slab.c 107.1 KB
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/*
 * linux/mm/slab.c
 * Written by Mark Hemment, 1996/97.
 * (markhe@nextd.demon.co.uk)
 *
 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
 *
 * Major cleanup, different bufctl logic, per-cpu arrays
 *	(c) 2000 Manfred Spraul
 *
 * Cleanup, make the head arrays unconditional, preparation for NUMA
 * 	(c) 2002 Manfred Spraul
 *
 * An implementation of the Slab Allocator as described in outline in;
 *	UNIX Internals: The New Frontiers by Uresh Vahalia
 *	Pub: Prentice Hall	ISBN 0-13-101908-2
 * or with a little more detail in;
 *	The Slab Allocator: An Object-Caching Kernel Memory Allocator
 *	Jeff Bonwick (Sun Microsystems).
 *	Presented at: USENIX Summer 1994 Technical Conference
 *
 * The memory is organized in caches, one cache for each object type.
 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
 * Each cache consists out of many slabs (they are small (usually one
 * page long) and always contiguous), and each slab contains multiple
 * initialized objects.
 *
 * This means, that your constructor is used only for newly allocated
 * slabs and you must pass objects with the same intializations to
 * kmem_cache_free.
 *
 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
 * normal). If you need a special memory type, then must create a new
 * cache for that memory type.
 *
 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
 *   full slabs with 0 free objects
 *   partial slabs
 *   empty slabs with no allocated objects
 *
 * If partial slabs exist, then new allocations come from these slabs,
 * otherwise from empty slabs or new slabs are allocated.
 *
 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
 *
 * Each cache has a short per-cpu head array, most allocs
 * and frees go into that array, and if that array overflows, then 1/2
 * of the entries in the array are given back into the global cache.
 * The head array is strictly LIFO and should improve the cache hit rates.
 * On SMP, it additionally reduces the spinlock operations.
 *
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 * The c_cpuarray may not be read with enabled local interrupts -
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 * it's changed with a smp_call_function().
 *
 * SMP synchronization:
 *  constructors and destructors are called without any locking.
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 *  Several members in struct kmem_cache and struct slab never change, they
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 *	are accessed without any locking.
 *  The per-cpu arrays are never accessed from the wrong cpu, no locking,
 *  	and local interrupts are disabled so slab code is preempt-safe.
 *  The non-constant members are protected with a per-cache irq spinlock.
 *
 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
 * in 2000 - many ideas in the current implementation are derived from
 * his patch.
 *
 * Further notes from the original documentation:
 *
 * 11 April '97.  Started multi-threading - markhe
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 *	The global cache-chain is protected by the mutex 'cache_chain_mutex'.
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 *	The sem is only needed when accessing/extending the cache-chain, which
 *	can never happen inside an interrupt (kmem_cache_create(),
 *	kmem_cache_shrink() and kmem_cache_reap()).
 *
 *	At present, each engine can be growing a cache.  This should be blocked.
 *
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 * 15 March 2005. NUMA slab allocator.
 *	Shai Fultheim <shai@scalex86.org>.
 *	Shobhit Dayal <shobhit@calsoftinc.com>
 *	Alok N Kataria <alokk@calsoftinc.com>
 *	Christoph Lameter <christoph@lameter.com>
 *
 *	Modified the slab allocator to be node aware on NUMA systems.
 *	Each node has its own list of partial, free and full slabs.
 *	All object allocations for a node occur from node specific slab lists.
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 */

#include	<linux/config.h>
#include	<linux/slab.h>
#include	<linux/mm.h>
#include	<linux/swap.h>
#include	<linux/cache.h>
#include	<linux/interrupt.h>
#include	<linux/init.h>
#include	<linux/compiler.h>
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#include	<linux/cpuset.h>
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#include	<linux/seq_file.h>
#include	<linux/notifier.h>
#include	<linux/kallsyms.h>
#include	<linux/cpu.h>
#include	<linux/sysctl.h>
#include	<linux/module.h>
#include	<linux/rcupdate.h>
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#include	<linux/string.h>
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#include	<linux/nodemask.h>
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#include	<linux/mempolicy.h>
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#include	<linux/mutex.h>
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#include	<asm/uaccess.h>
#include	<asm/cacheflush.h>
#include	<asm/tlbflush.h>
#include	<asm/page.h>

/*
 * DEBUG	- 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
 *		  SLAB_RED_ZONE & SLAB_POISON.
 *		  0 for faster, smaller code (especially in the critical paths).
 *
 * STATS	- 1 to collect stats for /proc/slabinfo.
 *		  0 for faster, smaller code (especially in the critical paths).
 *
 * FORCED_DEBUG	- 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
 */

#ifdef CONFIG_DEBUG_SLAB
#define	DEBUG		1
#define	STATS		1
#define	FORCED_DEBUG	1
#else
#define	DEBUG		0
#define	STATS		0
#define	FORCED_DEBUG	0
#endif

/* Shouldn't this be in a header file somewhere? */
#define	BYTES_PER_WORD		sizeof(void *)

#ifndef cache_line_size
#define cache_line_size()	L1_CACHE_BYTES
#endif

#ifndef ARCH_KMALLOC_MINALIGN
/*
 * Enforce a minimum alignment for the kmalloc caches.
 * Usually, the kmalloc caches are cache_line_size() aligned, except when
 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
 * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
 * Note that this flag disables some debug features.
 */
#define ARCH_KMALLOC_MINALIGN 0
#endif

#ifndef ARCH_SLAB_MINALIGN
/*
 * Enforce a minimum alignment for all caches.
 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
 * some debug features.
 */
#define ARCH_SLAB_MINALIGN 0
#endif

#ifndef ARCH_KMALLOC_FLAGS
#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
#endif

/* Legal flag mask for kmem_cache_create(). */
#if DEBUG
# define CREATE_MASK	(SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
			 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
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			 SLAB_CACHE_DMA | \
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			 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
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			 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
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#else
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# define CREATE_MASK	(SLAB_HWCACHE_ALIGN | \
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			 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
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			 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
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#endif

/*
 * kmem_bufctl_t:
 *
 * Bufctl's are used for linking objs within a slab
 * linked offsets.
 *
 * This implementation relies on "struct page" for locating the cache &
 * slab an object belongs to.
 * This allows the bufctl structure to be small (one int), but limits
 * the number of objects a slab (not a cache) can contain when off-slab
 * bufctls are used. The limit is the size of the largest general cache
 * that does not use off-slab slabs.
 * For 32bit archs with 4 kB pages, is this 56.
 * This is not serious, as it is only for large objects, when it is unwise
 * to have too many per slab.
 * Note: This limit can be raised by introducing a general cache whose size
 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
 */

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typedef unsigned int kmem_bufctl_t;
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#define BUFCTL_END	(((kmem_bufctl_t)(~0U))-0)
#define BUFCTL_FREE	(((kmem_bufctl_t)(~0U))-1)
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#define	BUFCTL_ACTIVE	(((kmem_bufctl_t)(~0U))-2)
#define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-3)
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/* Max number of objs-per-slab for caches which use off-slab slabs.
 * Needed to avoid a possible looping condition in cache_grow().
 */
static unsigned long offslab_limit;

/*
 * struct slab
 *
 * Manages the objs in a slab. Placed either at the beginning of mem allocated
 * for a slab, or allocated from an general cache.
 * Slabs are chained into three list: fully used, partial, fully free slabs.
 */
struct slab {
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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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 * 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;
}

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

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

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#define	MAKE_ALL_LISTS(cachep, ptr, nodeid)				\
	do {								\
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	MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid);	\
	MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
	MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid);	\
	} while (0)
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/*
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 * struct kmem_cache
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 *
 * manages a cache.
 */
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struct kmem_cache {
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/* 1) per-cpu data, touched during every alloc/free */
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	struct array_cache *array[NR_CPUS];
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/* 2) Cache tunables. Protected by cache_chain_mutex */
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	unsigned int batchcount;
	unsigned int limit;
	unsigned int shared;
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	unsigned int buffer_size;
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/* 3) touched by every alloc & free from the backend */
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	struct kmem_list3 *nodelists[MAX_NUMNODES];
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	unsigned int flags;		/* constant flags */
	unsigned int num;		/* # of objs per slab */
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/* 4) cache_grow/shrink */
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	/* order of pgs per slab (2^n) */
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	unsigned int gfporder;
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	/* force GFP flags, e.g. GFP_DMA */
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	gfp_t gfpflags;
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	size_t colour;			/* cache colouring range */
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	unsigned int colour_off;	/* colour offset */
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	struct kmem_cache *slabp_cache;
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	unsigned int slab_size;
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	unsigned int dflags;		/* dynamic flags */
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	/* constructor func */
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	void (*ctor) (void *, struct kmem_cache *, unsigned long);
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	/* de-constructor func */
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	void (*dtor) (void *, struct kmem_cache *, unsigned long);
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/* 5) cache creation/removal */
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	const char *name;
	struct list_head next;
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/* 6) statistics */
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#if STATS
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	unsigned long num_active;
	unsigned long num_allocations;
	unsigned long high_mark;
	unsigned long grown;
	unsigned long reaped;
	unsigned long errors;
	unsigned long max_freeable;
	unsigned long node_allocs;
	unsigned long node_frees;
	atomic_t allochit;
	atomic_t allocmiss;
	atomic_t freehit;
	atomic_t freemiss;
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#endif
#if DEBUG
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	/*
	 * If debugging is enabled, then the allocator can add additional
	 * fields and/or padding to every object. buffer_size contains the total
	 * object size including these internal fields, the following two
	 * variables contain the offset to the user object and its size.
	 */
	int obj_offset;
	int obj_size;
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#endif
};

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

#define BATCHREFILL_LIMIT	16
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/*
 * Optimization question: fewer reaps means less probability for unnessary
 * cpucache drain/refill cycles.
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 *
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 * OTOH the cpuarrays can contain lots of objects,
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 * which could lock up otherwise freeable slabs.
 */
#define REAPTIMEOUT_CPUC	(2*HZ)
#define REAPTIMEOUT_LIST3	(4*HZ)

#if STATS
#define	STATS_INC_ACTIVE(x)	((x)->num_active++)
#define	STATS_DEC_ACTIVE(x)	((x)->num_active--)
#define	STATS_INC_ALLOCED(x)	((x)->num_allocations++)
#define	STATS_INC_GROWN(x)	((x)->grown++)
#define	STATS_INC_REAPED(x)	((x)->reaped++)
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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_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)
#define	STATS_INC_REAPED(x)	do { } while (0)
#define	STATS_SET_HIGH(x)	do { } while (0)
#define	STATS_INC_ERR(x)	do { } while (0)
#define	STATS_INC_NODEALLOCS(x)	do { } while (0)
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#define	STATS_INC_NODEFREES(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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/*
 * Magic nums for obj red zoning.
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 * Placed in the first word before and the first word after an obj.
 */
#define	RED_INACTIVE	0x5A2CF071UL	/* when obj is inactive */
#define	RED_ACTIVE	0x170FC2A5UL	/* when obj is active */

/* ...and for poisoning */
#define	POISON_INUSE	0x5a	/* for use-uninitialised poisoning */
#define POISON_FREE	0x6b	/* for use-after-free poisoning */
#define	POISON_END	0xa5	/* end-byte of poisoning */

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

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static int obj_size(struct kmem_cache *cachep)
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{
527
	return cachep->obj_size;
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}

530
static unsigned long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
533
	return (unsigned long*) (objp+obj_offset(cachep)-BYTES_PER_WORD);
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}

536
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)
540
		return (unsigned long *)(objp + cachep->buffer_size -
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					 2 * BYTES_PER_WORD);
542
	return (unsigned long *)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

545
static void **dbg_userword(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
548
	return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

#else

553 554
#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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 */
588 589 590 591 592 593 594
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)
{
595 596
	if (unlikely(PageCompound(page)))
		page = (struct page *)page_private(page);
597 598 599 600 601 602 603 604 605 606
	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)
{
607 608
	if (unlikely(PageCompound(page)))
		page = (struct page *)page_private(page);
609 610
	return (struct slab *)page->lru.prev;
}
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612 613 614 615 616 617 618 619 620 621 622 623
static inline struct kmem_cache *virt_to_cache(const void *obj)
{
	struct page *page = virt_to_page(obj);
	return page_get_cache(page);
}

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

624 625 626 627 628 629 630 631 632 633 634 635
static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
				 unsigned int idx)
{
	return slab->s_mem + cache->buffer_size * idx;
}

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

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/*
 * These are the default caches for kmalloc. Custom caches can have other sizes.
 */
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struct cache_sizes malloc_sizes[] = {
#define CACHE(x) { .cs_size = (x) },
#include <linux/kmalloc_sizes.h>
	CACHE(ULONG_MAX)
#undef CACHE
};
EXPORT_SYMBOL(malloc_sizes);

/* Must match cache_sizes above. Out of line to keep cache footprint low. */
struct cache_names {
	char *name;
	char *name_dma;
};

static struct cache_names __initdata cache_names[] = {
#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
#include <linux/kmalloc_sizes.h>
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	{NULL,}
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#undef CACHE
};

static struct arraycache_init initarray_cache __initdata =
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    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
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static struct arraycache_init initarray_generic =
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    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
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/* internal cache of cache description objs */
666
static struct kmem_cache cache_cache = {
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	.batchcount = 1,
	.limit = BOOT_CPUCACHE_ENTRIES,
	.shared = 1,
670
	.buffer_size = sizeof(struct kmem_cache),
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	.name = "kmem_cache",
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#if DEBUG
673
	.obj_size = sizeof(struct kmem_cache),
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#endif
};

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

/*
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 * vm_enough_memory() looks at this to determine how many slab-allocated pages
 * are possibly freeable under pressure
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 *
 * SLAB_RECLAIM_ACCOUNT turns this on per-slab
 */
atomic_t slab_reclaim_pages;

/*
 * chicken and egg problem: delay the per-cpu array allocation
 * until the general caches are up.
 */
static enum {
	NONE,
695 696
	PARTIAL_AC,
	PARTIAL_L3,
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	FULL
} g_cpucache_up;

static DEFINE_PER_CPU(struct work_struct, reap_work);

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static void free_block(struct kmem_cache *cachep, void **objpp, int len,
			int node);
704
static void enable_cpucache(struct kmem_cache *cachep);
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static void cache_reap(void *unused);
706
static int __node_shrink(struct kmem_cache *cachep, int node);
L
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707

708
static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
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709 710 711 712
{
	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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715 716 717 718 719
{
	struct cache_sizes *csizep = malloc_sizes;

#if DEBUG
	/* This happens if someone tries to call
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720 721 722
	 * kmem_cache_create(), or __kmalloc(), before
	 * the generic caches are initialized.
	 */
723
	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
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724 725 726 727 728
#endif
	while (size > csizep->cs_size)
		csizep++;

	/*
729
	 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
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	 * has cs_{dma,}cachep==NULL. Thus no special case
	 * for large kmalloc calls required.
	 */
	if (unlikely(gfpflags & GFP_DMA))
		return csizep->cs_dmacachep;
	return csizep->cs_cachep;
}

738
struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
739 740 741 742 743
{
	return __find_general_cachep(size, gfpflags);
}
EXPORT_SYMBOL(kmem_find_general_cachep);

744
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
L
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745
{
746 747
	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
}
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748

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/*
 * Calculate the number of objects and left-over bytes for a given buffer size.
 */
752 753 754 755 756 757 758
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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760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807
	/*
	 * 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)

A
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static void __slab_error(const char *function, struct kmem_cache *cachep,
			char *msg)
L
Linus Torvalds 已提交
814 815
{
	printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
P
Pekka Enberg 已提交
816
	       function, cachep->name, msg);
L
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817 818 819
	dump_stack();
}

820 821 822 823 824 825 826 827 828 829 830 831 832 833 834
#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)
835
		node = first_node(node_online_map);
836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860

	__get_cpu_var(reap_node) = node;
}

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

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

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

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

L
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861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877
/*
 * Initiate the reap timer running on the target CPU.  We run at around 1 to 2Hz
 * via the workqueue/eventd.
 * Add the CPU number into the expiration time to minimize the possibility of
 * the CPUs getting into lockstep and contending for the global cache chain
 * lock.
 */
static void __devinit start_cpu_timer(int cpu)
{
	struct work_struct *reap_work = &per_cpu(reap_work, cpu);

	/*
	 * When this gets called from do_initcalls via cpucache_init(),
	 * init_workqueues() has already run, so keventd will be setup
	 * at that time.
	 */
	if (keventd_up() && reap_work->func == NULL) {
878
		init_reap_node(cpu);
L
Linus Torvalds 已提交
879 880 881 882 883
		INIT_WORK(reap_work, cache_reap, NULL);
		schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
	}
}

884
static struct array_cache *alloc_arraycache(int node, int entries,
P
Pekka Enberg 已提交
885
					    int batchcount)
L
Linus Torvalds 已提交
886
{
P
Pekka Enberg 已提交
887
	int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
L
Linus Torvalds 已提交
888 889
	struct array_cache *nc = NULL;

890
	nc = kmalloc_node(memsize, GFP_KERNEL, node);
L
Linus Torvalds 已提交
891 892 893 894 895
	if (nc) {
		nc->avail = 0;
		nc->limit = entries;
		nc->batchcount = batchcount;
		nc->touched = 0;
896
		spin_lock_init(&nc->lock);
L
Linus Torvalds 已提交
897 898 899 900
	}
	return nc;
}

901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924
/*
 * 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;
}

925
#ifdef CONFIG_NUMA
926
static void *__cache_alloc_node(struct kmem_cache *, gfp_t, int);
927
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
928

P
Pekka Enberg 已提交
929
static struct array_cache **alloc_alien_cache(int node, int limit)
930 931
{
	struct array_cache **ac_ptr;
P
Pekka Enberg 已提交
932
	int memsize = sizeof(void *) * MAX_NUMNODES;
933 934 935 936 937 938 939 940 941 942 943 944 945
	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]) {
P
Pekka Enberg 已提交
946
				for (i--; i <= 0; i--)
947 948 949 950 951 952 953 954 955
					kfree(ac_ptr[i]);
				kfree(ac_ptr);
				return NULL;
			}
		}
	}
	return ac_ptr;
}

P
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956
static void free_alien_cache(struct array_cache **ac_ptr)
957 958 959 960 961 962
{
	int i;

	if (!ac_ptr)
		return;
	for_each_node(i)
P
Pekka Enberg 已提交
963
	    kfree(ac_ptr[i]);
964 965 966
	kfree(ac_ptr);
}

967
static void __drain_alien_cache(struct kmem_cache *cachep,
P
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968
				struct array_cache *ac, int node)
969 970 971 972 973
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
974 975 976 977 978 979 980
		/*
		 * 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.
		 */
		transfer_objects(rl3->shared, ac, ac->limit);

981
		free_block(cachep, ac->entry, ac->avail, node);
982 983 984 985 986
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

987 988 989 990 991 992 993 994 995
/*
 * 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];
996 997

		if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
998 999 1000 1001 1002 1003
			__drain_alien_cache(cachep, ac, node);
			spin_unlock_irq(&ac->lock);
		}
	}
}

A
Andrew Morton 已提交
1004 1005
static void drain_alien_cache(struct kmem_cache *cachep,
				struct array_cache **alien)
1006
{
P
Pekka Enberg 已提交
1007
	int i = 0;
1008 1009 1010 1011
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
1012
		ac = alien[i];
1013 1014 1015 1016 1017 1018 1019 1020
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
#else
1021

1022
#define drain_alien_cache(cachep, alien) do { } while (0)
1023
#define reap_alien(cachep, l3) do { } while (0)
1024

1025 1026 1027 1028 1029
static inline struct array_cache **alloc_alien_cache(int node, int limit)
{
	return (struct array_cache **) 0x01020304ul;
}

1030 1031 1032
static inline void free_alien_cache(struct array_cache **ac_ptr)
{
}
1033

1034 1035
#endif

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1036
static int __devinit cpuup_callback(struct notifier_block *nfb,
P
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1037
				    unsigned long action, void *hcpu)
L
Linus Torvalds 已提交
1038 1039
{
	long cpu = (long)hcpu;
1040
	struct kmem_cache *cachep;
1041 1042 1043
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
	int memsize = sizeof(struct kmem_list3);
L
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1044 1045 1046

	switch (action) {
	case CPU_UP_PREPARE:
I
Ingo Molnar 已提交
1047
		mutex_lock(&cache_chain_mutex);
A
Andrew Morton 已提交
1048 1049
		/*
		 * We need to do this right in the beginning since
1050 1051 1052 1053 1054
		 * 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
1055
		list_for_each_entry(cachep, &cache_chain, next) {
A
Andrew Morton 已提交
1056 1057
			/*
			 * Set up the size64 kmemlist for cpu before we can
1058 1059 1060 1061
			 * 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
1062 1063
				l3 = kmalloc_node(memsize, GFP_KERNEL, node);
				if (!l3)
1064 1065 1066
					goto bad;
				kmem_list3_init(l3);
				l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
P
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1067
				    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1068

1069 1070 1071 1072 1073
				/*
				 * The l3s don't come and go as CPUs come and
				 * go.  cache_chain_mutex is sufficient
				 * protection here.
				 */
1074 1075
				cachep->nodelists[node] = l3;
			}
L
Linus Torvalds 已提交
1076

1077 1078
			spin_lock_irq(&cachep->nodelists[node]->list_lock);
			cachep->nodelists[node]->free_limit =
A
Andrew Morton 已提交
1079 1080
				(1 + nr_cpus_node(node)) *
				cachep->batchcount + cachep->num;
1081 1082 1083
			spin_unlock_irq(&cachep->nodelists[node]->list_lock);
		}

A
Andrew Morton 已提交
1084 1085 1086 1087
		/*
		 * Now we can go ahead with allocating the shared arrays and
		 * array caches
		 */
1088
		list_for_each_entry(cachep, &cache_chain, next) {
1089
			struct array_cache *nc;
1090 1091
			struct array_cache *shared;
			struct array_cache **alien;
1092

1093
			nc = alloc_arraycache(node, cachep->limit,
1094
						cachep->batchcount);
L
Linus Torvalds 已提交
1095 1096
			if (!nc)
				goto bad;
1097 1098 1099 1100 1101
			shared = alloc_arraycache(node,
					cachep->shared * cachep->batchcount,
					0xbaadf00d);
			if (!shared)
				goto bad;
1102

1103 1104 1105
			alien = alloc_alien_cache(node, cachep->limit);
			if (!alien)
				goto bad;
L
Linus Torvalds 已提交
1106
			cachep->array[cpu] = nc;
1107 1108 1109
			l3 = cachep->nodelists[node];
			BUG_ON(!l3);

1110 1111 1112 1113 1114 1115 1116 1117
			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;
1118
			}
1119 1120 1121 1122 1123 1124 1125 1126 1127
#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
1128
		}
I
Ingo Molnar 已提交
1129
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1130 1131 1132 1133 1134 1135
		break;
	case CPU_ONLINE:
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
	case CPU_DEAD:
1136 1137 1138 1139 1140 1141 1142 1143
		/*
		 * 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
1144 1145
		/* fall thru */
	case CPU_UP_CANCELED:
I
Ingo Molnar 已提交
1146
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1147 1148
		list_for_each_entry(cachep, &cache_chain, next) {
			struct array_cache *nc;
1149 1150
			struct array_cache *shared;
			struct array_cache **alien;
1151
			cpumask_t mask;
L
Linus Torvalds 已提交
1152

1153
			mask = node_to_cpumask(node);
L
Linus Torvalds 已提交
1154 1155 1156
			/* cpu is dead; no one can alloc from it. */
			nc = cachep->array[cpu];
			cachep->array[cpu] = NULL;
1157 1158 1159
			l3 = cachep->nodelists[node];

			if (!l3)
1160
				goto free_array_cache;
1161

1162
			spin_lock_irq(&l3->list_lock);
1163 1164 1165 1166

			/* Free limit for this kmem_list3 */
			l3->free_limit -= cachep->batchcount;
			if (nc)
1167
				free_block(cachep, nc->entry, nc->avail, node);
1168 1169

			if (!cpus_empty(mask)) {
1170
				spin_unlock_irq(&l3->list_lock);
1171
				goto free_array_cache;
P
Pekka Enberg 已提交
1172
			}
1173

1174 1175
			shared = l3->shared;
			if (shared) {
1176
				free_block(cachep, l3->shared->entry,
P
Pekka Enberg 已提交
1177
					   l3->shared->avail, node);
1178 1179 1180
				l3->shared = NULL;
			}

1181 1182 1183 1184 1185 1186 1187 1188 1189
			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);
1190
			}
1191
free_array_cache:
L
Linus Torvalds 已提交
1192 1193
			kfree(nc);
		}
1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207
		/*
		 * 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;
			spin_lock_irq(&l3->list_lock);
			/* free slabs belonging to this node */
			__node_shrink(cachep, node);
			spin_unlock_irq(&l3->list_lock);
		}
I
Ingo Molnar 已提交
1208
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1209 1210 1211 1212
		break;
#endif
	}
	return NOTIFY_OK;
A
Andrew Morton 已提交
1213
bad:
I
Ingo Molnar 已提交
1214
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1215 1216 1217 1218 1219
	return NOTIFY_BAD;
}

static struct notifier_block cpucache_notifier = { &cpuup_callback, NULL, 0 };

1220 1221 1222
/*
 * swap the static kmem_list3 with kmalloced memory
 */
A
Andrew Morton 已提交
1223 1224
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
			int nodeid)
1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238
{
	struct kmem_list3 *ptr;

	BUG_ON(cachep->nodelists[nodeid] != list);
	ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid);
	BUG_ON(!ptr);

	local_irq_disable();
	memcpy(ptr, list, sizeof(struct kmem_list3));
	MAKE_ALL_LISTS(cachep, ptr, nodeid);
	cachep->nodelists[nodeid] = ptr;
	local_irq_enable();
}

A
Andrew Morton 已提交
1239 1240 1241
/*
 * Initialisation.  Called after the page allocator have been initialised and
 * before smp_init().
L
Linus Torvalds 已提交
1242 1243 1244 1245 1246 1247
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1248
	int i;
1249
	int order;
1250 1251 1252 1253 1254 1255

	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
1256 1257 1258 1259 1260 1261 1262 1263 1264 1265

	/*
	 * 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
1266 1267 1268
	 * 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.
1269 1270 1271
	 *    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
1272
	 * 2) Create the first kmalloc cache.
1273
	 *    The struct kmem_cache for the new cache is allocated normally.
1274 1275 1276
	 *    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
1277 1278
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1279 1280 1281
	 * 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
1282 1283 1284 1285 1286 1287 1288
	 */

	/* 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;
1289
	cache_cache.nodelists[numa_node_id()] = &initkmem_list3[CACHE_CACHE];
L
Linus Torvalds 已提交
1290

A
Andrew Morton 已提交
1291 1292
	cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
					cache_line_size());
L
Linus Torvalds 已提交
1293

1294 1295 1296 1297 1298 1299
	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;
	}
L
Linus Torvalds 已提交
1300 1301
	if (!cache_cache.num)
		BUG();
1302
	cache_cache.gfporder = order;
P
Pekka Enberg 已提交
1303 1304 1305
	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
1306 1307 1308 1309 1310

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

A
Andrew Morton 已提交
1311 1312 1313 1314
	/*
	 * Initialize the caches that provide memory for the array cache and the
	 * kmem_list3 structures first.  Without this, further allocations will
	 * bug.
1315 1316 1317
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
A
Andrew Morton 已提交
1318 1319 1320 1321
					sizes[INDEX_AC].cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
1322

A
Andrew Morton 已提交
1323
	if (INDEX_AC != INDEX_L3) {
1324
		sizes[INDEX_L3].cs_cachep =
A
Andrew Morton 已提交
1325 1326 1327 1328 1329 1330
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size,
				ARCH_KMALLOC_MINALIGN,
				ARCH_KMALLOC_FLAGS|SLAB_PANIC,
				NULL, NULL);
	}
1331

L
Linus Torvalds 已提交
1332
	while (sizes->cs_size != ULONG_MAX) {
1333 1334
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1335 1336 1337
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1338 1339
		 * allow tighter packing of the smaller caches.
		 */
A
Andrew Morton 已提交
1340
		if (!sizes->cs_cachep) {
1341
			sizes->cs_cachep = kmem_cache_create(names->name,
A
Andrew Morton 已提交
1342 1343 1344 1345 1346
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
		}
L
Linus Torvalds 已提交
1347 1348 1349

		/* Inc off-slab bufctl limit until the ceiling is hit. */
		if (!(OFF_SLAB(sizes->cs_cachep))) {
P
Pekka Enberg 已提交
1350
			offslab_limit = sizes->cs_size - sizeof(struct slab);
L
Linus Torvalds 已提交
1351 1352 1353 1354
			offslab_limit /= sizeof(kmem_bufctl_t);
		}

		sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
A
Andrew Morton 已提交
1355 1356 1357 1358 1359
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
						SLAB_PANIC,
					NULL, NULL);
L
Linus Torvalds 已提交
1360 1361 1362 1363 1364
		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
P
Pekka Enberg 已提交
1365
		void *ptr;
1366

L
Linus Torvalds 已提交
1367
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1368

L
Linus Torvalds 已提交
1369
		local_irq_disable();
1370 1371
		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
		memcpy(ptr, cpu_cache_get(&cache_cache),
P
Pekka Enberg 已提交
1372
		       sizeof(struct arraycache_init));
L
Linus Torvalds 已提交
1373 1374
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1375

L
Linus Torvalds 已提交
1376
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1377

L
Linus Torvalds 已提交
1378
		local_irq_disable();
1379
		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
P
Pekka Enberg 已提交
1380
		       != &initarray_generic.cache);
1381
		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
P
Pekka Enberg 已提交
1382
		       sizeof(struct arraycache_init));
1383
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
P
Pekka Enberg 已提交
1384
		    ptr;
L
Linus Torvalds 已提交
1385 1386
		local_irq_enable();
	}
1387 1388 1389 1390 1391
	/* 5) Replace the bootstrap kmem_list3's */
	{
		int node;
		/* Replace the static kmem_list3 structures for the boot cpu */
		init_list(&cache_cache, &initkmem_list3[CACHE_CACHE],
P
Pekka Enberg 已提交
1392
			  numa_node_id());
1393 1394 1395

		for_each_online_node(node) {
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
P
Pekka Enberg 已提交
1396
				  &initkmem_list3[SIZE_AC + node], node);
1397 1398 1399

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
P
Pekka Enberg 已提交
1400 1401
					  &initkmem_list3[SIZE_L3 + node],
					  node);
1402 1403 1404
			}
		}
	}
L
Linus Torvalds 已提交
1405

1406
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1407
	{
1408
		struct kmem_cache *cachep;
I
Ingo Molnar 已提交
1409
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1410
		list_for_each_entry(cachep, &cache_chain, next)
A
Andrew Morton 已提交
1411
			enable_cpucache(cachep);
I
Ingo Molnar 已提交
1412
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1413 1414 1415 1416 1417
	}

	/* Done! */
	g_cpucache_up = FULL;

A
Andrew Morton 已提交
1418 1419 1420
	/*
	 * Register a cpu startup notifier callback that initializes
	 * cpu_cache_get for all new cpus
L
Linus Torvalds 已提交
1421 1422 1423
	 */
	register_cpu_notifier(&cpucache_notifier);

A
Andrew Morton 已提交
1424 1425 1426
	/*
	 * 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
1427 1428 1429 1430 1431 1432 1433
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

A
Andrew Morton 已提交
1434 1435
	/*
	 * Register the timers that return unneeded pages to the page allocator
L
Linus Torvalds 已提交
1436
	 */
1437
	for_each_online_cpu(cpu)
A
Andrew Morton 已提交
1438
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449
	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.
 */
1450
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1451 1452 1453 1454 1455 1456
{
	struct page *page;
	void *addr;
	int i;

	flags |= cachep->gfpflags;
1457
	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1458 1459 1460 1461 1462 1463 1464 1465 1466
	if (!page)
		return NULL;
	addr = page_address(page);

	i = (1 << cachep->gfporder);
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		atomic_add(i, &slab_reclaim_pages);
	add_page_state(nr_slab, i);
	while (i--) {
N
Nick Piggin 已提交
1467
		__SetPageSlab(page);
L
Linus Torvalds 已提交
1468 1469 1470 1471 1472 1473 1474 1475
		page++;
	}
	return addr;
}

/*
 * Interface to system's page release.
 */
1476
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
L
Linus Torvalds 已提交
1477
{
P
Pekka Enberg 已提交
1478
	unsigned long i = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1479 1480 1481 1482
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

	while (i--) {
N
Nick Piggin 已提交
1483 1484
		BUG_ON(!PageSlab(page));
		__ClearPageSlab(page);
L
Linus Torvalds 已提交
1485 1486 1487 1488 1489 1490
		page++;
	}
	sub_page_state(nr_slab, nr_freed);
	if (current->reclaim_state)
		current->reclaim_state->reclaimed_slab += nr_freed;
	free_pages((unsigned long)addr, cachep->gfporder);
P
Pekka Enberg 已提交
1491 1492
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		atomic_sub(1 << cachep->gfporder, &slab_reclaim_pages);
L
Linus Torvalds 已提交
1493 1494 1495 1496
}

static void kmem_rcu_free(struct rcu_head *head)
{
P
Pekka Enberg 已提交
1497
	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1498
	struct kmem_cache *cachep = slab_rcu->cachep;
L
Linus Torvalds 已提交
1499 1500 1501 1502 1503 1504 1505 1506 1507

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

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
1508
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
P
Pekka Enberg 已提交
1509
			    unsigned long caller)
L
Linus Torvalds 已提交
1510
{
1511
	int size = obj_size(cachep);
L
Linus Torvalds 已提交
1512

1513
	addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1514

P
Pekka Enberg 已提交
1515
	if (size < 5 * sizeof(unsigned long))
L
Linus Torvalds 已提交
1516 1517
		return;

P
Pekka Enberg 已提交
1518 1519 1520 1521
	*addr++ = 0x12345678;
	*addr++ = caller;
	*addr++ = smp_processor_id();
	size -= 3 * sizeof(unsigned long);
L
Linus Torvalds 已提交
1522 1523 1524 1525 1526 1527 1528
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
P
Pekka Enberg 已提交
1529
				*addr++ = svalue;
L
Linus Torvalds 已提交
1530 1531 1532 1533 1534 1535 1536
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
P
Pekka Enberg 已提交
1537
	*addr++ = 0x87654321;
L
Linus Torvalds 已提交
1538 1539 1540
}
#endif

1541
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
L
Linus Torvalds 已提交
1542
{
1543 1544
	int size = obj_size(cachep);
	addr = &((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1545 1546

	memset(addr, val, size);
P
Pekka Enberg 已提交
1547
	*(unsigned char *)(addr + size - 1) = POISON_END;
L
Linus Torvalds 已提交
1548 1549 1550 1551 1552 1553
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
	printk(KERN_ERR "%03x:", offset);
A
Andrew Morton 已提交
1554
	for (i = 0; i < limit; i++)
P
Pekka Enberg 已提交
1555
		printk(" %02x", (unsigned char)data[offset + i]);
L
Linus Torvalds 已提交
1556 1557 1558 1559 1560 1561
	printk("\n");
}
#endif

#if DEBUG

1562
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
L
Linus Torvalds 已提交
1563 1564 1565 1566 1567 1568
{
	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
1569 1570
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
1571 1572 1573 1574
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
A
Andrew Morton 已提交
1575
			*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1576
		print_symbol("(%s)",
A
Andrew Morton 已提交
1577
				(unsigned long)*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1578 1579
		printk("\n");
	}
1580 1581
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
P
Pekka Enberg 已提交
1582
	for (i = 0; i < size && lines; i += 16, lines--) {
L
Linus Torvalds 已提交
1583 1584
		int limit;
		limit = 16;
P
Pekka Enberg 已提交
1585 1586
		if (i + limit > size)
			limit = size - i;
L
Linus Torvalds 已提交
1587 1588 1589 1590
		dump_line(realobj, i, limit);
	}
}

1591
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
1592 1593 1594 1595 1596
{
	char *realobj;
	int size, i;
	int lines = 0;

1597 1598
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
L
Linus Torvalds 已提交
1599

P
Pekka Enberg 已提交
1600
	for (i = 0; i < size; i++) {
L
Linus Torvalds 已提交
1601
		char exp = POISON_FREE;
P
Pekka Enberg 已提交
1602
		if (i == size - 1)
L
Linus Torvalds 已提交
1603 1604 1605 1606 1607 1608
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
P
Pekka Enberg 已提交
1609
				printk(KERN_ERR
A
Andrew Morton 已提交
1610 1611
					"Slab corruption: start=%p, len=%d\n",
					realobj, size);
L
Linus Torvalds 已提交
1612 1613 1614
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
P
Pekka Enberg 已提交
1615
			i = (i / 16) * 16;
L
Linus Torvalds 已提交
1616
			limit = 16;
P
Pekka Enberg 已提交
1617 1618
			if (i + limit > size)
				limit = size - i;
L
Linus Torvalds 已提交
1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630
			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:
		 */
1631
		struct slab *slabp = virt_to_slab(objp);
1632
		unsigned int objnr;
L
Linus Torvalds 已提交
1633

1634
		objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
1635
		if (objnr) {
1636
			objp = index_to_obj(cachep, slabp, objnr - 1);
1637
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1638
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1639
			       realobj, size);
L
Linus Torvalds 已提交
1640 1641
			print_objinfo(cachep, objp, 2);
		}
P
Pekka Enberg 已提交
1642
		if (objnr + 1 < cachep->num) {
1643
			objp = index_to_obj(cachep, slabp, objnr + 1);
1644
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1645
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1646
			       realobj, size);
L
Linus Torvalds 已提交
1647 1648 1649 1650 1651 1652
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

1653 1654
#if DEBUG
/**
1655 1656 1657 1658 1659 1660
 * 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
1661
 */
1662
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
1663 1664 1665
{
	int i;
	for (i = 0; i < cachep->num; i++) {
1666
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
1667 1668 1669

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
1670 1671
			if (cachep->buffer_size % PAGE_SIZE == 0 &&
					OFF_SLAB(cachep))
P
Pekka Enberg 已提交
1672
				kernel_map_pages(virt_to_page(objp),
A
Andrew Morton 已提交
1673
					cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
1674 1675 1676 1677 1678 1679 1680 1681 1682
			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
1683
					   "was overwritten");
L
Linus Torvalds 已提交
1684 1685
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
P
Pekka Enberg 已提交
1686
					   "was overwritten");
L
Linus Torvalds 已提交
1687 1688
		}
		if (cachep->dtor && !(cachep->flags & SLAB_POISON))
1689
			(cachep->dtor) (objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
1690
	}
1691
}
L
Linus Torvalds 已提交
1692
#else
1693
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
1694
{
L
Linus Torvalds 已提交
1695 1696 1697
	if (cachep->dtor) {
		int i;
		for (i = 0; i < cachep->num; i++) {
1698
			void *objp = index_to_obj(cachep, slabp, i);
P
Pekka Enberg 已提交
1699
			(cachep->dtor) (objp, cachep, 0);
L
Linus Torvalds 已提交
1700 1701
		}
	}
1702
}
L
Linus Torvalds 已提交
1703 1704
#endif

1705 1706 1707 1708 1709
/**
 * slab_destroy - destroy and release all objects in a slab
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
1710
 * Destroy all the objs in a slab, and release the mem back to the system.
A
Andrew Morton 已提交
1711 1712
 * Before calling the slab must have been unlinked from the cache.  The
 * cache-lock is not held/needed.
1713
 */
1714
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1715 1716 1717 1718
{
	void *addr = slabp->s_mem - slabp->colouroff;

	slab_destroy_objs(cachep, slabp);
L
Linus Torvalds 已提交
1719 1720 1721
	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

P
Pekka Enberg 已提交
1722
		slab_rcu = (struct slab_rcu *)slabp;
L
Linus Torvalds 已提交
1723 1724 1725 1726 1727 1728 1729 1730 1731 1732
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
	}
}

A
Andrew Morton 已提交
1733 1734 1735 1736
/*
 * For setting up all the kmem_list3s for cache whose buffer_size is same as
 * size of kmem_list3.
 */
1737
static void set_up_list3s(struct kmem_cache *cachep, int index)
1738 1739 1740 1741
{
	int node;

	for_each_online_node(node) {
P
Pekka Enberg 已提交
1742
		cachep->nodelists[node] = &initkmem_list3[index + node];
1743
		cachep->nodelists[node]->next_reap = jiffies +
P
Pekka Enberg 已提交
1744 1745
		    REAPTIMEOUT_LIST3 +
		    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1746 1747 1748
	}
}

1749
/**
1750 1751 1752 1753 1754 1755 1756
 * 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.
1757 1758 1759 1760 1761
 *
 * 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
1762
static size_t calculate_slab_order(struct kmem_cache *cachep,
R
Randy Dunlap 已提交
1763
			size_t size, size_t align, unsigned long flags)
1764 1765
{
	size_t left_over = 0;
1766
	int gfporder;
1767

A
Andrew Morton 已提交
1768
	for (gfporder = 0; gfporder <= MAX_GFP_ORDER; gfporder++) {
1769 1770 1771
		unsigned int num;
		size_t remainder;

1772
		cache_estimate(gfporder, size, align, flags, &remainder, &num);
1773 1774
		if (!num)
			continue;
1775

1776
		/* More than offslab_limit objects will cause problems */
1777
		if ((flags & CFLGS_OFF_SLAB) && num > offslab_limit)
1778 1779
			break;

1780
		/* Found something acceptable - save it away */
1781
		cachep->num = num;
1782
		cachep->gfporder = gfporder;
1783 1784
		left_over = remainder;

1785 1786 1787 1788 1789 1790 1791 1792
		/*
		 * 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;

1793 1794 1795 1796
		/*
		 * Large number of objects is good, but very large slabs are
		 * currently bad for the gfp()s.
		 */
1797
		if (gfporder >= slab_break_gfp_order)
1798 1799
			break;

1800 1801 1802
		/*
		 * Acceptable internal fragmentation?
		 */
A
Andrew Morton 已提交
1803
		if (left_over * 8 <= (PAGE_SIZE << gfporder))
1804 1805 1806 1807 1808
			break;
	}
	return left_over;
}

1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862
static void setup_cpu_cache(struct kmem_cache *cachep)
{
	if (g_cpucache_up == FULL) {
		enable_cpucache(cachep);
		return;
	}
	if (g_cpucache_up == NONE) {
		/*
		 * Note: the first kmem_cache_create must create the cache
		 * that's used by kmalloc(24), otherwise the creation of
		 * further caches will BUG().
		 */
		cachep->array[smp_processor_id()] = &initarray_generic.cache;

		/*
		 * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
		 * the first cache, then we need to set up all its list3s,
		 * otherwise the creation of further caches will BUG().
		 */
		set_up_list3s(cachep, SIZE_AC);
		if (INDEX_AC == INDEX_L3)
			g_cpucache_up = PARTIAL_L3;
		else
			g_cpucache_up = PARTIAL_AC;
	} else {
		cachep->array[smp_processor_id()] =
			kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);

		if (g_cpucache_up == PARTIAL_AC) {
			set_up_list3s(cachep, SIZE_L3);
			g_cpucache_up = PARTIAL_L3;
		} else {
			int node;
			for_each_online_node(node) {
				cachep->nodelists[node] =
				    kmalloc_node(sizeof(struct kmem_list3),
						GFP_KERNEL, node);
				BUG_ON(!cachep->nodelists[node]);
				kmem_list3_init(cachep->nodelists[node]);
			}
		}
	}
	cachep->nodelists[numa_node_id()]->next_reap =
			jiffies + REAPTIMEOUT_LIST3 +
			((unsigned long)cachep) % REAPTIMEOUT_LIST3;

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

L
Linus Torvalds 已提交
1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877
/**
 * 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
1878 1879
 * the module calling this has to destroy the cache before getting unloaded.
 *
L
Linus Torvalds 已提交
1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891
 * 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.
 */
1892
struct kmem_cache *
L
Linus Torvalds 已提交
1893
kmem_cache_create (const char *name, size_t size, size_t align,
A
Andrew Morton 已提交
1894 1895
	unsigned long flags,
	void (*ctor)(void*, struct kmem_cache *, unsigned long),
1896
	void (*dtor)(void*, struct kmem_cache *, unsigned long))
L
Linus Torvalds 已提交
1897 1898
{
	size_t left_over, slab_size, ralign;
1899
	struct kmem_cache *cachep = NULL;
1900
	struct list_head *p;
L
Linus Torvalds 已提交
1901 1902 1903 1904

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
A
Andrew Morton 已提交
1905
	if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
P
Pekka Enberg 已提交
1906
	    (size > (1 << MAX_OBJ_ORDER) * PAGE_SIZE) || (dtor && !ctor)) {
A
Andrew Morton 已提交
1907 1908
		printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
				name);
P
Pekka Enberg 已提交
1909 1910
		BUG();
	}
L
Linus Torvalds 已提交
1911

1912 1913 1914 1915 1916 1917
	/*
	 * Prevent CPUs from coming and going.
	 * lock_cpu_hotplug() nests outside cache_chain_mutex
	 */
	lock_cpu_hotplug();

I
Ingo Molnar 已提交
1918
	mutex_lock(&cache_chain_mutex);
1919 1920

	list_for_each(p, &cache_chain) {
1921
		struct kmem_cache *pc = list_entry(p, struct kmem_cache, next);
1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
		mm_segment_t old_fs = get_fs();
		char tmp;
		int res;

		/*
		 * This happens when the module gets unloaded and doesn't
		 * destroy its slab cache and no-one else reuses the vmalloc
		 * area of the module.  Print a warning.
		 */
		set_fs(KERNEL_DS);
		res = __get_user(tmp, pc->name);
		set_fs(old_fs);
		if (res) {
			printk("SLAB: cache with size %d has lost its name\n",
1936
			       pc->buffer_size);
1937 1938 1939
			continue;
		}

P
Pekka Enberg 已提交
1940
		if (!strcmp(pc->name, name)) {
1941 1942 1943 1944 1945 1946
			printk("kmem_cache_create: duplicate cache %s\n", name);
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
1947 1948 1949 1950 1951
#if DEBUG
	WARN_ON(strchr(name, ' '));	/* It confuses parsers */
	if ((flags & SLAB_DEBUG_INITIAL) && !ctor) {
		/* No constructor, but inital state check requested */
		printk(KERN_ERR "%s: No con, but init state check "
P
Pekka Enberg 已提交
1952
		       "requested - %s\n", __FUNCTION__, name);
L
Linus Torvalds 已提交
1953 1954 1955 1956 1957 1958 1959 1960 1961
		flags &= ~SLAB_DEBUG_INITIAL;
	}
#if FORCED_DEBUG
	/*
	 * Enable redzoning and last user accounting, except for caches with
	 * large objects, if the increased size would increase the object size
	 * above the next power of two: caches with object sizes just above a
	 * power of two have a significant amount of internal fragmentation.
	 */
A
Andrew Morton 已提交
1962
	if (size < 4096 || fls(size - 1) == fls(size-1 + 3 * BYTES_PER_WORD))
P
Pekka Enberg 已提交
1963
		flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
L
Linus Torvalds 已提交
1964 1965 1966 1967 1968 1969 1970 1971 1972 1973
	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
1974 1975
	 * Always checks flags, a caller might be expecting debug support which
	 * isn't available.
L
Linus Torvalds 已提交
1976 1977 1978 1979
	 */
	if (flags & ~CREATE_MASK)
		BUG();

A
Andrew Morton 已提交
1980 1981
	/*
	 * Check that size is in terms of words.  This is needed to avoid
L
Linus Torvalds 已提交
1982 1983 1984
	 * 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
1985 1986 1987
	if (size & (BYTES_PER_WORD - 1)) {
		size += (BYTES_PER_WORD - 1);
		size &= ~(BYTES_PER_WORD - 1);
L
Linus Torvalds 已提交
1988 1989
	}

A
Andrew Morton 已提交
1990 1991
	/* calculate the final buffer alignment: */

L
Linus Torvalds 已提交
1992 1993
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
A
Andrew Morton 已提交
1994 1995 1996 1997
		/*
		 * 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
1998 1999
		 */
		ralign = cache_line_size();
P
Pekka Enberg 已提交
2000
		while (size <= ralign / 2)
L
Linus Torvalds 已提交
2001 2002 2003 2004 2005 2006 2007 2008
			ralign /= 2;
	} else {
		ralign = BYTES_PER_WORD;
	}
	/* 2) arch mandated alignment: disables debug if necessary */
	if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
		if (ralign > BYTES_PER_WORD)
P
Pekka Enberg 已提交
2009
			flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
L
Linus Torvalds 已提交
2010 2011 2012 2013 2014
	}
	/* 3) caller mandated alignment: disables debug if necessary */
	if (ralign < align) {
		ralign = align;
		if (ralign > BYTES_PER_WORD)
P
Pekka Enberg 已提交
2015
			flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
L
Linus Torvalds 已提交
2016
	}
A
Andrew Morton 已提交
2017 2018
	/*
	 * 4) Store it. Note that the debug code below can reduce
L
Linus Torvalds 已提交
2019 2020 2021 2022 2023
	 *    the alignment to BYTES_PER_WORD.
	 */
	align = ralign;

	/* Get cache's description obj. */
P
Pekka Enberg 已提交
2024
	cachep = kmem_cache_zalloc(&cache_cache, SLAB_KERNEL);
L
Linus Torvalds 已提交
2025
	if (!cachep)
2026
		goto oops;
L
Linus Torvalds 已提交
2027 2028

#if DEBUG
2029
	cachep->obj_size = size;
L
Linus Torvalds 已提交
2030 2031 2032 2033 2034 2035

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

		/* add space for red zone words */
2036
		cachep->obj_offset += BYTES_PER_WORD;
P
Pekka Enberg 已提交
2037
		size += 2 * BYTES_PER_WORD;
L
Linus Torvalds 已提交
2038 2039 2040 2041 2042 2043 2044 2045 2046 2047
	}
	if (flags & SLAB_STORE_USER) {
		/* user store requires word alignment and
		 * one word storage behind the end of the real
		 * object.
		 */
		align = BYTES_PER_WORD;
		size += BYTES_PER_WORD;
	}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
P
Pekka Enberg 已提交
2048
	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2049 2050
	    && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
		cachep->obj_offset += PAGE_SIZE - size;
L
Linus Torvalds 已提交
2051 2052 2053 2054 2055 2056
		size = PAGE_SIZE;
	}
#endif
#endif

	/* Determine if the slab management is 'on' or 'off' slab. */
P
Pekka Enberg 已提交
2057
	if (size >= (PAGE_SIZE >> 3))
L
Linus Torvalds 已提交
2058 2059 2060 2061 2062 2063 2064 2065
		/*
		 * 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);

2066
	left_over = calculate_slab_order(cachep, size, align, flags);
L
Linus Torvalds 已提交
2067 2068 2069 2070 2071

	if (!cachep->num) {
		printk("kmem_cache_create: couldn't create cache %s.\n", name);
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
2072
		goto oops;
L
Linus Torvalds 已提交
2073
	}
P
Pekka Enberg 已提交
2074 2075
	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
			  + sizeof(struct slab), align);
L
Linus Torvalds 已提交
2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087

	/*
	 * 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
2088 2089
		slab_size =
		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
L
Linus Torvalds 已提交
2090 2091 2092 2093 2094 2095
	}

	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
2096
	cachep->colour = left_over / cachep->colour_off;
L
Linus Torvalds 已提交
2097 2098 2099 2100 2101
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
	if (flags & SLAB_CACHE_DMA)
		cachep->gfpflags |= GFP_DMA;
2102
	cachep->buffer_size = size;
L
Linus Torvalds 已提交
2103 2104

	if (flags & CFLGS_OFF_SLAB)
2105
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
L
Linus Torvalds 已提交
2106 2107 2108 2109 2110
	cachep->ctor = ctor;
	cachep->dtor = dtor;
	cachep->name = name;


2111
	setup_cpu_cache(cachep);
L
Linus Torvalds 已提交
2112 2113 2114

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
A
Andrew Morton 已提交
2115
oops:
L
Linus Torvalds 已提交
2116 2117
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
P
Pekka Enberg 已提交
2118
		      name);
I
Ingo Molnar 已提交
2119
	mutex_unlock(&cache_chain_mutex);
2120
	unlock_cpu_hotplug();
L
Linus Torvalds 已提交
2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135
	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());
}

2136
static void check_spinlock_acquired(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2137 2138 2139
{
#ifdef CONFIG_SMP
	check_irq_off();
2140
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
2141 2142
#endif
}
2143

2144
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2145 2146 2147 2148 2149 2150 2151
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
2152 2153 2154 2155
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
2156
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
2157 2158
#endif

2159 2160 2161 2162
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
2163 2164
static void do_drain(void *arg)
{
A
Andrew Morton 已提交
2165
	struct kmem_cache *cachep = arg;
L
Linus Torvalds 已提交
2166
	struct array_cache *ac;
2167
	int node = numa_node_id();
L
Linus Torvalds 已提交
2168 2169

	check_irq_off();
2170
	ac = cpu_cache_get(cachep);
2171 2172 2173
	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
2174 2175 2176
	ac->avail = 0;
}

2177
static void drain_cpu_caches(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2178
{
2179 2180 2181
	struct kmem_list3 *l3;
	int node;

A
Andrew Morton 已提交
2182
	on_each_cpu(do_drain, cachep, 1, 1);
L
Linus Torvalds 已提交
2183
	check_irq_on();
P
Pekka Enberg 已提交
2184
	for_each_online_node(node) {
2185 2186
		l3 = cachep->nodelists[node];
		if (l3) {
2187
			drain_array(cachep, l3, l3->shared, 1, node);
2188
			if (l3->alien)
2189
				drain_alien_cache(cachep, l3->alien);
2190 2191
		}
	}
L
Linus Torvalds 已提交
2192 2193
}

2194
static int __node_shrink(struct kmem_cache *cachep, int node)
L
Linus Torvalds 已提交
2195 2196
{
	struct slab *slabp;
2197
	struct kmem_list3 *l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
2198 2199
	int ret;

2200
	for (;;) {
L
Linus Torvalds 已提交
2201 2202
		struct list_head *p;

2203 2204
		p = l3->slabs_free.prev;
		if (p == &l3->slabs_free)
L
Linus Torvalds 已提交
2205 2206
			break;

2207
		slabp = list_entry(l3->slabs_free.prev, struct slab, list);
L
Linus Torvalds 已提交
2208 2209 2210 2211 2212 2213
#if DEBUG
		if (slabp->inuse)
			BUG();
#endif
		list_del(&slabp->list);

2214 2215
		l3->free_objects -= cachep->num;
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
2216
		slab_destroy(cachep, slabp);
2217
		spin_lock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
2218
	}
P
Pekka Enberg 已提交
2219
	ret = !list_empty(&l3->slabs_full) || !list_empty(&l3->slabs_partial);
L
Linus Torvalds 已提交
2220 2221 2222
	return ret;
}

2223
static int __cache_shrink(struct kmem_cache *cachep)
2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241
{
	int ret = 0, i = 0;
	struct kmem_list3 *l3;

	drain_cpu_caches(cachep);

	check_irq_on();
	for_each_online_node(i) {
		l3 = cachep->nodelists[i];
		if (l3) {
			spin_lock_irq(&l3->list_lock);
			ret += __node_shrink(cachep, i);
			spin_unlock_irq(&l3->list_lock);
		}
	}
	return (ret ? 1 : 0);
}

L
Linus Torvalds 已提交
2242 2243 2244 2245 2246 2247 2248
/**
 * 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.
 */
2249
int kmem_cache_shrink(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261
{
	if (!cachep || in_interrupt())
		BUG();

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

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
2262
 * Remove a struct kmem_cache object from the slab cache.
L
Linus Torvalds 已提交
2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274
 * Returns 0 on success.
 *
 * It is expected this function will be called by a module when it is
 * unloaded.  This will remove the cache completely, and avoid a duplicate
 * cache being allocated each time a module is loaded and unloaded, if the
 * module doesn't have persistent in-kernel storage across loads and unloads.
 *
 * The cache must be empty before calling this function.
 *
 * The caller must guarantee that noone will allocate memory from the cache
 * during the kmem_cache_destroy().
 */
2275
int kmem_cache_destroy(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2276 2277
{
	int i;
2278
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2279 2280 2281 2282 2283 2284 2285 2286

	if (!cachep || in_interrupt())
		BUG();

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

	/* Find the cache in the chain of caches. */
I
Ingo Molnar 已提交
2287
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2288 2289 2290 2291
	/*
	 * the chain is never empty, cache_cache is never destroyed
	 */
	list_del(&cachep->next);
I
Ingo Molnar 已提交
2292
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2293 2294 2295

	if (__cache_shrink(cachep)) {
		slab_error(cachep, "Can't free all objects");
I
Ingo Molnar 已提交
2296
		mutex_lock(&cache_chain_mutex);
P
Pekka Enberg 已提交
2297
		list_add(&cachep->next, &cache_chain);
I
Ingo Molnar 已提交
2298
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2299 2300 2301 2302 2303
		unlock_cpu_hotplug();
		return 1;
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2304
		synchronize_rcu();
L
Linus Torvalds 已提交
2305

2306
	for_each_online_cpu(i)
P
Pekka Enberg 已提交
2307
	    kfree(cachep->array[i]);
L
Linus Torvalds 已提交
2308 2309

	/* NUMA: free the list3 structures */
2310
	for_each_online_node(i) {
A
Andrew Morton 已提交
2311 2312
		l3 = cachep->nodelists[i];
		if (l3) {
2313 2314 2315 2316 2317
			kfree(l3->shared);
			free_alien_cache(l3->alien);
			kfree(l3);
		}
	}
L
Linus Torvalds 已提交
2318 2319 2320 2321 2322 2323 2324
	kmem_cache_free(&cache_cache, cachep);
	unlock_cpu_hotplug();
	return 0;
}
EXPORT_SYMBOL(kmem_cache_destroy);

/* Get the memory for a slab management obj. */
2325
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2326
				   int colour_off, gfp_t local_flags)
L
Linus Torvalds 已提交
2327 2328
{
	struct slab *slabp;
P
Pekka Enberg 已提交
2329

L
Linus Torvalds 已提交
2330 2331 2332 2333 2334 2335
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
		slabp = kmem_cache_alloc(cachep->slabp_cache, local_flags);
		if (!slabp)
			return NULL;
	} else {
P
Pekka Enberg 已提交
2336
		slabp = objp + colour_off;
L
Linus Torvalds 已提交
2337 2338 2339 2340
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
P
Pekka Enberg 已提交
2341
	slabp->s_mem = objp + colour_off;
L
Linus Torvalds 已提交
2342 2343 2344 2345 2346
	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
P
Pekka Enberg 已提交
2347
	return (kmem_bufctl_t *) (slabp + 1);
L
Linus Torvalds 已提交
2348 2349
}

2350
static void cache_init_objs(struct kmem_cache *cachep,
P
Pekka Enberg 已提交
2351
			    struct slab *slabp, unsigned long ctor_flags)
L
Linus Torvalds 已提交
2352 2353 2354 2355
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2356
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368
#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
2369 2370 2371
		 * 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
2372 2373
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2374
			cachep->ctor(objp + obj_offset(cachep), cachep,
P
Pekka Enberg 已提交
2375
				     ctor_flags);
L
Linus Torvalds 已提交
2376 2377 2378 2379

		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
2380
					   " end of an object");
L
Linus Torvalds 已提交
2381 2382
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2383
					   " start of an object");
L
Linus Torvalds 已提交
2384
		}
A
Andrew Morton 已提交
2385 2386
		if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
			    OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
P
Pekka Enberg 已提交
2387
			kernel_map_pages(virt_to_page(objp),
2388
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2389 2390 2391 2392
#else
		if (cachep->ctor)
			cachep->ctor(objp, cachep, ctor_flags);
#endif
P
Pekka Enberg 已提交
2393
		slab_bufctl(slabp)[i] = i + 1;
L
Linus Torvalds 已提交
2394
	}
P
Pekka Enberg 已提交
2395
	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
L
Linus Torvalds 已提交
2396 2397 2398
	slabp->free = 0;
}

2399
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2400
{
A
Andrew Morton 已提交
2401 2402 2403 2404
	if (flags & SLAB_DMA)
		BUG_ON(!(cachep->gfpflags & GFP_DMA));
	else
		BUG_ON(cachep->gfpflags & GFP_DMA);
L
Linus Torvalds 已提交
2405 2406
}

A
Andrew Morton 已提交
2407 2408
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
				int nodeid)
2409
{
2410
	void *objp = index_to_obj(cachep, slabp, slabp->free);
2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423
	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
2424 2425
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
				void *objp, int nodeid)
2426
{
2427
	unsigned int objnr = obj_to_index(cachep, slabp, objp);
2428 2429 2430 2431 2432

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

2433
	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
2434
		printk(KERN_ERR "slab: double free detected in cache "
A
Andrew Morton 已提交
2435
				"'%s', objp %p\n", cachep->name, objp);
2436 2437 2438 2439 2440 2441 2442 2443
		BUG();
	}
#endif
	slab_bufctl(slabp)[objnr] = slabp->free;
	slabp->free = objnr;
	slabp->inuse--;
}

A
Andrew Morton 已提交
2444 2445
static void set_slab_attr(struct kmem_cache *cachep, struct slab *slabp,
			void *objp)
L
Linus Torvalds 已提交
2446 2447 2448 2449 2450 2451
{
	int i;
	struct page *page;

	/* Nasty!!!!!! I hope this is OK. */
	page = virt_to_page(objp);
2452 2453 2454 2455

	i = 1;
	if (likely(!PageCompound(page)))
		i <<= cachep->gfporder;
L
Linus Torvalds 已提交
2456
	do {
2457 2458
		page_set_cache(page, cachep);
		page_set_slab(page, slabp);
L
Linus Torvalds 已提交
2459 2460 2461 2462 2463 2464 2465 2466
		page++;
	} while (--i);
}

/*
 * Grow (by 1) the number of slabs within a cache.  This is called by
 * kmem_cache_alloc() when there are no active objs left in a cache.
 */
2467
static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
2468
{
P
Pekka Enberg 已提交
2469 2470 2471 2472 2473
	struct slab *slabp;
	void *objp;
	size_t offset;
	gfp_t local_flags;
	unsigned long ctor_flags;
2474
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2475

A
Andrew Morton 已提交
2476 2477 2478
	/*
	 * 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
2479
	 */
P
Pekka Enberg 已提交
2480
	if (flags & ~(SLAB_DMA | SLAB_LEVEL_MASK | SLAB_NO_GROW))
L
Linus Torvalds 已提交
2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493
		BUG();
	if (flags & SLAB_NO_GROW)
		return 0;

	ctor_flags = SLAB_CTOR_CONSTRUCTOR;
	local_flags = (flags & SLAB_LEVEL_MASK);
	if (!(local_flags & __GFP_WAIT))
		/*
		 * Not allowed to sleep.  Need to tell a constructor about
		 * this - it might need to know...
		 */
		ctor_flags |= SLAB_CTOR_ATOMIC;

2494
	/* Take the l3 list lock to change the colour_next on this node */
L
Linus Torvalds 已提交
2495
	check_irq_off();
2496 2497
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2498 2499

	/* Get colour for the slab, and cal the next value. */
2500 2501 2502 2503 2504
	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
2505

2506
	offset *= cachep->colour_off;
L
Linus Torvalds 已提交
2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518

	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
2519 2520 2521
	/*
	 * Get mem for the objs.  Attempt to allocate a physical page from
	 * 'nodeid'.
2522
	 */
A
Andrew Morton 已提交
2523 2524
	objp = kmem_getpages(cachep, flags, nodeid);
	if (!objp)
L
Linus Torvalds 已提交
2525 2526 2527
		goto failed;

	/* Get slab management. */
A
Andrew Morton 已提交
2528 2529
	slabp = alloc_slabmgmt(cachep, objp, offset, local_flags);
	if (!slabp)
L
Linus Torvalds 已提交
2530 2531
		goto opps1;

2532
	slabp->nodeid = nodeid;
L
Linus Torvalds 已提交
2533 2534 2535 2536 2537 2538 2539
	set_slab_attr(cachep, slabp, objp);

	cache_init_objs(cachep, slabp, ctor_flags);

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2540
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2541 2542

	/* Make slab active. */
2543
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2544
	STATS_INC_GROWN(cachep);
2545 2546
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2547
	return 1;
A
Andrew Morton 已提交
2548
opps1:
L
Linus Torvalds 已提交
2549
	kmem_freepages(cachep, objp);
A
Andrew Morton 已提交
2550
failed:
L
Linus Torvalds 已提交
2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569
	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	return 0;
}

#if DEBUG

/*
 * Perform extra freeing checks:
 * - detect bad pointers.
 * - POISON/RED_ZONE checking
 * - destructor calls, for caches with POISON+dtor
 */
static void kfree_debugcheck(const void *objp)
{
	struct page *page;

	if (!virt_addr_valid(objp)) {
		printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
P
Pekka Enberg 已提交
2570 2571
		       (unsigned long)objp);
		BUG();
L
Linus Torvalds 已提交
2572 2573 2574
	}
	page = virt_to_page(objp);
	if (!PageSlab(page)) {
P
Pekka Enberg 已提交
2575 2576
		printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n",
		       (unsigned long)objp);
L
Linus Torvalds 已提交
2577 2578 2579 2580
		BUG();
	}
}

2581
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2582
				   void *caller)
L
Linus Torvalds 已提交
2583 2584 2585 2586 2587
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

2588
	objp -= obj_offset(cachep);
L
Linus Torvalds 已提交
2589 2590 2591
	kfree_debugcheck(objp);
	page = virt_to_page(objp);

2592
	if (page_get_cache(page) != cachep) {
A
Andrew Morton 已提交
2593 2594
		printk(KERN_ERR "mismatch in kmem_cache_free: expected "
				"cache %p, got %p\n",
P
Pekka Enberg 已提交
2595
		       page_get_cache(page), cachep);
L
Linus Torvalds 已提交
2596
		printk(KERN_ERR "%p is %s.\n", cachep, cachep->name);
P
Pekka Enberg 已提交
2597 2598
		printk(KERN_ERR "%p is %s.\n", page_get_cache(page),
		       page_get_cache(page)->name);
L
Linus Torvalds 已提交
2599 2600
		WARN_ON(1);
	}
2601
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2602 2603

	if (cachep->flags & SLAB_RED_ZONE) {
A
Andrew Morton 已提交
2604 2605 2606 2607 2608 2609
		if (*dbg_redzone1(cachep, objp) != RED_ACTIVE ||
				*dbg_redzone2(cachep, objp) != RED_ACTIVE) {
			slab_error(cachep, "double free, or memory outside"
						" object was overwritten");
			printk(KERN_ERR "%p: redzone 1:0x%lx, "
					"redzone 2:0x%lx.\n",
P
Pekka Enberg 已提交
2610 2611
			       objp, *dbg_redzone1(cachep, objp),
			       *dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
2612 2613 2614 2615 2616 2617 2618
		}
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

2619
	objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
2620 2621

	BUG_ON(objnr >= cachep->num);
2622
	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
L
Linus Torvalds 已提交
2623 2624

	if (cachep->flags & SLAB_DEBUG_INITIAL) {
A
Andrew Morton 已提交
2625 2626 2627 2628
		/*
		 * Need to call the slab's constructor so the caller can
		 * perform a verify of its state (debugging).  Called without
		 * the cache-lock held.
L
Linus Torvalds 已提交
2629
		 */
2630
		cachep->ctor(objp + obj_offset(cachep),
P
Pekka Enberg 已提交
2631
			     cachep, SLAB_CTOR_CONSTRUCTOR | SLAB_CTOR_VERIFY);
L
Linus Torvalds 已提交
2632 2633 2634 2635 2636
	}
	if (cachep->flags & SLAB_POISON && cachep->dtor) {
		/* we want to cache poison the object,
		 * call the destruction callback
		 */
2637
		cachep->dtor(objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
2638
	}
2639 2640 2641
#ifdef CONFIG_DEBUG_SLAB_LEAK
	slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
#endif
L
Linus Torvalds 已提交
2642 2643
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
2644
		if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
L
Linus Torvalds 已提交
2645
			store_stackinfo(cachep, objp, (unsigned long)caller);
P
Pekka Enberg 已提交
2646
			kernel_map_pages(virt_to_page(objp),
2647
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2648 2649 2650 2651 2652 2653 2654 2655 2656 2657
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

2658
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
2659 2660 2661
{
	kmem_bufctl_t i;
	int entries = 0;
P
Pekka Enberg 已提交
2662

L
Linus Torvalds 已提交
2663 2664 2665 2666 2667 2668 2669
	/* 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
2670 2671 2672 2673
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
2674
		for (i = 0;
2675
		     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
P
Pekka Enberg 已提交
2676
		     i++) {
A
Andrew Morton 已提交
2677
			if (i % 16 == 0)
L
Linus Torvalds 已提交
2678
				printk("\n%03x:", i);
P
Pekka Enberg 已提交
2679
			printk(" %02x", ((unsigned char *)slabp)[i]);
L
Linus Torvalds 已提交
2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690
		}
		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

2691
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2692 2693 2694 2695 2696 2697
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;

	check_irq_off();
2698
	ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2699
retry:
L
Linus Torvalds 已提交
2700 2701
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
A
Andrew Morton 已提交
2702 2703 2704 2705
		/*
		 * 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
2706 2707 2708
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
2709 2710 2711 2712
	l3 = cachep->nodelists[numa_node_id()];

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2713

2714 2715 2716 2717
	/* 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
2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737
	while (batchcount > 0) {
		struct list_head *entry;
		struct slab *slabp;
		/* Get slab alloc is to come from. */
		entry = l3->slabs_partial.next;
		if (entry == &l3->slabs_partial) {
			l3->free_touched = 1;
			entry = l3->slabs_free.next;
			if (entry == &l3->slabs_free)
				goto must_grow;
		}

		slabp = list_entry(entry, struct slab, list);
		check_slabp(cachep, slabp);
		check_spinlock_acquired(cachep);
		while (slabp->inuse < cachep->num && batchcount--) {
			STATS_INC_ALLOCED(cachep);
			STATS_INC_ACTIVE(cachep);
			STATS_SET_HIGH(cachep);

2738 2739
			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
							    numa_node_id());
L
Linus Torvalds 已提交
2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750
		}
		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
2751
must_grow:
L
Linus Torvalds 已提交
2752
	l3->free_objects -= ac->avail;
A
Andrew Morton 已提交
2753
alloc_done:
2754
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2755 2756 2757

	if (unlikely(!ac->avail)) {
		int x;
2758 2759
		x = cache_grow(cachep, flags, numa_node_id());

A
Andrew Morton 已提交
2760
		/* cache_grow can reenable interrupts, then ac could change. */
2761
		ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2762
		if (!x && ac->avail == 0)	/* no objects in sight? abort */
L
Linus Torvalds 已提交
2763 2764
			return NULL;

A
Andrew Morton 已提交
2765
		if (!ac->avail)		/* objects refilled by interrupt? */
L
Linus Torvalds 已提交
2766 2767 2768
			goto retry;
	}
	ac->touched = 1;
2769
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
2770 2771
}

A
Andrew Morton 已提交
2772 2773
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
						gfp_t flags)
L
Linus Torvalds 已提交
2774 2775 2776 2777 2778 2779 2780 2781
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
A
Andrew Morton 已提交
2782 2783
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
				gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
2784
{
P
Pekka Enberg 已提交
2785
	if (!objp)
L
Linus Torvalds 已提交
2786
		return objp;
P
Pekka Enberg 已提交
2787
	if (cachep->flags & SLAB_POISON) {
L
Linus Torvalds 已提交
2788
#ifdef CONFIG_DEBUG_PAGEALLOC
2789
		if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
P
Pekka Enberg 已提交
2790
			kernel_map_pages(virt_to_page(objp),
2791
					 cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802
		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
2803 2804 2805 2806
		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
2807
			printk(KERN_ERR
A
Andrew Morton 已提交
2808 2809 2810
				"%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
2811 2812 2813 2814
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
2815 2816 2817 2818 2819 2820 2821 2822 2823 2824
#ifdef CONFIG_DEBUG_SLAB_LEAK
	{
		struct slab *slabp;
		unsigned objnr;

		slabp = page_get_slab(virt_to_page(objp));
		objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
	}
#endif
2825
	objp += obj_offset(cachep);
L
Linus Torvalds 已提交
2826
	if (cachep->ctor && cachep->flags & SLAB_POISON) {
P
Pekka Enberg 已提交
2827
		unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
L
Linus Torvalds 已提交
2828 2829 2830 2831 2832

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

		cachep->ctor(objp, cachep, ctor_flags);
P
Pekka Enberg 已提交
2833
	}
L
Linus Torvalds 已提交
2834 2835 2836 2837 2838 2839
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

2840
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2841
{
P
Pekka Enberg 已提交
2842
	void *objp;
L
Linus Torvalds 已提交
2843 2844
	struct array_cache *ac;

2845
#ifdef CONFIG_NUMA
2846
	if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
2847 2848 2849
		objp = alternate_node_alloc(cachep, flags);
		if (objp != NULL)
			return objp;
2850 2851 2852
	}
#endif

2853
	check_irq_off();
2854
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
2855 2856 2857
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
2858
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
2859 2860 2861 2862
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
2863 2864 2865
	return objp;
}

A
Andrew Morton 已提交
2866 2867
static __always_inline void *__cache_alloc(struct kmem_cache *cachep,
						gfp_t flags, void *caller)
2868 2869
{
	unsigned long save_flags;
P
Pekka Enberg 已提交
2870
	void *objp;
2871 2872 2873 2874 2875

	cache_alloc_debugcheck_before(cachep, flags);

	local_irq_save(save_flags);
	objp = ____cache_alloc(cachep, flags);
L
Linus Torvalds 已提交
2876
	local_irq_restore(save_flags);
2877
	objp = cache_alloc_debugcheck_after(cachep, flags, objp,
2878
					    caller);
2879
	prefetchw(objp);
L
Linus Torvalds 已提交
2880 2881 2882
	return objp;
}

2883
#ifdef CONFIG_NUMA
2884
/*
2885
 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905
 *
 * If we are in_interrupt, then process context, including cpusets and
 * mempolicy, may not apply and should not be used for allocation policy.
 */
static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
{
	int nid_alloc, nid_here;

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

2906 2907
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
2908
 */
A
Andrew Morton 已提交
2909 2910
static void *__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
				int nodeid)
2911 2912
{
	struct list_head *entry;
P
Pekka Enberg 已提交
2913 2914 2915 2916 2917 2918 2919 2920
	struct slab *slabp;
	struct kmem_list3 *l3;
	void *obj;
	int x;

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

A
Andrew Morton 已提交
2921
retry:
2922
	check_irq_off();
P
Pekka Enberg 已提交
2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941
	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);

2942
	obj = slab_get_obj(cachep, slabp, nodeid);
P
Pekka Enberg 已提交
2943 2944 2945 2946 2947
	check_slabp(cachep, slabp);
	l3->free_objects--;
	/* move slabp to correct slabp list: */
	list_del(&slabp->list);

A
Andrew Morton 已提交
2948
	if (slabp->free == BUFCTL_END)
P
Pekka Enberg 已提交
2949
		list_add(&slabp->list, &l3->slabs_full);
A
Andrew Morton 已提交
2950
	else
P
Pekka Enberg 已提交
2951
		list_add(&slabp->list, &l3->slabs_partial);
2952

P
Pekka Enberg 已提交
2953 2954
	spin_unlock(&l3->list_lock);
	goto done;
2955

A
Andrew Morton 已提交
2956
must_grow:
P
Pekka Enberg 已提交
2957 2958
	spin_unlock(&l3->list_lock);
	x = cache_grow(cachep, flags, nodeid);
L
Linus Torvalds 已提交
2959

P
Pekka Enberg 已提交
2960 2961
	if (!x)
		return NULL;
2962

P
Pekka Enberg 已提交
2963
	goto retry;
A
Andrew Morton 已提交
2964
done:
P
Pekka Enberg 已提交
2965
	return obj;
2966 2967 2968 2969 2970 2971
}
#endif

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
2972
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
P
Pekka Enberg 已提交
2973
		       int node)
L
Linus Torvalds 已提交
2974 2975
{
	int i;
2976
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2977 2978 2979 2980 2981

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

2982
		slabp = virt_to_slab(objp);
2983
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
2984
		list_del(&slabp->list);
2985
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
2986
		check_slabp(cachep, slabp);
2987
		slab_put_obj(cachep, slabp, objp, node);
L
Linus Torvalds 已提交
2988
		STATS_DEC_ACTIVE(cachep);
2989
		l3->free_objects++;
L
Linus Torvalds 已提交
2990 2991 2992 2993
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
2994 2995
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
L
Linus Torvalds 已提交
2996 2997
				slab_destroy(cachep, slabp);
			} else {
2998
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
2999 3000 3001 3002 3003 3004
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
3005
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
3006 3007 3008 3009
		}
	}
}

3010
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
L
Linus Torvalds 已提交
3011 3012
{
	int batchcount;
3013
	struct kmem_list3 *l3;
3014
	int node = numa_node_id();
L
Linus Torvalds 已提交
3015 3016 3017 3018 3019 3020

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
3021
	l3 = cachep->nodelists[node];
3022 3023 3024
	spin_lock(&l3->list_lock);
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
P
Pekka Enberg 已提交
3025
		int max = shared_array->limit - shared_array->avail;
L
Linus Torvalds 已提交
3026 3027 3028
		if (max) {
			if (batchcount > max)
				batchcount = max;
3029
			memcpy(&(shared_array->entry[shared_array->avail]),
P
Pekka Enberg 已提交
3030
			       ac->entry, sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
3031 3032 3033 3034 3035
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

3036
	free_block(cachep, ac->entry, batchcount, node);
A
Andrew Morton 已提交
3037
free_done:
L
Linus Torvalds 已提交
3038 3039 3040 3041 3042
#if STATS
	{
		int i = 0;
		struct list_head *p;

3043 3044
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055
			struct slab *slabp;

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

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
3056
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3057
	ac->avail -= batchcount;
A
Andrew Morton 已提交
3058
	memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
L
Linus Torvalds 已提交
3059 3060 3061
}

/*
A
Andrew Morton 已提交
3062 3063
 * 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
3064
 */
3065
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3066
{
3067
	struct array_cache *ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3068 3069 3070 3071

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

3072 3073 3074 3075 3076 3077
	/* Make sure we are not freeing a object from another
	 * node to the array cache on this cpu.
	 */
#ifdef CONFIG_NUMA
	{
		struct slab *slabp;
3078
		slabp = virt_to_slab(objp);
3079 3080 3081
		if (unlikely(slabp->nodeid != numa_node_id())) {
			struct array_cache *alien = NULL;
			int nodeid = slabp->nodeid;
A
Andrew Morton 已提交
3082
			struct kmem_list3 *l3;
3083

A
Andrew Morton 已提交
3084
			l3 = cachep->nodelists[numa_node_id()];
3085 3086 3087 3088 3089 3090
			STATS_INC_NODEFREES(cachep);
			if (l3->alien && l3->alien[nodeid]) {
				alien = l3->alien[nodeid];
				spin_lock(&alien->lock);
				if (unlikely(alien->avail == alien->limit))
					__drain_alien_cache(cachep,
P
Pekka Enberg 已提交
3091
							    alien, nodeid);
3092 3093 3094 3095
				alien->entry[alien->avail++] = objp;
				spin_unlock(&alien->lock);
			} else {
				spin_lock(&(cachep->nodelists[nodeid])->
P
Pekka Enberg 已提交
3096
					  list_lock);
3097
				free_block(cachep, &objp, 1, nodeid);
3098
				spin_unlock(&(cachep->nodelists[nodeid])->
P
Pekka Enberg 已提交
3099
					    list_lock);
3100 3101 3102 3103 3104
			}
			return;
		}
	}
#endif
L
Linus Torvalds 已提交
3105 3106
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
3107
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3108 3109 3110 3111
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
3112
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123
	}
}

/**
 * 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.
 */
3124
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3125
{
3126
	return __cache_alloc(cachep, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3127 3128 3129
}
EXPORT_SYMBOL(kmem_cache_alloc);

3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146
/**
 * kmem_cache_alloc - Allocate an object. The memory is set to zero.
 * @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
3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160
/**
 * 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.
 */
3161
int fastcall kmem_ptr_validate(struct kmem_cache *cachep, void *ptr)
L
Linus Torvalds 已提交
3162
{
P
Pekka Enberg 已提交
3163
	unsigned long addr = (unsigned long)ptr;
L
Linus Torvalds 已提交
3164
	unsigned long min_addr = PAGE_OFFSET;
P
Pekka Enberg 已提交
3165
	unsigned long align_mask = BYTES_PER_WORD - 1;
3166
	unsigned long size = cachep->buffer_size;
L
Linus Torvalds 已提交
3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181
	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;
3182
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
3183 3184
		goto out;
	return 1;
A
Andrew Morton 已提交
3185
out:
L
Linus Torvalds 已提交
3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198
	return 0;
}

#ifdef CONFIG_NUMA
/**
 * kmem_cache_alloc_node - Allocate an object on the specified node
 * @cachep: The cache to allocate from.
 * @flags: See kmalloc().
 * @nodeid: node number of the target node.
 *
 * Identical to kmem_cache_alloc, except that this function is slow
 * and can sleep. And it will allocate memory on the given node, which
 * can improve the performance for cpu bound structures.
3199 3200
 * New and improved: it will now make sure that the object gets
 * put on the correct node list so that there is no false sharing.
L
Linus Torvalds 已提交
3201
 */
3202
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
3203
{
3204 3205
	unsigned long save_flags;
	void *ptr;
L
Linus Torvalds 已提交
3206

3207 3208
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
3209 3210

	if (nodeid == -1 || nodeid == numa_node_id() ||
A
Andrew Morton 已提交
3211
			!cachep->nodelists[nodeid])
3212 3213 3214
		ptr = ____cache_alloc(cachep, flags);
	else
		ptr = __cache_alloc_node(cachep, flags, nodeid);
3215
	local_irq_restore(save_flags);
3216 3217 3218

	ptr = cache_alloc_debugcheck_after(cachep, flags, ptr,
					   __builtin_return_address(0));
L
Linus Torvalds 已提交
3219

3220
	return ptr;
L
Linus Torvalds 已提交
3221 3222 3223
}
EXPORT_SYMBOL(kmem_cache_alloc_node);

A
Al Viro 已提交
3224
void *kmalloc_node(size_t size, gfp_t flags, int node)
3225
{
3226
	struct kmem_cache *cachep;
3227 3228 3229 3230 3231 3232 3233

	cachep = kmem_find_general_cachep(size, flags);
	if (unlikely(cachep == NULL))
		return NULL;
	return kmem_cache_alloc_node(cachep, flags, node);
}
EXPORT_SYMBOL(kmalloc_node);
L
Linus Torvalds 已提交
3234 3235 3236 3237 3238 3239
#endif

/**
 * kmalloc - allocate memory
 * @size: how many bytes of memory are required.
 * @flags: the type of memory to allocate.
3240
 * @caller: function caller for debug tracking of the caller
L
Linus Torvalds 已提交
3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257
 *
 * kmalloc is the normal method of allocating memory
 * in the kernel.
 *
 * The @flags argument may be one of:
 *
 * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 *
 * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 *
 * %GFP_ATOMIC - Allocation will not sleep.  Use inside interrupt handlers.
 *
 * Additionally, the %GFP_DMA flag may be set to indicate the memory
 * must be suitable for DMA.  This can mean different things on different
 * platforms.  For example, on i386, it means that the memory must come
 * from the first 16MB.
 */
3258 3259
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
					  void *caller)
L
Linus Torvalds 已提交
3260
{
3261
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3262

3263 3264 3265 3266 3267 3268
	/* 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);
3269 3270
	if (unlikely(cachep == NULL))
		return NULL;
3271 3272 3273 3274 3275 3276
	return __cache_alloc(cachep, flags, caller);
}


void *__kmalloc(size_t size, gfp_t flags)
{
3277
#ifndef CONFIG_DEBUG_SLAB
3278
	return __do_kmalloc(size, flags, NULL);
3279 3280 3281
#else
	return __do_kmalloc(size, flags, __builtin_return_address(0));
#endif
L
Linus Torvalds 已提交
3282 3283 3284
}
EXPORT_SYMBOL(__kmalloc);

3285
#ifdef CONFIG_DEBUG_SLAB
3286 3287 3288 3289 3290 3291 3292
void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
{
	return __do_kmalloc(size, flags, caller);
}
EXPORT_SYMBOL(__kmalloc_track_caller);
#endif

L
Linus Torvalds 已提交
3293 3294 3295 3296 3297 3298 3299 3300
#ifdef CONFIG_SMP
/**
 * __alloc_percpu - allocate one copy of the object for every present
 * cpu in the system, zeroing them.
 * Objects should be dereferenced using the per_cpu_ptr macro only.
 *
 * @size: how many bytes of memory are required.
 */
3301
void *__alloc_percpu(size_t size)
L
Linus Torvalds 已提交
3302 3303
{
	int i;
P
Pekka Enberg 已提交
3304
	struct percpu_data *pdata = kmalloc(sizeof(*pdata), GFP_KERNEL);
L
Linus Torvalds 已提交
3305 3306 3307 3308

	if (!pdata)
		return NULL;

3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320
	/*
	 * Cannot use for_each_online_cpu since a cpu may come online
	 * and we have no way of figuring out how to fix the array
	 * that we have allocated then....
	 */
	for_each_cpu(i) {
		int node = cpu_to_node(i);

		if (node_online(node))
			pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node);
		else
			pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
L
Linus Torvalds 已提交
3321 3322 3323 3324 3325 3326 3327

		if (!pdata->ptrs[i])
			goto unwind_oom;
		memset(pdata->ptrs[i], 0, size);
	}

	/* Catch derefs w/o wrappers */
P
Pekka Enberg 已提交
3328
	return (void *)(~(unsigned long)pdata);
L
Linus Torvalds 已提交
3329

A
Andrew Morton 已提交
3330
unwind_oom:
L
Linus Torvalds 已提交
3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349
	while (--i >= 0) {
		if (!cpu_possible(i))
			continue;
		kfree(pdata->ptrs[i]);
	}
	kfree(pdata);
	return NULL;
}
EXPORT_SYMBOL(__alloc_percpu);
#endif

/**
 * kmem_cache_free - Deallocate an object
 * @cachep: The cache the allocation was from.
 * @objp: The previously allocated object.
 *
 * Free an object which was previously allocated from this
 * cache.
 */
3350
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363
{
	unsigned long flags;

	local_irq_save(flags);
	__cache_free(cachep, objp);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kmem_cache_free);

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3364 3365
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3366 3367 3368 3369 3370
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
3371
	struct kmem_cache *c;
L
Linus Torvalds 已提交
3372 3373 3374 3375 3376 3377
	unsigned long flags;

	if (unlikely(!objp))
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3378
	c = virt_to_cache(objp);
3379
	mutex_debug_check_no_locks_freed(objp, obj_size(c));
P
Pekka Enberg 已提交
3380
	__cache_free(c, (void *)objp);
L
Linus Torvalds 已提交
3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

#ifdef CONFIG_SMP
/**
 * free_percpu - free previously allocated percpu memory
 * @objp: pointer returned by alloc_percpu.
 *
 * Don't free memory not originally allocated by alloc_percpu()
 * The complemented objp is to check for that.
 */
P
Pekka Enberg 已提交
3393
void free_percpu(const void *objp)
L
Linus Torvalds 已提交
3394 3395
{
	int i;
P
Pekka Enberg 已提交
3396
	struct percpu_data *p = (struct percpu_data *)(~(unsigned long)objp);
L
Linus Torvalds 已提交
3397

3398 3399 3400 3401
	/*
	 * We allocate for all cpus so we cannot use for online cpu here.
	 */
	for_each_cpu(i)
P
Pekka Enberg 已提交
3402
	    kfree(p->ptrs[i]);
L
Linus Torvalds 已提交
3403 3404 3405 3406 3407
	kfree(p);
}
EXPORT_SYMBOL(free_percpu);
#endif

3408
unsigned int kmem_cache_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3409
{
3410
	return obj_size(cachep);
L
Linus Torvalds 已提交
3411 3412 3413
}
EXPORT_SYMBOL(kmem_cache_size);

3414
const char *kmem_cache_name(struct kmem_cache *cachep)
3415 3416 3417 3418 3419
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3420
/*
3421
 * This initializes kmem_list3 or resizes varioius caches for all nodes.
3422
 */
3423
static int alloc_kmemlist(struct kmem_cache *cachep)
3424 3425 3426
{
	int node;
	struct kmem_list3 *l3;
3427 3428
	struct array_cache *new_shared;
	struct array_cache **new_alien;
3429 3430

	for_each_online_node(node) {
3431

A
Andrew Morton 已提交
3432 3433
		new_alien = alloc_alien_cache(node, cachep->limit);
		if (!new_alien)
3434
			goto fail;
3435

3436 3437
		new_shared = alloc_arraycache(node,
				cachep->shared*cachep->batchcount,
A
Andrew Morton 已提交
3438
					0xbaadf00d);
3439 3440
		if (!new_shared) {
			free_alien_cache(new_alien);
3441
			goto fail;
3442
		}
3443

A
Andrew Morton 已提交
3444 3445
		l3 = cachep->nodelists[node];
		if (l3) {
3446 3447
			struct array_cache *shared = l3->shared;

3448 3449
			spin_lock_irq(&l3->list_lock);

3450
			if (shared)
3451 3452
				free_block(cachep, shared->entry,
						shared->avail, node);
3453

3454 3455
			l3->shared = new_shared;
			if (!l3->alien) {
3456 3457 3458
				l3->alien = new_alien;
				new_alien = NULL;
			}
P
Pekka Enberg 已提交
3459
			l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3460
					cachep->batchcount + cachep->num;
3461
			spin_unlock_irq(&l3->list_lock);
3462
			kfree(shared);
3463 3464 3465
			free_alien_cache(new_alien);
			continue;
		}
A
Andrew Morton 已提交
3466
		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
3467 3468 3469
		if (!l3) {
			free_alien_cache(new_alien);
			kfree(new_shared);
3470
			goto fail;
3471
		}
3472 3473 3474

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
A
Andrew Morton 已提交
3475
				((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3476
		l3->shared = new_shared;
3477
		l3->alien = new_alien;
P
Pekka Enberg 已提交
3478
		l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3479
					cachep->batchcount + cachep->num;
3480 3481
		cachep->nodelists[node] = l3;
	}
3482
	return 0;
3483

A
Andrew Morton 已提交
3484
fail:
3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499
	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--;
		}
	}
3500
	return -ENOMEM;
3501 3502
}

L
Linus Torvalds 已提交
3503
struct ccupdate_struct {
3504
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3505 3506 3507 3508 3509
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
A
Andrew Morton 已提交
3510
	struct ccupdate_struct *new = info;
L
Linus Torvalds 已提交
3511 3512 3513
	struct array_cache *old;

	check_irq_off();
3514
	old = cpu_cache_get(new->cachep);
3515

L
Linus Torvalds 已提交
3516 3517 3518 3519
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}

3520
/* Always called with the cache_chain_mutex held */
A
Andrew Morton 已提交
3521 3522
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
				int batchcount, int shared)
L
Linus Torvalds 已提交
3523 3524
{
	struct ccupdate_struct new;
3525
	int i, err;
L
Linus Torvalds 已提交
3526

P
Pekka Enberg 已提交
3527
	memset(&new.new, 0, sizeof(new.new));
3528
	for_each_online_cpu(i) {
A
Andrew Morton 已提交
3529 3530
		new.new[i] = alloc_arraycache(cpu_to_node(i), limit,
						batchcount);
3531
		if (!new.new[i]) {
P
Pekka Enberg 已提交
3532 3533
			for (i--; i >= 0; i--)
				kfree(new.new[i]);
3534
			return -ENOMEM;
L
Linus Torvalds 已提交
3535 3536 3537 3538
		}
	}
	new.cachep = cachep;

A
Andrew Morton 已提交
3539
	on_each_cpu(do_ccupdate_local, (void *)&new, 1, 1);
3540

L
Linus Torvalds 已提交
3541 3542 3543
	check_irq_on();
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3544
	cachep->shared = shared;
L
Linus Torvalds 已提交
3545

3546
	for_each_online_cpu(i) {
L
Linus Torvalds 已提交
3547 3548 3549
		struct array_cache *ccold = new.new[i];
		if (!ccold)
			continue;
3550
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3551
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3552
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3553 3554 3555
		kfree(ccold);
	}

3556 3557 3558
	err = alloc_kmemlist(cachep);
	if (err) {
		printk(KERN_ERR "alloc_kmemlist failed for %s, error %d.\n",
P
Pekka Enberg 已提交
3559
		       cachep->name, -err);
3560
		BUG();
L
Linus Torvalds 已提交
3561 3562 3563 3564
	}
	return 0;
}

3565
/* Called with cache_chain_mutex held always */
3566
static void enable_cpucache(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3567 3568 3569 3570
{
	int err;
	int limit, shared;

A
Andrew Morton 已提交
3571 3572
	/*
	 * The head array serves three purposes:
L
Linus Torvalds 已提交
3573 3574
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
A
Andrew Morton 已提交
3575
	 * - reduce the number of linked list operations on the slab and
L
Linus Torvalds 已提交
3576 3577 3578 3579
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
3580
	if (cachep->buffer_size > 131072)
L
Linus Torvalds 已提交
3581
		limit = 1;
3582
	else if (cachep->buffer_size > PAGE_SIZE)
L
Linus Torvalds 已提交
3583
		limit = 8;
3584
	else if (cachep->buffer_size > 1024)
L
Linus Torvalds 已提交
3585
		limit = 24;
3586
	else if (cachep->buffer_size > 256)
L
Linus Torvalds 已提交
3587 3588 3589 3590
		limit = 54;
	else
		limit = 120;

A
Andrew Morton 已提交
3591 3592
	/*
	 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
L
Linus Torvalds 已提交
3593 3594 3595 3596 3597 3598 3599 3600 3601
	 * allocation behaviour: Most allocs on one cpu, most free operations
	 * on another cpu. For these cases, an efficient object passing between
	 * cpus is necessary. This is provided by a shared array. The array
	 * replaces Bonwick's magazine layer.
	 * On uniprocessor, it's functionally equivalent (but less efficient)
	 * to a larger limit. Thus disabled by default.
	 */
	shared = 0;
#ifdef CONFIG_SMP
3602
	if (cachep->buffer_size <= PAGE_SIZE)
L
Linus Torvalds 已提交
3603 3604 3605 3606
		shared = 8;
#endif

#if DEBUG
A
Andrew Morton 已提交
3607 3608 3609
	/*
	 * With debugging enabled, large batchcount lead to excessively long
	 * periods with disabled local interrupts. Limit the batchcount
L
Linus Torvalds 已提交
3610 3611 3612 3613
	 */
	if (limit > 32)
		limit = 32;
#endif
P
Pekka Enberg 已提交
3614
	err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
L
Linus Torvalds 已提交
3615 3616
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
P
Pekka Enberg 已提交
3617
		       cachep->name, -err);
L
Linus Torvalds 已提交
3618 3619
}

3620 3621
/*
 * Drain an array if it contains any elements taking the l3 lock only if
3622 3623
 * necessary. Note that the l3 listlock also protects the array_cache
 * if drain_array() is used on the shared array.
3624 3625 3626
 */
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
3627 3628 3629
{
	int tofree;

3630 3631
	if (!ac || !ac->avail)
		return;
L
Linus Torvalds 已提交
3632 3633
	if (ac->touched && !force) {
		ac->touched = 0;
3634
	} else {
3635
		spin_lock_irq(&l3->list_lock);
3636 3637 3638 3639 3640 3641 3642 3643 3644
		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);
		}
3645
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3646 3647 3648 3649 3650
	}
}

/**
 * cache_reap - Reclaim memory from caches.
3651
 * @unused: unused parameter
L
Linus Torvalds 已提交
3652 3653 3654 3655 3656 3657
 *
 * 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
3658 3659
 * 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
3660 3661 3662 3663
 */
static void cache_reap(void *unused)
{
	struct list_head *walk;
3664
	struct kmem_list3 *l3;
3665
	int node = numa_node_id();
L
Linus Torvalds 已提交
3666

I
Ingo Molnar 已提交
3667
	if (!mutex_trylock(&cache_chain_mutex)) {
L
Linus Torvalds 已提交
3668
		/* Give up. Setup the next iteration. */
P
Pekka Enberg 已提交
3669 3670
		schedule_delayed_work(&__get_cpu_var(reap_work),
				      REAPTIMEOUT_CPUC);
L
Linus Torvalds 已提交
3671 3672 3673 3674
		return;
	}

	list_for_each(walk, &cache_chain) {
3675
		struct kmem_cache *searchp;
P
Pekka Enberg 已提交
3676
		struct list_head *p;
L
Linus Torvalds 已提交
3677 3678 3679
		int tofree;
		struct slab *slabp;

3680
		searchp = list_entry(walk, struct kmem_cache, next);
L
Linus Torvalds 已提交
3681 3682
		check_irq_on();

3683 3684 3685 3686 3687
		/*
		 * 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.
		 */
3688
		l3 = searchp->nodelists[node];
3689

3690
		reap_alien(searchp, l3);
L
Linus Torvalds 已提交
3691

3692
		drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
L
Linus Torvalds 已提交
3693

3694 3695 3696 3697
		/*
		 * These are racy checks but it does not matter
		 * if we skip one check or scan twice.
		 */
3698
		if (time_after(l3->next_reap, jiffies))
3699
			goto next;
L
Linus Torvalds 已提交
3700

3701
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
3702

3703
		drain_array(searchp, l3, l3->shared, 0, node);
L
Linus Torvalds 已提交
3704

3705 3706
		if (l3->free_touched) {
			l3->free_touched = 0;
3707
			goto next;
L
Linus Torvalds 已提交
3708 3709
		}

A
Andrew Morton 已提交
3710 3711
		tofree = (l3->free_limit + 5 * searchp->num - 1) /
				(5 * searchp->num);
L
Linus Torvalds 已提交
3712
		do {
3713 3714 3715 3716 3717 3718 3719
			/*
			 * Do not lock if there are no free blocks.
			 */
			if (list_empty(&l3->slabs_free))
				break;

			spin_lock_irq(&l3->list_lock);
3720
			p = l3->slabs_free.next;
3721 3722
			if (p == &(l3->slabs_free)) {
				spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3723
				break;
3724
			}
L
Linus Torvalds 已提交
3725 3726 3727 3728 3729 3730

			slabp = list_entry(p, struct slab, list);
			BUG_ON(slabp->inuse);
			list_del(&slabp->list);
			STATS_INC_REAPED(searchp);

A
Andrew Morton 已提交
3731 3732 3733
			/*
			 * Safe to drop the lock. The slab is no longer linked
			 * to the cache. searchp cannot disappear, we hold
L
Linus Torvalds 已提交
3734 3735
			 * cache_chain_lock
			 */
3736 3737
			l3->free_objects -= searchp->num;
			spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3738
			slab_destroy(searchp, slabp);
P
Pekka Enberg 已提交
3739
		} while (--tofree > 0);
3740
next:
L
Linus Torvalds 已提交
3741 3742 3743
		cond_resched();
	}
	check_irq_on();
I
Ingo Molnar 已提交
3744
	mutex_unlock(&cache_chain_mutex);
3745
	next_reap_node();
A
Andrew Morton 已提交
3746
	/* Set up the next iteration */
3747
	schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
L
Linus Torvalds 已提交
3748 3749 3750 3751
}

#ifdef CONFIG_PROC_FS

3752
static void print_slabinfo_header(struct seq_file *m)
L
Linus Torvalds 已提交
3753
{
3754 3755 3756 3757
	/*
	 * Output format version, so at least we can change it
	 * without _too_ many complaints.
	 */
L
Linus Torvalds 已提交
3758
#if STATS
3759
	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
L
Linus Torvalds 已提交
3760
#else
3761
	seq_puts(m, "slabinfo - version: 2.1\n");
L
Linus Torvalds 已提交
3762
#endif
3763 3764 3765 3766
	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
3767
#if STATS
3768 3769 3770
	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
		 "<error> <maxfreeable> <nodeallocs> <remotefrees>");
	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
L
Linus Torvalds 已提交
3771
#endif
3772 3773 3774 3775 3776 3777 3778 3779
	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
3780
	mutex_lock(&cache_chain_mutex);
3781 3782
	if (!n)
		print_slabinfo_header(m);
L
Linus Torvalds 已提交
3783 3784 3785 3786 3787 3788
	p = cache_chain.next;
	while (n--) {
		p = p->next;
		if (p == &cache_chain)
			return NULL;
	}
3789
	return list_entry(p, struct kmem_cache, next);
L
Linus Torvalds 已提交
3790 3791 3792 3793
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
3794
	struct kmem_cache *cachep = p;
L
Linus Torvalds 已提交
3795
	++*pos;
A
Andrew Morton 已提交
3796 3797
	return cachep->next.next == &cache_chain ?
		NULL : list_entry(cachep->next.next, struct kmem_cache, next);
L
Linus Torvalds 已提交
3798 3799 3800 3801
}

static void s_stop(struct seq_file *m, void *p)
{
I
Ingo Molnar 已提交
3802
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
3803 3804 3805 3806
}

static int s_show(struct seq_file *m, void *p)
{
3807
	struct kmem_cache *cachep = p;
L
Linus Torvalds 已提交
3808
	struct list_head *q;
P
Pekka Enberg 已提交
3809 3810 3811 3812 3813
	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;
3814
	const char *name;
L
Linus Torvalds 已提交
3815
	char *error = NULL;
3816 3817
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3818 3819 3820

	active_objs = 0;
	num_slabs = 0;
3821 3822 3823 3824 3825
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

3826 3827
		check_irq_on();
		spin_lock_irq(&l3->list_lock);
3828

P
Pekka Enberg 已提交
3829
		list_for_each(q, &l3->slabs_full) {
3830 3831 3832 3833 3834 3835
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
P
Pekka Enberg 已提交
3836
		list_for_each(q, &l3->slabs_partial) {
3837 3838 3839 3840 3841 3842 3843 3844
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse == cachep->num && !error)
				error = "slabs_partial inuse accounting error";
			if (!slabp->inuse && !error)
				error = "slabs_partial/inuse accounting error";
			active_objs += slabp->inuse;
			active_slabs++;
		}
P
Pekka Enberg 已提交
3845
		list_for_each(q, &l3->slabs_free) {
3846 3847 3848 3849 3850 3851
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
3852 3853
		if (l3->shared)
			shared_avail += l3->shared->avail;
3854

3855
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3856
	}
P
Pekka Enberg 已提交
3857 3858
	num_slabs += active_slabs;
	num_objs = num_slabs * cachep->num;
3859
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
3860 3861
		error = "free_objects accounting error";

P
Pekka Enberg 已提交
3862
	name = cachep->name;
L
Linus Torvalds 已提交
3863 3864 3865 3866
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
3867
		   name, active_objs, num_objs, cachep->buffer_size,
P
Pekka Enberg 已提交
3868
		   cachep->num, (1 << cachep->gfporder));
L
Linus Torvalds 已提交
3869
	seq_printf(m, " : tunables %4u %4u %4u",
P
Pekka Enberg 已提交
3870
		   cachep->limit, cachep->batchcount, cachep->shared);
3871
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
P
Pekka Enberg 已提交
3872
		   active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
3873
#if STATS
P
Pekka Enberg 已提交
3874
	{			/* list3 stats */
L
Linus Torvalds 已提交
3875 3876 3877 3878 3879 3880 3881
		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;
3882
		unsigned long node_frees = cachep->node_frees;
L
Linus Torvalds 已提交
3883

3884
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
A
Andrew Morton 已提交
3885 3886 3887
				%4lu %4lu %4lu %4lu", allocs, high, grown,
				reaped, errors, max_freeable, node_allocs,
				node_frees);
L
Linus Torvalds 已提交
3888 3889 3890 3891 3892 3893 3894 3895 3896
	}
	/* 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
3897
			   allochit, allocmiss, freehit, freemiss);
L
Linus Torvalds 已提交
3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918
	}
#endif
	seq_putc(m, '\n');
	return 0;
}

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

struct seq_operations slabinfo_op = {
P
Pekka Enberg 已提交
3919 3920 3921 3922
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
L
Linus Torvalds 已提交
3923 3924 3925 3926 3927 3928 3929 3930 3931 3932
};

#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
3933 3934
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
		       size_t count, loff_t *ppos)
L
Linus Torvalds 已提交
3935
{
P
Pekka Enberg 已提交
3936
	char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
L
Linus Torvalds 已提交
3937 3938
	int limit, batchcount, shared, res;
	struct list_head *p;
P
Pekka Enberg 已提交
3939

L
Linus Torvalds 已提交
3940 3941 3942 3943
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
P
Pekka Enberg 已提交
3944
	kbuf[MAX_SLABINFO_WRITE] = '\0';
L
Linus Torvalds 已提交
3945 3946 3947 3948 3949 3950 3951 3952 3953 3954

	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
3955
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
3956
	res = -EINVAL;
P
Pekka Enberg 已提交
3957
	list_for_each(p, &cache_chain) {
A
Andrew Morton 已提交
3958
		struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3959

A
Andrew Morton 已提交
3960
		cachep = list_entry(p, struct kmem_cache, next);
L
Linus Torvalds 已提交
3961
		if (!strcmp(cachep->name, kbuf)) {
A
Andrew Morton 已提交
3962 3963
			if (limit < 1 || batchcount < 1 ||
					batchcount > limit || shared < 0) {
3964
				res = 0;
L
Linus Torvalds 已提交
3965
			} else {
3966
				res = do_tune_cpucache(cachep, limit,
P
Pekka Enberg 已提交
3967
						       batchcount, shared);
L
Linus Torvalds 已提交
3968 3969 3970 3971
			}
			break;
		}
	}
I
Ingo Molnar 已提交
3972
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
3973 3974 3975 3976
	if (res >= 0)
		res = count;
	return res;
}
3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129

#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 list_head *q;
	struct slab *slabp;
	struct kmem_list3 *l3;
	const char *name;
	unsigned long *n = m->private;
	int node;
	int i;

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

	/* OK, we can do it */

	n[1] = 0;

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

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

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

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

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