slab.c 115.2 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
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 * slabs and you must pass objects with the same initializations to
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 * kmem_cache_free.
 *
 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
 * normal). If you need a special memory type, then must create a new
 * cache for that memory type.
 *
 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
 *   full slabs with 0 free objects
 *   partial slabs
 *   empty slabs with no allocated objects
 *
 * If partial slabs exist, then new allocations come from these slabs,
 * otherwise from empty slabs or new slabs are allocated.
 *
 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
 *
 * Each cache has a short per-cpu head array, most allocs
 * and frees go into that array, and if that array overflows, then 1/2
 * of the entries in the array are given back into the global cache.
 * The head array is strictly LIFO and should improve the cache hit rates.
 * On SMP, it additionally reduces the spinlock operations.
 *
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 * The c_cpuarray may not be read with enabled local interrupts -
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 * it's changed with a smp_call_function().
 *
 * SMP synchronization:
 *  constructors and destructors are called without any locking.
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 *  Several members in struct kmem_cache and struct slab never change, they
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 *	are accessed without any locking.
 *  The per-cpu arrays are never accessed from the wrong cpu, no locking,
 *  	and local interrupts are disabled so slab code is preempt-safe.
 *  The non-constant members are protected with a per-cache irq spinlock.
 *
 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
 * in 2000 - many ideas in the current implementation are derived from
 * his patch.
 *
 * Further notes from the original documentation:
 *
 * 11 April '97.  Started multi-threading - markhe
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 *	The global cache-chain is protected by the mutex 'cache_chain_mutex'.
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 *	The sem is only needed when accessing/extending the cache-chain, which
 *	can never happen inside an interrupt (kmem_cache_create(),
 *	kmem_cache_shrink() and kmem_cache_reap()).
 *
 *	At present, each engine can be growing a cache.  This should be blocked.
 *
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 * 15 March 2005. NUMA slab allocator.
 *	Shai Fultheim <shai@scalex86.org>.
 *	Shobhit Dayal <shobhit@calsoftinc.com>
 *	Alok N Kataria <alokk@calsoftinc.com>
 *	Christoph Lameter <christoph@lameter.com>
 *
 *	Modified the slab allocator to be node aware on NUMA systems.
 *	Each node has its own list of partial, free and full slabs.
 *	All object allocations for a node occur from node specific slab lists.
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 */

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

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

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

/* Shouldn't this be in a header file somewhere? */
#define	BYTES_PER_WORD		sizeof(void *)
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#define	REDZONE_ALIGN		max(BYTES_PER_WORD, __alignof__(unsigned long long))
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#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
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 * alignment larger than the alignment of a 64-bit integer.
 * ARCH_KMALLOC_MINALIGN allows that.
 * Note that increasing this value may disable some debug features.
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 */
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#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
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#endif

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

#ifndef ARCH_KMALLOC_FLAGS
#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
#endif

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

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

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typedef unsigned int kmem_bufctl_t;
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#define BUFCTL_END	(((kmem_bufctl_t)(~0U))-0)
#define BUFCTL_FREE	(((kmem_bufctl_t)(~0U))-1)
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#define	BUFCTL_ACTIVE	(((kmem_bufctl_t)(~0U))-2)
#define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-3)
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/*
 * struct slab
 *
 * Manages the objs in a slab. Placed either at the beginning of mem allocated
 * for a slab, or allocated from an general cache.
 * Slabs are chained into three list: fully used, partial, fully free slabs.
 */
struct slab {
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	struct list_head list;
	unsigned long colouroff;
	void *s_mem;		/* including colour offset */
	unsigned int inuse;	/* num of objs active in slab */
	kmem_bufctl_t free;
	unsigned short nodeid;
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};

/*
 * struct slab_rcu
 *
 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
 * arrange for kmem_freepages to be called via RCU.  This is useful if
 * we need to approach a kernel structure obliquely, from its address
 * obtained without the usual locking.  We can lock the structure to
 * stabilize it and check it's still at the given address, only if we
 * can be sure that the memory has not been meanwhile reused for some
 * other kind of object (which our subsystem's lock might corrupt).
 *
 * rcu_read_lock before reading the address, then rcu_read_unlock after
 * taking the spinlock within the structure expected at that address.
 *
 * We assume struct slab_rcu can overlay struct slab when destroying.
 */
struct slab_rcu {
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	struct rcu_head head;
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	struct kmem_cache *cachep;
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	void *addr;
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};

/*
 * struct array_cache
 *
 * Purpose:
 * - LIFO ordering, to hand out cache-warm objects from _alloc
 * - reduce the number of linked list operations
 * - reduce spinlock operations
 *
 * The limit is stored in the per-cpu structure to reduce the data cache
 * footprint.
 *
 */
struct array_cache {
	unsigned int avail;
	unsigned int limit;
	unsigned int batchcount;
	unsigned int touched;
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	spinlock_t lock;
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	void *entry[];	/*
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			 * Must have this definition in here for the proper
			 * alignment of array_cache. Also simplifies accessing
			 * the entries.
			 */
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};

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

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

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/*
 * Need this for bootstrapping a per node allocator.
 */
#define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
#define	CACHE_CACHE 0
#define	SIZE_AC 1
#define	SIZE_L3 (1 + MAX_NUMNODES)

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static int drain_freelist(struct kmem_cache *cache,
			struct kmem_list3 *l3, int tofree);
static void free_block(struct kmem_cache *cachep, void **objpp, int len,
			int node);
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static int enable_cpucache(struct kmem_cache *cachep);
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static void cache_reap(struct work_struct *unused);
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/*
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 * This function must be completely optimized away if a constant is passed to
 * it.  Mostly the same as what is in linux/slab.h except it returns an index.
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 */
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static __always_inline int index_of(const size_t size)
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{
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	extern void __bad_size(void);

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	if (__builtin_constant_p(size)) {
		int i = 0;

#define CACHE(x) \
	if (size <=x) \
		return i; \
	else \
		i++;
#include "linux/kmalloc_sizes.h"
#undef CACHE
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		__bad_size();
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	} else
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		__bad_size();
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	return 0;
}

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static int slab_early_init = 1;

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

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

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#define	MAKE_ALL_LISTS(cachep, ptr, nodeid)				\
	do {								\
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	MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid);	\
	MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
	MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid);	\
	} while (0)
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/*
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 * struct kmem_cache
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 *
 * manages a cache.
 */
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struct kmem_cache {
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/* 1) per-cpu data, touched during every alloc/free */
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	struct array_cache *array[NR_CPUS];
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/* 2) Cache tunables. Protected by cache_chain_mutex */
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	unsigned int batchcount;
	unsigned int limit;
	unsigned int shared;
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	unsigned int buffer_size;
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	u32 reciprocal_buffer_size;
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/* 3) touched by every alloc & free from the backend */

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	unsigned int flags;		/* constant flags */
	unsigned int num;		/* # of objs per slab */
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/* 4) cache_grow/shrink */
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	/* order of pgs per slab (2^n) */
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	unsigned int gfporder;
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	/* force GFP flags, e.g. GFP_DMA */
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	gfp_t gfpflags;
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	size_t colour;			/* cache colouring range */
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	unsigned int colour_off;	/* colour offset */
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	struct kmem_cache *slabp_cache;
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	unsigned int slab_size;
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	unsigned int dflags;		/* dynamic flags */
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	/* constructor func */
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	void (*ctor)(struct kmem_cache *, void *);
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/* 5) cache creation/removal */
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	const char *name;
	struct list_head next;
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/* 6) statistics */
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#if STATS
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	unsigned long num_active;
	unsigned long num_allocations;
	unsigned long high_mark;
	unsigned long grown;
	unsigned long reaped;
	unsigned long errors;
	unsigned long max_freeable;
	unsigned long node_allocs;
	unsigned long node_frees;
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	unsigned long node_overflow;
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	atomic_t allochit;
	atomic_t allocmiss;
	atomic_t freehit;
	atomic_t freemiss;
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#endif
#if DEBUG
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	/*
	 * If debugging is enabled, then the allocator can add additional
	 * fields and/or padding to every object. buffer_size contains the total
	 * object size including these internal fields, the following two
	 * variables contain the offset to the user object and its size.
	 */
	int obj_offset;
	int obj_size;
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#endif
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	/*
	 * We put nodelists[] at the end of kmem_cache, because we want to size
	 * this array to nr_node_ids slots instead of MAX_NUMNODES
	 * (see kmem_cache_init())
	 * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache
	 * is statically defined, so we reserve the max number of nodes.
	 */
	struct kmem_list3 *nodelists[MAX_NUMNODES];
	/*
	 * Do not add fields after nodelists[]
	 */
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};

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

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

#if STATS
#define	STATS_INC_ACTIVE(x)	((x)->num_active++)
#define	STATS_DEC_ACTIVE(x)	((x)->num_active--)
#define	STATS_INC_ALLOCED(x)	((x)->num_allocations++)
#define	STATS_INC_GROWN(x)	((x)->grown++)
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#define	STATS_ADD_REAPED(x,y)	((x)->reaped += (y))
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#define	STATS_SET_HIGH(x)						\
	do {								\
		if ((x)->num_active > (x)->high_mark)			\
			(x)->high_mark = (x)->num_active;		\
	} while (0)
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#define	STATS_INC_ERR(x)	((x)->errors++)
#define	STATS_INC_NODEALLOCS(x)	((x)->node_allocs++)
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#define	STATS_INC_NODEFREES(x)	((x)->node_frees++)
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#define STATS_INC_ACOVERFLOW(x)   ((x)->node_overflow++)
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#define	STATS_SET_FREEABLE(x, i)					\
	do {								\
		if ((x)->max_freeable < i)				\
			(x)->max_freeable = i;				\
	} while (0)
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#define STATS_INC_ALLOCHIT(x)	atomic_inc(&(x)->allochit)
#define STATS_INC_ALLOCMISS(x)	atomic_inc(&(x)->allocmiss)
#define STATS_INC_FREEHIT(x)	atomic_inc(&(x)->freehit)
#define STATS_INC_FREEMISS(x)	atomic_inc(&(x)->freemiss)
#else
#define	STATS_INC_ACTIVE(x)	do { } while (0)
#define	STATS_DEC_ACTIVE(x)	do { } while (0)
#define	STATS_INC_ALLOCED(x)	do { } while (0)
#define	STATS_INC_GROWN(x)	do { } while (0)
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#define	STATS_ADD_REAPED(x,y)	do { } while (0)
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#define	STATS_SET_HIGH(x)	do { } while (0)
#define	STATS_INC_ERR(x)	do { } while (0)
#define	STATS_INC_NODEALLOCS(x)	do { } while (0)
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#define	STATS_INC_NODEFREES(x)	do { } while (0)
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#define STATS_INC_ACOVERFLOW(x)   do { } while (0)
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#define	STATS_SET_FREEABLE(x, i) do { } while (0)
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#define STATS_INC_ALLOCHIT(x)	do { } while (0)
#define STATS_INC_ALLOCMISS(x)	do { } while (0)
#define STATS_INC_FREEHIT(x)	do { } while (0)
#define STATS_INC_FREEMISS(x)	do { } while (0)
#endif

#if DEBUG

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/*
 * memory layout of objects:
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 * 0		: objp
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 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
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 * 		the end of an object is aligned with the end of the real
 * 		allocation. Catches writes behind the end of the allocation.
520
 * 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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 */
527
static int obj_offset(struct kmem_cache *cachep)
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{
529
	return cachep->obj_offset;
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}

532
static int obj_size(struct kmem_cache *cachep)
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{
534
	return cachep->obj_size;
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}

537
static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
540 541
	return (unsigned long long*) (objp + obj_offset(cachep) -
				      sizeof(unsigned long long));
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}

544
static unsigned long 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)
548 549
		return (unsigned long long *)(objp + cachep->buffer_size -
					      sizeof(unsigned long long) -
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					      REDZONE_ALIGN);
551 552
	return (unsigned long long *) (objp + cachep->buffer_size -
				       sizeof(unsigned long long));
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}

555
static void **dbg_userword(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
558
	return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

#else

563 564
#define obj_offset(x)			0
#define obj_size(cachep)		(cachep->buffer_size)
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#define dbg_redzone1(cachep, objp)	({BUG(); (unsigned long long *)NULL;})
#define dbg_redzone2(cachep, objp)	({BUG(); (unsigned long long *)NULL;})
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#define dbg_userword(cachep, objp)	({BUG(); (void **)NULL;})

#endif

/*
 * Do not go above this order unless 0 objects fit into the slab.
 */
#define	BREAK_GFP_ORDER_HI	1
#define	BREAK_GFP_ORDER_LO	0
static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;

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/*
 * Functions for storing/retrieving the cachep and or slab from the page
 * allocator.  These are used to find the slab an obj belongs to.  With kfree(),
 * these are used to find the cache which an obj belongs to.
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 */
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static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
{
	page->lru.next = (struct list_head *)cache;
}

static inline struct kmem_cache *page_get_cache(struct page *page)
{
590
	page = compound_head(page);
591
	BUG_ON(!PageSlab(page));
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	return (struct kmem_cache *)page->lru.next;
}

static inline void page_set_slab(struct page *page, struct slab *slab)
{
	page->lru.prev = (struct list_head *)slab;
}

static inline struct slab *page_get_slab(struct page *page)
{
602
	BUG_ON(!PageSlab(page));
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	return (struct slab *)page->lru.prev;
}
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606 607
static inline struct kmem_cache *virt_to_cache(const void *obj)
{
608
	struct page *page = virt_to_head_page(obj);
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	return page_get_cache(page);
}

static inline struct slab *virt_to_slab(const void *obj)
{
614
	struct page *page = virt_to_head_page(obj);
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	return page_get_slab(page);
}

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

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/*
 * We want to avoid an expensive divide : (offset / cache->buffer_size)
 *   Using the fact that buffer_size is a constant for a particular cache,
 *   we can replace (offset / cache->buffer_size) by
 *   reciprocal_divide(offset, cache->reciprocal_buffer_size)
 */
static inline unsigned int obj_to_index(const struct kmem_cache *cache,
					const struct slab *slab, void *obj)
632
{
633 634
	u32 offset = (obj - slab->s_mem);
	return reciprocal_divide(offset, cache->reciprocal_buffer_size);
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}

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

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

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

static struct arraycache_init initarray_cache __initdata =
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    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
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static struct arraycache_init initarray_generic =
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    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
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/* internal cache of cache description objs */
667
static struct kmem_cache cache_cache = {
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	.batchcount = 1,
	.limit = BOOT_CPUCACHE_ENTRIES,
	.shared = 1,
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	.buffer_size = sizeof(struct kmem_cache),
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	.name = "kmem_cache",
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};

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#define BAD_ALIEN_MAGIC 0x01020304ul

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#ifdef CONFIG_LOCKDEP

/*
 * Slab sometimes uses the kmalloc slabs to store the slab headers
 * for other slabs "off slab".
 * The locking for this is tricky in that it nests within the locks
 * of all other slabs in a few places; to deal with this special
 * locking we put on-slab caches into a separate lock-class.
685 686 687 688
 *
 * We set lock class for alien array caches which are up during init.
 * The lock annotation will be lost if all cpus of a node goes down and
 * then comes back up during hotplug
689
 */
690 691 692 693
static struct lock_class_key on_slab_l3_key;
static struct lock_class_key on_slab_alc_key;

static inline void init_lock_keys(void)
694 695 696

{
	int q;
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	struct cache_sizes *s = malloc_sizes;

	while (s->cs_size != ULONG_MAX) {
		for_each_node(q) {
			struct array_cache **alc;
			int r;
			struct kmem_list3 *l3 = s->cs_cachep->nodelists[q];
			if (!l3 || OFF_SLAB(s->cs_cachep))
				continue;
			lockdep_set_class(&l3->list_lock, &on_slab_l3_key);
			alc = l3->alien;
			/*
			 * FIXME: This check for BAD_ALIEN_MAGIC
			 * should go away when common slab code is taught to
			 * work even without alien caches.
			 * Currently, non NUMA code returns BAD_ALIEN_MAGIC
			 * for alloc_alien_cache,
			 */
			if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC)
				continue;
			for_each_node(r) {
				if (alc[r])
					lockdep_set_class(&alc[r]->lock,
					     &on_slab_alc_key);
			}
		}
		s++;
724 725 726
	}
}
#else
727
static inline void init_lock_keys(void)
728 729 730 731
{
}
#endif

732 733 734 735
/*
 * 1. Guard access to the cache-chain.
 * 2. Protect sanity of cpu_online_map against cpu hotplug events
 */
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static DEFINE_MUTEX(cache_chain_mutex);
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static struct list_head cache_chain;

/*
 * chicken and egg problem: delay the per-cpu array allocation
 * until the general caches are up.
 */
static enum {
	NONE,
745 746
	PARTIAL_AC,
	PARTIAL_L3,
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	FULL
} g_cpucache_up;

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

758
static DEFINE_PER_CPU(struct delayed_work, reap_work);
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760
static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
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{
	return cachep->array[smp_processor_id()];
}

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

#if DEBUG
	/* This happens if someone tries to call
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	 * kmem_cache_create(), or __kmalloc(), before
	 * the generic caches are initialized.
	 */
775
	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
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#endif
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	if (!size)
		return ZERO_SIZE_PTR;

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	while (size > csizep->cs_size)
		csizep++;

	/*
784
	 * 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.
	 */
788
#ifdef CONFIG_ZONE_DMA
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	if (unlikely(gfpflags & GFP_DMA))
		return csizep->cs_dmacachep;
791
#endif
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	return csizep->cs_cachep;
}

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static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
796 797 798 799
{
	return __find_general_cachep(size, gfpflags);
}

800
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
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{
802 803
	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
}
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/*
 * Calculate the number of objects and left-over bytes for a given buffer size.
 */
808 809 810 811 812 813 814
static void cache_estimate(unsigned long gfporder, size_t buffer_size,
			   size_t align, int flags, size_t *left_over,
			   unsigned int *num)
{
	int nr_objs;
	size_t mgmt_size;
	size_t slab_size = PAGE_SIZE << gfporder;
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	/*
	 * The slab management structure can be either off the slab or
	 * on it. For the latter case, the memory allocated for a
	 * slab is used for:
	 *
	 * - The struct slab
	 * - One kmem_bufctl_t for each object
	 * - Padding to respect alignment of @align
	 * - @buffer_size bytes for each object
	 *
	 * If the slab management structure is off the slab, then the
	 * alignment will already be calculated into the size. Because
	 * the slabs are all pages aligned, the objects will be at the
	 * correct alignment when allocated.
	 */
	if (flags & CFLGS_OFF_SLAB) {
		mgmt_size = 0;
		nr_objs = slab_size / buffer_size;

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

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

		if (nr_objs > SLAB_LIMIT)
			nr_objs = SLAB_LIMIT;

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

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

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

876 877 878 879 880 881 882 883 884
/*
 * By default on NUMA we use alien caches to stage the freeing of
 * objects allocated from other nodes. This causes massive memory
 * inefficiencies when using fake NUMA setup to split memory into a
 * large number of small nodes, so it can be disabled on the command
 * line
  */

static int use_alien_caches __read_mostly = 1;
885
static int numa_platform __read_mostly = 1;
886 887 888 889 890 891 892
static int __init noaliencache_setup(char *s)
{
	use_alien_caches = 0;
	return 1;
}
__setup("noaliencache", noaliencache_setup);

893 894 895 896 897 898 899 900 901 902 903 904 905 906 907
#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)
908
		node = first_node(node_online_map);
909

910
	per_cpu(reap_node, cpu) = node;
911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927
}

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

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

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

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/*
 * Initiate the reap timer running on the target CPU.  We run at around 1 to 2Hz
 * via the workqueue/eventd.
 * Add the CPU number into the expiration time to minimize the possibility of
 * the CPUs getting into lockstep and contending for the global cache chain
 * lock.
 */
935
static void __cpuinit start_cpu_timer(int cpu)
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{
937
	struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
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	/*
	 * When this gets called from do_initcalls via cpucache_init(),
	 * init_workqueues() has already run, so keventd will be setup
	 * at that time.
	 */
944
	if (keventd_up() && reap_work->work.func == NULL) {
945
		init_reap_node(cpu);
946
		INIT_DELAYED_WORK(reap_work, cache_reap);
947 948
		schedule_delayed_work_on(cpu, reap_work,
					__round_jiffies_relative(HZ, cpu));
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	}
}

952
static struct array_cache *alloc_arraycache(int node, int entries,
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					    int batchcount)
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{
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	int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
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	struct array_cache *nc = NULL;

958
	nc = kmalloc_node(memsize, GFP_KERNEL, node);
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	if (nc) {
		nc->avail = 0;
		nc->limit = entries;
		nc->batchcount = batchcount;
		nc->touched = 0;
964
		spin_lock_init(&nc->lock);
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	}
	return nc;
}

969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992
/*
 * 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;
}

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#ifndef CONFIG_NUMA

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

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

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

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

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

1018
static inline void *____cache_alloc_node(struct kmem_cache *cachep,
1019 1020 1021 1022 1023 1024 1025
		 gfp_t flags, int nodeid)
{
	return NULL;
}

#else	/* CONFIG_NUMA */

1026
static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
1027
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
1028

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static struct array_cache **alloc_alien_cache(int node, int limit)
1030 1031
{
	struct array_cache **ac_ptr;
1032
	int memsize = sizeof(void *) * nr_node_ids;
1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
	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]) {
1046
				for (i--; i >= 0; i--)
1047 1048 1049 1050 1051 1052 1053 1054 1055
					kfree(ac_ptr[i]);
				kfree(ac_ptr);
				return NULL;
			}
		}
	}
	return ac_ptr;
}

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static void free_alien_cache(struct array_cache **ac_ptr)
1057 1058 1059 1060 1061 1062
{
	int i;

	if (!ac_ptr)
		return;
	for_each_node(i)
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	    kfree(ac_ptr[i]);
1064 1065 1066
	kfree(ac_ptr);
}

1067
static void __drain_alien_cache(struct kmem_cache *cachep,
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				struct array_cache *ac, int node)
1069 1070 1071 1072 1073
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
1074 1075 1076 1077 1078
		/*
		 * 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.
		 */
1079 1080
		if (rl3->shared)
			transfer_objects(rl3->shared, ac, ac->limit);
1081

1082
		free_block(cachep, ac->entry, ac->avail, node);
1083 1084 1085 1086 1087
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

1088 1089 1090 1091 1092 1093 1094 1095 1096
/*
 * 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];
1097 1098

		if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
1099 1100 1101 1102 1103 1104
			__drain_alien_cache(cachep, ac, node);
			spin_unlock_irq(&ac->lock);
		}
	}
}

A
Andrew Morton 已提交
1105 1106
static void drain_alien_cache(struct kmem_cache *cachep,
				struct array_cache **alien)
1107
{
P
Pekka Enberg 已提交
1108
	int i = 0;
1109 1110 1111 1112
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
1113
		ac = alien[i];
1114 1115 1116 1117 1118 1119 1120
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
1121

1122
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1123 1124 1125 1126 1127
{
	struct slab *slabp = virt_to_slab(objp);
	int nodeid = slabp->nodeid;
	struct kmem_list3 *l3;
	struct array_cache *alien = NULL;
P
Pekka Enberg 已提交
1128 1129 1130
	int node;

	node = numa_node_id();
1131 1132 1133 1134 1135

	/*
	 * Make sure we are not freeing a object from another node to the array
	 * cache on this cpu.
	 */
1136
	if (likely(slabp->nodeid == node))
1137 1138
		return 0;

P
Pekka Enberg 已提交
1139
	l3 = cachep->nodelists[node];
1140 1141 1142
	STATS_INC_NODEFREES(cachep);
	if (l3->alien && l3->alien[nodeid]) {
		alien = l3->alien[nodeid];
1143
		spin_lock(&alien->lock);
1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156
		if (unlikely(alien->avail == alien->limit)) {
			STATS_INC_ACOVERFLOW(cachep);
			__drain_alien_cache(cachep, alien, nodeid);
		}
		alien->entry[alien->avail++] = objp;
		spin_unlock(&alien->lock);
	} else {
		spin_lock(&(cachep->nodelists[nodeid])->list_lock);
		free_block(cachep, &objp, 1, nodeid);
		spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
	}
	return 1;
}
1157 1158
#endif

1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225
static void __cpuinit cpuup_canceled(long cpu)
{
	struct kmem_cache *cachep;
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);

	list_for_each_entry(cachep, &cache_chain, next) {
		struct array_cache *nc;
		struct array_cache *shared;
		struct array_cache **alien;
		cpumask_t mask;

		mask = node_to_cpumask(node);
		/* cpu is dead; no one can alloc from it. */
		nc = cachep->array[cpu];
		cachep->array[cpu] = NULL;
		l3 = cachep->nodelists[node];

		if (!l3)
			goto free_array_cache;

		spin_lock_irq(&l3->list_lock);

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

		if (!cpus_empty(mask)) {
			spin_unlock_irq(&l3->list_lock);
			goto free_array_cache;
		}

		shared = l3->shared;
		if (shared) {
			free_block(cachep, shared->entry,
				   shared->avail, node);
			l3->shared = NULL;
		}

		alien = l3->alien;
		l3->alien = NULL;

		spin_unlock_irq(&l3->list_lock);

		kfree(shared);
		if (alien) {
			drain_alien_cache(cachep, alien);
			free_alien_cache(alien);
		}
free_array_cache:
		kfree(nc);
	}
	/*
	 * In the previous loop, all the objects were freed to
	 * the respective cache's slabs,  now we can go ahead and
	 * shrink each nodelist to its limit.
	 */
	list_for_each_entry(cachep, &cache_chain, next) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;
		drain_freelist(cachep, l3, l3->free_objects);
	}
}

static int __cpuinit cpuup_prepare(long cpu)
L
Linus Torvalds 已提交
1226
{
1227
	struct kmem_cache *cachep;
1228 1229
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
1230
	const int memsize = sizeof(struct kmem_list3);
L
Linus Torvalds 已提交
1231

1232 1233 1234 1235 1236 1237 1238 1239
	/*
	 * We need to do this right in the beginning since
	 * alloc_arraycache's are going to use this list.
	 * kmalloc_node allows us to add the slab to the right
	 * kmem_list3 and not this cpu's kmem_list3
	 */

	list_for_each_entry(cachep, &cache_chain, next) {
A
Andrew Morton 已提交
1240
		/*
1241 1242 1243
		 * Set up the size64 kmemlist for cpu before we can
		 * begin anything. Make sure some other cpu on this
		 * node has not already allocated this
1244
		 */
1245 1246 1247 1248 1249 1250 1251
		if (!cachep->nodelists[node]) {
			l3 = kmalloc_node(memsize, GFP_KERNEL, node);
			if (!l3)
				goto bad;
			kmem_list3_init(l3);
			l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
			    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1252

A
Andrew Morton 已提交
1253
			/*
1254 1255 1256
			 * The l3s don't come and go as CPUs come and
			 * go.  cache_chain_mutex is sufficient
			 * protection here.
1257
			 */
1258
			cachep->nodelists[node] = l3;
1259 1260
		}

1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284
		spin_lock_irq(&cachep->nodelists[node]->list_lock);
		cachep->nodelists[node]->free_limit =
			(1 + nr_cpus_node(node)) *
			cachep->batchcount + cachep->num;
		spin_unlock_irq(&cachep->nodelists[node]->list_lock);
	}

	/*
	 * Now we can go ahead with allocating the shared arrays and
	 * array caches
	 */
	list_for_each_entry(cachep, &cache_chain, next) {
		struct array_cache *nc;
		struct array_cache *shared = NULL;
		struct array_cache **alien = NULL;

		nc = alloc_arraycache(node, cachep->limit,
					cachep->batchcount);
		if (!nc)
			goto bad;
		if (cachep->shared) {
			shared = alloc_arraycache(node,
				cachep->shared * cachep->batchcount,
				0xbaadf00d);
1285 1286
			if (!shared) {
				kfree(nc);
L
Linus Torvalds 已提交
1287
				goto bad;
1288
			}
1289 1290 1291
		}
		if (use_alien_caches) {
			alien = alloc_alien_cache(node, cachep->limit);
1292 1293 1294
			if (!alien) {
				kfree(shared);
				kfree(nc);
1295
				goto bad;
1296
			}
1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310
		}
		cachep->array[cpu] = nc;
		l3 = cachep->nodelists[node];
		BUG_ON(!l3);

		spin_lock_irq(&l3->list_lock);
		if (!l3->shared) {
			/*
			 * We are serialised from CPU_DEAD or
			 * CPU_UP_CANCELLED by the cpucontrol lock
			 */
			l3->shared = shared;
			shared = NULL;
		}
1311
#ifdef CONFIG_NUMA
1312 1313 1314
		if (!l3->alien) {
			l3->alien = alien;
			alien = NULL;
L
Linus Torvalds 已提交
1315
		}
1316 1317 1318 1319 1320 1321 1322
#endif
		spin_unlock_irq(&l3->list_lock);
		kfree(shared);
		free_alien_cache(alien);
	}
	return 0;
bad:
1323
	cpuup_canceled(cpu);
1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339
	return -ENOMEM;
}

static int __cpuinit cpuup_callback(struct notifier_block *nfb,
				    unsigned long action, void *hcpu)
{
	long cpu = (long)hcpu;
	int err = 0;

	switch (action) {
	case CPU_LOCK_ACQUIRE:
		mutex_lock(&cache_chain_mutex);
		break;
	case CPU_UP_PREPARE:
	case CPU_UP_PREPARE_FROZEN:
		err = cpuup_prepare(cpu);
L
Linus Torvalds 已提交
1340 1341
		break;
	case CPU_ONLINE:
1342
	case CPU_ONLINE_FROZEN:
L
Linus Torvalds 已提交
1343 1344 1345
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
1346
  	case CPU_DOWN_PREPARE:
1347
  	case CPU_DOWN_PREPARE_FROZEN:
1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358
		/*
		 * Shutdown cache reaper. Note that the cache_chain_mutex is
		 * held so that if cache_reap() is invoked it cannot do
		 * anything expensive but will only modify reap_work
		 * and reschedule the timer.
		*/
		cancel_rearming_delayed_work(&per_cpu(reap_work, cpu));
		/* Now the cache_reaper is guaranteed to be not running. */
		per_cpu(reap_work, cpu).work.func = NULL;
  		break;
  	case CPU_DOWN_FAILED:
1359
  	case CPU_DOWN_FAILED_FROZEN:
1360 1361
		start_cpu_timer(cpu);
  		break;
L
Linus Torvalds 已提交
1362
	case CPU_DEAD:
1363
	case CPU_DEAD_FROZEN:
1364 1365 1366 1367 1368 1369 1370 1371
		/*
		 * 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().
		 */
S
Simon Arlott 已提交
1372
		/* fall through */
1373
#endif
L
Linus Torvalds 已提交
1374
	case CPU_UP_CANCELED:
1375
	case CPU_UP_CANCELED_FROZEN:
1376
		cpuup_canceled(cpu);
1377 1378
		break;
	case CPU_LOCK_RELEASE:
I
Ingo Molnar 已提交
1379
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1380 1381
		break;
	}
1382
	return err ? NOTIFY_BAD : NOTIFY_OK;
L
Linus Torvalds 已提交
1383 1384
}

1385 1386 1387
static struct notifier_block __cpuinitdata cpucache_notifier = {
	&cpuup_callback, NULL, 0
};
L
Linus Torvalds 已提交
1388

1389 1390 1391
/*
 * swap the static kmem_list3 with kmalloced memory
 */
A
Andrew Morton 已提交
1392 1393
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
			int nodeid)
1394 1395 1396 1397 1398 1399 1400 1401
{
	struct kmem_list3 *ptr;

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

	local_irq_disable();
	memcpy(ptr, list, sizeof(struct kmem_list3));
1402 1403 1404 1405 1406
	/*
	 * Do not assume that spinlocks can be initialized via memcpy:
	 */
	spin_lock_init(&ptr->list_lock);

1407 1408 1409 1410 1411
	MAKE_ALL_LISTS(cachep, ptr, nodeid);
	cachep->nodelists[nodeid] = ptr;
	local_irq_enable();
}

A
Andrew Morton 已提交
1412 1413 1414
/*
 * Initialisation.  Called after the page allocator have been initialised and
 * before smp_init().
L
Linus Torvalds 已提交
1415 1416 1417 1418 1419 1420
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1421
	int i;
1422
	int order;
P
Pekka Enberg 已提交
1423
	int node;
1424

1425
	if (num_possible_nodes() == 1) {
1426
		use_alien_caches = 0;
1427 1428
		numa_platform = 0;
	}
1429

1430 1431 1432 1433 1434
	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
1435 1436 1437 1438 1439 1440 1441 1442 1443 1444

	/*
	 * 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
1445 1446 1447
	 * 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.
1448 1449 1450
	 *    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
1451
	 * 2) Create the first kmalloc cache.
1452
	 *    The struct kmem_cache for the new cache is allocated normally.
1453 1454 1455
	 *    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
1456 1457
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1458 1459 1460
	 * 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
1461 1462
	 */

P
Pekka Enberg 已提交
1463 1464
	node = numa_node_id();

L
Linus Torvalds 已提交
1465 1466 1467 1468 1469
	/* 1) create the cache_cache */
	INIT_LIST_HEAD(&cache_chain);
	list_add(&cache_cache.next, &cache_chain);
	cache_cache.colour_off = cache_line_size();
	cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
P
Pekka Enberg 已提交
1470
	cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
L
Linus Torvalds 已提交
1471

E
Eric Dumazet 已提交
1472 1473 1474 1475 1476 1477 1478 1479 1480
	/*
	 * struct kmem_cache size depends on nr_node_ids, which
	 * can be less than MAX_NUMNODES.
	 */
	cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) +
				 nr_node_ids * sizeof(struct kmem_list3 *);
#if DEBUG
	cache_cache.obj_size = cache_cache.buffer_size;
#endif
A
Andrew Morton 已提交
1481 1482
	cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
					cache_line_size());
1483 1484
	cache_cache.reciprocal_buffer_size =
		reciprocal_value(cache_cache.buffer_size);
L
Linus Torvalds 已提交
1485

1486 1487 1488 1489 1490 1491
	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;
	}
1492
	BUG_ON(!cache_cache.num);
1493
	cache_cache.gfporder = order;
P
Pekka Enberg 已提交
1494 1495 1496
	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
1497 1498 1499 1500 1501

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

A
Andrew Morton 已提交
1502 1503 1504 1505
	/*
	 * Initialize the caches that provide memory for the array cache and the
	 * kmem_list3 structures first.  Without this, further allocations will
	 * bug.
1506 1507 1508
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
A
Andrew Morton 已提交
1509 1510 1511
					sizes[INDEX_AC].cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1512
					NULL);
1513

A
Andrew Morton 已提交
1514
	if (INDEX_AC != INDEX_L3) {
1515
		sizes[INDEX_L3].cs_cachep =
A
Andrew Morton 已提交
1516 1517 1518 1519
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size,
				ARCH_KMALLOC_MINALIGN,
				ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1520
				NULL);
A
Andrew Morton 已提交
1521
	}
1522

1523 1524
	slab_early_init = 0;

L
Linus Torvalds 已提交
1525
	while (sizes->cs_size != ULONG_MAX) {
1526 1527
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1528 1529 1530
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1531 1532
		 * allow tighter packing of the smaller caches.
		 */
A
Andrew Morton 已提交
1533
		if (!sizes->cs_cachep) {
1534
			sizes->cs_cachep = kmem_cache_create(names->name,
A
Andrew Morton 已提交
1535 1536 1537
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1538
					NULL);
A
Andrew Morton 已提交
1539
		}
1540 1541 1542
#ifdef CONFIG_ZONE_DMA
		sizes->cs_dmacachep = kmem_cache_create(
					names->name_dma,
A
Andrew Morton 已提交
1543 1544 1545 1546
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
						SLAB_PANIC,
1547
					NULL);
1548
#endif
L
Linus Torvalds 已提交
1549 1550 1551 1552 1553
		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
1554
		struct array_cache *ptr;
1555

L
Linus Torvalds 已提交
1556
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1557

L
Linus Torvalds 已提交
1558
		local_irq_disable();
1559 1560
		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
		memcpy(ptr, cpu_cache_get(&cache_cache),
P
Pekka Enberg 已提交
1561
		       sizeof(struct arraycache_init));
1562 1563 1564 1565 1566
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

L
Linus Torvalds 已提交
1567 1568
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1569

L
Linus Torvalds 已提交
1570
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1571

L
Linus Torvalds 已提交
1572
		local_irq_disable();
1573
		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
P
Pekka Enberg 已提交
1574
		       != &initarray_generic.cache);
1575
		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
P
Pekka Enberg 已提交
1576
		       sizeof(struct arraycache_init));
1577 1578 1579 1580 1581
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

1582
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
P
Pekka Enberg 已提交
1583
		    ptr;
L
Linus Torvalds 已提交
1584 1585
		local_irq_enable();
	}
1586 1587
	/* 5) Replace the bootstrap kmem_list3's */
	{
P
Pekka Enberg 已提交
1588 1589
		int nid;

1590
		/* Replace the static kmem_list3 structures for the boot cpu */
P
Pekka Enberg 已提交
1591
		init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node);
1592

1593
		for_each_online_node(nid) {
1594
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
P
Pekka Enberg 已提交
1595
				  &initkmem_list3[SIZE_AC + nid], nid);
1596 1597 1598

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
P
Pekka Enberg 已提交
1599
					  &initkmem_list3[SIZE_L3 + nid], nid);
1600 1601 1602
			}
		}
	}
L
Linus Torvalds 已提交
1603

1604
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1605
	{
1606
		struct kmem_cache *cachep;
I
Ingo Molnar 已提交
1607
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1608
		list_for_each_entry(cachep, &cache_chain, next)
1609 1610
			if (enable_cpucache(cachep))
				BUG();
I
Ingo Molnar 已提交
1611
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1612 1613
	}

1614 1615 1616 1617
	/* Annotate slab for lockdep -- annotate the malloc caches */
	init_lock_keys();


L
Linus Torvalds 已提交
1618 1619 1620
	/* Done! */
	g_cpucache_up = FULL;

A
Andrew Morton 已提交
1621 1622 1623
	/*
	 * Register a cpu startup notifier callback that initializes
	 * cpu_cache_get for all new cpus
L
Linus Torvalds 已提交
1624 1625 1626
	 */
	register_cpu_notifier(&cpucache_notifier);

A
Andrew Morton 已提交
1627 1628 1629
	/*
	 * 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
1630 1631 1632 1633 1634 1635 1636
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

A
Andrew Morton 已提交
1637 1638
	/*
	 * Register the timers that return unneeded pages to the page allocator
L
Linus Torvalds 已提交
1639
	 */
1640
	for_each_online_cpu(cpu)
A
Andrew Morton 已提交
1641
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652
	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.
 */
1653
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1654 1655
{
	struct page *page;
1656
	int nr_pages;
L
Linus Torvalds 已提交
1657 1658
	int i;

1659
#ifndef CONFIG_MMU
1660 1661 1662
	/*
	 * Nommu uses slab's for process anonymous memory allocations, and thus
	 * requires __GFP_COMP to properly refcount higher order allocations
1663
	 */
1664
	flags |= __GFP_COMP;
1665
#endif
1666

1667
	flags |= cachep->gfpflags;
1668 1669
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		flags |= __GFP_RECLAIMABLE;
1670 1671

	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1672 1673 1674
	if (!page)
		return NULL;

1675
	nr_pages = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1676
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1677 1678 1679 1680 1681
		add_zone_page_state(page_zone(page),
			NR_SLAB_RECLAIMABLE, nr_pages);
	else
		add_zone_page_state(page_zone(page),
			NR_SLAB_UNRECLAIMABLE, nr_pages);
1682 1683 1684
	for (i = 0; i < nr_pages; i++)
		__SetPageSlab(page + i);
	return page_address(page);
L
Linus Torvalds 已提交
1685 1686 1687 1688 1689
}

/*
 * Interface to system's page release.
 */
1690
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
L
Linus Torvalds 已提交
1691
{
P
Pekka Enberg 已提交
1692
	unsigned long i = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1693 1694 1695
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

1696 1697 1698 1699 1700 1701
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		sub_zone_page_state(page_zone(page),
				NR_SLAB_RECLAIMABLE, nr_freed);
	else
		sub_zone_page_state(page_zone(page),
				NR_SLAB_UNRECLAIMABLE, nr_freed);
L
Linus Torvalds 已提交
1702
	while (i--) {
N
Nick Piggin 已提交
1703 1704
		BUG_ON(!PageSlab(page));
		__ClearPageSlab(page);
L
Linus Torvalds 已提交
1705 1706 1707 1708 1709 1710 1711 1712 1713
		page++;
	}
	if (current->reclaim_state)
		current->reclaim_state->reclaimed_slab += nr_freed;
	free_pages((unsigned long)addr, cachep->gfporder);
}

static void kmem_rcu_free(struct rcu_head *head)
{
P
Pekka Enberg 已提交
1714
	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1715
	struct kmem_cache *cachep = slab_rcu->cachep;
L
Linus Torvalds 已提交
1716 1717 1718 1719 1720 1721 1722 1723 1724

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

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
1725
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
P
Pekka Enberg 已提交
1726
			    unsigned long caller)
L
Linus Torvalds 已提交
1727
{
1728
	int size = obj_size(cachep);
L
Linus Torvalds 已提交
1729

1730
	addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1731

P
Pekka Enberg 已提交
1732
	if (size < 5 * sizeof(unsigned long))
L
Linus Torvalds 已提交
1733 1734
		return;

P
Pekka Enberg 已提交
1735 1736 1737 1738
	*addr++ = 0x12345678;
	*addr++ = caller;
	*addr++ = smp_processor_id();
	size -= 3 * sizeof(unsigned long);
L
Linus Torvalds 已提交
1739 1740 1741 1742 1743 1744 1745
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
P
Pekka Enberg 已提交
1746
				*addr++ = svalue;
L
Linus Torvalds 已提交
1747 1748 1749 1750 1751 1752 1753
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
P
Pekka Enberg 已提交
1754
	*addr++ = 0x87654321;
L
Linus Torvalds 已提交
1755 1756 1757
}
#endif

1758
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
L
Linus Torvalds 已提交
1759
{
1760 1761
	int size = obj_size(cachep);
	addr = &((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1762 1763

	memset(addr, val, size);
P
Pekka Enberg 已提交
1764
	*(unsigned char *)(addr + size - 1) = POISON_END;
L
Linus Torvalds 已提交
1765 1766 1767 1768 1769
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
D
Dave Jones 已提交
1770 1771 1772
	unsigned char error = 0;
	int bad_count = 0;

L
Linus Torvalds 已提交
1773
	printk(KERN_ERR "%03x:", offset);
D
Dave Jones 已提交
1774 1775 1776 1777 1778
	for (i = 0; i < limit; i++) {
		if (data[offset + i] != POISON_FREE) {
			error = data[offset + i];
			bad_count++;
		}
P
Pekka Enberg 已提交
1779
		printk(" %02x", (unsigned char)data[offset + i]);
D
Dave Jones 已提交
1780
	}
L
Linus Torvalds 已提交
1781
	printk("\n");
D
Dave Jones 已提交
1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795

	if (bad_count == 1) {
		error ^= POISON_FREE;
		if (!(error & (error - 1))) {
			printk(KERN_ERR "Single bit error detected. Probably "
					"bad RAM.\n");
#ifdef CONFIG_X86
			printk(KERN_ERR "Run memtest86+ or a similar memory "
					"test tool.\n");
#else
			printk(KERN_ERR "Run a memory test tool.\n");
#endif
		}
	}
L
Linus Torvalds 已提交
1796 1797 1798 1799 1800
}
#endif

#if DEBUG

1801
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
L
Linus Torvalds 已提交
1802 1803 1804 1805 1806
{
	int i, size;
	char *realobj;

	if (cachep->flags & SLAB_RED_ZONE) {
1807
		printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n",
A
Andrew Morton 已提交
1808 1809
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
1810 1811 1812 1813
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
A
Andrew Morton 已提交
1814
			*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1815
		print_symbol("(%s)",
A
Andrew Morton 已提交
1816
				(unsigned long)*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1817 1818
		printk("\n");
	}
1819 1820
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
P
Pekka Enberg 已提交
1821
	for (i = 0; i < size && lines; i += 16, lines--) {
L
Linus Torvalds 已提交
1822 1823
		int limit;
		limit = 16;
P
Pekka Enberg 已提交
1824 1825
		if (i + limit > size)
			limit = size - i;
L
Linus Torvalds 已提交
1826 1827 1828 1829
		dump_line(realobj, i, limit);
	}
}

1830
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
1831 1832 1833 1834 1835
{
	char *realobj;
	int size, i;
	int lines = 0;

1836 1837
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
L
Linus Torvalds 已提交
1838

P
Pekka Enberg 已提交
1839
	for (i = 0; i < size; i++) {
L
Linus Torvalds 已提交
1840
		char exp = POISON_FREE;
P
Pekka Enberg 已提交
1841
		if (i == size - 1)
L
Linus Torvalds 已提交
1842 1843 1844 1845 1846 1847
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
P
Pekka Enberg 已提交
1848
				printk(KERN_ERR
1849 1850
					"Slab corruption: %s start=%p, len=%d\n",
					cachep->name, realobj, size);
L
Linus Torvalds 已提交
1851 1852 1853
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
P
Pekka Enberg 已提交
1854
			i = (i / 16) * 16;
L
Linus Torvalds 已提交
1855
			limit = 16;
P
Pekka Enberg 已提交
1856 1857
			if (i + limit > size)
				limit = size - i;
L
Linus Torvalds 已提交
1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869
			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:
		 */
1870
		struct slab *slabp = virt_to_slab(objp);
1871
		unsigned int objnr;
L
Linus Torvalds 已提交
1872

1873
		objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
1874
		if (objnr) {
1875
			objp = index_to_obj(cachep, slabp, objnr - 1);
1876
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1877
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1878
			       realobj, size);
L
Linus Torvalds 已提交
1879 1880
			print_objinfo(cachep, objp, 2);
		}
P
Pekka Enberg 已提交
1881
		if (objnr + 1 < cachep->num) {
1882
			objp = index_to_obj(cachep, slabp, objnr + 1);
1883
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1884
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1885
			       realobj, size);
L
Linus Torvalds 已提交
1886 1887 1888 1889 1890 1891
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

1892 1893
#if DEBUG
/**
1894 1895 1896 1897 1898 1899
 * 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
1900
 */
1901
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
1902 1903 1904
{
	int i;
	for (i = 0; i < cachep->num; i++) {
1905
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
1906 1907 1908

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
1909 1910
			if (cachep->buffer_size % PAGE_SIZE == 0 &&
					OFF_SLAB(cachep))
P
Pekka Enberg 已提交
1911
				kernel_map_pages(virt_to_page(objp),
A
Andrew Morton 已提交
1912
					cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
1913 1914 1915 1916 1917 1918 1919 1920 1921
			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
1922
					   "was overwritten");
L
Linus Torvalds 已提交
1923 1924
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
P
Pekka Enberg 已提交
1925
					   "was overwritten");
L
Linus Torvalds 已提交
1926 1927
		}
	}
1928
}
L
Linus Torvalds 已提交
1929
#else
1930
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
1931 1932
{
}
L
Linus Torvalds 已提交
1933 1934
#endif

1935 1936 1937 1938 1939
/**
 * slab_destroy - destroy and release all objects in a slab
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
1940
 * Destroy all the objs in a slab, and release the mem back to the system.
A
Andrew Morton 已提交
1941 1942
 * Before calling the slab must have been unlinked from the cache.  The
 * cache-lock is not held/needed.
1943
 */
1944
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1945 1946 1947 1948
{
	void *addr = slabp->s_mem - slabp->colouroff;

	slab_destroy_objs(cachep, slabp);
L
Linus Torvalds 已提交
1949 1950 1951
	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

P
Pekka Enberg 已提交
1952
		slab_rcu = (struct slab_rcu *)slabp;
L
Linus Torvalds 已提交
1953 1954 1955 1956 1957
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
1958 1959
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
L
Linus Torvalds 已提交
1960 1961 1962
	}
}

A
Andrew Morton 已提交
1963 1964 1965 1966
/*
 * For setting up all the kmem_list3s for cache whose buffer_size is same as
 * size of kmem_list3.
 */
1967
static void __init set_up_list3s(struct kmem_cache *cachep, int index)
1968 1969 1970
{
	int node;

1971
	for_each_online_node(node) {
P
Pekka Enberg 已提交
1972
		cachep->nodelists[node] = &initkmem_list3[index + node];
1973
		cachep->nodelists[node]->next_reap = jiffies +
P
Pekka Enberg 已提交
1974 1975
		    REAPTIMEOUT_LIST3 +
		    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1976 1977 1978
	}
}

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
static void __kmem_cache_destroy(struct kmem_cache *cachep)
{
	int i;
	struct kmem_list3 *l3;

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

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


2000
/**
2001 2002 2003 2004 2005 2006 2007
 * 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.
2008 2009 2010 2011 2012
 *
 * 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
2013
static size_t calculate_slab_order(struct kmem_cache *cachep,
R
Randy Dunlap 已提交
2014
			size_t size, size_t align, unsigned long flags)
2015
{
2016
	unsigned long offslab_limit;
2017
	size_t left_over = 0;
2018
	int gfporder;
2019

2020
	for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
2021 2022 2023
		unsigned int num;
		size_t remainder;

2024
		cache_estimate(gfporder, size, align, flags, &remainder, &num);
2025 2026
		if (!num)
			continue;
2027

2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039
		if (flags & CFLGS_OFF_SLAB) {
			/*
			 * Max number of objs-per-slab for caches which
			 * use off-slab slabs. Needed to avoid a possible
			 * looping condition in cache_grow().
			 */
			offslab_limit = size - sizeof(struct slab);
			offslab_limit /= sizeof(kmem_bufctl_t);

 			if (num > offslab_limit)
				break;
		}
2040

2041
		/* Found something acceptable - save it away */
2042
		cachep->num = num;
2043
		cachep->gfporder = gfporder;
2044 2045
		left_over = remainder;

2046 2047 2048 2049 2050 2051 2052 2053
		/*
		 * 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;

2054 2055 2056 2057
		/*
		 * Large number of objects is good, but very large slabs are
		 * currently bad for the gfp()s.
		 */
2058
		if (gfporder >= slab_break_gfp_order)
2059 2060
			break;

2061 2062 2063
		/*
		 * Acceptable internal fragmentation?
		 */
A
Andrew Morton 已提交
2064
		if (left_over * 8 <= (PAGE_SIZE << gfporder))
2065 2066 2067 2068 2069
			break;
	}
	return left_over;
}

2070
static int __init_refok setup_cpu_cache(struct kmem_cache *cachep)
2071
{
2072 2073 2074
	if (g_cpucache_up == FULL)
		return enable_cpucache(cachep);

2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101
	if (g_cpucache_up == NONE) {
		/*
		 * Note: the first kmem_cache_create must create the cache
		 * that's used by kmalloc(24), otherwise the creation of
		 * further caches will BUG().
		 */
		cachep->array[smp_processor_id()] = &initarray_generic.cache;

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

		if (g_cpucache_up == PARTIAL_AC) {
			set_up_list3s(cachep, SIZE_L3);
			g_cpucache_up = PARTIAL_L3;
		} else {
			int node;
C
Christoph Lameter 已提交
2102
			for_each_node_state(node, N_NORMAL_MEMORY) {
2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120
				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;
2121
	return 0;
2122 2123
}

L
Linus Torvalds 已提交
2124 2125 2126 2127 2128 2129 2130 2131 2132 2133
/**
 * kmem_cache_create - Create a cache.
 * @name: A string which is used in /proc/slabinfo to identify this cache.
 * @size: The size of objects to be created in this cache.
 * @align: The required alignment for the objects.
 * @flags: SLAB flags
 * @ctor: A constructor for the objects.
 *
 * Returns a ptr to the cache on success, NULL on failure.
 * Cannot be called within a int, but can be interrupted.
2134
 * The @ctor is run when new pages are allocated by the cache.
L
Linus Torvalds 已提交
2135 2136
 *
 * @name must be valid until the cache is destroyed. This implies that
A
Andrew Morton 已提交
2137 2138
 * the module calling this has to destroy the cache before getting unloaded.
 *
L
Linus Torvalds 已提交
2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150
 * 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.
 */
2151
struct kmem_cache *
L
Linus Torvalds 已提交
2152
kmem_cache_create (const char *name, size_t size, size_t align,
A
Andrew Morton 已提交
2153
	unsigned long flags,
2154
	void (*ctor)(struct kmem_cache *, void *))
L
Linus Torvalds 已提交
2155 2156
{
	size_t left_over, slab_size, ralign;
2157
	struct kmem_cache *cachep = NULL, *pc;
L
Linus Torvalds 已提交
2158 2159 2160 2161

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
A
Andrew Morton 已提交
2162
	if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
2163
	    size > KMALLOC_MAX_SIZE) {
A
Andrew Morton 已提交
2164 2165
		printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
				name);
P
Pekka Enberg 已提交
2166 2167
		BUG();
	}
L
Linus Torvalds 已提交
2168

2169
	/*
2170 2171
	 * We use cache_chain_mutex to ensure a consistent view of
	 * cpu_online_map as well.  Please see cpuup_callback
2172
	 */
I
Ingo Molnar 已提交
2173
	mutex_lock(&cache_chain_mutex);
2174

2175
	list_for_each_entry(pc, &cache_chain, next) {
2176 2177 2178 2179 2180 2181 2182 2183
		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.
		 */
2184
		res = probe_kernel_address(pc->name, tmp);
2185
		if (res) {
2186 2187
			printk(KERN_ERR
			       "SLAB: cache with size %d has lost its name\n",
2188
			       pc->buffer_size);
2189 2190 2191
			continue;
		}

P
Pekka Enberg 已提交
2192
		if (!strcmp(pc->name, name)) {
2193 2194
			printk(KERN_ERR
			       "kmem_cache_create: duplicate cache %s\n", name);
2195 2196 2197 2198 2199
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
2200 2201 2202 2203 2204 2205 2206 2207 2208
#if DEBUG
	WARN_ON(strchr(name, ' '));	/* It confuses parsers */
#if FORCED_DEBUG
	/*
	 * Enable redzoning and last user accounting, except for caches with
	 * large objects, if the increased size would increase the object size
	 * above the next power of two: caches with object sizes just above a
	 * power of two have a significant amount of internal fragmentation.
	 */
D
David Woodhouse 已提交
2209 2210
	if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
						2 * sizeof(unsigned long long)))
P
Pekka Enberg 已提交
2211
		flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
L
Linus Torvalds 已提交
2212 2213 2214 2215 2216 2217 2218
	if (!(flags & SLAB_DESTROY_BY_RCU))
		flags |= SLAB_POISON;
#endif
	if (flags & SLAB_DESTROY_BY_RCU)
		BUG_ON(flags & SLAB_POISON);
#endif
	/*
A
Andrew Morton 已提交
2219 2220
	 * Always checks flags, a caller might be expecting debug support which
	 * isn't available.
L
Linus Torvalds 已提交
2221
	 */
2222
	BUG_ON(flags & ~CREATE_MASK);
L
Linus Torvalds 已提交
2223

A
Andrew Morton 已提交
2224 2225
	/*
	 * Check that size is in terms of words.  This is needed to avoid
L
Linus Torvalds 已提交
2226 2227 2228
	 * 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
2229 2230 2231
	if (size & (BYTES_PER_WORD - 1)) {
		size += (BYTES_PER_WORD - 1);
		size &= ~(BYTES_PER_WORD - 1);
L
Linus Torvalds 已提交
2232 2233
	}

A
Andrew Morton 已提交
2234 2235
	/* calculate the final buffer alignment: */

L
Linus Torvalds 已提交
2236 2237
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
A
Andrew Morton 已提交
2238 2239 2240 2241
		/*
		 * 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
2242 2243
		 */
		ralign = cache_line_size();
P
Pekka Enberg 已提交
2244
		while (size <= ralign / 2)
L
Linus Torvalds 已提交
2245 2246 2247 2248
			ralign /= 2;
	} else {
		ralign = BYTES_PER_WORD;
	}
2249 2250

	/*
D
David Woodhouse 已提交
2251 2252 2253
	 * Redzoning and user store require word alignment or possibly larger.
	 * Note this will be overridden by architecture or caller mandated
	 * alignment if either is greater than BYTES_PER_WORD.
2254
	 */
D
David Woodhouse 已提交
2255 2256 2257 2258 2259 2260 2261 2262 2263 2264
	if (flags & SLAB_STORE_USER)
		ralign = BYTES_PER_WORD;

	if (flags & SLAB_RED_ZONE) {
		ralign = REDZONE_ALIGN;
		/* If redzoning, ensure that the second redzone is suitably
		 * aligned, by adjusting the object size accordingly. */
		size += REDZONE_ALIGN - 1;
		size &= ~(REDZONE_ALIGN - 1);
	}
2265

2266
	/* 2) arch mandated alignment */
L
Linus Torvalds 已提交
2267 2268 2269
	if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
	}
2270
	/* 3) caller mandated alignment */
L
Linus Torvalds 已提交
2271 2272 2273
	if (ralign < align) {
		ralign = align;
	}
2274
	/* disable debug if necessary */
2275
	if (ralign > __alignof__(unsigned long long))
2276
		flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
A
Andrew Morton 已提交
2277
	/*
2278
	 * 4) Store it.
L
Linus Torvalds 已提交
2279 2280 2281 2282
	 */
	align = ralign;

	/* Get cache's description obj. */
2283
	cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
L
Linus Torvalds 已提交
2284
	if (!cachep)
2285
		goto oops;
L
Linus Torvalds 已提交
2286 2287

#if DEBUG
2288
	cachep->obj_size = size;
L
Linus Torvalds 已提交
2289

2290 2291 2292 2293
	/*
	 * Both debugging options require word-alignment which is calculated
	 * into align above.
	 */
L
Linus Torvalds 已提交
2294 2295
	if (flags & SLAB_RED_ZONE) {
		/* add space for red zone words */
2296 2297
		cachep->obj_offset += sizeof(unsigned long long);
		size += 2 * sizeof(unsigned long long);
L
Linus Torvalds 已提交
2298 2299
	}
	if (flags & SLAB_STORE_USER) {
2300
		/* user store requires one word storage behind the end of
D
David Woodhouse 已提交
2301 2302
		 * the real object. But if the second red zone needs to be
		 * aligned to 64 bits, we must allow that much space.
L
Linus Torvalds 已提交
2303
		 */
D
David Woodhouse 已提交
2304 2305 2306 2307
		if (flags & SLAB_RED_ZONE)
			size += REDZONE_ALIGN;
		else
			size += BYTES_PER_WORD;
L
Linus Torvalds 已提交
2308 2309
	}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
P
Pekka Enberg 已提交
2310
	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2311 2312
	    && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
		cachep->obj_offset += PAGE_SIZE - size;
L
Linus Torvalds 已提交
2313 2314 2315 2316 2317
		size = PAGE_SIZE;
	}
#endif
#endif

2318 2319 2320 2321 2322 2323
	/*
	 * Determine if the slab management is 'on' or 'off' slab.
	 * (bootstrapping cannot cope with offslab caches so don't do
	 * it too early on.)
	 */
	if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init)
L
Linus Torvalds 已提交
2324 2325 2326 2327 2328 2329 2330 2331
		/*
		 * 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);

2332
	left_over = calculate_slab_order(cachep, size, align, flags);
L
Linus Torvalds 已提交
2333 2334

	if (!cachep->num) {
2335 2336
		printk(KERN_ERR
		       "kmem_cache_create: couldn't create cache %s.\n", name);
L
Linus Torvalds 已提交
2337 2338
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
2339
		goto oops;
L
Linus Torvalds 已提交
2340
	}
P
Pekka Enberg 已提交
2341 2342
	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
			  + sizeof(struct slab), align);
L
Linus Torvalds 已提交
2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354

	/*
	 * 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
2355 2356
		slab_size =
		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
L
Linus Torvalds 已提交
2357 2358 2359 2360 2361 2362
	}

	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
2363
	cachep->colour = left_over / cachep->colour_off;
L
Linus Torvalds 已提交
2364 2365 2366
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
2367
	if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
L
Linus Torvalds 已提交
2368
		cachep->gfpflags |= GFP_DMA;
2369
	cachep->buffer_size = size;
2370
	cachep->reciprocal_buffer_size = reciprocal_value(size);
L
Linus Torvalds 已提交
2371

2372
	if (flags & CFLGS_OFF_SLAB) {
2373
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
2374 2375 2376 2377 2378 2379 2380
		/*
		 * This is a possibility for one of the malloc_sizes caches.
		 * But since we go off slab only for object size greater than
		 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
		 * this should not happen at all.
		 * But leave a BUG_ON for some lucky dude.
		 */
2381
		BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));
2382
	}
L
Linus Torvalds 已提交
2383 2384 2385
	cachep->ctor = ctor;
	cachep->name = name;

2386 2387 2388 2389 2390
	if (setup_cpu_cache(cachep)) {
		__kmem_cache_destroy(cachep);
		cachep = NULL;
		goto oops;
	}
L
Linus Torvalds 已提交
2391 2392 2393

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
A
Andrew Morton 已提交
2394
oops:
L
Linus Torvalds 已提交
2395 2396
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
P
Pekka Enberg 已提交
2397
		      name);
I
Ingo Molnar 已提交
2398
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413
	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());
}

2414
static void check_spinlock_acquired(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2415 2416 2417
{
#ifdef CONFIG_SMP
	check_irq_off();
2418
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
2419 2420
#endif
}
2421

2422
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2423 2424 2425 2426 2427 2428 2429
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
2430 2431 2432 2433
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
2434
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
2435 2436
#endif

2437 2438 2439 2440
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
2441 2442
static void do_drain(void *arg)
{
A
Andrew Morton 已提交
2443
	struct kmem_cache *cachep = arg;
L
Linus Torvalds 已提交
2444
	struct array_cache *ac;
2445
	int node = numa_node_id();
L
Linus Torvalds 已提交
2446 2447

	check_irq_off();
2448
	ac = cpu_cache_get(cachep);
2449 2450 2451
	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
2452 2453 2454
	ac->avail = 0;
}

2455
static void drain_cpu_caches(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2456
{
2457 2458 2459
	struct kmem_list3 *l3;
	int node;

A
Andrew Morton 已提交
2460
	on_each_cpu(do_drain, cachep, 1, 1);
L
Linus Torvalds 已提交
2461
	check_irq_on();
P
Pekka Enberg 已提交
2462
	for_each_online_node(node) {
2463
		l3 = cachep->nodelists[node];
2464 2465 2466 2467 2468 2469 2470
		if (l3 && l3->alien)
			drain_alien_cache(cachep, l3->alien);
	}

	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (l3)
2471
			drain_array(cachep, l3, l3->shared, 1, node);
2472
	}
L
Linus Torvalds 已提交
2473 2474
}

2475 2476 2477 2478 2479 2480 2481 2482
/*
 * Remove slabs from the list of free slabs.
 * Specify the number of slabs to drain in tofree.
 *
 * Returns the actual number of slabs released.
 */
static int drain_freelist(struct kmem_cache *cache,
			struct kmem_list3 *l3, int tofree)
L
Linus Torvalds 已提交
2483
{
2484 2485
	struct list_head *p;
	int nr_freed;
L
Linus Torvalds 已提交
2486 2487
	struct slab *slabp;

2488 2489
	nr_freed = 0;
	while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
L
Linus Torvalds 已提交
2490

2491
		spin_lock_irq(&l3->list_lock);
2492
		p = l3->slabs_free.prev;
2493 2494 2495 2496
		if (p == &l3->slabs_free) {
			spin_unlock_irq(&l3->list_lock);
			goto out;
		}
L
Linus Torvalds 已提交
2497

2498
		slabp = list_entry(p, struct slab, list);
L
Linus Torvalds 已提交
2499
#if DEBUG
2500
		BUG_ON(slabp->inuse);
L
Linus Torvalds 已提交
2501 2502
#endif
		list_del(&slabp->list);
2503 2504 2505 2506 2507
		/*
		 * Safe to drop the lock. The slab is no longer linked
		 * to the cache.
		 */
		l3->free_objects -= cache->num;
2508
		spin_unlock_irq(&l3->list_lock);
2509 2510
		slab_destroy(cache, slabp);
		nr_freed++;
L
Linus Torvalds 已提交
2511
	}
2512 2513
out:
	return nr_freed;
L
Linus Torvalds 已提交
2514 2515
}

2516
/* Called with cache_chain_mutex held to protect against cpu hotplug */
2517
static int __cache_shrink(struct kmem_cache *cachep)
2518 2519 2520 2521 2522 2523 2524 2525 2526
{
	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];
2527 2528 2529 2530 2531 2532 2533
		if (!l3)
			continue;

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

		ret += !list_empty(&l3->slabs_full) ||
			!list_empty(&l3->slabs_partial);
2534 2535 2536 2537
	}
	return (ret ? 1 : 0);
}

L
Linus Torvalds 已提交
2538 2539 2540 2541 2542 2543 2544
/**
 * 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.
 */
2545
int kmem_cache_shrink(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2546
{
2547
	int ret;
2548
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2549

2550 2551 2552 2553
	mutex_lock(&cache_chain_mutex);
	ret = __cache_shrink(cachep);
	mutex_unlock(&cache_chain_mutex);
	return ret;
L
Linus Torvalds 已提交
2554 2555 2556 2557 2558 2559 2560
}
EXPORT_SYMBOL(kmem_cache_shrink);

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
2561
 * Remove a &struct kmem_cache object from the slab cache.
L
Linus Torvalds 已提交
2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572
 *
 * 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().
 */
2573
void kmem_cache_destroy(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2574
{
2575
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2576 2577

	/* Find the cache in the chain of caches. */
I
Ingo Molnar 已提交
2578
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2579 2580 2581 2582 2583 2584
	/*
	 * the chain is never empty, cache_cache is never destroyed
	 */
	list_del(&cachep->next);
	if (__cache_shrink(cachep)) {
		slab_error(cachep, "Can't free all objects");
P
Pekka Enberg 已提交
2585
		list_add(&cachep->next, &cache_chain);
I
Ingo Molnar 已提交
2586
		mutex_unlock(&cache_chain_mutex);
2587
		return;
L
Linus Torvalds 已提交
2588 2589 2590
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2591
		synchronize_rcu();
L
Linus Torvalds 已提交
2592

2593
	__kmem_cache_destroy(cachep);
2594
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2595 2596 2597
}
EXPORT_SYMBOL(kmem_cache_destroy);

2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608
/*
 * Get the memory for a slab management obj.
 * For a slab cache when the slab descriptor is off-slab, slab descriptors
 * always come from malloc_sizes caches.  The slab descriptor cannot
 * come from the same cache which is getting created because,
 * when we are searching for an appropriate cache for these
 * descriptors in kmem_cache_create, we search through the malloc_sizes array.
 * If we are creating a malloc_sizes cache here it would not be visible to
 * kmem_find_general_cachep till the initialization is complete.
 * Hence we cannot have slabp_cache same as the original cache.
 */
2609
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
2610 2611
				   int colour_off, gfp_t local_flags,
				   int nodeid)
L
Linus Torvalds 已提交
2612 2613
{
	struct slab *slabp;
P
Pekka Enberg 已提交
2614

L
Linus Torvalds 已提交
2615 2616
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
2617
		slabp = kmem_cache_alloc_node(cachep->slabp_cache,
2618
					      local_flags & ~GFP_THISNODE, nodeid);
L
Linus Torvalds 已提交
2619 2620 2621
		if (!slabp)
			return NULL;
	} else {
P
Pekka Enberg 已提交
2622
		slabp = objp + colour_off;
L
Linus Torvalds 已提交
2623 2624 2625 2626
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
P
Pekka Enberg 已提交
2627
	slabp->s_mem = objp + colour_off;
2628
	slabp->nodeid = nodeid;
L
Linus Torvalds 已提交
2629 2630 2631 2632 2633
	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
P
Pekka Enberg 已提交
2634
	return (kmem_bufctl_t *) (slabp + 1);
L
Linus Torvalds 已提交
2635 2636
}

2637
static void cache_init_objs(struct kmem_cache *cachep,
C
Christoph Lameter 已提交
2638
			    struct slab *slabp)
L
Linus Torvalds 已提交
2639 2640 2641 2642
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2643
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655
#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
2656 2657 2658
		 * 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
2659 2660
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2661
			cachep->ctor(cachep, objp + obj_offset(cachep));
L
Linus Torvalds 已提交
2662 2663 2664 2665

		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
2666
					   " end of an object");
L
Linus Torvalds 已提交
2667 2668
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2669
					   " start of an object");
L
Linus Torvalds 已提交
2670
		}
A
Andrew Morton 已提交
2671 2672
		if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
			    OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
P
Pekka Enberg 已提交
2673
			kernel_map_pages(virt_to_page(objp),
2674
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2675 2676
#else
		if (cachep->ctor)
2677
			cachep->ctor(cachep, objp);
L
Linus Torvalds 已提交
2678
#endif
P
Pekka Enberg 已提交
2679
		slab_bufctl(slabp)[i] = i + 1;
L
Linus Torvalds 已提交
2680
	}
P
Pekka Enberg 已提交
2681
	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
L
Linus Torvalds 已提交
2682 2683 2684
	slabp->free = 0;
}

2685
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2686
{
2687 2688 2689 2690 2691 2692
	if (CONFIG_ZONE_DMA_FLAG) {
		if (flags & GFP_DMA)
			BUG_ON(!(cachep->gfpflags & GFP_DMA));
		else
			BUG_ON(cachep->gfpflags & GFP_DMA);
	}
L
Linus Torvalds 已提交
2693 2694
}

A
Andrew Morton 已提交
2695 2696
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
				int nodeid)
2697
{
2698
	void *objp = index_to_obj(cachep, slabp, slabp->free);
2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711
	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
2712 2713
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
				void *objp, int nodeid)
2714
{
2715
	unsigned int objnr = obj_to_index(cachep, slabp, objp);
2716 2717 2718 2719 2720

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

2721
	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
2722
		printk(KERN_ERR "slab: double free detected in cache "
A
Andrew Morton 已提交
2723
				"'%s', objp %p\n", cachep->name, objp);
2724 2725 2726 2727 2728 2729 2730 2731
		BUG();
	}
#endif
	slab_bufctl(slabp)[objnr] = slabp->free;
	slabp->free = objnr;
	slabp->inuse--;
}

2732 2733 2734 2735 2736 2737 2738
/*
 * Map pages beginning at addr to the given cache and slab. This is required
 * for the slab allocator to be able to lookup the cache and slab of a
 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
 */
static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
			   void *addr)
L
Linus Torvalds 已提交
2739
{
2740
	int nr_pages;
L
Linus Torvalds 已提交
2741 2742
	struct page *page;

2743
	page = virt_to_page(addr);
2744

2745
	nr_pages = 1;
2746
	if (likely(!PageCompound(page)))
2747 2748
		nr_pages <<= cache->gfporder;

L
Linus Torvalds 已提交
2749
	do {
2750 2751
		page_set_cache(page, cache);
		page_set_slab(page, slab);
L
Linus Torvalds 已提交
2752
		page++;
2753
	} while (--nr_pages);
L
Linus Torvalds 已提交
2754 2755 2756 2757 2758 2759
}

/*
 * 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.
 */
2760 2761
static int cache_grow(struct kmem_cache *cachep,
		gfp_t flags, int nodeid, void *objp)
L
Linus Torvalds 已提交
2762
{
P
Pekka Enberg 已提交
2763 2764 2765
	struct slab *slabp;
	size_t offset;
	gfp_t local_flags;
2766
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2767

A
Andrew Morton 已提交
2768 2769 2770
	/*
	 * 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
2771
	 */
C
Christoph Lameter 已提交
2772 2773
	BUG_ON(flags & GFP_SLAB_BUG_MASK);
	local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
L
Linus Torvalds 已提交
2774

2775
	/* Take the l3 list lock to change the colour_next on this node */
L
Linus Torvalds 已提交
2776
	check_irq_off();
2777 2778
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2779 2780

	/* Get colour for the slab, and cal the next value. */
2781 2782 2783 2784 2785
	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
2786

2787
	offset *= cachep->colour_off;
L
Linus Torvalds 已提交
2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799

	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
2800 2801 2802
	/*
	 * Get mem for the objs.  Attempt to allocate a physical page from
	 * 'nodeid'.
2803
	 */
2804
	if (!objp)
2805
		objp = kmem_getpages(cachep, local_flags, nodeid);
A
Andrew Morton 已提交
2806
	if (!objp)
L
Linus Torvalds 已提交
2807 2808 2809
		goto failed;

	/* Get slab management. */
2810
	slabp = alloc_slabmgmt(cachep, objp, offset,
C
Christoph Lameter 已提交
2811
			local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
A
Andrew Morton 已提交
2812
	if (!slabp)
L
Linus Torvalds 已提交
2813 2814
		goto opps1;

2815
	slabp->nodeid = nodeid;
2816
	slab_map_pages(cachep, slabp, objp);
L
Linus Torvalds 已提交
2817

C
Christoph Lameter 已提交
2818
	cache_init_objs(cachep, slabp);
L
Linus Torvalds 已提交
2819 2820 2821 2822

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2823
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2824 2825

	/* Make slab active. */
2826
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2827
	STATS_INC_GROWN(cachep);
2828 2829
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2830
	return 1;
A
Andrew Morton 已提交
2831
opps1:
L
Linus Torvalds 已提交
2832
	kmem_freepages(cachep, objp);
A
Andrew Morton 已提交
2833
failed:
L
Linus Torvalds 已提交
2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849
	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	return 0;
}

#if DEBUG

/*
 * Perform extra freeing checks:
 * - detect bad pointers.
 * - POISON/RED_ZONE checking
 */
static void kfree_debugcheck(const void *objp)
{
	if (!virt_addr_valid(objp)) {
		printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
P
Pekka Enberg 已提交
2850 2851
		       (unsigned long)objp);
		BUG();
L
Linus Torvalds 已提交
2852 2853 2854
	}
}

2855 2856
static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
{
2857
	unsigned long long redzone1, redzone2;
2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872

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

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

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

2873
	printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
2874 2875 2876
			obj, redzone1, redzone2);
}

2877
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2878
				   void *caller)
L
Linus Torvalds 已提交
2879 2880 2881 2882 2883
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

2884 2885
	BUG_ON(virt_to_cache(objp) != cachep);

2886
	objp -= obj_offset(cachep);
L
Linus Torvalds 已提交
2887
	kfree_debugcheck(objp);
2888
	page = virt_to_head_page(objp);
L
Linus Torvalds 已提交
2889

2890
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2891 2892

	if (cachep->flags & SLAB_RED_ZONE) {
2893
		verify_redzone_free(cachep, objp);
L
Linus Torvalds 已提交
2894 2895 2896 2897 2898 2899
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

2900
	objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
2901 2902

	BUG_ON(objnr >= cachep->num);
2903
	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
L
Linus Torvalds 已提交
2904

2905 2906 2907
#ifdef CONFIG_DEBUG_SLAB_LEAK
	slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
#endif
L
Linus Torvalds 已提交
2908 2909
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
2910
		if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
L
Linus Torvalds 已提交
2911
			store_stackinfo(cachep, objp, (unsigned long)caller);
P
Pekka Enberg 已提交
2912
			kernel_map_pages(virt_to_page(objp),
2913
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2914 2915 2916 2917 2918 2919 2920 2921 2922 2923
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

2924
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
2925 2926 2927
{
	kmem_bufctl_t i;
	int entries = 0;
P
Pekka Enberg 已提交
2928

L
Linus Torvalds 已提交
2929 2930 2931 2932 2933 2934 2935
	/* 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
2936 2937 2938 2939
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
2940
		for (i = 0;
2941
		     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
P
Pekka Enberg 已提交
2942
		     i++) {
A
Andrew Morton 已提交
2943
			if (i % 16 == 0)
L
Linus Torvalds 已提交
2944
				printk("\n%03x:", i);
P
Pekka Enberg 已提交
2945
			printk(" %02x", ((unsigned char *)slabp)[i]);
L
Linus Torvalds 已提交
2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956
		}
		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

2957
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2958 2959 2960 2961
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;
P
Pekka Enberg 已提交
2962 2963 2964
	int node;

	node = numa_node_id();
L
Linus Torvalds 已提交
2965 2966

	check_irq_off();
2967
	ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2968
retry:
L
Linus Torvalds 已提交
2969 2970
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
A
Andrew Morton 已提交
2971 2972 2973 2974
		/*
		 * 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
2975 2976 2977
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
P
Pekka Enberg 已提交
2978
	l3 = cachep->nodelists[node];
2979 2980 2981

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2982

2983 2984 2985 2986
	/* 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
2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001
	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);
3002 3003 3004 3005 3006 3007 3008 3009

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

L
Linus Torvalds 已提交
3010 3011 3012 3013 3014
		while (slabp->inuse < cachep->num && batchcount--) {
			STATS_INC_ALLOCED(cachep);
			STATS_INC_ACTIVE(cachep);
			STATS_SET_HIGH(cachep);

3015
			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
P
Pekka Enberg 已提交
3016
							    node);
L
Linus Torvalds 已提交
3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027
		}
		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
3028
must_grow:
L
Linus Torvalds 已提交
3029
	l3->free_objects -= ac->avail;
A
Andrew Morton 已提交
3030
alloc_done:
3031
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3032 3033 3034

	if (unlikely(!ac->avail)) {
		int x;
3035
		x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
3036

A
Andrew Morton 已提交
3037
		/* cache_grow can reenable interrupts, then ac could change. */
3038
		ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
3039
		if (!x && ac->avail == 0)	/* no objects in sight? abort */
L
Linus Torvalds 已提交
3040 3041
			return NULL;

A
Andrew Morton 已提交
3042
		if (!ac->avail)		/* objects refilled by interrupt? */
L
Linus Torvalds 已提交
3043 3044 3045
			goto retry;
	}
	ac->touched = 1;
3046
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3047 3048
}

A
Andrew Morton 已提交
3049 3050
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
						gfp_t flags)
L
Linus Torvalds 已提交
3051 3052 3053 3054 3055 3056 3057 3058
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
A
Andrew Morton 已提交
3059 3060
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
				gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
3061
{
P
Pekka Enberg 已提交
3062
	if (!objp)
L
Linus Torvalds 已提交
3063
		return objp;
P
Pekka Enberg 已提交
3064
	if (cachep->flags & SLAB_POISON) {
L
Linus Torvalds 已提交
3065
#ifdef CONFIG_DEBUG_PAGEALLOC
3066
		if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
P
Pekka Enberg 已提交
3067
			kernel_map_pages(virt_to_page(objp),
3068
					 cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079
		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
3080 3081 3082 3083
		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
3084
			printk(KERN_ERR
3085
				"%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
A
Andrew Morton 已提交
3086 3087
				objp, *dbg_redzone1(cachep, objp),
				*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
3088 3089 3090 3091
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
3092 3093 3094 3095 3096
#ifdef CONFIG_DEBUG_SLAB_LEAK
	{
		struct slab *slabp;
		unsigned objnr;

3097
		slabp = page_get_slab(virt_to_head_page(objp));
3098 3099 3100 3101
		objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
	}
#endif
3102
	objp += obj_offset(cachep);
3103
	if (cachep->ctor && cachep->flags & SLAB_POISON)
3104
		cachep->ctor(cachep, objp);
3105 3106 3107 3108 3109 3110
#if ARCH_SLAB_MINALIGN
	if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
		printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
		       objp, ARCH_SLAB_MINALIGN);
	}
#endif
L
Linus Torvalds 已提交
3111 3112 3113 3114 3115 3116
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129
#ifdef CONFIG_FAILSLAB

static struct failslab_attr {

	struct fault_attr attr;

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

} failslab = {
	.attr = FAULT_ATTR_INITIALIZER,
3130
	.ignore_gfp_wait = 1,
3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158
};

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

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

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

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

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

3159
	err = init_fault_attr_dentries(&failslab.attr, "failslab");
3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189
	if (err)
		return err;
	dir = failslab.attr.dentries.dir;

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

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

	return err;
}

late_initcall(failslab_debugfs);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#else /* CONFIG_FAILSLAB */

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

#endif /* CONFIG_FAILSLAB */

3190
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3191
{
P
Pekka Enberg 已提交
3192
	void *objp;
L
Linus Torvalds 已提交
3193 3194
	struct array_cache *ac;

3195
	check_irq_off();
3196

3197
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3198 3199 3200
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
3201
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3202 3203 3204 3205
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
3206 3207 3208
	return objp;
}

3209
#ifdef CONFIG_NUMA
3210
/*
3211
 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
3212 3213 3214 3215 3216 3217 3218 3219
 *
 * 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;

3220
	if (in_interrupt() || (flags & __GFP_THISNODE))
3221 3222 3223 3224 3225 3226 3227
		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)
3228
		return ____cache_alloc_node(cachep, flags, nid_alloc);
3229 3230 3231
	return NULL;
}

3232 3233
/*
 * Fallback function if there was no memory available and no objects on a
3234 3235 3236 3237 3238
 * certain node and fall back is permitted. First we scan all the
 * available nodelists for available objects. If that fails then we
 * perform an allocation without specifying a node. This allows the page
 * allocator to do its reclaim / fallback magic. We then insert the
 * slab into the proper nodelist and then allocate from it.
3239
 */
3240
static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
3241
{
3242 3243
	struct zonelist *zonelist;
	gfp_t local_flags;
3244 3245
	struct zone **z;
	void *obj = NULL;
3246
	int nid;
3247 3248 3249 3250 3251 3252

	if (flags & __GFP_THISNODE)
		return NULL;

	zonelist = &NODE_DATA(slab_node(current->mempolicy))
			->node_zonelists[gfp_zone(flags)];
C
Christoph Lameter 已提交
3253
	local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
3254

3255 3256 3257 3258 3259
retry:
	/*
	 * Look through allowed nodes for objects available
	 * from existing per node queues.
	 */
3260
	for (z = zonelist->zones; *z && !obj; z++) {
3261
		nid = zone_to_nid(*z);
3262

3263
		if (cpuset_zone_allowed_hardwall(*z, flags) &&
3264 3265 3266 3267 3268 3269
			cache->nodelists[nid] &&
			cache->nodelists[nid]->free_objects)
				obj = ____cache_alloc_node(cache,
					flags | GFP_THISNODE, nid);
	}

3270
	if (!obj) {
3271 3272 3273 3274 3275 3276
		/*
		 * This allocation will be performed within the constraints
		 * of the current cpuset / memory policy requirements.
		 * We may trigger various forms of reclaim on the allowed
		 * set and go into memory reserves if necessary.
		 */
3277 3278 3279
		if (local_flags & __GFP_WAIT)
			local_irq_enable();
		kmem_flagcheck(cache, flags);
3280
		obj = kmem_getpages(cache, flags, -1);
3281 3282
		if (local_flags & __GFP_WAIT)
			local_irq_disable();
3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298
		if (obj) {
			/*
			 * Insert into the appropriate per node queues
			 */
			nid = page_to_nid(virt_to_page(obj));
			if (cache_grow(cache, flags, nid, obj)) {
				obj = ____cache_alloc_node(cache,
					flags | GFP_THISNODE, nid);
				if (!obj)
					/*
					 * Another processor may allocate the
					 * objects in the slab since we are
					 * not holding any locks.
					 */
					goto retry;
			} else {
3299
				/* cache_grow already freed obj */
3300 3301 3302
				obj = NULL;
			}
		}
3303
	}
3304 3305 3306
	return obj;
}

3307 3308
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
3309
 */
3310
static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
A
Andrew Morton 已提交
3311
				int nodeid)
3312 3313
{
	struct list_head *entry;
P
Pekka Enberg 已提交
3314 3315 3316 3317 3318 3319 3320 3321
	struct slab *slabp;
	struct kmem_list3 *l3;
	void *obj;
	int x;

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

A
Andrew Morton 已提交
3322
retry:
3323
	check_irq_off();
P
Pekka Enberg 已提交
3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342
	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);

3343
	obj = slab_get_obj(cachep, slabp, nodeid);
P
Pekka Enberg 已提交
3344 3345 3346 3347 3348
	check_slabp(cachep, slabp);
	l3->free_objects--;
	/* move slabp to correct slabp list: */
	list_del(&slabp->list);

A
Andrew Morton 已提交
3349
	if (slabp->free == BUFCTL_END)
P
Pekka Enberg 已提交
3350
		list_add(&slabp->list, &l3->slabs_full);
A
Andrew Morton 已提交
3351
	else
P
Pekka Enberg 已提交
3352
		list_add(&slabp->list, &l3->slabs_partial);
3353

P
Pekka Enberg 已提交
3354 3355
	spin_unlock(&l3->list_lock);
	goto done;
3356

A
Andrew Morton 已提交
3357
must_grow:
P
Pekka Enberg 已提交
3358
	spin_unlock(&l3->list_lock);
3359
	x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
3360 3361
	if (x)
		goto retry;
L
Linus Torvalds 已提交
3362

3363
	return fallback_alloc(cachep, flags);
3364

A
Andrew Morton 已提交
3365
done:
P
Pekka Enberg 已提交
3366
	return obj;
3367
}
3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387

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

3388 3389 3390
	if (should_failslab(cachep, flags))
		return NULL;

3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);

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

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

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

3420 3421 3422
	if (unlikely((flags & __GFP_ZERO) && ptr))
		memset(ptr, 0, obj_size(cachep));

3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463
	return ptr;
}

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

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

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

  out:
	return objp;
}
#else

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

#endif /* CONFIG_NUMA */

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

3464 3465 3466
	if (should_failslab(cachep, flags))
		return NULL;

3467 3468 3469 3470 3471 3472 3473
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
	objp = __do_cache_alloc(cachep, flags);
	local_irq_restore(save_flags);
	objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
	prefetchw(objp);

3474 3475 3476
	if (unlikely((flags & __GFP_ZERO) && objp))
		memset(objp, 0, obj_size(cachep));

3477 3478
	return objp;
}
3479 3480 3481 3482

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
3483
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
P
Pekka Enberg 已提交
3484
		       int node)
L
Linus Torvalds 已提交
3485 3486
{
	int i;
3487
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3488 3489 3490 3491 3492

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

3493
		slabp = virt_to_slab(objp);
3494
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
3495
		list_del(&slabp->list);
3496
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
3497
		check_slabp(cachep, slabp);
3498
		slab_put_obj(cachep, slabp, objp, node);
L
Linus Torvalds 已提交
3499
		STATS_DEC_ACTIVE(cachep);
3500
		l3->free_objects++;
L
Linus Torvalds 已提交
3501 3502 3503 3504
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
3505 3506
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
3507 3508 3509 3510 3511 3512
				/* No need to drop any previously held
				 * lock here, even if we have a off-slab slab
				 * descriptor it is guaranteed to come from
				 * a different cache, refer to comments before
				 * alloc_slabmgmt.
				 */
L
Linus Torvalds 已提交
3513 3514
				slab_destroy(cachep, slabp);
			} else {
3515
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
3516 3517 3518 3519 3520 3521
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
3522
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
3523 3524 3525 3526
		}
	}
}

3527
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
L
Linus Torvalds 已提交
3528 3529
{
	int batchcount;
3530
	struct kmem_list3 *l3;
3531
	int node = numa_node_id();
L
Linus Torvalds 已提交
3532 3533 3534 3535 3536 3537

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
3538
	l3 = cachep->nodelists[node];
3539
	spin_lock(&l3->list_lock);
3540 3541
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
P
Pekka Enberg 已提交
3542
		int max = shared_array->limit - shared_array->avail;
L
Linus Torvalds 已提交
3543 3544 3545
		if (max) {
			if (batchcount > max)
				batchcount = max;
3546
			memcpy(&(shared_array->entry[shared_array->avail]),
P
Pekka Enberg 已提交
3547
			       ac->entry, sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
3548 3549 3550 3551 3552
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

3553
	free_block(cachep, ac->entry, batchcount, node);
A
Andrew Morton 已提交
3554
free_done:
L
Linus Torvalds 已提交
3555 3556 3557 3558 3559
#if STATS
	{
		int i = 0;
		struct list_head *p;

3560 3561
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572
			struct slab *slabp;

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

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
3573
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3574
	ac->avail -= batchcount;
A
Andrew Morton 已提交
3575
	memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
L
Linus Torvalds 已提交
3576 3577 3578
}

/*
A
Andrew Morton 已提交
3579 3580
 * 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
3581
 */
3582
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3583
{
3584
	struct array_cache *ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3585 3586 3587 3588

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

3589 3590 3591 3592 3593 3594 3595 3596
	/*
	 * Skip calling cache_free_alien() when the platform is not numa.
	 * This will avoid cache misses that happen while accessing slabp (which
	 * is per page memory  reference) to get nodeid. Instead use a global
	 * variable to skip the call, which is mostly likely to be present in
	 * the cache.
	 */
	if (numa_platform && cache_free_alien(cachep, objp))
3597 3598
		return;

L
Linus Torvalds 已提交
3599 3600
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
3601
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3602 3603 3604 3605
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
3606
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617
	}
}

/**
 * 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.
 */
3618
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3619
{
3620
	return __cache_alloc(cachep, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637
}
EXPORT_SYMBOL(kmem_cache_alloc);

/**
 * kmem_ptr_validate - check if an untrusted pointer might
 *	be a slab entry.
 * @cachep: the cache we're checking against
 * @ptr: pointer to validate
 *
 * This verifies that the untrusted pointer looks sane:
 * it is _not_ a guarantee that the pointer is actually
 * part of the slab cache in question, but it at least
 * validates that the pointer can be dereferenced and
 * looks half-way sane.
 *
 * Currently only used for dentry validation.
 */
3638
int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
L
Linus Torvalds 已提交
3639
{
P
Pekka Enberg 已提交
3640
	unsigned long addr = (unsigned long)ptr;
L
Linus Torvalds 已提交
3641
	unsigned long min_addr = PAGE_OFFSET;
P
Pekka Enberg 已提交
3642
	unsigned long align_mask = BYTES_PER_WORD - 1;
3643
	unsigned long size = cachep->buffer_size;
L
Linus Torvalds 已提交
3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658
	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;
3659
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
3660 3661
		goto out;
	return 1;
A
Andrew Morton 已提交
3662
out:
L
Linus Torvalds 已提交
3663 3664 3665 3666
	return 0;
}

#ifdef CONFIG_NUMA
3667 3668 3669 3670 3671
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
{
	return __cache_alloc_node(cachep, flags, nodeid,
			__builtin_return_address(0));
}
L
Linus Torvalds 已提交
3672 3673
EXPORT_SYMBOL(kmem_cache_alloc_node);

3674 3675
static __always_inline void *
__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
3676
{
3677
	struct kmem_cache *cachep;
3678 3679

	cachep = kmem_find_general_cachep(size, flags);
3680 3681
	if (unlikely(ZERO_OR_NULL_PTR(cachep)))
		return cachep;
3682 3683
	return kmem_cache_alloc_node(cachep, flags, node);
}
3684 3685 3686 3687 3688 3689 3690

#ifdef CONFIG_DEBUG_SLAB
void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
	return __do_kmalloc_node(size, flags, node,
			__builtin_return_address(0));
}
3691
EXPORT_SYMBOL(__kmalloc_node);
3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706

void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
		int node, void *caller)
{
	return __do_kmalloc_node(size, flags, node, caller);
}
EXPORT_SYMBOL(__kmalloc_node_track_caller);
#else
void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
	return __do_kmalloc_node(size, flags, node, NULL);
}
EXPORT_SYMBOL(__kmalloc_node);
#endif /* CONFIG_DEBUG_SLAB */
#endif /* CONFIG_NUMA */
L
Linus Torvalds 已提交
3707 3708

/**
3709
 * __do_kmalloc - allocate memory
L
Linus Torvalds 已提交
3710
 * @size: how many bytes of memory are required.
3711
 * @flags: the type of memory to allocate (see kmalloc).
3712
 * @caller: function caller for debug tracking of the caller
L
Linus Torvalds 已提交
3713
 */
3714 3715
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
					  void *caller)
L
Linus Torvalds 已提交
3716
{
3717
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3718

3719 3720 3721 3722 3723 3724
	/* 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);
3725 3726
	if (unlikely(ZERO_OR_NULL_PTR(cachep)))
		return cachep;
3727 3728 3729 3730
	return __cache_alloc(cachep, flags, caller);
}


3731
#ifdef CONFIG_DEBUG_SLAB
3732 3733
void *__kmalloc(size_t size, gfp_t flags)
{
3734
	return __do_kmalloc(size, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3735 3736 3737
}
EXPORT_SYMBOL(__kmalloc);

3738 3739 3740 3741 3742
void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
{
	return __do_kmalloc(size, flags, caller);
}
EXPORT_SYMBOL(__kmalloc_track_caller);
3743 3744 3745 3746 3747 3748 3749

#else
void *__kmalloc(size_t size, gfp_t flags)
{
	return __do_kmalloc(size, flags, NULL);
}
EXPORT_SYMBOL(__kmalloc);
3750 3751
#endif

L
Linus Torvalds 已提交
3752 3753 3754 3755 3756 3757 3758 3759
/**
 * 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.
 */
3760
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3761 3762 3763 3764
{
	unsigned long flags;

	local_irq_save(flags);
3765
	debug_check_no_locks_freed(objp, obj_size(cachep));
3766
	__cache_free(cachep, objp);
L
Linus Torvalds 已提交
3767 3768 3769 3770 3771 3772 3773 3774
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kmem_cache_free);

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3775 3776
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3777 3778 3779 3780 3781
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
3782
	struct kmem_cache *c;
L
Linus Torvalds 已提交
3783 3784
	unsigned long flags;

3785
	if (unlikely(ZERO_OR_NULL_PTR(objp)))
L
Linus Torvalds 已提交
3786 3787 3788
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3789
	c = virt_to_cache(objp);
3790
	debug_check_no_locks_freed(objp, obj_size(c));
3791
	__cache_free(c, (void *)objp);
L
Linus Torvalds 已提交
3792 3793 3794 3795
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

3796
unsigned int kmem_cache_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3797
{
3798
	return obj_size(cachep);
L
Linus Torvalds 已提交
3799 3800 3801
}
EXPORT_SYMBOL(kmem_cache_size);

3802
const char *kmem_cache_name(struct kmem_cache *cachep)
3803 3804 3805 3806 3807
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3808
/*
S
Simon Arlott 已提交
3809
 * This initializes kmem_list3 or resizes various caches for all nodes.
3810
 */
3811
static int alloc_kmemlist(struct kmem_cache *cachep)
3812 3813 3814
{
	int node;
	struct kmem_list3 *l3;
3815
	struct array_cache *new_shared;
3816
	struct array_cache **new_alien = NULL;
3817

3818
	for_each_online_node(node) {
3819

3820 3821 3822 3823 3824
                if (use_alien_caches) {
                        new_alien = alloc_alien_cache(node, cachep->limit);
                        if (!new_alien)
                                goto fail;
                }
3825

3826 3827 3828
		new_shared = NULL;
		if (cachep->shared) {
			new_shared = alloc_arraycache(node,
3829
				cachep->shared*cachep->batchcount,
A
Andrew Morton 已提交
3830
					0xbaadf00d);
3831 3832 3833 3834
			if (!new_shared) {
				free_alien_cache(new_alien);
				goto fail;
			}
3835
		}
3836

A
Andrew Morton 已提交
3837 3838
		l3 = cachep->nodelists[node];
		if (l3) {
3839 3840
			struct array_cache *shared = l3->shared;

3841 3842
			spin_lock_irq(&l3->list_lock);

3843
			if (shared)
3844 3845
				free_block(cachep, shared->entry,
						shared->avail, node);
3846

3847 3848
			l3->shared = new_shared;
			if (!l3->alien) {
3849 3850 3851
				l3->alien = new_alien;
				new_alien = NULL;
			}
P
Pekka Enberg 已提交
3852
			l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3853
					cachep->batchcount + cachep->num;
3854
			spin_unlock_irq(&l3->list_lock);
3855
			kfree(shared);
3856 3857 3858
			free_alien_cache(new_alien);
			continue;
		}
A
Andrew Morton 已提交
3859
		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
3860 3861 3862
		if (!l3) {
			free_alien_cache(new_alien);
			kfree(new_shared);
3863
			goto fail;
3864
		}
3865 3866 3867

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
A
Andrew Morton 已提交
3868
				((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3869
		l3->shared = new_shared;
3870
		l3->alien = new_alien;
P
Pekka Enberg 已提交
3871
		l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3872
					cachep->batchcount + cachep->num;
3873 3874
		cachep->nodelists[node] = l3;
	}
3875
	return 0;
3876

A
Andrew Morton 已提交
3877
fail:
3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892
	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--;
		}
	}
3893
	return -ENOMEM;
3894 3895
}

L
Linus Torvalds 已提交
3896
struct ccupdate_struct {
3897
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3898 3899 3900 3901 3902
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
A
Andrew Morton 已提交
3903
	struct ccupdate_struct *new = info;
L
Linus Torvalds 已提交
3904 3905 3906
	struct array_cache *old;

	check_irq_off();
3907
	old = cpu_cache_get(new->cachep);
3908

L
Linus Torvalds 已提交
3909 3910 3911 3912
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}

3913
/* Always called with the cache_chain_mutex held */
A
Andrew Morton 已提交
3914 3915
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
				int batchcount, int shared)
L
Linus Torvalds 已提交
3916
{
3917
	struct ccupdate_struct *new;
3918
	int i;
L
Linus Torvalds 已提交
3919

3920 3921 3922 3923
	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		return -ENOMEM;

3924
	for_each_online_cpu(i) {
3925
		new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
A
Andrew Morton 已提交
3926
						batchcount);
3927
		if (!new->new[i]) {
P
Pekka Enberg 已提交
3928
			for (i--; i >= 0; i--)
3929 3930
				kfree(new->new[i]);
			kfree(new);
3931
			return -ENOMEM;
L
Linus Torvalds 已提交
3932 3933
		}
	}
3934
	new->cachep = cachep;
L
Linus Torvalds 已提交
3935

3936
	on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
3937

L
Linus Torvalds 已提交
3938 3939 3940
	check_irq_on();
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3941
	cachep->shared = shared;
L
Linus Torvalds 已提交
3942

3943
	for_each_online_cpu(i) {
3944
		struct array_cache *ccold = new->new[i];
L
Linus Torvalds 已提交
3945 3946
		if (!ccold)
			continue;
3947
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3948
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3949
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3950 3951
		kfree(ccold);
	}
3952
	kfree(new);
3953
	return alloc_kmemlist(cachep);
L
Linus Torvalds 已提交
3954 3955
}

3956
/* Called with cache_chain_mutex held always */
3957
static int enable_cpucache(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3958 3959 3960 3961
{
	int err;
	int limit, shared;

A
Andrew Morton 已提交
3962 3963
	/*
	 * The head array serves three purposes:
L
Linus Torvalds 已提交
3964 3965
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
A
Andrew Morton 已提交
3966
	 * - reduce the number of linked list operations on the slab and
L
Linus Torvalds 已提交
3967 3968 3969 3970
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
3971
	if (cachep->buffer_size > 131072)
L
Linus Torvalds 已提交
3972
		limit = 1;
3973
	else if (cachep->buffer_size > PAGE_SIZE)
L
Linus Torvalds 已提交
3974
		limit = 8;
3975
	else if (cachep->buffer_size > 1024)
L
Linus Torvalds 已提交
3976
		limit = 24;
3977
	else if (cachep->buffer_size > 256)
L
Linus Torvalds 已提交
3978 3979 3980 3981
		limit = 54;
	else
		limit = 120;

A
Andrew Morton 已提交
3982 3983
	/*
	 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
L
Linus Torvalds 已提交
3984 3985 3986 3987 3988 3989 3990 3991
	 * 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;
3992
	if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1)
L
Linus Torvalds 已提交
3993 3994 3995
		shared = 8;

#if DEBUG
A
Andrew Morton 已提交
3996 3997 3998
	/*
	 * With debugging enabled, large batchcount lead to excessively long
	 * periods with disabled local interrupts. Limit the batchcount
L
Linus Torvalds 已提交
3999 4000 4001 4002
	 */
	if (limit > 32)
		limit = 32;
#endif
P
Pekka Enberg 已提交
4003
	err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
L
Linus Torvalds 已提交
4004 4005
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
P
Pekka Enberg 已提交
4006
		       cachep->name, -err);
4007
	return err;
L
Linus Torvalds 已提交
4008 4009
}

4010 4011
/*
 * Drain an array if it contains any elements taking the l3 lock only if
4012 4013
 * necessary. Note that the l3 listlock also protects the array_cache
 * if drain_array() is used on the shared array.
4014 4015 4016
 */
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
4017 4018 4019
{
	int tofree;

4020 4021
	if (!ac || !ac->avail)
		return;
L
Linus Torvalds 已提交
4022 4023
	if (ac->touched && !force) {
		ac->touched = 0;
4024
	} else {
4025
		spin_lock_irq(&l3->list_lock);
4026 4027 4028 4029 4030 4031 4032 4033 4034
		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);
		}
4035
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4036 4037 4038 4039 4040
	}
}

/**
 * cache_reap - Reclaim memory from caches.
4041
 * @w: work descriptor
L
Linus Torvalds 已提交
4042 4043 4044 4045 4046 4047
 *
 * 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
4048 4049
 * 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
4050
 */
4051
static void cache_reap(struct work_struct *w)
L
Linus Torvalds 已提交
4052
{
4053
	struct kmem_cache *searchp;
4054
	struct kmem_list3 *l3;
4055
	int node = numa_node_id();
4056 4057
	struct delayed_work *work =
		container_of(w, struct delayed_work, work);
L
Linus Torvalds 已提交
4058

4059
	if (!mutex_trylock(&cache_chain_mutex))
L
Linus Torvalds 已提交
4060
		/* Give up. Setup the next iteration. */
4061
		goto out;
L
Linus Torvalds 已提交
4062

4063
	list_for_each_entry(searchp, &cache_chain, next) {
L
Linus Torvalds 已提交
4064 4065
		check_irq_on();

4066 4067 4068 4069 4070
		/*
		 * 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.
		 */
4071
		l3 = searchp->nodelists[node];
4072

4073
		reap_alien(searchp, l3);
L
Linus Torvalds 已提交
4074

4075
		drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
L
Linus Torvalds 已提交
4076

4077 4078 4079 4080
		/*
		 * These are racy checks but it does not matter
		 * if we skip one check or scan twice.
		 */
4081
		if (time_after(l3->next_reap, jiffies))
4082
			goto next;
L
Linus Torvalds 已提交
4083

4084
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
4085

4086
		drain_array(searchp, l3, l3->shared, 0, node);
L
Linus Torvalds 已提交
4087

4088
		if (l3->free_touched)
4089
			l3->free_touched = 0;
4090 4091
		else {
			int freed;
L
Linus Torvalds 已提交
4092

4093 4094 4095 4096
			freed = drain_freelist(searchp, l3, (l3->free_limit +
				5 * searchp->num - 1) / (5 * searchp->num));
			STATS_ADD_REAPED(searchp, freed);
		}
4097
next:
L
Linus Torvalds 已提交
4098 4099 4100
		cond_resched();
	}
	check_irq_on();
I
Ingo Molnar 已提交
4101
	mutex_unlock(&cache_chain_mutex);
4102
	next_reap_node();
4103
out:
A
Andrew Morton 已提交
4104
	/* Set up the next iteration */
4105
	schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
L
Linus Torvalds 已提交
4106 4107
}

4108
#ifdef CONFIG_SLABINFO
L
Linus Torvalds 已提交
4109

4110
static void print_slabinfo_header(struct seq_file *m)
L
Linus Torvalds 已提交
4111
{
4112 4113 4114 4115
	/*
	 * Output format version, so at least we can change it
	 * without _too_ many complaints.
	 */
L
Linus Torvalds 已提交
4116
#if STATS
4117
	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
L
Linus Torvalds 已提交
4118
#else
4119
	seq_puts(m, "slabinfo - version: 2.1\n");
L
Linus Torvalds 已提交
4120
#endif
4121 4122 4123 4124
	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
4125
#if STATS
4126
	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
4127
		 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
4128
	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
L
Linus Torvalds 已提交
4129
#endif
4130 4131 4132 4133 4134 4135 4136
	seq_putc(m, '\n');
}

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

I
Ingo Molnar 已提交
4137
	mutex_lock(&cache_chain_mutex);
4138 4139
	if (!n)
		print_slabinfo_header(m);
4140 4141

	return seq_list_start(&cache_chain, *pos);
L
Linus Torvalds 已提交
4142 4143 4144 4145
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
4146
	return seq_list_next(p, &cache_chain, pos);
L
Linus Torvalds 已提交
4147 4148 4149 4150
}

static void s_stop(struct seq_file *m, void *p)
{
I
Ingo Molnar 已提交
4151
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4152 4153 4154 4155
}

static int s_show(struct seq_file *m, void *p)
{
4156
	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
P
Pekka Enberg 已提交
4157 4158 4159 4160 4161
	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;
4162
	const char *name;
L
Linus Torvalds 已提交
4163
	char *error = NULL;
4164 4165
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
4166 4167 4168

	active_objs = 0;
	num_slabs = 0;
4169 4170 4171 4172 4173
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

4174 4175
		check_irq_on();
		spin_lock_irq(&l3->list_lock);
4176

4177
		list_for_each_entry(slabp, &l3->slabs_full, list) {
4178 4179 4180 4181 4182
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
4183
		list_for_each_entry(slabp, &l3->slabs_partial, list) {
4184 4185 4186 4187 4188 4189 4190
			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++;
		}
4191
		list_for_each_entry(slabp, &l3->slabs_free, list) {
4192 4193 4194 4195 4196
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
4197 4198
		if (l3->shared)
			shared_avail += l3->shared->avail;
4199

4200
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4201
	}
P
Pekka Enberg 已提交
4202 4203
	num_slabs += active_slabs;
	num_objs = num_slabs * cachep->num;
4204
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
4205 4206
		error = "free_objects accounting error";

P
Pekka Enberg 已提交
4207
	name = cachep->name;
L
Linus Torvalds 已提交
4208 4209 4210 4211
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
4212
		   name, active_objs, num_objs, cachep->buffer_size,
P
Pekka Enberg 已提交
4213
		   cachep->num, (1 << cachep->gfporder));
L
Linus Torvalds 已提交
4214
	seq_printf(m, " : tunables %4u %4u %4u",
P
Pekka Enberg 已提交
4215
		   cachep->limit, cachep->batchcount, cachep->shared);
4216
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
P
Pekka Enberg 已提交
4217
		   active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
4218
#if STATS
P
Pekka Enberg 已提交
4219
	{			/* list3 stats */
L
Linus Torvalds 已提交
4220 4221 4222 4223 4224 4225 4226
		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;
4227
		unsigned long node_frees = cachep->node_frees;
4228
		unsigned long overflows = cachep->node_overflow;
L
Linus Torvalds 已提交
4229

4230
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
4231
				%4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
A
Andrew Morton 已提交
4232
				reaped, errors, max_freeable, node_allocs,
4233
				node_frees, overflows);
L
Linus Torvalds 已提交
4234 4235 4236 4237 4238 4239 4240 4241 4242
	}
	/* 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
4243
			   allochit, allocmiss, freehit, freemiss);
L
Linus Torvalds 已提交
4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263
	}
#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
 */

4264
const struct seq_operations slabinfo_op = {
P
Pekka Enberg 已提交
4265 4266 4267 4268
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
L
Linus Torvalds 已提交
4269 4270 4271 4272 4273 4274 4275 4276 4277 4278
};

#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
4279 4280
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
		       size_t count, loff_t *ppos)
L
Linus Torvalds 已提交
4281
{
P
Pekka Enberg 已提交
4282
	char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
L
Linus Torvalds 已提交
4283
	int limit, batchcount, shared, res;
4284
	struct kmem_cache *cachep;
P
Pekka Enberg 已提交
4285

L
Linus Torvalds 已提交
4286 4287 4288 4289
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
P
Pekka Enberg 已提交
4290
	kbuf[MAX_SLABINFO_WRITE] = '\0';
L
Linus Torvalds 已提交
4291 4292 4293 4294 4295 4296 4297 4298 4299 4300

	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
4301
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4302
	res = -EINVAL;
4303
	list_for_each_entry(cachep, &cache_chain, next) {
L
Linus Torvalds 已提交
4304
		if (!strcmp(cachep->name, kbuf)) {
A
Andrew Morton 已提交
4305 4306
			if (limit < 1 || batchcount < 1 ||
					batchcount > limit || shared < 0) {
4307
				res = 0;
L
Linus Torvalds 已提交
4308
			} else {
4309
				res = do_tune_cpucache(cachep, limit,
P
Pekka Enberg 已提交
4310
						       batchcount, shared);
L
Linus Torvalds 已提交
4311 4312 4313 4314
			}
			break;
		}
	}
I
Ingo Molnar 已提交
4315
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4316 4317 4318 4319
	if (res >= 0)
		res = count;
	return res;
}
4320 4321 4322 4323 4324 4325

#ifdef CONFIG_DEBUG_SLAB_LEAK

static void *leaks_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&cache_chain_mutex);
4326
	return seq_list_start(&cache_chain, *pos);
4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376
}

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

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

static void show_symbol(struct seq_file *m, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
	unsigned long offset, size;
4377
	char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN];
4378

4379
	if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) {
4380
		seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
4381
		if (modname[0])
4382 4383 4384 4385 4386 4387 4388 4389 4390
			seq_printf(m, " [%s]", modname);
		return;
	}
#endif
	seq_printf(m, "%p", (void *)address);
}

static int leaks_show(struct seq_file *m, void *p)
{
4391
	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415
	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);

4416
		list_for_each_entry(slabp, &l3->slabs_full, list)
4417
			handle_slab(n, cachep, slabp);
4418
		list_for_each_entry(slabp, &l3->slabs_partial, list)
4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444
			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');
	}
4445

4446 4447 4448
	return 0;
}

4449
const struct seq_operations slabstats_op = {
4450 4451 4452 4453 4454 4455
	.start = leaks_start,
	.next = s_next,
	.stop = s_stop,
	.show = leaks_show,
};
#endif
L
Linus Torvalds 已提交
4456 4457
#endif

4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469
/**
 * ksize - get the actual amount of memory allocated for a given object
 * @objp: Pointer to the object
 *
 * kmalloc may internally round up allocations and return more memory
 * than requested. ksize() can be used to determine the actual amount of
 * memory allocated. The caller may use this additional memory, even though
 * a smaller amount of memory was initially specified with the kmalloc call.
 * The caller must guarantee that objp points to a valid object previously
 * allocated with either kmalloc() or kmem_cache_alloc(). The object
 * must not be freed during the duration of the call.
 */
P
Pekka Enberg 已提交
4470
size_t ksize(const void *objp)
L
Linus Torvalds 已提交
4471
{
4472 4473
	BUG_ON(!objp);
	if (unlikely(objp == ZERO_SIZE_PTR))
4474
		return 0;
L
Linus Torvalds 已提交
4475

4476
	return obj_size(virt_to_cache(objp));
L
Linus Torvalds 已提交
4477
}
T
Tetsuo Handa 已提交
4478
EXPORT_SYMBOL(ksize);