[node] = l3;
			}
L
Linus Torvalds 已提交
1215

1216 1217
			spin_lock_irq(&cachep->nodelists[node]->list_lock);
			cachep->nodelists[node]->free_limit =
A
Andrew Morton 已提交
1218 1219
				(1 + nr_cpus_node(node)) *
				cachep->batchcount + cachep->num;
1220 1221 1222
			spin_unlock_irq(&cachep->nodelists[node]->list_lock);
		}

A
Andrew Morton 已提交
1223 1224 1225 1226
		/*
		 * Now we can go ahead with allocating the shared arrays and
		 * array caches
		 */
1227
		list_for_each_entry(cachep, &cache_chain, next) {
1228
			struct array_cache *nc;
1229
			struct array_cache *shared = NULL;
1230
			struct array_cache **alien = NULL;
1231

1232
			nc = alloc_arraycache(node, cachep->limit,
1233
						cachep->batchcount);
L
Linus Torvalds 已提交
1234 1235
			if (!nc)
				goto bad;
1236 1237
			if (cachep->shared) {
				shared = alloc_arraycache(node,
1238 1239
					cachep->shared * cachep->batchcount,
					0xbaadf00d);
1240 1241 1242
				if (!shared)
					goto bad;
			}
1243 1244 1245 1246 1247
			if (use_alien_caches) {
                                alien = alloc_alien_cache(node, cachep->limit);
                                if (!alien)
                                        goto bad;
                        }
L
Linus Torvalds 已提交
1248
			cachep->array[cpu] = nc;
1249 1250 1251
			l3 = cachep->nodelists[node];
			BUG_ON(!l3);

1252 1253 1254 1255 1256 1257 1258 1259
			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;
1260
			}
1261 1262 1263 1264 1265 1266 1267 1268 1269
#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
1270 1271 1272
		}
		break;
	case CPU_ONLINE:
1273
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1274 1275 1276
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
1277 1278 1279 1280 1281 1282
	case CPU_DOWN_PREPARE:
		mutex_lock(&cache_chain_mutex);
		break;
	case CPU_DOWN_FAILED:
		mutex_unlock(&cache_chain_mutex);
		break;
L
Linus Torvalds 已提交
1283
	case CPU_DEAD:
1284 1285 1286 1287 1288 1289 1290 1291
		/*
		 * 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
1292
		/* fall thru */
1293
#endif
L
Linus Torvalds 已提交
1294 1295 1296
	case CPU_UP_CANCELED:
		list_for_each_entry(cachep, &cache_chain, next) {
			struct array_cache *nc;
1297 1298
			struct array_cache *shared;
			struct array_cache **alien;
1299
			cpumask_t mask;
L
Linus Torvalds 已提交
1300

1301
			mask = node_to_cpumask(node);
L
Linus Torvalds 已提交
1302 1303 1304
			/* cpu is dead; no one can alloc from it. */
			nc = cachep->array[cpu];
			cachep->array[cpu] = NULL;
1305 1306 1307
			l3 = cachep->nodelists[node];

			if (!l3)
1308
				goto free_array_cache;
1309

1310
			spin_lock_irq(&l3->list_lock);
1311 1312 1313 1314

			/* Free limit for this kmem_list3 */
			l3->free_limit -= cachep->batchcount;
			if (nc)
1315
				free_block(cachep, nc->entry, nc->avail, node);
1316 1317

			if (!cpus_empty(mask)) {
1318
				spin_unlock_irq(&l3->list_lock);
1319
				goto free_array_cache;
P
Pekka Enberg 已提交
1320
			}
1321

1322 1323
			shared = l3->shared;
			if (shared) {
1324 1325
				free_block(cachep, shared->entry,
					   shared->avail, node);
1326 1327 1328
				l3->shared = NULL;
			}

1329 1330 1331 1332 1333 1334 1335 1336 1337
			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);
1338
			}
1339
free_array_cache:
L
Linus Torvalds 已提交
1340 1341
			kfree(nc);
		}
1342 1343 1344 1345 1346 1347 1348 1349 1350
		/*
		 * 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;
1351
			drain_freelist(cachep, l3, l3->free_objects);
1352
		}
I
Ingo Molnar 已提交
1353
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1354 1355 1356
		break;
	}
	return NOTIFY_OK;
A
Andrew Morton 已提交
1357
bad:
L
Linus Torvalds 已提交
1358 1359 1360
	return NOTIFY_BAD;
}

1361 1362 1363
static struct notifier_block __cpuinitdata cpucache_notifier = {
	&cpuup_callback, NULL, 0
};
L
Linus Torvalds 已提交
1364

1365 1366 1367
/*
 * swap the static kmem_list3 with kmalloced memory
 */
A
Andrew Morton 已提交
1368 1369
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
			int nodeid)
1370 1371 1372 1373 1374 1375 1376 1377
{
	struct kmem_list3 *ptr;

	ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid);
	BUG_ON(!ptr);

	local_irq_disable();
	memcpy(ptr, list, sizeof(struct kmem_list3));
1378 1379 1380 1381 1382
	/*
	 * Do not assume that spinlocks can be initialized via memcpy:
	 */
	spin_lock_init(&ptr->list_lock);

1383 1384 1385 1386 1387
	MAKE_ALL_LISTS(cachep, ptr, nodeid);
	cachep->nodelists[nodeid] = ptr;
	local_irq_enable();
}

A
Andrew Morton 已提交
1388 1389 1390
/*
 * Initialisation.  Called after the page allocator have been initialised and
 * before smp_init().
L
Linus Torvalds 已提交
1391 1392 1393 1394 1395 1396
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1397
	int i;
1398
	int order;
P
Pekka Enberg 已提交
1399
	int node;
1400

1401 1402 1403
	if (num_possible_nodes() == 1)
		use_alien_caches = 0;

1404 1405 1406 1407 1408
	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
1409 1410 1411 1412 1413 1414 1415 1416 1417 1418

	/*
	 * 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
1419 1420 1421
	 * 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.
1422 1423 1424
	 *    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
1425
	 * 2) Create the first kmalloc cache.
1426
	 *    The struct kmem_cache for the new cache is allocated normally.
1427 1428 1429
	 *    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
1430 1431
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1432 1433 1434
	 * 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
1435 1436
	 */

P
Pekka Enberg 已提交
1437 1438
	node = numa_node_id();

L
Linus Torvalds 已提交
1439 1440 1441 1442 1443
	/* 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;
P
Pekka Enberg 已提交
1444
	cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
L
Linus Torvalds 已提交
1445

E
Eric Dumazet 已提交
1446 1447 1448 1449 1450 1451 1452 1453 1454
	/*
	 * struct kmem_cache size depends on nr_node_ids, which
	 * can be less than MAX_NUMNODES.
	 */
	cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) +
				 nr_node_ids * sizeof(struct kmem_list3 *);
#if DEBUG
	cache_cache.obj_size = cache_cache.buffer_size;
#endif
A
Andrew Morton 已提交
1455 1456
	cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
					cache_line_size());
1457 1458
	cache_cache.reciprocal_buffer_size =
		reciprocal_value(cache_cache.buffer_size);
L
Linus Torvalds 已提交
1459

1460 1461 1462 1463 1464 1465
	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;
	}
1466
	BUG_ON(!cache_cache.num);
1467
	cache_cache.gfporder = order;
P
Pekka Enberg 已提交
1468 1469 1470
	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
Linus Torvalds 已提交
1471 1472 1473 1474 1475

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

A
Andrew Morton 已提交
1476 1477 1478 1479
	/*
	 * Initialize the caches that provide memory for the array cache and the
	 * kmem_list3 structures first.  Without this, further allocations will
	 * bug.
1480 1481 1482
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
A
Andrew Morton 已提交
1483 1484 1485 1486
					sizes[INDEX_AC].cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
1487

A
Andrew Morton 已提交
1488
	if (INDEX_AC != INDEX_L3) {
1489
		sizes[INDEX_L3].cs_cachep =
A
Andrew Morton 已提交
1490 1491 1492 1493 1494 1495
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size,
				ARCH_KMALLOC_MINALIGN,
				ARCH_KMALLOC_FLAGS|SLAB_PANIC,
				NULL, NULL);
	}
1496

1497 1498
	slab_early_init = 0;

L
Linus Torvalds 已提交
1499
	while (sizes->cs_size != ULONG_MAX) {
1500 1501
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1502 1503 1504
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1505 1506
		 * allow tighter packing of the smaller caches.
		 */
A
Andrew Morton 已提交
1507
		if (!sizes->cs_cachep) {
1508
			sizes->cs_cachep = kmem_cache_create(names->name,
A
Andrew Morton 已提交
1509 1510 1511 1512 1513
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
		}
1514 1515 1516
#ifdef CONFIG_ZONE_DMA
		sizes->cs_dmacachep = kmem_cache_create(
					names->name_dma,
A
Andrew Morton 已提交
1517 1518 1519 1520 1521
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
						SLAB_PANIC,
					NULL, NULL);
1522
#endif
L
Linus Torvalds 已提交
1523 1524 1525 1526 1527
		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
1528
		struct array_cache *ptr;
1529

L
Linus Torvalds 已提交
1530
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1531

L
Linus Torvalds 已提交
1532
		local_irq_disable();
1533 1534
		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
		memcpy(ptr, cpu_cache_get(&cache_cache),
P
Pekka Enberg 已提交
1535
		       sizeof(struct arraycache_init));
1536 1537 1538 1539 1540
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

L
Linus Torvalds 已提交
1541 1542
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1543

L
Linus Torvalds 已提交
1544
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1545

L
Linus Torvalds 已提交
1546
		local_irq_disable();
1547
		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
P
Pekka Enberg 已提交
1548
		       != &initarray_generic.cache);
1549
		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
P
Pekka Enberg 已提交
1550
		       sizeof(struct arraycache_init));
1551 1552 1553 1554 1555
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

1556
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
P
Pekka Enberg 已提交
1557
		    ptr;
L
Linus Torvalds 已提交
1558 1559
		local_irq_enable();
	}
1560 1561
	/* 5) Replace the bootstrap kmem_list3's */
	{
P
Pekka Enberg 已提交
1562 1563
		int nid;

1564
		/* Replace the static kmem_list3 structures for the boot cpu */
P
Pekka Enberg 已提交
1565
		init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node);
1566

P
Pekka Enberg 已提交
1567
		for_each_online_node(nid) {
1568
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
P
Pekka Enberg 已提交
1569
				  &initkmem_list3[SIZE_AC + nid], nid);
1570 1571 1572

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
P
Pekka Enberg 已提交
1573
					  &initkmem_list3[SIZE_L3 + nid], nid);
1574 1575 1576
			}
		}
	}
L
Linus Torvalds 已提交
1577

1578
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1579
	{
1580
		struct kmem_cache *cachep;
I
Ingo Molnar 已提交
1581
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1582
		list_for_each_entry(cachep, &cache_chain, next)
1583 1584
			if (enable_cpucache(cachep))
				BUG();
I
Ingo Molnar 已提交
1585
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1586 1587
	}

1588 1589 1590 1591
	/* Annotate slab for lockdep -- annotate the malloc caches */
	init_lock_keys();


L
Linus Torvalds 已提交
1592 1593 1594
	/* Done! */
	g_cpucache_up = FULL;

A
Andrew Morton 已提交
1595 1596 1597
	/*
	 * Register a cpu startup notifier callback that initializes
	 * cpu_cache_get for all new cpus
L
Linus Torvalds 已提交
1598 1599 1600
	 */
	register_cpu_notifier(&cpucache_notifier);

A
Andrew Morton 已提交
1601 1602 1603
	/*
	 * 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
1604 1605 1606 1607 1608 1609 1610
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

A
Andrew Morton 已提交
1611 1612
	/*
	 * Register the timers that return unneeded pages to the page allocator
L
Linus Torvalds 已提交
1613
	 */
1614
	for_each_online_cpu(cpu)
A
Andrew Morton 已提交
1615
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626
	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.
 */
1627
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1628 1629
{
	struct page *page;
1630
	int nr_pages;
L
Linus Torvalds 已提交
1631 1632
	int i;

1633
#ifndef CONFIG_MMU
1634 1635 1636
	/*
	 * Nommu uses slab's for process anonymous memory allocations, and thus
	 * requires __GFP_COMP to properly refcount higher order allocations
1637
	 */
1638
	flags |= __GFP_COMP;
1639
#endif
1640

1641
	flags |= cachep->gfpflags;
1642 1643

	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1644 1645 1646
	if (!page)
		return NULL;

1647
	nr_pages = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1648
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1649 1650 1651 1652 1653
		add_zone_page_state(page_zone(page),
			NR_SLAB_RECLAIMABLE, nr_pages);
	else
		add_zone_page_state(page_zone(page),
			NR_SLAB_UNRECLAIMABLE, nr_pages);
1654 1655 1656
	for (i = 0; i < nr_pages; i++)
		__SetPageSlab(page + i);
	return page_address(page);
L
Linus Torvalds 已提交
1657 1658 1659 1660 1661
}

/*
 * Interface to system's page release.
 */
1662
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
L
Linus Torvalds 已提交
1663
{
P
Pekka Enberg 已提交
1664
	unsigned long i = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1665 1666 1667
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

1668 1669 1670 1671 1672 1673
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		sub_zone_page_state(page_zone(page),
				NR_SLAB_RECLAIMABLE, nr_freed);
	else
		sub_zone_page_state(page_zone(page),
				NR_SLAB_UNRECLAIMABLE, nr_freed);
L
Linus Torvalds 已提交
1674
	while (i--) {
N
Nick Piggin 已提交
1675 1676
		BUG_ON(!PageSlab(page));
		__ClearPageSlab(page);
L
Linus Torvalds 已提交
1677 1678 1679 1680 1681 1682 1683 1684 1685
		page++;
	}
	if (current->reclaim_state)
		current->reclaim_state->reclaimed_slab += nr_freed;
	free_pages((unsigned long)addr, cachep->gfporder);
}

static void kmem_rcu_free(struct rcu_head *head)
{
P
Pekka Enberg 已提交
1686
	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1687
	struct kmem_cache *cachep = slab_rcu->cachep;
L
Linus Torvalds 已提交
1688 1689 1690 1691 1692 1693 1694 1695 1696

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

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
1697
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
P
Pekka Enberg 已提交
1698
			    unsigned long caller)
L
Linus Torvalds 已提交
1699
{
1700
	int size = obj_size(cachep);
L
Linus Torvalds 已提交
1701

1702
	addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1703

P
Pekka Enberg 已提交
1704
	if (size < 5 * sizeof(unsigned long))
L
Linus Torvalds 已提交
1705 1706
		return;

P
Pekka Enberg 已提交
1707 1708 1709 1710
	*addr++ = 0x12345678;
	*addr++ = caller;
	*addr++ = smp_processor_id();
	size -= 3 * sizeof(unsigned long);
L
Linus Torvalds 已提交
1711 1712 1713 1714 1715 1716 1717
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
P
Pekka Enberg 已提交
1718
				*addr++ = svalue;
L
Linus Torvalds 已提交
1719 1720 1721 1722 1723 1724 1725
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
P
Pekka Enberg 已提交
1726
	*addr++ = 0x87654321;
L
Linus Torvalds 已提交
1727 1728 1729
}
#endif

1730
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
L
Linus Torvalds 已提交
1731
{
1732 1733
	int size = obj_size(cachep);
	addr = &((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1734 1735

	memset(addr, val, size);
P
Pekka Enberg 已提交
1736
	*(unsigned char *)(addr + size - 1) = POISON_END;
L
Linus Torvalds 已提交
1737 1738 1739 1740 1741
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
D
Dave Jones 已提交
1742 1743 1744
	unsigned char error = 0;
	int bad_count = 0;

L
Linus Torvalds 已提交
1745
	printk(KERN_ERR "%03x:", offset);
D
Dave Jones 已提交
1746 1747 1748 1749 1750
	for (i = 0; i < limit; i++) {
		if (data[offset + i] != POISON_FREE) {
			error = data[offset + i];
			bad_count++;
		}
P
Pekka Enberg 已提交
1751
		printk(" %02x", (unsigned char)data[offset + i]);
D
Dave Jones 已提交
1752
	}
L
Linus Torvalds 已提交
1753
	printk("\n");
D
Dave Jones 已提交
1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767

	if (bad_count == 1) {
		error ^= POISON_FREE;
		if (!(error & (error - 1))) {
			printk(KERN_ERR "Single bit error detected. Probably "
					"bad RAM.\n");
#ifdef CONFIG_X86
			printk(KERN_ERR "Run memtest86+ or a similar memory "
					"test tool.\n");
#else
			printk(KERN_ERR "Run a memory test tool.\n");
#endif
		}
	}
L
Linus Torvalds 已提交
1768 1769 1770 1771 1772
}
#endif

#if DEBUG

1773
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
L
Linus Torvalds 已提交
1774 1775 1776 1777 1778 1779
{
	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
1780 1781
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
1782 1783 1784 1785
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
A
Andrew Morton 已提交
1786
			*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1787
		print_symbol("(%s)",
A
Andrew Morton 已提交
1788
				(unsigned long)*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1789 1790
		printk("\n");
	}
1791 1792
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
P
Pekka Enberg 已提交
1793
	for (i = 0; i < size && lines; i += 16, lines--) {
L
Linus Torvalds 已提交
1794 1795
		int limit;
		limit = 16;
P
Pekka Enberg 已提交
1796 1797
		if (i + limit > size)
			limit = size - i;
L
Linus Torvalds 已提交
1798 1799 1800 1801
		dump_line(realobj, i, limit);
	}
}

1802
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
1803 1804 1805 1806 1807
{
	char *realobj;
	int size, i;
	int lines = 0;

1808 1809
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
L
Linus Torvalds 已提交
1810

P
Pekka Enberg 已提交
1811
	for (i = 0; i < size; i++) {
L
Linus Torvalds 已提交
1812
		char exp = POISON_FREE;
P
Pekka Enberg 已提交
1813
		if (i == size - 1)
L
Linus Torvalds 已提交
1814 1815 1816 1817 1818 1819
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
P
Pekka Enberg 已提交
1820
				printk(KERN_ERR
1821 1822
					"Slab corruption: %s start=%p, len=%d\n",
					cachep->name, realobj, size);
L
Linus Torvalds 已提交
1823 1824 1825
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
P
Pekka Enberg 已提交
1826
			i = (i / 16) * 16;
L
Linus Torvalds 已提交
1827
			limit = 16;
P
Pekka Enberg 已提交
1828 1829
			if (i + limit > size)
				limit = size - i;
L
Linus Torvalds 已提交
1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841
			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:
		 */
1842
		struct slab *slabp = virt_to_slab(objp);
1843
		unsigned int objnr;
L
Linus Torvalds 已提交
1844

1845
		objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
1846
		if (objnr) {
1847
			objp = index_to_obj(cachep, slabp, objnr - 1);
1848
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1849
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1850
			       realobj, size);
L
Linus Torvalds 已提交
1851 1852
			print_objinfo(cachep, objp, 2);
		}
P
Pekka Enberg 已提交
1853
		if (objnr + 1 < cachep->num) {
1854
			objp = index_to_obj(cachep, slabp, objnr + 1);
1855
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1856
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1857
			       realobj, size);
L
Linus Torvalds 已提交
1858 1859 1860 1861 1862 1863
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

1864 1865
#if DEBUG
/**
1866 1867 1868 1869 1870 1871
 * 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
1872
 */
1873
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
1874 1875 1876
{
	int i;
	for (i = 0; i < cachep->num; i++) {
1877
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
1878 1879 1880

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
1881 1882
			if (cachep->buffer_size % PAGE_SIZE == 0 &&
					OFF_SLAB(cachep))
P
Pekka Enberg 已提交
1883
				kernel_map_pages(virt_to_page(objp),
A
Andrew Morton 已提交
1884
					cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
1885 1886 1887 1888 1889 1890 1891 1892 1893
			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
1894
					   "was overwritten");
L
Linus Torvalds 已提交
1895 1896
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
P
Pekka Enberg 已提交
1897
					   "was overwritten");
L
Linus Torvalds 已提交
1898 1899
		}
		if (cachep->dtor && !(cachep->flags & SLAB_POISON))
1900
			(cachep->dtor) (objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
1901
	}
1902
}
L
Linus Torvalds 已提交
1903
#else
1904
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
1905
{
L
Linus Torvalds 已提交
1906 1907 1908
	if (cachep->dtor) {
		int i;
		for (i = 0; i < cachep->num; i++) {
1909
			void *objp = index_to_obj(cachep, slabp, i);
P
Pekka Enberg 已提交
1910
			(cachep->dtor) (objp, cachep, 0);
L
Linus Torvalds 已提交
1911 1912
		}
	}
1913
}
L
Linus Torvalds 已提交
1914 1915
#endif

1916 1917 1918 1919 1920
/**
 * slab_destroy - destroy and release all objects in a slab
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
1921
 * Destroy all the objs in a slab, and release the mem back to the system.
A
Andrew Morton 已提交
1922 1923
 * Before calling the slab must have been unlinked from the cache.  The
 * cache-lock is not held/needed.
1924
 */
1925
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1926 1927 1928 1929
{
	void *addr = slabp->s_mem - slabp->colouroff;

	slab_destroy_objs(cachep, slabp);
L
Linus Torvalds 已提交
1930 1931 1932
	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

P
Pekka Enberg 已提交
1933
		slab_rcu = (struct slab_rcu *)slabp;
L
Linus Torvalds 已提交
1934 1935 1936 1937 1938
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
1939 1940
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
L
Linus Torvalds 已提交
1941 1942 1943
	}
}

A
Andrew Morton 已提交
1944 1945 1946 1947
/*
 * For setting up all the kmem_list3s for cache whose buffer_size is same as
 * size of kmem_list3.
 */
1948
static void __init set_up_list3s(struct kmem_cache *cachep, int index)
1949 1950 1951 1952
{
	int node;

	for_each_online_node(node) {
P
Pekka Enberg 已提交
1953
		cachep->nodelists[node] = &initkmem_list3[index + node];
1954
		cachep->nodelists[node]->next_reap = jiffies +
P
Pekka Enberg 已提交
1955 1956
		    REAPTIMEOUT_LIST3 +
		    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1957 1958 1959
	}
}

1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980
static void __kmem_cache_destroy(struct kmem_cache *cachep)
{
	int i;
	struct kmem_list3 *l3;

	for_each_online_cpu(i)
	    kfree(cachep->array[i]);

	/* NUMA: free the list3 structures */
	for_each_online_node(i) {
		l3 = cachep->nodelists[i];
		if (l3) {
			kfree(l3->shared);
			free_alien_cache(l3->alien);
			kfree(l3);
		}
	}
	kmem_cache_free(&cache_cache, cachep);
}


1981
/**
1982 1983 1984 1985 1986 1987 1988
 * 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.
1989 1990 1991 1992 1993
 *
 * 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
1994
static size_t calculate_slab_order(struct kmem_cache *cachep,
R
Randy Dunlap 已提交
1995
			size_t size, size_t align, unsigned long flags)
1996
{
1997
	unsigned long offslab_limit;
1998
	size_t left_over = 0;
1999
	int gfporder;
2000

A
Andrew Morton 已提交
2001
	for (gfporder = 0; gfporder <= MAX_GFP_ORDER; gfporder++) {
2002 2003 2004
		unsigned int num;
		size_t remainder;

2005
		cache_estimate(gfporder, size, align, flags, &remainder, &num);
2006 2007
		if (!num)
			continue;
2008

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
		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;
		}
2021

2022
		/* Found something acceptable - save it away */
2023
		cachep->num = num;
2024
		cachep->gfporder = gfporder;
2025 2026
		left_over = remainder;

2027 2028 2029 2030 2031 2032 2033 2034
		/*
		 * 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;

2035 2036 2037 2038
		/*
		 * Large number of objects is good, but very large slabs are
		 * currently bad for the gfp()s.
		 */
2039
		if (gfporder >= slab_break_gfp_order)
2040 2041
			break;

2042 2043 2044
		/*
		 * Acceptable internal fragmentation?
		 */
A
Andrew Morton 已提交
2045
		if (left_over * 8 <= (PAGE_SIZE << gfporder))
2046 2047 2048 2049 2050
			break;
	}
	return left_over;
}

2051
static int setup_cpu_cache(struct kmem_cache *cachep)
2052
{
2053 2054 2055
	if (g_cpucache_up == FULL)
		return enable_cpucache(cachep);

2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101
	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;
2102
	return 0;
2103 2104
}

L
Linus Torvalds 已提交
2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119
/**
 * 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
2120 2121
 * the module calling this has to destroy the cache before getting unloaded.
 *
L
Linus Torvalds 已提交
2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133
 * 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.
 */
2134
struct kmem_cache *
L
Linus Torvalds 已提交
2135
kmem_cache_create (const char *name, size_t size, size_t align,
A
Andrew Morton 已提交
2136 2137
	unsigned long flags,
	void (*ctor)(void*, struct kmem_cache *, unsigned long),
2138
	void (*dtor)(void*, struct kmem_cache *, unsigned long))
L
Linus Torvalds 已提交
2139 2140
{
	size_t left_over, slab_size, ralign;
2141
	struct kmem_cache *cachep = NULL, *pc;
L
Linus Torvalds 已提交
2142 2143 2144 2145

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
A
Andrew Morton 已提交
2146
	if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
P
Pekka Enberg 已提交
2147
	    (size > (1 << MAX_OBJ_ORDER) * PAGE_SIZE) || (dtor && !ctor)) {
A
Andrew Morton 已提交
2148 2149
		printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
				name);
P
Pekka Enberg 已提交
2150 2151
		BUG();
	}
L
Linus Torvalds 已提交
2152

2153
	/*
2154 2155
	 * We use cache_chain_mutex to ensure a consistent view of
	 * cpu_online_map as well.  Please see cpuup_callback
2156
	 */
I
Ingo Molnar 已提交
2157
	mutex_lock(&cache_chain_mutex);
2158

2159
	list_for_each_entry(pc, &cache_chain, next) {
2160 2161 2162 2163 2164 2165 2166 2167
		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.
		 */
2168
		res = probe_kernel_address(pc->name, tmp);
2169
		if (res) {
2170 2171
			printk(KERN_ERR
			       "SLAB: cache with size %d has lost its name\n",
2172
			       pc->buffer_size);
2173 2174 2175
			continue;
		}

P
Pekka Enberg 已提交
2176
		if (!strcmp(pc->name, name)) {
2177 2178
			printk(KERN_ERR
			       "kmem_cache_create: duplicate cache %s\n", name);
2179 2180 2181 2182 2183
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
2184 2185 2186 2187 2188 2189 2190 2191 2192
#if DEBUG
	WARN_ON(strchr(name, ' '));	/* It confuses parsers */
#if FORCED_DEBUG
	/*
	 * Enable redzoning and last user accounting, except for caches with
	 * large objects, if the increased size would increase the object size
	 * above the next power of two: caches with object sizes just above a
	 * power of two have a significant amount of internal fragmentation.
	 */
A
Andrew Morton 已提交
2193
	if (size < 4096 || fls(size - 1) == fls(size-1 + 3 * BYTES_PER_WORD))
P
Pekka Enberg 已提交
2194
		flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
L
Linus Torvalds 已提交
2195 2196 2197 2198 2199 2200 2201 2202 2203 2204
	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
2205 2206
	 * Always checks flags, a caller might be expecting debug support which
	 * isn't available.
L
Linus Torvalds 已提交
2207
	 */
2208
	BUG_ON(flags & ~CREATE_MASK);
L
Linus Torvalds 已提交
2209

A
Andrew Morton 已提交
2210 2211
	/*
	 * Check that size is in terms of words.  This is needed to avoid
L
Linus Torvalds 已提交
2212 2213 2214
	 * 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
2215 2216 2217
	if (size & (BYTES_PER_WORD - 1)) {
		size += (BYTES_PER_WORD - 1);
		size &= ~(BYTES_PER_WORD - 1);
L
Linus Torvalds 已提交
2218 2219
	}

A
Andrew Morton 已提交
2220 2221
	/* calculate the final buffer alignment: */

L
Linus Torvalds 已提交
2222 2223
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
A
Andrew Morton 已提交
2224 2225 2226 2227
		/*
		 * 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
2228 2229
		 */
		ralign = cache_line_size();
P
Pekka Enberg 已提交
2230
		while (size <= ralign / 2)
L
Linus Torvalds 已提交
2231 2232 2233 2234
			ralign /= 2;
	} else {
		ralign = BYTES_PER_WORD;
	}
2235 2236 2237 2238 2239 2240 2241 2242 2243

	/*
	 * Redzoning and user store require word alignment. Note this will be
	 * overridden by architecture or caller mandated alignment if either
	 * is greater than BYTES_PER_WORD.
	 */
	if (flags & SLAB_RED_ZONE || flags & SLAB_STORE_USER)
		ralign = BYTES_PER_WORD;

2244
	/* 2) arch mandated alignment */
L
Linus Torvalds 已提交
2245 2246 2247
	if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
	}
2248
	/* 3) caller mandated alignment */
L
Linus Torvalds 已提交
2249 2250 2251
	if (ralign < align) {
		ralign = align;
	}
2252 2253 2254
	/* disable debug if necessary */
	if (ralign > BYTES_PER_WORD)
		flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
A
Andrew Morton 已提交
2255
	/*
2256
	 * 4) Store it.
L
Linus Torvalds 已提交
2257 2258 2259 2260
	 */
	align = ralign;

	/* Get cache's description obj. */
2261
	cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
L
Linus Torvalds 已提交
2262
	if (!cachep)
2263
		goto oops;
L
Linus Torvalds 已提交
2264 2265

#if DEBUG
2266
	cachep->obj_size = size;
L
Linus Torvalds 已提交
2267

2268 2269 2270 2271
	/*
	 * Both debugging options require word-alignment which is calculated
	 * into align above.
	 */
L
Linus Torvalds 已提交
2272 2273
	if (flags & SLAB_RED_ZONE) {
		/* add space for red zone words */
2274
		cachep->obj_offset += BYTES_PER_WORD;
P
Pekka Enberg 已提交
2275
		size += 2 * BYTES_PER_WORD;
L
Linus Torvalds 已提交
2276 2277
	}
	if (flags & SLAB_STORE_USER) {
2278 2279
		/* user store requires one word storage behind the end of
		 * the real object.
L
Linus Torvalds 已提交
2280 2281 2282 2283
		 */
		size += BYTES_PER_WORD;
	}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
P
Pekka Enberg 已提交
2284
	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2285 2286
	    && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
		cachep->obj_offset += PAGE_SIZE - size;
L
Linus Torvalds 已提交
2287 2288 2289 2290 2291
		size = PAGE_SIZE;
	}
#endif
#endif

2292 2293 2294 2295 2296 2297
	/*
	 * 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
2298 2299 2300 2301 2302 2303 2304 2305
		/*
		 * 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);

2306
	left_over = calculate_slab_order(cachep, size, align, flags);
L
Linus Torvalds 已提交
2307 2308

	if (!cachep->num) {
2309 2310
		printk(KERN_ERR
		       "kmem_cache_create: couldn't create cache %s.\n", name);
L
Linus Torvalds 已提交
2311 2312
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
2313
		goto oops;
L
Linus Torvalds 已提交
2314
	}
P
Pekka Enberg 已提交
2315 2316
	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
			  + sizeof(struct slab), align);
L
Linus Torvalds 已提交
2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328

	/*
	 * 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
2329 2330
		slab_size =
		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
L
Linus Torvalds 已提交
2331 2332 2333 2334 2335 2336
	}

	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
2337
	cachep->colour = left_over / cachep->colour_off;
L
Linus Torvalds 已提交
2338 2339 2340
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
2341
	if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
L
Linus Torvalds 已提交
2342
		cachep->gfpflags |= GFP_DMA;
2343
	cachep->buffer_size = size;
2344
	cachep->reciprocal_buffer_size = reciprocal_value(size);
L
Linus Torvalds 已提交
2345

2346
	if (flags & CFLGS_OFF_SLAB) {
2347
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
2348 2349 2350 2351 2352 2353 2354 2355 2356
		/*
		 * This is a possibility for one of the malloc_sizes caches.
		 * But since we go off slab only for object size greater than
		 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
		 * this should not happen at all.
		 * But leave a BUG_ON for some lucky dude.
		 */
		BUG_ON(!cachep->slabp_cache);
	}
L
Linus Torvalds 已提交
2357 2358 2359 2360
	cachep->ctor = ctor;
	cachep->dtor = dtor;
	cachep->name = name;

2361 2362 2363 2364 2365
	if (setup_cpu_cache(cachep)) {
		__kmem_cache_destroy(cachep);
		cachep = NULL;
		goto oops;
	}
L
Linus Torvalds 已提交
2366 2367 2368

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
A
Andrew Morton 已提交
2369
oops:
L
Linus Torvalds 已提交
2370 2371
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
P
Pekka Enberg 已提交
2372
		      name);
I
Ingo Molnar 已提交
2373
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388
	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());
}

2389
static void check_spinlock_acquired(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2390 2391 2392
{
#ifdef CONFIG_SMP
	check_irq_off();
2393
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
2394 2395
#endif
}
2396

2397
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2398 2399 2400 2401 2402 2403 2404
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
2405 2406 2407 2408
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
2409
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
2410 2411
#endif

2412 2413 2414 2415
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
2416 2417
static void do_drain(void *arg)
{
A
Andrew Morton 已提交
2418
	struct kmem_cache *cachep = arg;
L
Linus Torvalds 已提交
2419
	struct array_cache *ac;
2420
	int node = numa_node_id();
L
Linus Torvalds 已提交
2421 2422

	check_irq_off();
2423
	ac = cpu_cache_get(cachep);
2424 2425 2426
	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
2427 2428 2429
	ac->avail = 0;
}

2430
static void drain_cpu_caches(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2431
{
2432 2433 2434
	struct kmem_list3 *l3;
	int node;

A
Andrew Morton 已提交
2435
	on_each_cpu(do_drain, cachep, 1, 1);
L
Linus Torvalds 已提交
2436
	check_irq_on();
P
Pekka Enberg 已提交
2437
	for_each_online_node(node) {
2438
		l3 = cachep->nodelists[node];
2439 2440 2441 2442 2443 2444 2445
		if (l3 && l3->alien)
			drain_alien_cache(cachep, l3->alien);
	}

	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (l3)
2446
			drain_array(cachep, l3, l3->shared, 1, node);
2447
	}
L
Linus Torvalds 已提交
2448 2449
}

2450 2451 2452 2453 2454 2455 2456 2457
/*
 * 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
2458
{
2459 2460
	struct list_head *p;
	int nr_freed;
L
Linus Torvalds 已提交
2461 2462
	struct slab *slabp;

2463 2464
	nr_freed = 0;
	while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
L
Linus Torvalds 已提交
2465

2466
		spin_lock_irq(&l3->list_lock);
2467
		p = l3->slabs_free.prev;
2468 2469 2470 2471
		if (p == &l3->slabs_free) {
			spin_unlock_irq(&l3->list_lock);
			goto out;
		}
L
Linus Torvalds 已提交
2472

2473
		slabp = list_entry(p, struct slab, list);
L
Linus Torvalds 已提交
2474
#if DEBUG
2475
		BUG_ON(slabp->inuse);
L
Linus Torvalds 已提交
2476 2477
#endif
		list_del(&slabp->list);
2478 2479 2480 2481 2482
		/*
		 * Safe to drop the lock. The slab is no longer linked
		 * to the cache.
		 */
		l3->free_objects -= cache->num;
2483
		spin_unlock_irq(&l3->list_lock);
2484 2485
		slab_destroy(cache, slabp);
		nr_freed++;
L
Linus Torvalds 已提交
2486
	}
2487 2488
out:
	return nr_freed;
L
Linus Torvalds 已提交
2489 2490
}

2491
/* Called with cache_chain_mutex held to protect against cpu hotplug */
2492
static int __cache_shrink(struct kmem_cache *cachep)
2493 2494 2495 2496 2497 2498 2499 2500 2501
{
	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];
2502 2503 2504 2505 2506 2507 2508
		if (!l3)
			continue;

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

		ret += !list_empty(&l3->slabs_full) ||
			!list_empty(&l3->slabs_partial);
2509 2510 2511 2512
	}
	return (ret ? 1 : 0);
}

L
Linus Torvalds 已提交
2513 2514 2515 2516 2517 2518 2519
/**
 * 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.
 */
2520
int kmem_cache_shrink(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2521
{
2522
	int ret;
2523
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2524

2525 2526 2527 2528
	mutex_lock(&cache_chain_mutex);
	ret = __cache_shrink(cachep);
	mutex_unlock(&cache_chain_mutex);
	return ret;
L
Linus Torvalds 已提交
2529 2530 2531 2532 2533 2534 2535
}
EXPORT_SYMBOL(kmem_cache_shrink);

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
2536
 * Remove a &struct kmem_cache object from the slab cache.
L
Linus Torvalds 已提交
2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547
 *
 * 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().
 */
2548
void kmem_cache_destroy(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2549
{
2550
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2551 2552

	/* Find the cache in the chain of caches. */
I
Ingo Molnar 已提交
2553
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2554 2555 2556 2557 2558 2559
	/*
	 * the chain is never empty, cache_cache is never destroyed
	 */
	list_del(&cachep->next);
	if (__cache_shrink(cachep)) {
		slab_error(cachep, "Can't free all objects");
P
Pekka Enberg 已提交
2560
		list_add(&cachep->next, &cache_chain);
I
Ingo Molnar 已提交
2561
		mutex_unlock(&cache_chain_mutex);
2562
		return;
L
Linus Torvalds 已提交
2563 2564 2565
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2566
		synchronize_rcu();
L
Linus Torvalds 已提交
2567

2568
	__kmem_cache_destroy(cachep);
2569
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2570 2571 2572
}
EXPORT_SYMBOL(kmem_cache_destroy);

2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583
/*
 * Get the memory for a slab management obj.
 * For a slab cache when the slab descriptor is off-slab, slab descriptors
 * always come from malloc_sizes caches.  The slab descriptor cannot
 * come from the same cache which is getting created because,
 * when we are searching for an appropriate cache for these
 * descriptors in kmem_cache_create, we search through the malloc_sizes array.
 * If we are creating a malloc_sizes cache here it would not be visible to
 * kmem_find_general_cachep till the initialization is complete.
 * Hence we cannot have slabp_cache same as the original cache.
 */
2584
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
2585 2586
				   int colour_off, gfp_t local_flags,
				   int nodeid)
L
Linus Torvalds 已提交
2587 2588
{
	struct slab *slabp;
P
Pekka Enberg 已提交
2589

L
Linus Torvalds 已提交
2590 2591
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
2592
		slabp = kmem_cache_alloc_node(cachep->slabp_cache,
2593
					      local_flags & ~GFP_THISNODE, nodeid);
L
Linus Torvalds 已提交
2594 2595 2596
		if (!slabp)
			return NULL;
	} else {
P
Pekka Enberg 已提交
2597
		slabp = objp + colour_off;
L
Linus Torvalds 已提交
2598 2599 2600 2601
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
P
Pekka Enberg 已提交
2602
	slabp->s_mem = objp + colour_off;
2603
	slabp->nodeid = nodeid;
L
Linus Torvalds 已提交
2604 2605 2606 2607 2608
	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
P
Pekka Enberg 已提交
2609
	return (kmem_bufctl_t *) (slabp + 1);
L
Linus Torvalds 已提交
2610 2611
}

2612
static void cache_init_objs(struct kmem_cache *cachep,
P
Pekka Enberg 已提交
2613
			    struct slab *slabp, unsigned long ctor_flags)
L
Linus Torvalds 已提交
2614 2615 2616 2617
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2618
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630
#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
2631 2632 2633
		 * 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
2634 2635
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2636
			cachep->ctor(objp + obj_offset(cachep), cachep,
P
Pekka Enberg 已提交
2637
				     ctor_flags);
L
Linus Torvalds 已提交
2638 2639 2640 2641

		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
2642
					   " end of an object");
L
Linus Torvalds 已提交
2643 2644
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2645
					   " start of an object");
L
Linus Torvalds 已提交
2646
		}
A
Andrew Morton 已提交
2647 2648
		if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
			    OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
P
Pekka Enberg 已提交
2649
			kernel_map_pages(virt_to_page(objp),
2650
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2651 2652 2653 2654
#else
		if (cachep->ctor)
			cachep->ctor(objp, cachep, ctor_flags);
#endif
P
Pekka Enberg 已提交
2655
		slab_bufctl(slabp)[i] = i + 1;
L
Linus Torvalds 已提交
2656
	}
P
Pekka Enberg 已提交
2657
	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
L
Linus Torvalds 已提交
2658 2659 2660
	slabp->free = 0;
}

2661
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2662
{
2663 2664 2665 2666 2667 2668
	if (CONFIG_ZONE_DMA_FLAG) {
		if (flags & GFP_DMA)
			BUG_ON(!(cachep->gfpflags & GFP_DMA));
		else
			BUG_ON(cachep->gfpflags & GFP_DMA);
	}
L
Linus Torvalds 已提交
2669 2670
}

A
Andrew Morton 已提交
2671 2672
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
				int nodeid)
2673
{
2674
	void *objp = index_to_obj(cachep, slabp, slabp->free);
2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687
	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
2688 2689
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
				void *objp, int nodeid)
2690
{
2691
	unsigned int objnr = obj_to_index(cachep, slabp, objp);
2692 2693 2694 2695 2696

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

2697
	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
2698
		printk(KERN_ERR "slab: double free detected in cache "
A
Andrew Morton 已提交
2699
				"'%s', objp %p\n", cachep->name, objp);
2700 2701 2702 2703 2704 2705 2706 2707
		BUG();
	}
#endif
	slab_bufctl(slabp)[objnr] = slabp->free;
	slabp->free = objnr;
	slabp->inuse--;
}

2708 2709 2710 2711 2712 2713 2714
/*
 * 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
2715
{
2716
	int nr_pages;
L
Linus Torvalds 已提交
2717 2718
	struct page *page;

2719
	page = virt_to_page(addr);
2720

2721
	nr_pages = 1;
2722
	if (likely(!PageCompound(page)))
2723 2724
		nr_pages <<= cache->gfporder;

L
Linus Torvalds 已提交
2725
	do {
2726 2727
		page_set_cache(page, cache);
		page_set_slab(page, slab);
L
Linus Torvalds 已提交
2728
		page++;
2729
	} while (--nr_pages);
L
Linus Torvalds 已提交
2730 2731 2732 2733 2734 2735
}

/*
 * 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.
 */
2736 2737
static int cache_grow(struct kmem_cache *cachep,
		gfp_t flags, int nodeid, void *objp)
L
Linus Torvalds 已提交
2738
{
P
Pekka Enberg 已提交
2739 2740 2741 2742
	struct slab *slabp;
	size_t offset;
	gfp_t local_flags;
	unsigned long ctor_flags;
2743
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2744

A
Andrew Morton 已提交
2745 2746 2747
	/*
	 * 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
2748
	 */
2749
	BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK));
L
Linus Torvalds 已提交
2750 2751

	ctor_flags = SLAB_CTOR_CONSTRUCTOR;
2752
	local_flags = (flags & GFP_LEVEL_MASK);
2753
	/* Take the l3 list lock to change the colour_next on this node */
L
Linus Torvalds 已提交
2754
	check_irq_off();
2755 2756
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2757 2758

	/* Get colour for the slab, and cal the next value. */
2759 2760 2761 2762 2763
	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
2764

2765
	offset *= cachep->colour_off;
L
Linus Torvalds 已提交
2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777

	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
2778 2779 2780
	/*
	 * Get mem for the objs.  Attempt to allocate a physical page from
	 * 'nodeid'.
2781
	 */
2782 2783
	if (!objp)
		objp = kmem_getpages(cachep, flags, nodeid);
A
Andrew Morton 已提交
2784
	if (!objp)
L
Linus Torvalds 已提交
2785 2786 2787
		goto failed;

	/* Get slab management. */
2788 2789
	slabp = alloc_slabmgmt(cachep, objp, offset,
			local_flags & ~GFP_THISNODE, nodeid);
A
Andrew Morton 已提交
2790
	if (!slabp)
L
Linus Torvalds 已提交
2791 2792
		goto opps1;

2793
	slabp->nodeid = nodeid;
2794
	slab_map_pages(cachep, slabp, objp);
L
Linus Torvalds 已提交
2795 2796 2797 2798 2799 2800

	cache_init_objs(cachep, slabp, ctor_flags);

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2801
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2802 2803

	/* Make slab active. */
2804
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2805
	STATS_INC_GROWN(cachep);
2806 2807
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2808
	return 1;
A
Andrew Morton 已提交
2809
opps1:
L
Linus Torvalds 已提交
2810
	kmem_freepages(cachep, objp);
A
Andrew Morton 已提交
2811
failed:
L
Linus Torvalds 已提交
2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828
	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)
{
	if (!virt_addr_valid(objp)) {
		printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
P
Pekka Enberg 已提交
2829 2830
		       (unsigned long)objp);
		BUG();
L
Linus Torvalds 已提交
2831 2832 2833
	}
}

2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855
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);
}

2856
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2857
				   void *caller)
L
Linus Torvalds 已提交
2858 2859 2860 2861 2862
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

2863
	objp -= obj_offset(cachep);
L
Linus Torvalds 已提交
2864
	kfree_debugcheck(objp);
2865
	page = virt_to_head_page(objp);
L
Linus Torvalds 已提交
2866

2867
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2868 2869

	if (cachep->flags & SLAB_RED_ZONE) {
2870
		verify_redzone_free(cachep, objp);
L
Linus Torvalds 已提交
2871 2872 2873 2874 2875 2876
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

2877
	objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
2878 2879

	BUG_ON(objnr >= cachep->num);
2880
	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
L
Linus Torvalds 已提交
2881 2882 2883 2884 2885

	if (cachep->flags & SLAB_POISON && cachep->dtor) {
		/* we want to cache poison the object,
		 * call the destruction callback
		 */
2886
		cachep->dtor(objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
2887
	}
2888 2889 2890
#ifdef CONFIG_DEBUG_SLAB_LEAK
	slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
#endif
L
Linus Torvalds 已提交
2891 2892
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
2893
		if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
L
Linus Torvalds 已提交
2894
			store_stackinfo(cachep, objp, (unsigned long)caller);
P
Pekka Enberg 已提交
2895
			kernel_map_pages(virt_to_page(objp),
2896
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2897 2898 2899 2900 2901 2902 2903 2904 2905 2906
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

2907
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
2908 2909 2910
{
	kmem_bufctl_t i;
	int entries = 0;
P
Pekka Enberg 已提交
2911

L
Linus Torvalds 已提交
2912 2913 2914 2915 2916 2917 2918
	/* 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
2919 2920 2921 2922
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
2923
		for (i = 0;
2924
		     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
P
Pekka Enberg 已提交
2925
		     i++) {
A
Andrew Morton 已提交
2926
			if (i % 16 == 0)
L
Linus Torvalds 已提交
2927
				printk("\n%03x:", i);
P
Pekka Enberg 已提交
2928
			printk(" %02x", ((unsigned char *)slabp)[i]);
L
Linus Torvalds 已提交
2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939
		}
		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

2940
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2941 2942 2943 2944
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;
P
Pekka Enberg 已提交
2945 2946 2947
	int node;

	node = numa_node_id();
L
Linus Torvalds 已提交
2948 2949

	check_irq_off();
2950
	ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2951
retry:
L
Linus Torvalds 已提交
2952 2953
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
A
Andrew Morton 已提交
2954 2955 2956 2957
		/*
		 * 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
2958 2959 2960
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
P
Pekka Enberg 已提交
2961
	l3 = cachep->nodelists[node];
2962 2963 2964

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2965

2966 2967 2968 2969
	/* 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
2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984
	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);
2985 2986 2987 2988 2989 2990 2991 2992

		/*
		 * The slab was either on partial or free list so
		 * there must be at least one object available for
		 * allocation.
		 */
		BUG_ON(slabp->inuse < 0 || slabp->inuse >= cachep->num);

L
Linus Torvalds 已提交
2993 2994 2995 2996 2997
		while (slabp->inuse < cachep->num && batchcount--) {
			STATS_INC_ALLOCED(cachep);
			STATS_INC_ACTIVE(cachep);
			STATS_SET_HIGH(cachep);

2998
			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
P
Pekka Enberg 已提交
2999
							    node);
L
Linus Torvalds 已提交
3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010
		}
		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
3011
must_grow:
L
Linus Torvalds 已提交
3012
	l3->free_objects -= ac->avail;
A
Andrew Morton 已提交
3013
alloc_done:
3014
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3015 3016 3017

	if (unlikely(!ac->avail)) {
		int x;
3018
		x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
3019

A
Andrew Morton 已提交
3020
		/* cache_grow can reenable interrupts, then ac could change. */
3021
		ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
3022
		if (!x && ac->avail == 0)	/* no objects in sight? abort */
L
Linus Torvalds 已提交
3023 3024
			return NULL;

A
Andrew Morton 已提交
3025
		if (!ac->avail)		/* objects refilled by interrupt? */
L
Linus Torvalds 已提交
3026 3027 3028
			goto retry;
	}
	ac->touched = 1;
3029
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3030 3031
}

A
Andrew Morton 已提交
3032 3033
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
						gfp_t flags)
L
Linus Torvalds 已提交
3034 3035 3036 3037 3038 3039 3040 3041
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
A
Andrew Morton 已提交
3042 3043
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
				gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
3044
{
P
Pekka Enberg 已提交
3045
	if (!objp)
L
Linus Torvalds 已提交
3046
		return objp;
P
Pekka Enberg 已提交
3047
	if (cachep->flags & SLAB_POISON) {
L
Linus Torvalds 已提交
3048
#ifdef CONFIG_DEBUG_PAGEALLOC
3049
		if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
P
Pekka Enberg 已提交
3050
			kernel_map_pages(virt_to_page(objp),
3051
					 cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062
		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
3063 3064 3065 3066
		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
3067
			printk(KERN_ERR
A
Andrew Morton 已提交
3068 3069 3070
				"%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
3071 3072 3073 3074
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
3075 3076 3077 3078 3079
#ifdef CONFIG_DEBUG_SLAB_LEAK
	{
		struct slab *slabp;
		unsigned objnr;

3080
		slabp = page_get_slab(virt_to_head_page(objp));
3081 3082 3083 3084
		objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
	}
#endif
3085
	objp += obj_offset(cachep);
3086 3087
	if (cachep->ctor && cachep->flags & SLAB_POISON)
		cachep->ctor(objp, cachep, SLAB_CTOR_CONSTRUCTOR);
3088 3089 3090 3091 3092 3093
#if ARCH_SLAB_MINALIGN
	if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
		printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
		       objp, ARCH_SLAB_MINALIGN);
	}
#endif
L
Linus Torvalds 已提交
3094 3095 3096 3097 3098 3099
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112
#ifdef CONFIG_FAILSLAB

static struct failslab_attr {

	struct fault_attr attr;

	u32 ignore_gfp_wait;
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
	struct dentry *ignore_gfp_wait_file;
#endif

} failslab = {
	.attr = FAULT_ATTR_INITIALIZER,
3113
	.ignore_gfp_wait = 1,
3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141
};

static int __init setup_failslab(char *str)
{
	return setup_fault_attr(&failslab.attr, str);
}
__setup("failslab=", setup_failslab);

static int should_failslab(struct kmem_cache *cachep, gfp_t flags)
{
	if (cachep == &cache_cache)
		return 0;
	if (flags & __GFP_NOFAIL)
		return 0;
	if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT))
		return 0;

	return should_fail(&failslab.attr, obj_size(cachep));
}

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

static int __init failslab_debugfs(void)
{
	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
	struct dentry *dir;
	int err;

3142
	err = init_fault_attr_dentries(&failslab.attr, "failslab");
3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172
	if (err)
		return err;
	dir = failslab.attr.dentries.dir;

	failslab.ignore_gfp_wait_file =
		debugfs_create_bool("ignore-gfp-wait", mode, dir,
				      &failslab.ignore_gfp_wait);

	if (!failslab.ignore_gfp_wait_file) {
		err = -ENOMEM;
		debugfs_remove(failslab.ignore_gfp_wait_file);
		cleanup_fault_attr_dentries(&failslab.attr);
	}

	return err;
}

late_initcall(failslab_debugfs);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#else /* CONFIG_FAILSLAB */

static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags)
{
	return 0;
}

#endif /* CONFIG_FAILSLAB */

3173
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3174
{
P
Pekka Enberg 已提交
3175
	void *objp;
L
Linus Torvalds 已提交
3176 3177
	struct array_cache *ac;

3178
	check_irq_off();
3179

3180
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3181 3182 3183
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
3184
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3185 3186 3187 3188
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
3189 3190 3191
	return objp;
}

3192
#ifdef CONFIG_NUMA
3193
/*
3194
 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
3195 3196 3197 3198 3199 3200 3201 3202
 *
 * 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;

3203
	if (in_interrupt() || (flags & __GFP_THISNODE))
3204 3205 3206 3207 3208 3209 3210
		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)
3211
		return ____cache_alloc_node(cachep, flags, nid_alloc);
3212 3213 3214
	return NULL;
}

3215 3216
/*
 * Fallback function if there was no memory available and no objects on a
3217 3218 3219 3220 3221
 * certain node and fall back is permitted. First we scan all the
 * available nodelists for available objects. If that fails then we
 * perform an allocation without specifying a node. This allows the page
 * allocator to do its reclaim / fallback magic. We then insert the
 * slab into the proper nodelist and then allocate from it.
3222
 */
3223
static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
3224
{
3225 3226
	struct zonelist *zonelist;
	gfp_t local_flags;
3227 3228
	struct zone **z;
	void *obj = NULL;
3229
	int nid;
3230 3231 3232 3233 3234 3235 3236

	if (flags & __GFP_THISNODE)
		return NULL;

	zonelist = &NODE_DATA(slab_node(current->mempolicy))
			->node_zonelists[gfp_zone(flags)];
	local_flags = (flags & GFP_LEVEL_MASK);
3237

3238 3239 3240 3241 3242
retry:
	/*
	 * Look through allowed nodes for objects available
	 * from existing per node queues.
	 */
3243
	for (z = zonelist->zones; *z && !obj; z++) {
3244
		nid = zone_to_nid(*z);
3245

3246
		if (cpuset_zone_allowed_hardwall(*z, flags) &&
3247 3248 3249 3250 3251 3252
			cache->nodelists[nid] &&
			cache->nodelists[nid]->free_objects)
				obj = ____cache_alloc_node(cache,
					flags | GFP_THISNODE, nid);
	}

3253
	if (!obj) {
3254 3255 3256 3257 3258 3259
		/*
		 * This allocation will be performed within the constraints
		 * of the current cpuset / memory policy requirements.
		 * We may trigger various forms of reclaim on the allowed
		 * set and go into memory reserves if necessary.
		 */
3260 3261 3262
		if (local_flags & __GFP_WAIT)
			local_irq_enable();
		kmem_flagcheck(cache, flags);
3263
		obj = kmem_getpages(cache, flags, -1);
3264 3265
		if (local_flags & __GFP_WAIT)
			local_irq_disable();
3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281
		if (obj) {
			/*
			 * Insert into the appropriate per node queues
			 */
			nid = page_to_nid(virt_to_page(obj));
			if (cache_grow(cache, flags, nid, obj)) {
				obj = ____cache_alloc_node(cache,
					flags | GFP_THISNODE, nid);
				if (!obj)
					/*
					 * Another processor may allocate the
					 * objects in the slab since we are
					 * not holding any locks.
					 */
					goto retry;
			} else {
3282
				/* cache_grow already freed obj */
3283 3284 3285
				obj = NULL;
			}
		}
3286
	}
3287 3288 3289
	return obj;
}

3290 3291
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
3292
 */
3293
static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
A
Andrew Morton 已提交
3294
				int nodeid)
3295 3296
{
	struct list_head *entry;
P
Pekka Enberg 已提交
3297 3298 3299 3300 3301 3302 3303 3304
	struct slab *slabp;
	struct kmem_list3 *l3;
	void *obj;
	int x;

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

A
Andrew Morton 已提交
3305
retry:
3306
	check_irq_off();
P
Pekka Enberg 已提交
3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325
	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);

3326
	obj = slab_get_obj(cachep, slabp, nodeid);
P
Pekka Enberg 已提交
3327 3328 3329 3330 3331
	check_slabp(cachep, slabp);
	l3->free_objects--;
	/* move slabp to correct slabp list: */
	list_del(&slabp->list);

A
Andrew Morton 已提交
3332
	if (slabp->free == BUFCTL_END)
P
Pekka Enberg 已提交
3333
		list_add(&slabp->list, &l3->slabs_full);
A
Andrew Morton 已提交
3334
	else
P
Pekka Enberg 已提交
3335
		list_add(&slabp->list, &l3->slabs_partial);
3336

P
Pekka Enberg 已提交
3337 3338
	spin_unlock(&l3->list_lock);
	goto done;
3339

A
Andrew Morton 已提交
3340
must_grow:
P
Pekka Enberg 已提交
3341
	spin_unlock(&l3->list_lock);
3342
	x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
3343 3344
	if (x)
		goto retry;
L
Linus Torvalds 已提交
3345

3346
	return fallback_alloc(cachep, flags);
3347

A
Andrew Morton 已提交
3348
done:
P
Pekka Enberg 已提交
3349
	return obj;
3350
}
3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370

/**
 * kmem_cache_alloc_node - Allocate an object on the specified node
 * @cachep: The cache to allocate from.
 * @flags: See kmalloc().
 * @nodeid: node number of the target node.
 * @caller: return address of caller, used for debug information
 *
 * Identical to kmem_cache_alloc but it will allocate memory on the given
 * node, which can improve the performance for cpu bound structures.
 *
 * Fallback to other node is possible if __GFP_THISNODE is not set.
 */
static __always_inline void *
__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
		   void *caller)
{
	unsigned long save_flags;
	void *ptr;

3371 3372 3373
	if (should_failslab(cachep, flags))
		return NULL;

3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);

	if (unlikely(nodeid == -1))
		nodeid = numa_node_id();

	if (unlikely(!cachep->nodelists[nodeid])) {
		/* Node not bootstrapped yet */
		ptr = fallback_alloc(cachep, flags);
		goto out;
	}

	if (nodeid == numa_node_id()) {
		/*
		 * Use the locally cached objects if possible.
		 * However ____cache_alloc does not allow fallback
		 * to other nodes. It may fail while we still have
		 * objects on other nodes available.
		 */
		ptr = ____cache_alloc(cachep, flags);
		if (ptr)
			goto out;
	}
	/* ___cache_alloc_node can fall back to other nodes */
	ptr = ____cache_alloc_node(cachep, flags, nodeid);
  out:
	local_irq_restore(save_flags);
	ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);

	return ptr;
}

static __always_inline void *
__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
{
	void *objp;

	if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
		objp = alternate_node_alloc(cache, flags);
		if (objp)
			goto out;
	}
	objp = ____cache_alloc(cache, flags);

	/*
	 * We may just have run out of memory on the local node.
	 * ____cache_alloc_node() knows how to locate memory on other nodes
	 */
 	if (!objp)
 		objp = ____cache_alloc_node(cache, flags, numa_node_id());

  out:
	return objp;
}
#else

static __always_inline void *
__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
{
	return ____cache_alloc(cachep, flags);
}

#endif /* CONFIG_NUMA */

static __always_inline void *
__cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
{
	unsigned long save_flags;
	void *objp;

3444 3445 3446
	if (should_failslab(cachep, flags))
		return NULL;

3447 3448 3449 3450 3451 3452 3453 3454 3455
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
	objp = __do_cache_alloc(cachep, flags);
	local_irq_restore(save_flags);
	objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
	prefetchw(objp);

	return objp;
}
3456 3457 3458 3459

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
3460
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
P
Pekka Enberg 已提交
3461
		       int node)
L
Linus Torvalds 已提交
3462 3463
{
	int i;
3464
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3465 3466 3467 3468 3469

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

3470
		slabp = virt_to_slab(objp);
3471
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
3472
		list_del(&slabp->list);
3473
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
3474
		check_slabp(cachep, slabp);
3475
		slab_put_obj(cachep, slabp, objp, node);
L
Linus Torvalds 已提交
3476
		STATS_DEC_ACTIVE(cachep);
3477
		l3->free_objects++;
L
Linus Torvalds 已提交
3478 3479 3480 3481
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
3482 3483
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
3484 3485 3486 3487 3488 3489
				/* No need to drop any previously held
				 * lock here, even if we have a off-slab slab
				 * descriptor it is guaranteed to come from
				 * a different cache, refer to comments before
				 * alloc_slabmgmt.
				 */
L
Linus Torvalds 已提交
3490 3491
				slab_destroy(cachep, slabp);
			} else {
3492
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
3493 3494 3495 3496 3497 3498
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
3499
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
3500 3501 3502 3503
		}
	}
}

3504
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
L
Linus Torvalds 已提交
3505 3506
{
	int batchcount;
3507
	struct kmem_list3 *l3;
3508
	int node = numa_node_id();
L
Linus Torvalds 已提交
3509 3510 3511 3512 3513 3514

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
3515
	l3 = cachep->nodelists[node];
3516
	spin_lock(&l3->list_lock);
3517 3518
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
P
Pekka Enberg 已提交
3519
		int max = shared_array->limit - shared_array->avail;
L
Linus Torvalds 已提交
3520 3521 3522
		if (max) {
			if (batchcount > max)
				batchcount = max;
3523
			memcpy(&(shared_array->entry[shared_array->avail]),
P
Pekka Enberg 已提交
3524
			       ac->entry, sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
3525 3526 3527 3528 3529
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

3530
	free_block(cachep, ac->entry, batchcount, node);
A
Andrew Morton 已提交
3531
free_done:
L
Linus Torvalds 已提交
3532 3533 3534 3535 3536
#if STATS
	{
		int i = 0;
		struct list_head *p;

3537 3538
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549
			struct slab *slabp;

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

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
3550
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3551
	ac->avail -= batchcount;
A
Andrew Morton 已提交
3552
	memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
L
Linus Torvalds 已提交
3553 3554 3555
}

/*
A
Andrew Morton 已提交
3556 3557
 * 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
3558
 */
3559
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3560
{
3561
	struct array_cache *ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3562 3563 3564 3565

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

3566
	if (use_alien_caches && cache_free_alien(cachep, objp))
3567 3568
		return;

L
Linus Torvalds 已提交
3569 3570
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
3571
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3572 3573 3574 3575
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
3576
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587
	}
}

/**
 * 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.
 */
3588
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3589
{
3590
	return __cache_alloc(cachep, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3591 3592 3593
}
EXPORT_SYMBOL(kmem_cache_alloc);

3594
/**
3595
 * kmem_cache_zalloc - Allocate an object. The memory is set to zero.
3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610
 * @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
3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624
/**
 * 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.
 */
3625
int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
L
Linus Torvalds 已提交
3626
{
P
Pekka Enberg 已提交
3627
	unsigned long addr = (unsigned long)ptr;
L
Linus Torvalds 已提交
3628
	unsigned long min_addr = PAGE_OFFSET;
P
Pekka Enberg 已提交
3629
	unsigned long align_mask = BYTES_PER_WORD - 1;
3630
	unsigned long size = cachep->buffer_size;
L
Linus Torvalds 已提交
3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645
	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;
3646
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
3647 3648
		goto out;
	return 1;
A
Andrew Morton 已提交
3649
out:
L
Linus Torvalds 已提交
3650 3651 3652 3653
	return 0;
}

#ifdef CONFIG_NUMA
3654 3655 3656 3657 3658
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
{
	return __cache_alloc_node(cachep, flags, nodeid,
			__builtin_return_address(0));
}
L
Linus Torvalds 已提交
3659 3660
EXPORT_SYMBOL(kmem_cache_alloc_node);

3661 3662
static __always_inline void *
__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
3663
{
3664
	struct kmem_cache *cachep;
3665 3666 3667 3668 3669 3670

	cachep = kmem_find_general_cachep(size, flags);
	if (unlikely(cachep == NULL))
		return NULL;
	return kmem_cache_alloc_node(cachep, flags, node);
}
3671 3672 3673 3674 3675 3676 3677

#ifdef CONFIG_DEBUG_SLAB
void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
	return __do_kmalloc_node(size, flags, node,
			__builtin_return_address(0));
}
3678
EXPORT_SYMBOL(__kmalloc_node);
3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693

void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
		int node, void *caller)
{
	return __do_kmalloc_node(size, flags, node, caller);
}
EXPORT_SYMBOL(__kmalloc_node_track_caller);
#else
void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
	return __do_kmalloc_node(size, flags, node, NULL);
}
EXPORT_SYMBOL(__kmalloc_node);
#endif /* CONFIG_DEBUG_SLAB */
#endif /* CONFIG_NUMA */
L
Linus Torvalds 已提交
3694 3695

/**
3696
 * __do_kmalloc - allocate memory
L
Linus Torvalds 已提交
3697
 * @size: how many bytes of memory are required.
3698
 * @flags: the type of memory to allocate (see kmalloc).
3699
 * @caller: function caller for debug tracking of the caller
L
Linus Torvalds 已提交
3700
 */
3701 3702
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
					  void *caller)
L
Linus Torvalds 已提交
3703
{
3704
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3705

3706 3707 3708 3709 3710 3711
	/* 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);
3712 3713
	if (unlikely(cachep == NULL))
		return NULL;
3714 3715 3716 3717
	return __cache_alloc(cachep, flags, caller);
}


3718
#ifdef CONFIG_DEBUG_SLAB
3719 3720
void *__kmalloc(size_t size, gfp_t flags)
{
3721
	return __do_kmalloc(size, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3722 3723 3724
}
EXPORT_SYMBOL(__kmalloc);

3725 3726 3727 3728 3729
void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
{
	return __do_kmalloc(size, flags, caller);
}
EXPORT_SYMBOL(__kmalloc_track_caller);
3730 3731 3732 3733 3734 3735 3736

#else
void *__kmalloc(size_t size, gfp_t flags)
{
	return __do_kmalloc(size, flags, NULL);
}
EXPORT_SYMBOL(__kmalloc);
3737 3738
#endif

P
Pekka Enberg 已提交
3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785
/**
 * krealloc - reallocate memory. The contents will remain unchanged.
 *
 * @p: object to reallocate memory for.
 * @new_size: how many bytes of memory are required.
 * @flags: the type of memory to allocate.
 *
 * The contents of the object pointed to are preserved up to the
 * lesser of the new and old sizes.  If @p is %NULL, krealloc()
 * behaves exactly like kmalloc().  If @size is 0 and @p is not a
 * %NULL pointer, the object pointed to is freed.
 */
void *krealloc(const void *p, size_t new_size, gfp_t flags)
{
	struct kmem_cache *cache, *new_cache;
	void *ret;

	if (unlikely(!p))
		return kmalloc_track_caller(new_size, flags);

	if (unlikely(!new_size)) {
		kfree(p);
		return NULL;
	}

	cache = virt_to_cache(p);
	new_cache = __find_general_cachep(new_size, flags);

	/*
 	 * If new size fits in the current cache, bail out.
 	 */
	if (likely(cache == new_cache))
		return (void *)p;

	/*
 	 * We are on the slow-path here so do not use __cache_alloc
 	 * because it bloats kernel text.
 	 */
	ret = kmalloc_track_caller(new_size, flags);
	if (ret) {
		memcpy(ret, p, min(new_size, ksize(p)));
		kfree(p);
	}
	return ret;
}
EXPORT_SYMBOL(krealloc);

L
Linus Torvalds 已提交
3786 3787 3788 3789 3790 3791 3792 3793
/**
 * 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.
 */
3794
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3795 3796 3797
{
	unsigned long flags;

3798 3799
	BUG_ON(virt_to_cache(objp) != cachep);

L
Linus Torvalds 已提交
3800
	local_irq_save(flags);
3801
	debug_check_no_locks_freed(objp, obj_size(cachep));
3802
	__cache_free(cachep, objp);
L
Linus Torvalds 已提交
3803 3804 3805 3806 3807 3808 3809 3810
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kmem_cache_free);

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3811 3812
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3813 3814 3815 3816 3817
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
3818
	struct kmem_cache *c;
L
Linus Torvalds 已提交
3819 3820 3821 3822 3823 3824
	unsigned long flags;

	if (unlikely(!objp))
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3825
	c = virt_to_cache(objp);
3826
	debug_check_no_locks_freed(objp, obj_size(c));
3827
	__cache_free(c, (void *)objp);
L
Linus Torvalds 已提交
3828 3829 3830 3831
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

3832
unsigned int kmem_cache_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3833
{
3834
	return obj_size(cachep);
L
Linus Torvalds 已提交
3835 3836 3837
}
EXPORT_SYMBOL(kmem_cache_size);

3838
const char *kmem_cache_name(struct kmem_cache *cachep)
3839 3840 3841 3842 3843
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3844
/*
3845
 * This initializes kmem_list3 or resizes varioius caches for all nodes.
3846
 */
3847
static int alloc_kmemlist(struct kmem_cache *cachep)
3848 3849 3850
{
	int node;
	struct kmem_list3 *l3;
3851
	struct array_cache *new_shared;
3852
	struct array_cache **new_alien = NULL;
3853 3854

	for_each_online_node(node) {
3855

3856 3857 3858 3859 3860
                if (use_alien_caches) {
                        new_alien = alloc_alien_cache(node, cachep->limit);
                        if (!new_alien)
                                goto fail;
                }
3861

3862 3863 3864
		new_shared = NULL;
		if (cachep->shared) {
			new_shared = alloc_arraycache(node,
3865
				cachep->shared*cachep->batchcount,
A
Andrew Morton 已提交
3866
					0xbaadf00d);
3867 3868 3869 3870
			if (!new_shared) {
				free_alien_cache(new_alien);
				goto fail;
			}
3871
		}
3872

A
Andrew Morton 已提交
3873 3874
		l3 = cachep->nodelists[node];
		if (l3) {
3875 3876
			struct array_cache *shared = l3->shared;

3877 3878
			spin_lock_irq(&l3->list_lock);

3879
			if (shared)
3880 3881
				free_block(cachep, shared->entry,
						shared->avail, node);
3882

3883 3884
			l3->shared = new_shared;
			if (!l3->alien) {
3885 3886 3887
				l3->alien = new_alien;
				new_alien = NULL;
			}
P
Pekka Enberg 已提交
3888
			l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3889
					cachep->batchcount + cachep->num;
3890
			spin_unlock_irq(&l3->list_lock);
3891
			kfree(shared);
3892 3893 3894
			free_alien_cache(new_alien);
			continue;
		}
A
Andrew Morton 已提交
3895
		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
3896 3897 3898
		if (!l3) {
			free_alien_cache(new_alien);
			kfree(new_shared);
3899
			goto fail;
3900
		}
3901 3902 3903

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
A
Andrew Morton 已提交
3904
				((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3905
		l3->shared = new_shared;
3906
		l3->alien = new_alien;
P
Pekka Enberg 已提交
3907
		l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3908
					cachep->batchcount + cachep->num;
3909 3910
		cachep->nodelists[node] = l3;
	}
3911
	return 0;
3912

A
Andrew Morton 已提交
3913
fail:
3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928
	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--;
		}
	}
3929
	return -ENOMEM;
3930 3931
}

L
Linus Torvalds 已提交
3932
struct ccupdate_struct {
3933
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3934 3935 3936 3937 3938
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
A
Andrew Morton 已提交
3939
	struct ccupdate_struct *new = info;
L
Linus Torvalds 已提交
3940 3941 3942
	struct array_cache *old;

	check_irq_off();
3943
	old = cpu_cache_get(new->cachep);
3944

L
Linus Torvalds 已提交
3945 3946 3947 3948
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}

3949
/* Always called with the cache_chain_mutex held */
A
Andrew Morton 已提交
3950 3951
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
				int batchcount, int shared)
L
Linus Torvalds 已提交
3952
{
3953
	struct ccupdate_struct *new;
3954
	int i;
L
Linus Torvalds 已提交
3955

3956 3957 3958 3959
	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		return -ENOMEM;

3960
	for_each_online_cpu(i) {
3961
		new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
A
Andrew Morton 已提交
3962
						batchcount);
3963
		if (!new->new[i]) {
P
Pekka Enberg 已提交
3964
			for (i--; i >= 0; i--)
3965 3966
				kfree(new->new[i]);
			kfree(new);
3967
			return -ENOMEM;
L
Linus Torvalds 已提交
3968 3969
		}
	}
3970
	new->cachep = cachep;
L
Linus Torvalds 已提交
3971

3972
	on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
3973

L
Linus Torvalds 已提交
3974 3975 3976
	check_irq_on();
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3977
	cachep->shared = shared;
L
Linus Torvalds 已提交
3978

3979
	for_each_online_cpu(i) {
3980
		struct array_cache *ccold = new->new[i];
L
Linus Torvalds 已提交
3981 3982
		if (!ccold)
			continue;
3983
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3984
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3985
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3986 3987
		kfree(ccold);
	}
3988
	kfree(new);
3989
	return alloc_kmemlist(cachep);
L
Linus Torvalds 已提交
3990 3991
}

3992
/* Called with cache_chain_mutex held always */
3993
static int enable_cpucache(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3994 3995 3996 3997
{
	int err;
	int limit, shared;

A
Andrew Morton 已提交
3998 3999
	/*
	 * The head array serves three purposes:
L
Linus Torvalds 已提交
4000 4001
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
A
Andrew Morton 已提交
4002
	 * - reduce the number of linked list operations on the slab and
L
Linus Torvalds 已提交
4003 4004 4005 4006
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
4007
	if (cachep->buffer_size > 131072)
L
Linus Torvalds 已提交
4008
		limit = 1;
4009
	else if (cachep->buffer_size > PAGE_SIZE)
L
Linus Torvalds 已提交
4010
		limit = 8;
4011
	else if (cachep->buffer_size > 1024)
L
Linus Torvalds 已提交
4012
		limit = 24;
4013
	else if (cachep->buffer_size > 256)
L
Linus Torvalds 已提交
4014 4015 4016 4017
		limit = 54;
	else
		limit = 120;

A
Andrew Morton 已提交
4018 4019
	/*
	 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
L
Linus Torvalds 已提交
4020 4021 4022 4023 4024 4025 4026 4027
	 * 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;
4028
	if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1)
L
Linus Torvalds 已提交
4029 4030 4031
		shared = 8;

#if DEBUG
A
Andrew Morton 已提交
4032 4033 4034
	/*
	 * With debugging enabled, large batchcount lead to excessively long
	 * periods with disabled local interrupts. Limit the batchcount
L
Linus Torvalds 已提交
4035 4036 4037 4038
	 */
	if (limit > 32)
		limit = 32;
#endif
P
Pekka Enberg 已提交
4039
	err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
L
Linus Torvalds 已提交
4040 4041
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
P
Pekka Enberg 已提交
4042
		       cachep->name, -err);
4043
	return err;
L
Linus Torvalds 已提交
4044 4045
}

4046 4047
/*
 * Drain an array if it contains any elements taking the l3 lock only if
4048 4049
 * necessary. Note that the l3 listlock also protects the array_cache
 * if drain_array() is used on the shared array.
4050 4051 4052
 */
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
4053 4054 4055
{
	int tofree;

4056 4057
	if (!ac || !ac->avail)
		return;
L
Linus Torvalds 已提交
4058 4059
	if (ac->touched && !force) {
		ac->touched = 0;
4060
	} else {
4061
		spin_lock_irq(&l3->list_lock);
4062 4063 4064 4065 4066 4067 4068 4069 4070
		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);
		}
4071
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4072 4073 4074 4075 4076
	}
}

/**
 * cache_reap - Reclaim memory from caches.
4077
 * @w: work descriptor
L
Linus Torvalds 已提交
4078 4079 4080 4081 4082 4083
 *
 * 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
4084 4085
 * 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
4086
 */
4087
static void cache_reap(struct work_struct *w)
L
Linus Torvalds 已提交
4088
{
4089
	struct kmem_cache *searchp;
4090
	struct kmem_list3 *l3;
4091
	int node = numa_node_id();
4092 4093
	struct delayed_work *work =
		container_of(w, struct delayed_work, work);
L
Linus Torvalds 已提交
4094

4095
	if (!mutex_trylock(&cache_chain_mutex))
L
Linus Torvalds 已提交
4096
		/* Give up. Setup the next iteration. */
4097
		goto out;
L
Linus Torvalds 已提交
4098

4099
	list_for_each_entry(searchp, &cache_chain, next) {
L
Linus Torvalds 已提交
4100 4101
		check_irq_on();

4102 4103 4104 4105 4106
		/*
		 * 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.
		 */
4107
		l3 = searchp->nodelists[node];
4108

4109
		reap_alien(searchp, l3);
L
Linus Torvalds 已提交
4110

4111
		drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
L
Linus Torvalds 已提交
4112

4113 4114 4115 4116
		/*
		 * These are racy checks but it does not matter
		 * if we skip one check or scan twice.
		 */
4117
		if (time_after(l3->next_reap, jiffies))
4118
			goto next;
L
Linus Torvalds 已提交
4119

4120
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
4121

4122
		drain_array(searchp, l3, l3->shared, 0, node);
L
Linus Torvalds 已提交
4123

4124
		if (l3->free_touched)
4125
			l3->free_touched = 0;
4126 4127
		else {
			int freed;
L
Linus Torvalds 已提交
4128

4129 4130 4131 4132
			freed = drain_freelist(searchp, l3, (l3->free_limit +
				5 * searchp->num - 1) / (5 * searchp->num));
			STATS_ADD_REAPED(searchp, freed);
		}
4133
next:
L
Linus Torvalds 已提交
4134 4135 4136
		cond_resched();
	}
	check_irq_on();
I
Ingo Molnar 已提交
4137
	mutex_unlock(&cache_chain_mutex);
4138
	next_reap_node();
4139
	refresh_cpu_vm_stats(smp_processor_id());
4140
out:
A
Andrew Morton 已提交
4141
	/* Set up the next iteration */
4142
	schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
L
Linus Torvalds 已提交
4143 4144 4145 4146
}

#ifdef CONFIG_PROC_FS

4147
static void print_slabinfo_header(struct seq_file *m)
L
Linus Torvalds 已提交
4148
{
4149 4150 4151 4152
	/*
	 * Output format version, so at least we can change it
	 * without _too_ many complaints.
	 */
L
Linus Torvalds 已提交
4153
#if STATS
4154
	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
L
Linus Torvalds 已提交
4155
#else
4156
	seq_puts(m, "slabinfo - version: 2.1\n");
L
Linus Torvalds 已提交
4157
#endif
4158 4159 4160 4161
	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
4162
#if STATS
4163
	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
4164
		 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
4165
	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
L
Linus Torvalds 已提交
4166
#endif
4167 4168 4169 4170 4171 4172 4173 4174
	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
4175
	mutex_lock(&cache_chain_mutex);
4176 4177
	if (!n)
		print_slabinfo_header(m);
L
Linus Torvalds 已提交
4178 4179 4180 4181 4182 4183
	p = cache_chain.next;
	while (n--) {
		p = p->next;
		if (p == &cache_chain)
			return NULL;
	}
4184
	return list_entry(p, struct kmem_cache, next);
L
Linus Torvalds 已提交
4185 4186 4187 4188
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
4189
	struct kmem_cache *cachep = p;
L
Linus Torvalds 已提交
4190
	++*pos;
A
Andrew Morton 已提交
4191 4192
	return cachep->next.next == &cache_chain ?
		NULL : list_entry(cachep->next.next, struct kmem_cache, next);
L
Linus Torvalds 已提交
4193 4194 4195 4196
}

static void s_stop(struct seq_file *m, void *p)
{
I
Ingo Molnar 已提交
4197
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4198 4199 4200 4201
}

static int s_show(struct seq_file *m, void *p)
{
4202
	struct kmem_cache *cachep = p;
P
Pekka Enberg 已提交
4203 4204 4205 4206 4207
	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;
4208
	const char *name;
L
Linus Torvalds 已提交
4209
	char *error = NULL;
4210 4211
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
4212 4213 4214

	active_objs = 0;
	num_slabs = 0;
4215 4216 4217 4218 4219
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

4220 4221
		check_irq_on();
		spin_lock_irq(&l3->list_lock);
4222

4223
		list_for_each_entry(slabp, &l3->slabs_full, list) {
4224 4225 4226 4227 4228
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
4229
		list_for_each_entry(slabp, &l3->slabs_partial, list) {
4230 4231 4232 4233 4234 4235 4236
			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++;
		}
4237
		list_for_each_entry(slabp, &l3->slabs_free, list) {
4238 4239 4240 4241 4242
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
4243 4244
		if (l3->shared)
			shared_avail += l3->shared->avail;
4245

4246
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4247
	}
P
Pekka Enberg 已提交
4248 4249
	num_slabs += active_slabs;
	num_objs = num_slabs * cachep->num;
4250
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
4251 4252
		error = "free_objects accounting error";

P
Pekka Enberg 已提交
4253
	name = cachep->name;
L
Linus Torvalds 已提交
4254 4255 4256 4257
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
4258
		   name, active_objs, num_objs, cachep->buffer_size,
P
Pekka Enberg 已提交
4259
		   cachep->num, (1 << cachep->gfporder));
L
Linus Torvalds 已提交
4260
	seq_printf(m, " : tunables %4u %4u %4u",
P
Pekka Enberg 已提交
4261
		   cachep->limit, cachep->batchcount, cachep->shared);
4262
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
P
Pekka Enberg 已提交
4263
		   active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
4264
#if STATS
P
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4265
	{			/* list3 stats */
L
Linus Torvalds 已提交
4266 4267 4268 4269 4270 4271 4272
		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;
4273
		unsigned long node_frees = cachep->node_frees;
4274
		unsigned long overflows = cachep->node_overflow;
L
Linus Torvalds 已提交
4275

4276
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
4277
				%4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
A
Andrew Morton 已提交
4278
				reaped, errors, max_freeable, node_allocs,
4279
				node_frees, overflows);
L
Linus Torvalds 已提交
4280 4281 4282 4283 4284 4285 4286 4287 4288
	}
	/* 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
4289
			   allochit, allocmiss, freehit, freemiss);
L
Linus Torvalds 已提交
4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309
	}
#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
 */

4310
const struct seq_operations slabinfo_op = {
P
Pekka Enberg 已提交
4311 4312 4313 4314
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
L
Linus Torvalds 已提交
4315 4316 4317 4318 4319 4320 4321 4322 4323 4324
};

#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
4325 4326
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
		       size_t count, loff_t *ppos)
L
Linus Torvalds 已提交
4327
{
P
Pekka Enberg 已提交
4328
	char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
L
Linus Torvalds 已提交
4329
	int limit, batchcount, shared, res;
4330
	struct kmem_cache *cachep;
P
Pekka Enberg 已提交
4331

L
Linus Torvalds 已提交
4332 4333 4334 4335
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
P
Pekka Enberg 已提交
4336
	kbuf[MAX_SLABINFO_WRITE] = '\0';
L
Linus Torvalds 已提交
4337 4338 4339 4340 4341 4342 4343 4344 4345 4346

	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
4347
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4348
	res = -EINVAL;
4349
	list_for_each_entry(cachep, &cache_chain, next) {
L
Linus Torvalds 已提交
4350
		if (!strcmp(cachep->name, kbuf)) {
A
Andrew Morton 已提交
4351 4352
			if (limit < 1 || batchcount < 1 ||
					batchcount > limit || shared < 0) {
4353
				res = 0;
L
Linus Torvalds 已提交
4354
			} else {
4355
				res = do_tune_cpucache(cachep, limit,
P
Pekka Enberg 已提交
4356
						       batchcount, shared);
L
Linus Torvalds 已提交
4357 4358 4359 4360
			}
			break;
		}
	}
I
Ingo Molnar 已提交
4361
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4362 4363 4364 4365
	if (res >= 0)
		res = count;
	return res;
}
4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473 4474

#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);

4475
		list_for_each_entry(slabp, &l3->slabs_full, list)
4476
			handle_slab(n, cachep, slabp);
4477
		list_for_each_entry(slabp, &l3->slabs_partial, list)
4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503
			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');
	}
4504

4505 4506 4507
	return 0;
}

4508
const struct seq_operations slabstats_op = {
4509 4510 4511 4512 4513 4514
	.start = leaks_start,
	.next = s_next,
	.stop = s_stop,
	.show = leaks_show,
};
#endif
L
Linus Torvalds 已提交
4515 4516
#endif

4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528
/**
 * 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.
 */
P
Pekka Enberg 已提交
4529
size_t ksize(const void *objp)
L
Linus Torvalds 已提交
4530
{
4531 4532
	if (unlikely(objp == NULL))
		return 0;
L
Linus Torvalds 已提交
4533

4534
	return obj_size(virt_to_cache(objp));
L
Linus Torvalds 已提交
4535
}