slab.c 115.1 KB
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/*
 * linux/mm/slab.c
 * Written by Mark Hemment, 1996/97.
 * (markhe@nextd.demon.co.uk)
 *
 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
 *
 * Major cleanup, different bufctl logic, per-cpu arrays
 *	(c) 2000 Manfred Spraul
 *
 * Cleanup, make the head arrays unconditional, preparation for NUMA
 * 	(c) 2002 Manfred Spraul
 *
 * An implementation of the Slab Allocator as described in outline in;
 *	UNIX Internals: The New Frontiers by Uresh Vahalia
 *	Pub: Prentice Hall	ISBN 0-13-101908-2
 * or with a little more detail in;
 *	The Slab Allocator: An Object-Caching Kernel Memory Allocator
 *	Jeff Bonwick (Sun Microsystems).
 *	Presented at: USENIX Summer 1994 Technical Conference
 *
 * The memory is organized in caches, one cache for each object type.
 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
 * Each cache consists out of many slabs (they are small (usually one
 * page long) and always contiguous), and each slab contains multiple
 * initialized objects.
 *
 * This means, that your constructor is used only for newly allocated
 * slabs and you must pass objects with the same intializations to
 * kmem_cache_free.
 *
 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
 * normal). If you need a special memory type, then must create a new
 * cache for that memory type.
 *
 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
 *   full slabs with 0 free objects
 *   partial slabs
 *   empty slabs with no allocated objects
 *
 * If partial slabs exist, then new allocations come from these slabs,
 * otherwise from empty slabs or new slabs are allocated.
 *
 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
 *
 * Each cache has a short per-cpu head array, most allocs
 * and frees go into that array, and if that array overflows, then 1/2
 * of the entries in the array are given back into the global cache.
 * The head array is strictly LIFO and should improve the cache hit rates.
 * On SMP, it additionally reduces the spinlock operations.
 *
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 * The c_cpuarray may not be read with enabled local interrupts -
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 * it's changed with a smp_call_function().
 *
 * SMP synchronization:
 *  constructors and destructors are called without any locking.
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 *  Several members in struct kmem_cache and struct slab never change, they
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 *	are accessed without any locking.
 *  The per-cpu arrays are never accessed from the wrong cpu, no locking,
 *  	and local interrupts are disabled so slab code is preempt-safe.
 *  The non-constant members are protected with a per-cache irq spinlock.
 *
 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
 * in 2000 - many ideas in the current implementation are derived from
 * his patch.
 *
 * Further notes from the original documentation:
 *
 * 11 April '97.  Started multi-threading - markhe
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 *	The global cache-chain is protected by the mutex 'cache_chain_mutex'.
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 *	The sem is only needed when accessing/extending the cache-chain, which
 *	can never happen inside an interrupt (kmem_cache_create(),
 *	kmem_cache_shrink() and kmem_cache_reap()).
 *
 *	At present, each engine can be growing a cache.  This should be blocked.
 *
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 * 15 March 2005. NUMA slab allocator.
 *	Shai Fultheim <shai@scalex86.org>.
 *	Shobhit Dayal <shobhit@calsoftinc.com>
 *	Alok N Kataria <alokk@calsoftinc.com>
 *	Christoph Lameter <christoph@lameter.com>
 *
 *	Modified the slab allocator to be node aware on NUMA systems.
 *	Each node has its own list of partial, free and full slabs.
 *	All object allocations for a node occur from node specific slab lists.
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 */

#include	<linux/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[0];	/*
			 * Must have this definition in here for the proper
			 * alignment of array_cache. Also simplifies accessing
			 * the entries.
			 * [0] is for gcc 2.95. It should really be [].
			 */
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};

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

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

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

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

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

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

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static int slab_early_init = 1;

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

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

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

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	unsigned int flags;		/* constant flags */
	unsigned int num;		/* # of objs per slab */
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/* 4) cache_grow/shrink */
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	/* order of pgs per slab (2^n) */
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	unsigned int gfporder;
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	/* force GFP flags, e.g. GFP_DMA */
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	gfp_t gfpflags;
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	size_t colour;			/* cache colouring range */
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	unsigned int colour_off;	/* colour offset */
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	struct kmem_cache *slabp_cache;
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	unsigned int slab_size;
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	unsigned int dflags;		/* dynamic flags */
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	/* constructor func */
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	void (*ctor) (void *, struct kmem_cache *, unsigned long);
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/* 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.
521
 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
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 * 		redzone word.
523 524
 * 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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 */
528
static int obj_offset(struct kmem_cache *cachep)
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{
530
	return cachep->obj_offset;
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}

533
static int obj_size(struct kmem_cache *cachep)
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{
535
	return cachep->obj_size;
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}

538
static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
541 542
	return (unsigned long long*) (objp + obj_offset(cachep) -
				      sizeof(unsigned long long));
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}

545
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)
549 550
		return (unsigned long long *)(objp + cachep->buffer_size -
					      sizeof(unsigned long long) -
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					      REDZONE_ALIGN);
552 553
	return (unsigned long long *) (objp + cachep->buffer_size -
				       sizeof(unsigned long long));
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}

556
static void **dbg_userword(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
559
	return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

#else

564 565
#define obj_offset(x)			0
#define obj_size(cachep)		(cachep->buffer_size)
566 567
#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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 */
584 585 586 587 588 589 590
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)
{
591
	page = compound_head(page);
592
	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)
{
603
	BUG_ON(!PageSlab(page));
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	return (struct slab *)page->lru.prev;
}
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607 608
static inline struct kmem_cache *virt_to_cache(const void *obj)
{
609
	struct page *page = virt_to_head_page(obj);
610 611 612 613 614
	return page_get_cache(page);
}

static inline struct slab *virt_to_slab(const void *obj)
{
615
	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)
633
{
634 635
	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 */
668
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.
686 687 688 689
 *
 * 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
690
 */
691 692 693 694
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)
695 696 697

{
	int q;
698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724
	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++;
725 726 727
	}
}
#else
728
static inline void init_lock_keys(void)
729 730 731 732
{
}
#endif

733 734 735 736
/*
 * 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,
746 747
	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;
}

759
static DEFINE_PER_CPU(struct delayed_work, reap_work);
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761
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.
	 */
776
	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
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#endif
	while (size > csizep->cs_size)
		csizep++;

	/*
782
	 * 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.
	 */
786
#ifdef CONFIG_ZONE_DMA
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	if (unlikely(gfpflags & GFP_DMA))
		return csizep->cs_dmacachep;
789
#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)
794 795 796 797
{
	return __find_general_cachep(size, gfpflags);
}

798
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
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{
800 801
	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.
 */
806 807 808 809 810 811 812
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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814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861
	/*
	 * 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();
}

874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889
/*
 * By default on NUMA we use alien caches to stage the freeing of
 * objects allocated from other nodes. This causes massive memory
 * inefficiencies when using fake NUMA setup to split memory into a
 * large number of small nodes, so it can be disabled on the command
 * line
  */

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

890 891 892 893 894 895 896 897 898 899 900 901 902 903 904
#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)
905
		node = first_node(node_online_map);
906

907
	per_cpu(reap_node, cpu) = node;
908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924
}

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.
 */
932
static void __cpuinit start_cpu_timer(int cpu)
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{
934
	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.
	 */
941
	if (keventd_up() && reap_work->work.func == NULL) {
942
		init_reap_node(cpu);
943
		INIT_DELAYED_WORK(reap_work, cache_reap);
944 945
		schedule_delayed_work_on(cpu, reap_work,
					__round_jiffies_relative(HZ, cpu));
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	}
}

949
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;

955
	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;
961
		spin_lock_init(&nc->lock);
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	}
	return nc;
}

966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989
/*
 * 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;
}

990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014
#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;
}

1015
static inline void *____cache_alloc_node(struct kmem_cache *cachep,
1016 1017 1018 1019 1020 1021 1022
		 gfp_t flags, int nodeid)
{
	return NULL;
}

#else	/* CONFIG_NUMA */

1023
static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
1024
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
1025

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static struct array_cache **alloc_alien_cache(int node, int limit)
1027 1028
{
	struct array_cache **ac_ptr;
1029
	int memsize = sizeof(void *) * nr_node_ids;
1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042
	int i;

	if (limit > 1)
		limit = 12;
	ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node);
	if (ac_ptr) {
		for_each_node(i) {
			if (i == node || !node_online(i)) {
				ac_ptr[i] = NULL;
				continue;
			}
			ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d);
			if (!ac_ptr[i]) {
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				for (i--; i <= 0; i--)
1044 1045 1046 1047 1048 1049 1050 1051 1052
					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)
1054 1055 1056 1057 1058 1059
{
	int i;

	if (!ac_ptr)
		return;
	for_each_node(i)
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	    kfree(ac_ptr[i]);
1061 1062 1063
	kfree(ac_ptr);
}

1064
static void __drain_alien_cache(struct kmem_cache *cachep,
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				struct array_cache *ac, int node)
1066 1067 1068 1069 1070
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
1071 1072 1073 1074 1075
		/*
		 * 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.
		 */
1076 1077
		if (rl3->shared)
			transfer_objects(rl3->shared, ac, ac->limit);
1078

1079
		free_block(cachep, ac->entry, ac->avail, node);
1080 1081 1082 1083 1084
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

1085 1086 1087 1088 1089 1090 1091 1092 1093
/*
 * 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];
1094 1095

		if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
1096 1097 1098 1099 1100 1101
			__drain_alien_cache(cachep, ac, node);
			spin_unlock_irq(&ac->lock);
		}
	}
}

A
Andrew Morton 已提交
1102 1103
static void drain_alien_cache(struct kmem_cache *cachep,
				struct array_cache **alien)
1104
{
P
Pekka Enberg 已提交
1105
	int i = 0;
1106 1107 1108 1109
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
1110
		ac = alien[i];
1111 1112 1113 1114 1115 1116 1117
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
1118

1119
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1120 1121 1122 1123 1124
{
	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
1125 1126 1127
	int node;

	node = numa_node_id();
1128 1129 1130 1131 1132

	/*
	 * Make sure we are not freeing a object from another node to the array
	 * cache on this cpu.
	 */
1133
	if (likely(slabp->nodeid == node))
1134 1135
		return 0;

P
Pekka Enberg 已提交
1136
	l3 = cachep->nodelists[node];
1137 1138 1139
	STATS_INC_NODEFREES(cachep);
	if (l3->alien && l3->alien[nodeid]) {
		alien = l3->alien[nodeid];
1140
		spin_lock(&alien->lock);
1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153
		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;
}
1154 1155
#endif

1156
static int __cpuinit cpuup_callback(struct notifier_block *nfb,
P
Pekka Enberg 已提交
1157
				    unsigned long action, void *hcpu)
L
Linus Torvalds 已提交
1158 1159
{
	long cpu = (long)hcpu;
1160
	struct kmem_cache *cachep;
1161 1162 1163
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
	int memsize = sizeof(struct kmem_list3);
L
Linus Torvalds 已提交
1164 1165

	switch (action) {
1166
	case CPU_LOCK_ACQUIRE:
I
Ingo Molnar 已提交
1167
		mutex_lock(&cache_chain_mutex);
1168 1169
		break;
	case CPU_UP_PREPARE:
1170
	case CPU_UP_PREPARE_FROZEN:
A
Andrew Morton 已提交
1171 1172
		/*
		 * We need to do this right in the beginning since
1173 1174 1175 1176 1177
		 * alloc_arraycache's are going to use this list.
		 * kmalloc_node allows us to add the slab to the right
		 * kmem_list3 and not this cpu's kmem_list3
		 */

L
Linus Torvalds 已提交
1178
		list_for_each_entry(cachep, &cache_chain, next) {
A
Andrew Morton 已提交
1179 1180
			/*
			 * Set up the size64 kmemlist for cpu before we can
1181 1182 1183 1184
			 * begin anything. Make sure some other cpu on this
			 * node has not already allocated this
			 */
			if (!cachep->nodelists[node]) {
A
Andrew Morton 已提交
1185 1186
				l3 = kmalloc_node(memsize, GFP_KERNEL, node);
				if (!l3)
1187 1188 1189
					goto bad;
				kmem_list3_init(l3);
				l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
P
Pekka Enberg 已提交
1190
				    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1191

1192 1193 1194 1195 1196
				/*
				 * The l3s don't come and go as CPUs come and
				 * go.  cache_chain_mutex is sufficient
				 * protection here.
				 */
1197 1198
				cachep->nodelists[node] = l3;
			}
L
Linus Torvalds 已提交
1199

1200 1201
			spin_lock_irq(&cachep->nodelists[node]->list_lock);
			cachep->nodelists[node]->free_limit =
A
Andrew Morton 已提交
1202 1203
				(1 + nr_cpus_node(node)) *
				cachep->batchcount + cachep->num;
1204 1205 1206
			spin_unlock_irq(&cachep->nodelists[node]->list_lock);
		}

A
Andrew Morton 已提交
1207 1208 1209 1210
		/*
		 * Now we can go ahead with allocating the shared arrays and
		 * array caches
		 */
1211
		list_for_each_entry(cachep, &cache_chain, next) {
1212
			struct array_cache *nc;
1213
			struct array_cache *shared = NULL;
1214
			struct array_cache **alien = NULL;
1215

1216
			nc = alloc_arraycache(node, cachep->limit,
1217
						cachep->batchcount);
L
Linus Torvalds 已提交
1218 1219
			if (!nc)
				goto bad;
1220 1221
			if (cachep->shared) {
				shared = alloc_arraycache(node,
1222 1223
					cachep->shared * cachep->batchcount,
					0xbaadf00d);
1224 1225 1226
				if (!shared)
					goto bad;
			}
1227 1228 1229 1230 1231
			if (use_alien_caches) {
                                alien = alloc_alien_cache(node, cachep->limit);
                                if (!alien)
                                        goto bad;
                        }
L
Linus Torvalds 已提交
1232
			cachep->array[cpu] = nc;
1233 1234 1235
			l3 = cachep->nodelists[node];
			BUG_ON(!l3);

1236 1237 1238 1239 1240 1241 1242 1243
			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;
1244
			}
1245 1246 1247 1248 1249 1250 1251 1252 1253
#ifdef CONFIG_NUMA
			if (!l3->alien) {
				l3->alien = alien;
				alien = NULL;
			}
#endif
			spin_unlock_irq(&l3->list_lock);
			kfree(shared);
			free_alien_cache(alien);
L
Linus Torvalds 已提交
1254 1255 1256
		}
		break;
	case CPU_ONLINE:
1257
	case CPU_ONLINE_FROZEN:
L
Linus Torvalds 已提交
1258 1259 1260
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
1261
  	case CPU_DOWN_PREPARE:
1262
  	case CPU_DOWN_PREPARE_FROZEN:
1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273
		/*
		 * 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:
1274
  	case CPU_DOWN_FAILED_FROZEN:
1275 1276
		start_cpu_timer(cpu);
  		break;
L
Linus Torvalds 已提交
1277
	case CPU_DEAD:
1278
	case CPU_DEAD_FROZEN:
1279 1280 1281 1282 1283 1284 1285 1286
		/*
		 * Even if all the cpus of a node are down, we don't free the
		 * kmem_list3 of any cache. This to avoid a race between
		 * cpu_down, and a kmalloc allocation from another cpu for
		 * memory from the node of the cpu going down.  The list3
		 * structure is usually allocated from kmem_cache_create() and
		 * gets destroyed at kmem_cache_destroy().
		 */
L
Linus Torvalds 已提交
1287
		/* fall thru */
1288
#endif
L
Linus Torvalds 已提交
1289
	case CPU_UP_CANCELED:
1290
	case CPU_UP_CANCELED_FROZEN:
L
Linus Torvalds 已提交
1291 1292
		list_for_each_entry(cachep, &cache_chain, next) {
			struct array_cache *nc;
1293 1294
			struct array_cache *shared;
			struct array_cache **alien;
1295
			cpumask_t mask;
L
Linus Torvalds 已提交
1296

1297
			mask = node_to_cpumask(node);
L
Linus Torvalds 已提交
1298 1299 1300
			/* cpu is dead; no one can alloc from it. */
			nc = cachep->array[cpu];
			cachep->array[cpu] = NULL;
1301 1302 1303
			l3 = cachep->nodelists[node];

			if (!l3)
1304
				goto free_array_cache;
1305

1306
			spin_lock_irq(&l3->list_lock);
1307 1308 1309 1310

			/* Free limit for this kmem_list3 */
			l3->free_limit -= cachep->batchcount;
			if (nc)
1311
				free_block(cachep, nc->entry, nc->avail, node);
1312 1313

			if (!cpus_empty(mask)) {
1314
				spin_unlock_irq(&l3->list_lock);
1315
				goto free_array_cache;
P
Pekka Enberg 已提交
1316
			}
1317

1318 1319
			shared = l3->shared;
			if (shared) {
1320 1321
				free_block(cachep, shared->entry,
					   shared->avail, node);
1322 1323 1324
				l3->shared = NULL;
			}

1325 1326 1327 1328 1329 1330 1331 1332 1333
			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);
1334
			}
1335
free_array_cache:
L
Linus Torvalds 已提交
1336 1337
			kfree(nc);
		}
1338 1339 1340 1341 1342 1343 1344 1345 1346
		/*
		 * 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;
1347
			drain_freelist(cachep, l3, l3->free_objects);
1348
		}
1349 1350
		break;
	case CPU_LOCK_RELEASE:
I
Ingo Molnar 已提交
1351
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1352 1353 1354
		break;
	}
	return NOTIFY_OK;
A
Andrew Morton 已提交
1355
bad:
L
Linus Torvalds 已提交
1356 1357 1358
	return NOTIFY_BAD;
}

1359 1360 1361
static struct notifier_block __cpuinitdata cpucache_notifier = {
	&cpuup_callback, NULL, 0
};
L
Linus Torvalds 已提交
1362

1363 1364 1365
/*
 * swap the static kmem_list3 with kmalloced memory
 */
A
Andrew Morton 已提交
1366 1367
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
			int nodeid)
1368 1369 1370 1371 1372 1373 1374 1375
{
	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));
1376 1377 1378 1379 1380
	/*
	 * Do not assume that spinlocks can be initialized via memcpy:
	 */
	spin_lock_init(&ptr->list_lock);

1381 1382 1383 1384 1385
	MAKE_ALL_LISTS(cachep, ptr, nodeid);
	cachep->nodelists[nodeid] = ptr;
	local_irq_enable();
}

A
Andrew Morton 已提交
1386 1387 1388
/*
 * Initialisation.  Called after the page allocator have been initialised and
 * before smp_init().
L
Linus Torvalds 已提交
1389 1390 1391 1392 1393 1394
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1395
	int i;
1396
	int order;
P
Pekka Enberg 已提交
1397
	int node;
1398

1399 1400 1401
	if (num_possible_nodes() == 1)
		use_alien_caches = 0;

1402 1403 1404 1405 1406
	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
1407 1408 1409 1410 1411 1412 1413 1414 1415 1416

	/*
	 * 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
1417 1418 1419
	 * 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.
1420 1421 1422
	 *    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
1423
	 * 2) Create the first kmalloc cache.
1424
	 *    The struct kmem_cache for the new cache is allocated normally.
1425 1426 1427
	 *    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
1428 1429
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1430 1431 1432
	 * 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
1433 1434
	 */

P
Pekka Enberg 已提交
1435 1436
	node = numa_node_id();

L
Linus Torvalds 已提交
1437 1438 1439 1440 1441
	/* 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
1442
	cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
L
Linus Torvalds 已提交
1443

E
Eric Dumazet 已提交
1444 1445 1446 1447 1448 1449 1450 1451 1452
	/*
	 * 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
1453 1454
	cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
					cache_line_size());
1455 1456
	cache_cache.reciprocal_buffer_size =
		reciprocal_value(cache_cache.buffer_size);
L
Linus Torvalds 已提交
1457

1458 1459 1460 1461 1462 1463
	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;
	}
1464
	BUG_ON(!cache_cache.num);
1465
	cache_cache.gfporder = order;
P
Pekka Enberg 已提交
1466 1467 1468
	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
1469 1470 1471 1472 1473

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

A
Andrew Morton 已提交
1474 1475 1476 1477
	/*
	 * Initialize the caches that provide memory for the array cache and the
	 * kmem_list3 structures first.  Without this, further allocations will
	 * bug.
1478 1479 1480
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
A
Andrew Morton 已提交
1481 1482 1483 1484
					sizes[INDEX_AC].cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
1485

A
Andrew Morton 已提交
1486
	if (INDEX_AC != INDEX_L3) {
1487
		sizes[INDEX_L3].cs_cachep =
A
Andrew Morton 已提交
1488 1489 1490 1491 1492 1493
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size,
				ARCH_KMALLOC_MINALIGN,
				ARCH_KMALLOC_FLAGS|SLAB_PANIC,
				NULL, NULL);
	}
1494

1495 1496
	slab_early_init = 0;

L
Linus Torvalds 已提交
1497
	while (sizes->cs_size != ULONG_MAX) {
1498 1499
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1500 1501 1502
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1503 1504
		 * allow tighter packing of the smaller caches.
		 */
A
Andrew Morton 已提交
1505
		if (!sizes->cs_cachep) {
1506
			sizes->cs_cachep = kmem_cache_create(names->name,
A
Andrew Morton 已提交
1507 1508 1509 1510 1511
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
		}
1512 1513 1514
#ifdef CONFIG_ZONE_DMA
		sizes->cs_dmacachep = kmem_cache_create(
					names->name_dma,
A
Andrew Morton 已提交
1515 1516 1517 1518 1519
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
						SLAB_PANIC,
					NULL, NULL);
1520
#endif
L
Linus Torvalds 已提交
1521 1522 1523 1524 1525
		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
1526
		struct array_cache *ptr;
1527

L
Linus Torvalds 已提交
1528
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1529

L
Linus Torvalds 已提交
1530
		local_irq_disable();
1531 1532
		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
		memcpy(ptr, cpu_cache_get(&cache_cache),
P
Pekka Enberg 已提交
1533
		       sizeof(struct arraycache_init));
1534 1535 1536 1537 1538
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

L
Linus Torvalds 已提交
1539 1540
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1541

L
Linus Torvalds 已提交
1542
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1543

L
Linus Torvalds 已提交
1544
		local_irq_disable();
1545
		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
P
Pekka Enberg 已提交
1546
		       != &initarray_generic.cache);
1547
		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
P
Pekka Enberg 已提交
1548
		       sizeof(struct arraycache_init));
1549 1550 1551 1552 1553
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

1554
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
P
Pekka Enberg 已提交
1555
		    ptr;
L
Linus Torvalds 已提交
1556 1557
		local_irq_enable();
	}
1558 1559
	/* 5) Replace the bootstrap kmem_list3's */
	{
P
Pekka Enberg 已提交
1560 1561
		int nid;

1562
		/* Replace the static kmem_list3 structures for the boot cpu */
P
Pekka Enberg 已提交
1563
		init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node);
1564

P
Pekka Enberg 已提交
1565
		for_each_online_node(nid) {
1566
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
P
Pekka Enberg 已提交
1567
				  &initkmem_list3[SIZE_AC + nid], nid);
1568 1569 1570

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
P
Pekka Enberg 已提交
1571
					  &initkmem_list3[SIZE_L3 + nid], nid);
1572 1573 1574
			}
		}
	}
L
Linus Torvalds 已提交
1575

1576
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1577
	{
1578
		struct kmem_cache *cachep;
I
Ingo Molnar 已提交
1579
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1580
		list_for_each_entry(cachep, &cache_chain, next)
1581 1582
			if (enable_cpucache(cachep))
				BUG();
I
Ingo Molnar 已提交
1583
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1584 1585
	}

1586 1587 1588 1589
	/* Annotate slab for lockdep -- annotate the malloc caches */
	init_lock_keys();


L
Linus Torvalds 已提交
1590 1591 1592
	/* Done! */
	g_cpucache_up = FULL;

A
Andrew Morton 已提交
1593 1594 1595
	/*
	 * Register a cpu startup notifier callback that initializes
	 * cpu_cache_get for all new cpus
L
Linus Torvalds 已提交
1596 1597 1598
	 */
	register_cpu_notifier(&cpucache_notifier);

A
Andrew Morton 已提交
1599 1600 1601
	/*
	 * 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
1602 1603 1604 1605 1606 1607 1608
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

A
Andrew Morton 已提交
1609 1610
	/*
	 * Register the timers that return unneeded pages to the page allocator
L
Linus Torvalds 已提交
1611
	 */
1612
	for_each_online_cpu(cpu)
A
Andrew Morton 已提交
1613
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624
	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.
 */
1625
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1626 1627
{
	struct page *page;
1628
	int nr_pages;
L
Linus Torvalds 已提交
1629 1630
	int i;

1631
#ifndef CONFIG_MMU
1632 1633 1634
	/*
	 * Nommu uses slab's for process anonymous memory allocations, and thus
	 * requires __GFP_COMP to properly refcount higher order allocations
1635
	 */
1636
	flags |= __GFP_COMP;
1637
#endif
1638

1639
	flags |= cachep->gfpflags;
1640 1641

	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1642 1643 1644
	if (!page)
		return NULL;

1645
	nr_pages = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1646
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1647 1648 1649 1650 1651
		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);
1652 1653 1654
	for (i = 0; i < nr_pages; i++)
		__SetPageSlab(page + i);
	return page_address(page);
L
Linus Torvalds 已提交
1655 1656 1657 1658 1659
}

/*
 * Interface to system's page release.
 */
1660
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
L
Linus Torvalds 已提交
1661
{
P
Pekka Enberg 已提交
1662
	unsigned long i = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1663 1664 1665
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

1666 1667 1668 1669 1670 1671
	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
1672
	while (i--) {
N
Nick Piggin 已提交
1673 1674
		BUG_ON(!PageSlab(page));
		__ClearPageSlab(page);
L
Linus Torvalds 已提交
1675 1676 1677 1678 1679 1680 1681 1682 1683
		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
1684
	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1685
	struct kmem_cache *cachep = slab_rcu->cachep;
L
Linus Torvalds 已提交
1686 1687 1688 1689 1690 1691 1692 1693 1694

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

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
1695
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
P
Pekka Enberg 已提交
1696
			    unsigned long caller)
L
Linus Torvalds 已提交
1697
{
1698
	int size = obj_size(cachep);
L
Linus Torvalds 已提交
1699

1700
	addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1701

P
Pekka Enberg 已提交
1702
	if (size < 5 * sizeof(unsigned long))
L
Linus Torvalds 已提交
1703 1704
		return;

P
Pekka Enberg 已提交
1705 1706 1707 1708
	*addr++ = 0x12345678;
	*addr++ = caller;
	*addr++ = smp_processor_id();
	size -= 3 * sizeof(unsigned long);
L
Linus Torvalds 已提交
1709 1710 1711 1712 1713 1714 1715
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
P
Pekka Enberg 已提交
1716
				*addr++ = svalue;
L
Linus Torvalds 已提交
1717 1718 1719 1720 1721 1722 1723
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
P
Pekka Enberg 已提交
1724
	*addr++ = 0x87654321;
L
Linus Torvalds 已提交
1725 1726 1727
}
#endif

1728
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
L
Linus Torvalds 已提交
1729
{
1730 1731
	int size = obj_size(cachep);
	addr = &((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1732 1733

	memset(addr, val, size);
P
Pekka Enberg 已提交
1734
	*(unsigned char *)(addr + size - 1) = POISON_END;
L
Linus Torvalds 已提交
1735 1736 1737 1738 1739
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
D
Dave Jones 已提交
1740 1741 1742
	unsigned char error = 0;
	int bad_count = 0;

L
Linus Torvalds 已提交
1743
	printk(KERN_ERR "%03x:", offset);
D
Dave Jones 已提交
1744 1745 1746 1747 1748
	for (i = 0; i < limit; i++) {
		if (data[offset + i] != POISON_FREE) {
			error = data[offset + i];
			bad_count++;
		}
P
Pekka Enberg 已提交
1749
		printk(" %02x", (unsigned char)data[offset + i]);
D
Dave Jones 已提交
1750
	}
L
Linus Torvalds 已提交
1751
	printk("\n");
D
Dave Jones 已提交
1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765

	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
1766 1767 1768 1769 1770
}
#endif

#if DEBUG

1771
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
L
Linus Torvalds 已提交
1772 1773 1774 1775 1776
{
	int i, size;
	char *realobj;

	if (cachep->flags & SLAB_RED_ZONE) {
1777
		printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n",
A
Andrew Morton 已提交
1778 1779
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
1780 1781 1782 1783
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
A
Andrew Morton 已提交
1784
			*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1785
		print_symbol("(%s)",
A
Andrew Morton 已提交
1786
				(unsigned long)*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1787 1788
		printk("\n");
	}
1789 1790
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
P
Pekka Enberg 已提交
1791
	for (i = 0; i < size && lines; i += 16, lines--) {
L
Linus Torvalds 已提交
1792 1793
		int limit;
		limit = 16;
P
Pekka Enberg 已提交
1794 1795
		if (i + limit > size)
			limit = size - i;
L
Linus Torvalds 已提交
1796 1797 1798 1799
		dump_line(realobj, i, limit);
	}
}

1800
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
1801 1802 1803 1804 1805
{
	char *realobj;
	int size, i;
	int lines = 0;

1806 1807
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
L
Linus Torvalds 已提交
1808

P
Pekka Enberg 已提交
1809
	for (i = 0; i < size; i++) {
L
Linus Torvalds 已提交
1810
		char exp = POISON_FREE;
P
Pekka Enberg 已提交
1811
		if (i == size - 1)
L
Linus Torvalds 已提交
1812 1813 1814 1815 1816 1817
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
P
Pekka Enberg 已提交
1818
				printk(KERN_ERR
1819 1820
					"Slab corruption: %s start=%p, len=%d\n",
					cachep->name, realobj, size);
L
Linus Torvalds 已提交
1821 1822 1823
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
P
Pekka Enberg 已提交
1824
			i = (i / 16) * 16;
L
Linus Torvalds 已提交
1825
			limit = 16;
P
Pekka Enberg 已提交
1826 1827
			if (i + limit > size)
				limit = size - i;
L
Linus Torvalds 已提交
1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839
			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:
		 */
1840
		struct slab *slabp = virt_to_slab(objp);
1841
		unsigned int objnr;
L
Linus Torvalds 已提交
1842

1843
		objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
1844
		if (objnr) {
1845
			objp = index_to_obj(cachep, slabp, objnr - 1);
1846
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1847
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1848
			       realobj, size);
L
Linus Torvalds 已提交
1849 1850
			print_objinfo(cachep, objp, 2);
		}
P
Pekka Enberg 已提交
1851
		if (objnr + 1 < cachep->num) {
1852
			objp = index_to_obj(cachep, slabp, objnr + 1);
1853
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1854
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1855
			       realobj, size);
L
Linus Torvalds 已提交
1856 1857 1858 1859 1860 1861
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

1862 1863
#if DEBUG
/**
1864 1865 1866 1867 1868 1869
 * 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
1870
 */
1871
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
1872 1873 1874
{
	int i;
	for (i = 0; i < cachep->num; i++) {
1875
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
1876 1877 1878

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
1879 1880
			if (cachep->buffer_size % PAGE_SIZE == 0 &&
					OFF_SLAB(cachep))
P
Pekka Enberg 已提交
1881
				kernel_map_pages(virt_to_page(objp),
A
Andrew Morton 已提交
1882
					cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
1883 1884 1885 1886 1887 1888 1889 1890 1891
			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
1892
					   "was overwritten");
L
Linus Torvalds 已提交
1893 1894
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
P
Pekka Enberg 已提交
1895
					   "was overwritten");
L
Linus Torvalds 已提交
1896 1897
		}
	}
1898
}
L
Linus Torvalds 已提交
1899
#else
1900
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
1901 1902
{
}
L
Linus Torvalds 已提交
1903 1904
#endif

1905 1906 1907 1908 1909
/**
 * slab_destroy - destroy and release all objects in a slab
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
1910
 * Destroy all the objs in a slab, and release the mem back to the system.
A
Andrew Morton 已提交
1911 1912
 * Before calling the slab must have been unlinked from the cache.  The
 * cache-lock is not held/needed.
1913
 */
1914
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1915 1916 1917 1918
{
	void *addr = slabp->s_mem - slabp->colouroff;

	slab_destroy_objs(cachep, slabp);
L
Linus Torvalds 已提交
1919 1920 1921
	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

P
Pekka Enberg 已提交
1922
		slab_rcu = (struct slab_rcu *)slabp;
L
Linus Torvalds 已提交
1923 1924 1925 1926 1927
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
1928 1929
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
L
Linus Torvalds 已提交
1930 1931 1932
	}
}

A
Andrew Morton 已提交
1933 1934 1935 1936
/*
 * For setting up all the kmem_list3s for cache whose buffer_size is same as
 * size of kmem_list3.
 */
1937
static void __init set_up_list3s(struct kmem_cache *cachep, int index)
1938 1939 1940 1941
{
	int node;

	for_each_online_node(node) {
P
Pekka Enberg 已提交
1942
		cachep->nodelists[node] = &initkmem_list3[index + node];
1943
		cachep->nodelists[node]->next_reap = jiffies +
P
Pekka Enberg 已提交
1944 1945
		    REAPTIMEOUT_LIST3 +
		    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1946 1947 1948
	}
}

1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969
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);
}


1970
/**
1971 1972 1973 1974 1975 1976 1977
 * 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.
1978 1979 1980 1981 1982
 *
 * 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
1983
static size_t calculate_slab_order(struct kmem_cache *cachep,
R
Randy Dunlap 已提交
1984
			size_t size, size_t align, unsigned long flags)
1985
{
1986
	unsigned long offslab_limit;
1987
	size_t left_over = 0;
1988
	int gfporder;
1989

1990
	for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
1991 1992 1993
		unsigned int num;
		size_t remainder;

1994
		cache_estimate(gfporder, size, align, flags, &remainder, &num);
1995 1996
		if (!num)
			continue;
1997

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
		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;
		}
2010

2011
		/* Found something acceptable - save it away */
2012
		cachep->num = num;
2013
		cachep->gfporder = gfporder;
2014 2015
		left_over = remainder;

2016 2017 2018 2019 2020 2021 2022 2023
		/*
		 * 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;

2024 2025 2026 2027
		/*
		 * Large number of objects is good, but very large slabs are
		 * currently bad for the gfp()s.
		 */
2028
		if (gfporder >= slab_break_gfp_order)
2029 2030
			break;

2031 2032 2033
		/*
		 * Acceptable internal fragmentation?
		 */
A
Andrew Morton 已提交
2034
		if (left_over * 8 <= (PAGE_SIZE << gfporder))
2035 2036 2037 2038 2039
			break;
	}
	return left_over;
}

2040
static int __init_refok setup_cpu_cache(struct kmem_cache *cachep)
2041
{
2042 2043 2044
	if (g_cpucache_up == FULL)
		return enable_cpucache(cachep);

2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090
	if (g_cpucache_up == NONE) {
		/*
		 * Note: the first kmem_cache_create must create the cache
		 * that's used by kmalloc(24), otherwise the creation of
		 * further caches will BUG().
		 */
		cachep->array[smp_processor_id()] = &initarray_generic.cache;

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

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

	cpu_cache_get(cachep)->avail = 0;
	cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
	cpu_cache_get(cachep)->batchcount = 1;
	cpu_cache_get(cachep)->touched = 0;
	cachep->batchcount = 1;
	cachep->limit = BOOT_CPUCACHE_ENTRIES;
2091
	return 0;
2092 2093
}

L
Linus Torvalds 已提交
2094 2095 2096 2097 2098 2099 2100
/**
 * 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.
2101
 * @dtor: A destructor for the objects (not implemented anymore).
L
Linus Torvalds 已提交
2102 2103 2104 2105 2106 2107 2108
 *
 * Returns a ptr to the cache on success, NULL on failure.
 * Cannot be called within a int, but can be interrupted.
 * The @ctor is run when new pages are allocated by the cache
 * and the @dtor is run before the pages are handed back.
 *
 * @name must be valid until the cache is destroyed. This implies that
A
Andrew Morton 已提交
2109 2110
 * the module calling this has to destroy the cache before getting unloaded.
 *
L
Linus Torvalds 已提交
2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122
 * 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.
 */
2123
struct kmem_cache *
L
Linus Torvalds 已提交
2124
kmem_cache_create (const char *name, size_t size, size_t align,
A
Andrew Morton 已提交
2125 2126
	unsigned long flags,
	void (*ctor)(void*, struct kmem_cache *, unsigned long),
2127
	void (*dtor)(void*, struct kmem_cache *, unsigned long))
L
Linus Torvalds 已提交
2128 2129
{
	size_t left_over, slab_size, ralign;
2130
	struct kmem_cache *cachep = NULL, *pc;
L
Linus Torvalds 已提交
2131 2132 2133 2134

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
A
Andrew Morton 已提交
2135
	if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
2136
	    size > KMALLOC_MAX_SIZE || dtor) {
A
Andrew Morton 已提交
2137 2138
		printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
				name);
P
Pekka Enberg 已提交
2139 2140
		BUG();
	}
L
Linus Torvalds 已提交
2141

2142
	/*
2143 2144
	 * We use cache_chain_mutex to ensure a consistent view of
	 * cpu_online_map as well.  Please see cpuup_callback
2145
	 */
I
Ingo Molnar 已提交
2146
	mutex_lock(&cache_chain_mutex);
2147

2148
	list_for_each_entry(pc, &cache_chain, next) {
2149 2150 2151 2152 2153 2154 2155 2156
		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.
		 */
2157
		res = probe_kernel_address(pc->name, tmp);
2158
		if (res) {
2159 2160
			printk(KERN_ERR
			       "SLAB: cache with size %d has lost its name\n",
2161
			       pc->buffer_size);
2162 2163 2164
			continue;
		}

P
Pekka Enberg 已提交
2165
		if (!strcmp(pc->name, name)) {
2166 2167
			printk(KERN_ERR
			       "kmem_cache_create: duplicate cache %s\n", name);
2168 2169 2170 2171 2172
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
2173 2174 2175 2176 2177 2178 2179 2180 2181
#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
2182 2183
	if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
						2 * sizeof(unsigned long long)))
P
Pekka Enberg 已提交
2184
		flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
L
Linus Torvalds 已提交
2185 2186 2187 2188 2189 2190 2191
	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
2192 2193
	 * Always checks flags, a caller might be expecting debug support which
	 * isn't available.
L
Linus Torvalds 已提交
2194
	 */
2195
	BUG_ON(flags & ~CREATE_MASK);
L
Linus Torvalds 已提交
2196

A
Andrew Morton 已提交
2197 2198
	/*
	 * Check that size is in terms of words.  This is needed to avoid
L
Linus Torvalds 已提交
2199 2200 2201
	 * 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
2202 2203 2204
	if (size & (BYTES_PER_WORD - 1)) {
		size += (BYTES_PER_WORD - 1);
		size &= ~(BYTES_PER_WORD - 1);
L
Linus Torvalds 已提交
2205 2206
	}

A
Andrew Morton 已提交
2207 2208
	/* calculate the final buffer alignment: */

L
Linus Torvalds 已提交
2209 2210
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
A
Andrew Morton 已提交
2211 2212 2213 2214
		/*
		 * 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
2215 2216
		 */
		ralign = cache_line_size();
P
Pekka Enberg 已提交
2217
		while (size <= ralign / 2)
L
Linus Torvalds 已提交
2218 2219 2220 2221
			ralign /= 2;
	} else {
		ralign = BYTES_PER_WORD;
	}
2222 2223

	/*
D
David Woodhouse 已提交
2224 2225 2226
	 * 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.
2227
	 */
D
David Woodhouse 已提交
2228 2229 2230 2231 2232 2233 2234 2235 2236 2237
	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);
	}
2238

2239
	/* 2) arch mandated alignment */
L
Linus Torvalds 已提交
2240 2241 2242
	if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
	}
2243
	/* 3) caller mandated alignment */
L
Linus Torvalds 已提交
2244 2245 2246
	if (ralign < align) {
		ralign = align;
	}
2247
	/* disable debug if necessary */
2248
	if (ralign > __alignof__(unsigned long long))
2249
		flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
A
Andrew Morton 已提交
2250
	/*
2251
	 * 4) Store it.
L
Linus Torvalds 已提交
2252 2253 2254 2255
	 */
	align = ralign;

	/* Get cache's description obj. */
2256
	cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
L
Linus Torvalds 已提交
2257
	if (!cachep)
2258
		goto oops;
L
Linus Torvalds 已提交
2259 2260

#if DEBUG
2261
	cachep->obj_size = size;
L
Linus Torvalds 已提交
2262

2263 2264 2265 2266
	/*
	 * Both debugging options require word-alignment which is calculated
	 * into align above.
	 */
L
Linus Torvalds 已提交
2267 2268
	if (flags & SLAB_RED_ZONE) {
		/* add space for red zone words */
2269 2270
		cachep->obj_offset += sizeof(unsigned long long);
		size += 2 * sizeof(unsigned long long);
L
Linus Torvalds 已提交
2271 2272
	}
	if (flags & SLAB_STORE_USER) {
2273
		/* user store requires one word storage behind the end of
D
David Woodhouse 已提交
2274 2275
		 * 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
2276
		 */
D
David Woodhouse 已提交
2277 2278 2279 2280
		if (flags & SLAB_RED_ZONE)
			size += REDZONE_ALIGN;
		else
			size += BYTES_PER_WORD;
L
Linus Torvalds 已提交
2281 2282
	}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
P
Pekka Enberg 已提交
2283
	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2284 2285
	    && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
		cachep->obj_offset += PAGE_SIZE - size;
L
Linus Torvalds 已提交
2286 2287 2288 2289 2290
		size = PAGE_SIZE;
	}
#endif
#endif

2291 2292 2293 2294 2295 2296
	/*
	 * 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
2297 2298 2299 2300 2301 2302 2303 2304
		/*
		 * 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);

2305
	left_over = calculate_slab_order(cachep, size, align, flags);
L
Linus Torvalds 已提交
2306 2307

	if (!cachep->num) {
2308 2309
		printk(KERN_ERR
		       "kmem_cache_create: couldn't create cache %s.\n", name);
L
Linus Torvalds 已提交
2310 2311
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
2312
		goto oops;
L
Linus Torvalds 已提交
2313
	}
P
Pekka Enberg 已提交
2314 2315
	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
			  + sizeof(struct slab), align);
L
Linus Torvalds 已提交
2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327

	/*
	 * 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
2328 2329
		slab_size =
		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
L
Linus Torvalds 已提交
2330 2331 2332 2333 2334 2335
	}

	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
2336
	cachep->colour = left_over / cachep->colour_off;
L
Linus Torvalds 已提交
2337 2338 2339
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
2340
	if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
L
Linus Torvalds 已提交
2341
		cachep->gfpflags |= GFP_DMA;
2342
	cachep->buffer_size = size;
2343
	cachep->reciprocal_buffer_size = reciprocal_value(size);
L
Linus Torvalds 已提交
2344

2345
	if (flags & CFLGS_OFF_SLAB) {
2346
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
2347 2348 2349 2350 2351 2352 2353 2354 2355
		/*
		 * This is a possibility for one of the malloc_sizes caches.
		 * But since we go off slab only for object size greater than
		 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
		 * this should not happen at all.
		 * But leave a BUG_ON for some lucky dude.
		 */
		BUG_ON(!cachep->slabp_cache);
	}
L
Linus Torvalds 已提交
2356 2357 2358
	cachep->ctor = ctor;
	cachep->name = name;

2359 2360 2361 2362 2363
	if (setup_cpu_cache(cachep)) {
		__kmem_cache_destroy(cachep);
		cachep = NULL;
		goto oops;
	}
L
Linus Torvalds 已提交
2364 2365 2366

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
A
Andrew Morton 已提交
2367
oops:
L
Linus Torvalds 已提交
2368 2369
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
P
Pekka Enberg 已提交
2370
		      name);
I
Ingo Molnar 已提交
2371
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386
	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());
}

2387
static void check_spinlock_acquired(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2388 2389 2390
{
#ifdef CONFIG_SMP
	check_irq_off();
2391
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
2392 2393
#endif
}
2394

2395
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2396 2397 2398 2399 2400 2401 2402
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
2403 2404 2405 2406
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
2407
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
2408 2409
#endif

2410 2411 2412 2413
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
2414 2415
static void do_drain(void *arg)
{
A
Andrew Morton 已提交
2416
	struct kmem_cache *cachep = arg;
L
Linus Torvalds 已提交
2417
	struct array_cache *ac;
2418
	int node = numa_node_id();
L
Linus Torvalds 已提交
2419 2420

	check_irq_off();
2421
	ac = cpu_cache_get(cachep);
2422 2423 2424
	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
2425 2426 2427
	ac->avail = 0;
}

2428
static void drain_cpu_caches(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2429
{
2430 2431 2432
	struct kmem_list3 *l3;
	int node;

A
Andrew Morton 已提交
2433
	on_each_cpu(do_drain, cachep, 1, 1);
L
Linus Torvalds 已提交
2434
	check_irq_on();
P
Pekka Enberg 已提交
2435
	for_each_online_node(node) {
2436
		l3 = cachep->nodelists[node];
2437 2438 2439 2440 2441 2442 2443
		if (l3 && l3->alien)
			drain_alien_cache(cachep, l3->alien);
	}

	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (l3)
2444
			drain_array(cachep, l3, l3->shared, 1, node);
2445
	}
L
Linus Torvalds 已提交
2446 2447
}

2448 2449 2450 2451 2452 2453 2454 2455
/*
 * 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
2456
{
2457 2458
	struct list_head *p;
	int nr_freed;
L
Linus Torvalds 已提交
2459 2460
	struct slab *slabp;

2461 2462
	nr_freed = 0;
	while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
L
Linus Torvalds 已提交
2463

2464
		spin_lock_irq(&l3->list_lock);
2465
		p = l3->slabs_free.prev;
2466 2467 2468 2469
		if (p == &l3->slabs_free) {
			spin_unlock_irq(&l3->list_lock);
			goto out;
		}
L
Linus Torvalds 已提交
2470

2471
		slabp = list_entry(p, struct slab, list);
L
Linus Torvalds 已提交
2472
#if DEBUG
2473
		BUG_ON(slabp->inuse);
L
Linus Torvalds 已提交
2474 2475
#endif
		list_del(&slabp->list);
2476 2477 2478 2479 2480
		/*
		 * Safe to drop the lock. The slab is no longer linked
		 * to the cache.
		 */
		l3->free_objects -= cache->num;
2481
		spin_unlock_irq(&l3->list_lock);
2482 2483
		slab_destroy(cache, slabp);
		nr_freed++;
L
Linus Torvalds 已提交
2484
	}
2485 2486
out:
	return nr_freed;
L
Linus Torvalds 已提交
2487 2488
}

2489
/* Called with cache_chain_mutex held to protect against cpu hotplug */
2490
static int __cache_shrink(struct kmem_cache *cachep)
2491 2492 2493 2494 2495 2496 2497 2498 2499
{
	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];
2500 2501 2502 2503 2504 2505 2506
		if (!l3)
			continue;

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

		ret += !list_empty(&l3->slabs_full) ||
			!list_empty(&l3->slabs_partial);
2507 2508 2509 2510
	}
	return (ret ? 1 : 0);
}

L
Linus Torvalds 已提交
2511 2512 2513 2514 2515 2516 2517
/**
 * 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.
 */
2518
int kmem_cache_shrink(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2519
{
2520
	int ret;
2521
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2522

2523 2524 2525 2526
	mutex_lock(&cache_chain_mutex);
	ret = __cache_shrink(cachep);
	mutex_unlock(&cache_chain_mutex);
	return ret;
L
Linus Torvalds 已提交
2527 2528 2529 2530 2531 2532 2533
}
EXPORT_SYMBOL(kmem_cache_shrink);

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
2534
 * Remove a &struct kmem_cache object from the slab cache.
L
Linus Torvalds 已提交
2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545
 *
 * 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().
 */
2546
void kmem_cache_destroy(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2547
{
2548
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2549 2550

	/* Find the cache in the chain of caches. */
I
Ingo Molnar 已提交
2551
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2552 2553 2554 2555 2556 2557
	/*
	 * 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
2558
		list_add(&cachep->next, &cache_chain);
I
Ingo Molnar 已提交
2559
		mutex_unlock(&cache_chain_mutex);
2560
		return;
L
Linus Torvalds 已提交
2561 2562 2563
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2564
		synchronize_rcu();
L
Linus Torvalds 已提交
2565

2566
	__kmem_cache_destroy(cachep);
2567
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2568 2569 2570
}
EXPORT_SYMBOL(kmem_cache_destroy);

2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581
/*
 * 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.
 */
2582
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
2583 2584
				   int colour_off, gfp_t local_flags,
				   int nodeid)
L
Linus Torvalds 已提交
2585 2586
{
	struct slab *slabp;
P
Pekka Enberg 已提交
2587

L
Linus Torvalds 已提交
2588 2589
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
2590
		slabp = kmem_cache_alloc_node(cachep->slabp_cache,
2591
					      local_flags & ~GFP_THISNODE, nodeid);
L
Linus Torvalds 已提交
2592 2593 2594
		if (!slabp)
			return NULL;
	} else {
P
Pekka Enberg 已提交
2595
		slabp = objp + colour_off;
L
Linus Torvalds 已提交
2596 2597 2598 2599
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
P
Pekka Enberg 已提交
2600
	slabp->s_mem = objp + colour_off;
2601
	slabp->nodeid = nodeid;
L
Linus Torvalds 已提交
2602 2603 2604 2605 2606
	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
P
Pekka Enberg 已提交
2607
	return (kmem_bufctl_t *) (slabp + 1);
L
Linus Torvalds 已提交
2608 2609
}

2610
static void cache_init_objs(struct kmem_cache *cachep,
C
Christoph Lameter 已提交
2611
			    struct slab *slabp)
L
Linus Torvalds 已提交
2612 2613 2614 2615
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2616
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628
#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
2629 2630 2631
		 * 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
2632 2633
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2634
			cachep->ctor(objp + obj_offset(cachep), cachep,
C
Christoph Lameter 已提交
2635
				     0);
L
Linus Torvalds 已提交
2636 2637 2638 2639

		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
2640
					   " end of an object");
L
Linus Torvalds 已提交
2641 2642
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2643
					   " start of an object");
L
Linus Torvalds 已提交
2644
		}
A
Andrew Morton 已提交
2645 2646
		if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
			    OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
P
Pekka Enberg 已提交
2647
			kernel_map_pages(virt_to_page(objp),
2648
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2649 2650
#else
		if (cachep->ctor)
C
Christoph Lameter 已提交
2651
			cachep->ctor(objp, cachep, 0);
L
Linus Torvalds 已提交
2652
#endif
P
Pekka Enberg 已提交
2653
		slab_bufctl(slabp)[i] = i + 1;
L
Linus Torvalds 已提交
2654
	}
P
Pekka Enberg 已提交
2655
	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
L
Linus Torvalds 已提交
2656 2657 2658
	slabp->free = 0;
}

2659
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2660
{
2661 2662 2663 2664 2665 2666
	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
2667 2668
}

A
Andrew Morton 已提交
2669 2670
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
				int nodeid)
2671
{
2672
	void *objp = index_to_obj(cachep, slabp, slabp->free);
2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685
	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
2686 2687
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
				void *objp, int nodeid)
2688
{
2689
	unsigned int objnr = obj_to_index(cachep, slabp, objp);
2690 2691 2692 2693 2694

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

2695
	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
2696
		printk(KERN_ERR "slab: double free detected in cache "
A
Andrew Morton 已提交
2697
				"'%s', objp %p\n", cachep->name, objp);
2698 2699 2700 2701 2702 2703 2704 2705
		BUG();
	}
#endif
	slab_bufctl(slabp)[objnr] = slabp->free;
	slabp->free = objnr;
	slabp->inuse--;
}

2706 2707 2708 2709 2710 2711 2712
/*
 * 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
2713
{
2714
	int nr_pages;
L
Linus Torvalds 已提交
2715 2716
	struct page *page;

2717
	page = virt_to_page(addr);
2718

2719
	nr_pages = 1;
2720
	if (likely(!PageCompound(page)))
2721 2722
		nr_pages <<= cache->gfporder;

L
Linus Torvalds 已提交
2723
	do {
2724 2725
		page_set_cache(page, cache);
		page_set_slab(page, slab);
L
Linus Torvalds 已提交
2726
		page++;
2727
	} while (--nr_pages);
L
Linus Torvalds 已提交
2728 2729 2730 2731 2732 2733
}

/*
 * 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.
 */
2734 2735
static int cache_grow(struct kmem_cache *cachep,
		gfp_t flags, int nodeid, void *objp)
L
Linus Torvalds 已提交
2736
{
P
Pekka Enberg 已提交
2737 2738 2739
	struct slab *slabp;
	size_t offset;
	gfp_t local_flags;
2740
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2741

A
Andrew Morton 已提交
2742 2743 2744
	/*
	 * 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
2745
	 */
2746
	BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK));
L
Linus Torvalds 已提交
2747

2748
	local_flags = (flags & GFP_LEVEL_MASK);
2749
	/* Take the l3 list lock to change the colour_next on this node */
L
Linus Torvalds 已提交
2750
	check_irq_off();
2751 2752
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2753 2754

	/* Get colour for the slab, and cal the next value. */
2755 2756 2757 2758 2759
	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
2760

2761
	offset *= cachep->colour_off;
L
Linus Torvalds 已提交
2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773

	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
2774 2775 2776
	/*
	 * Get mem for the objs.  Attempt to allocate a physical page from
	 * 'nodeid'.
2777
	 */
2778 2779
	if (!objp)
		objp = kmem_getpages(cachep, flags, nodeid);
A
Andrew Morton 已提交
2780
	if (!objp)
L
Linus Torvalds 已提交
2781 2782 2783
		goto failed;

	/* Get slab management. */
2784 2785
	slabp = alloc_slabmgmt(cachep, objp, offset,
			local_flags & ~GFP_THISNODE, nodeid);
A
Andrew Morton 已提交
2786
	if (!slabp)
L
Linus Torvalds 已提交
2787 2788
		goto opps1;

2789
	slabp->nodeid = nodeid;
2790
	slab_map_pages(cachep, slabp, objp);
L
Linus Torvalds 已提交
2791

C
Christoph Lameter 已提交
2792
	cache_init_objs(cachep, slabp);
L
Linus Torvalds 已提交
2793 2794 2795 2796

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2797
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2798 2799

	/* Make slab active. */
2800
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2801
	STATS_INC_GROWN(cachep);
2802 2803
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2804
	return 1;
A
Andrew Morton 已提交
2805
opps1:
L
Linus Torvalds 已提交
2806
	kmem_freepages(cachep, objp);
A
Andrew Morton 已提交
2807
failed:
L
Linus Torvalds 已提交
2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823
	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
2824 2825
		       (unsigned long)objp);
		BUG();
L
Linus Torvalds 已提交
2826 2827 2828
	}
}

2829 2830
static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
{
2831
	unsigned long long redzone1, redzone2;
2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846

	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");

2847
	printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
2848 2849 2850
			obj, redzone1, redzone2);
}

2851
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2852
				   void *caller)
L
Linus Torvalds 已提交
2853 2854 2855 2856 2857
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

2858
	objp -= obj_offset(cachep);
L
Linus Torvalds 已提交
2859
	kfree_debugcheck(objp);
2860
	page = virt_to_head_page(objp);
L
Linus Torvalds 已提交
2861

2862
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2863 2864

	if (cachep->flags & SLAB_RED_ZONE) {
2865
		verify_redzone_free(cachep, objp);
L
Linus Torvalds 已提交
2866 2867 2868 2869 2870 2871
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

2872
	objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
2873 2874

	BUG_ON(objnr >= cachep->num);
2875
	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
L
Linus Torvalds 已提交
2876

2877 2878 2879
#ifdef CONFIG_DEBUG_SLAB_LEAK
	slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
#endif
L
Linus Torvalds 已提交
2880 2881
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
2882
		if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
L
Linus Torvalds 已提交
2883
			store_stackinfo(cachep, objp, (unsigned long)caller);
P
Pekka Enberg 已提交
2884
			kernel_map_pages(virt_to_page(objp),
2885
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2886 2887 2888 2889 2890 2891 2892 2893 2894 2895
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

2896
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
2897 2898 2899
{
	kmem_bufctl_t i;
	int entries = 0;
P
Pekka Enberg 已提交
2900

L
Linus Torvalds 已提交
2901 2902 2903 2904 2905 2906 2907
	/* 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
2908 2909 2910 2911
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
2912
		for (i = 0;
2913
		     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
P
Pekka Enberg 已提交
2914
		     i++) {
A
Andrew Morton 已提交
2915
			if (i % 16 == 0)
L
Linus Torvalds 已提交
2916
				printk("\n%03x:", i);
P
Pekka Enberg 已提交
2917
			printk(" %02x", ((unsigned char *)slabp)[i]);
L
Linus Torvalds 已提交
2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928
		}
		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

2929
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2930 2931 2932 2933
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;
P
Pekka Enberg 已提交
2934 2935 2936
	int node;

	node = numa_node_id();
L
Linus Torvalds 已提交
2937 2938

	check_irq_off();
2939
	ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2940
retry:
L
Linus Torvalds 已提交
2941 2942
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
A
Andrew Morton 已提交
2943 2944 2945 2946
		/*
		 * 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
2947 2948 2949
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
P
Pekka Enberg 已提交
2950
	l3 = cachep->nodelists[node];
2951 2952 2953

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2954

2955 2956 2957 2958
	/* 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
2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973
	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);
2974 2975 2976 2977 2978 2979 2980 2981

		/*
		 * 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
2982 2983 2984 2985 2986
		while (slabp->inuse < cachep->num && batchcount--) {
			STATS_INC_ALLOCED(cachep);
			STATS_INC_ACTIVE(cachep);
			STATS_SET_HIGH(cachep);

2987
			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
P
Pekka Enberg 已提交
2988
							    node);
L
Linus Torvalds 已提交
2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999
		}
		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
3000
must_grow:
L
Linus Torvalds 已提交
3001
	l3->free_objects -= ac->avail;
A
Andrew Morton 已提交
3002
alloc_done:
3003
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3004 3005 3006

	if (unlikely(!ac->avail)) {
		int x;
3007
		x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
3008

A
Andrew Morton 已提交
3009
		/* cache_grow can reenable interrupts, then ac could change. */
3010
		ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
3011
		if (!x && ac->avail == 0)	/* no objects in sight? abort */
L
Linus Torvalds 已提交
3012 3013
			return NULL;

A
Andrew Morton 已提交
3014
		if (!ac->avail)		/* objects refilled by interrupt? */
L
Linus Torvalds 已提交
3015 3016 3017
			goto retry;
	}
	ac->touched = 1;
3018
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3019 3020
}

A
Andrew Morton 已提交
3021 3022
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
						gfp_t flags)
L
Linus Torvalds 已提交
3023 3024 3025 3026 3027 3028 3029 3030
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
A
Andrew Morton 已提交
3031 3032
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
				gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
3033
{
P
Pekka Enberg 已提交
3034
	if (!objp)
L
Linus Torvalds 已提交
3035
		return objp;
P
Pekka Enberg 已提交
3036
	if (cachep->flags & SLAB_POISON) {
L
Linus Torvalds 已提交
3037
#ifdef CONFIG_DEBUG_PAGEALLOC
3038
		if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
P
Pekka Enberg 已提交
3039
			kernel_map_pages(virt_to_page(objp),
3040
					 cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051
		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
3052 3053 3054 3055
		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
3056
			printk(KERN_ERR
3057
				"%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
A
Andrew Morton 已提交
3058 3059
				objp, *dbg_redzone1(cachep, objp),
				*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
3060 3061 3062 3063
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
3064 3065 3066 3067 3068
#ifdef CONFIG_DEBUG_SLAB_LEAK
	{
		struct slab *slabp;
		unsigned objnr;

3069
		slabp = page_get_slab(virt_to_head_page(objp));
3070 3071 3072 3073
		objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
	}
#endif
3074
	objp += obj_offset(cachep);
3075
	if (cachep->ctor && cachep->flags & SLAB_POISON)
C
Christoph Lameter 已提交
3076
		cachep->ctor(objp, cachep, 0);
3077 3078 3079 3080 3081 3082
#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
3083 3084 3085 3086 3087 3088
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101
#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,
3102
	.ignore_gfp_wait = 1,
3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130
};

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;

3131
	err = init_fault_attr_dentries(&failslab.attr, "failslab");
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 3159 3160 3161
	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 */

3162
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3163
{
P
Pekka Enberg 已提交
3164
	void *objp;
L
Linus Torvalds 已提交
3165 3166
	struct array_cache *ac;

3167
	check_irq_off();
3168

3169
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3170 3171 3172
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
3173
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3174 3175 3176 3177
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
3178 3179 3180
	return objp;
}

3181
#ifdef CONFIG_NUMA
3182
/*
3183
 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
3184 3185 3186 3187 3188 3189 3190 3191
 *
 * 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;

3192
	if (in_interrupt() || (flags & __GFP_THISNODE))
3193 3194 3195 3196 3197 3198 3199
		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)
3200
		return ____cache_alloc_node(cachep, flags, nid_alloc);
3201 3202 3203
	return NULL;
}

3204 3205
/*
 * Fallback function if there was no memory available and no objects on a
3206 3207 3208 3209 3210
 * 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.
3211
 */
3212
static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
3213
{
3214 3215
	struct zonelist *zonelist;
	gfp_t local_flags;
3216 3217
	struct zone **z;
	void *obj = NULL;
3218
	int nid;
3219 3220 3221 3222 3223 3224 3225

	if (flags & __GFP_THISNODE)
		return NULL;

	zonelist = &NODE_DATA(slab_node(current->mempolicy))
			->node_zonelists[gfp_zone(flags)];
	local_flags = (flags & GFP_LEVEL_MASK);
3226

3227 3228 3229 3230 3231
retry:
	/*
	 * Look through allowed nodes for objects available
	 * from existing per node queues.
	 */
3232
	for (z = zonelist->zones; *z && !obj; z++) {
3233
		nid = zone_to_nid(*z);
3234

3235
		if (cpuset_zone_allowed_hardwall(*z, flags) &&
3236 3237 3238 3239 3240 3241
			cache->nodelists[nid] &&
			cache->nodelists[nid]->free_objects)
				obj = ____cache_alloc_node(cache,
					flags | GFP_THISNODE, nid);
	}

3242
	if (!obj) {
3243 3244 3245 3246 3247 3248
		/*
		 * 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.
		 */
3249 3250 3251
		if (local_flags & __GFP_WAIT)
			local_irq_enable();
		kmem_flagcheck(cache, flags);
3252
		obj = kmem_getpages(cache, flags, -1);
3253 3254
		if (local_flags & __GFP_WAIT)
			local_irq_disable();
3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270
		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 {
3271
				/* cache_grow already freed obj */
3272 3273 3274
				obj = NULL;
			}
		}
3275
	}
3276 3277 3278
	return obj;
}

3279 3280
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
3281
 */
3282
static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
A
Andrew Morton 已提交
3283
				int nodeid)
3284 3285
{
	struct list_head *entry;
P
Pekka Enberg 已提交
3286 3287 3288 3289 3290 3291 3292 3293
	struct slab *slabp;
	struct kmem_list3 *l3;
	void *obj;
	int x;

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

A
Andrew Morton 已提交
3294
retry:
3295
	check_irq_off();
P
Pekka Enberg 已提交
3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314
	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);

3315
	obj = slab_get_obj(cachep, slabp, nodeid);
P
Pekka Enberg 已提交
3316 3317 3318 3319 3320
	check_slabp(cachep, slabp);
	l3->free_objects--;
	/* move slabp to correct slabp list: */
	list_del(&slabp->list);

A
Andrew Morton 已提交
3321
	if (slabp->free == BUFCTL_END)
P
Pekka Enberg 已提交
3322
		list_add(&slabp->list, &l3->slabs_full);
A
Andrew Morton 已提交
3323
	else
P
Pekka Enberg 已提交
3324
		list_add(&slabp->list, &l3->slabs_partial);
3325

P
Pekka Enberg 已提交
3326 3327
	spin_unlock(&l3->list_lock);
	goto done;
3328

A
Andrew Morton 已提交
3329
must_grow:
P
Pekka Enberg 已提交
3330
	spin_unlock(&l3->list_lock);
3331
	x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
3332 3333
	if (x)
		goto retry;
L
Linus Torvalds 已提交
3334

3335
	return fallback_alloc(cachep, flags);
3336

A
Andrew Morton 已提交
3337
done:
P
Pekka Enberg 已提交
3338
	return obj;
3339
}
3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359

/**
 * 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;

3360 3361 3362
	if (should_failslab(cachep, flags))
		return NULL;

3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);

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

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

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

	return ptr;
}

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

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

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

  out:
	return objp;
}
#else

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

#endif /* CONFIG_NUMA */

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

3433 3434 3435
	if (should_failslab(cachep, flags))
		return NULL;

3436 3437 3438 3439 3440 3441 3442 3443 3444
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
	objp = __do_cache_alloc(cachep, flags);
	local_irq_restore(save_flags);
	objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
	prefetchw(objp);

	return objp;
}
3445 3446 3447 3448

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
3449
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
P
Pekka Enberg 已提交
3450
		       int node)
L
Linus Torvalds 已提交
3451 3452
{
	int i;
3453
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3454 3455 3456 3457 3458

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

3459
		slabp = virt_to_slab(objp);
3460
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
3461
		list_del(&slabp->list);
3462
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
3463
		check_slabp(cachep, slabp);
3464
		slab_put_obj(cachep, slabp, objp, node);
L
Linus Torvalds 已提交
3465
		STATS_DEC_ACTIVE(cachep);
3466
		l3->free_objects++;
L
Linus Torvalds 已提交
3467 3468 3469 3470
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
3471 3472
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
3473 3474 3475 3476 3477 3478
				/* 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
3479 3480
				slab_destroy(cachep, slabp);
			} else {
3481
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
3482 3483 3484 3485 3486 3487
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
3488
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
3489 3490 3491 3492
		}
	}
}

3493
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
L
Linus Torvalds 已提交
3494 3495
{
	int batchcount;
3496
	struct kmem_list3 *l3;
3497
	int node = numa_node_id();
L
Linus Torvalds 已提交
3498 3499 3500 3501 3502 3503

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
3504
	l3 = cachep->nodelists[node];
3505
	spin_lock(&l3->list_lock);
3506 3507
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
P
Pekka Enberg 已提交
3508
		int max = shared_array->limit - shared_array->avail;
L
Linus Torvalds 已提交
3509 3510 3511
		if (max) {
			if (batchcount > max)
				batchcount = max;
3512
			memcpy(&(shared_array->entry[shared_array->avail]),
P
Pekka Enberg 已提交
3513
			       ac->entry, sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
3514 3515 3516 3517 3518
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

3519
	free_block(cachep, ac->entry, batchcount, node);
A
Andrew Morton 已提交
3520
free_done:
L
Linus Torvalds 已提交
3521 3522 3523 3524 3525
#if STATS
	{
		int i = 0;
		struct list_head *p;

3526 3527
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538
			struct slab *slabp;

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

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
3539
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3540
	ac->avail -= batchcount;
A
Andrew Morton 已提交
3541
	memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
L
Linus Torvalds 已提交
3542 3543 3544
}

/*
A
Andrew Morton 已提交
3545 3546
 * 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
3547
 */
3548
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3549
{
3550
	struct array_cache *ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3551 3552 3553 3554

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

3555
	if (cache_free_alien(cachep, objp))
3556 3557
		return;

L
Linus Torvalds 已提交
3558 3559
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
3560
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3561 3562 3563 3564
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
3565
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576
	}
}

/**
 * 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.
 */
3577
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3578
{
3579
	return __cache_alloc(cachep, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3580 3581 3582
}
EXPORT_SYMBOL(kmem_cache_alloc);

3583
/**
3584
 * kmem_cache_zalloc - Allocate an object. The memory is set to zero.
3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599
 * @cache: The cache to allocate from.
 * @flags: See kmalloc().
 *
 * Allocate an object from this cache and set the allocated memory to zero.
 * The flags are only relevant if the cache has no available objects.
 */
void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags)
{
	void *ret = __cache_alloc(cache, flags, __builtin_return_address(0));
	if (ret)
		memset(ret, 0, obj_size(cache));
	return ret;
}
EXPORT_SYMBOL(kmem_cache_zalloc);

L
Linus Torvalds 已提交
3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613
/**
 * 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.
 */
3614
int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
L
Linus Torvalds 已提交
3615
{
P
Pekka Enberg 已提交
3616
	unsigned long addr = (unsigned long)ptr;
L
Linus Torvalds 已提交
3617
	unsigned long min_addr = PAGE_OFFSET;
P
Pekka Enberg 已提交
3618
	unsigned long align_mask = BYTES_PER_WORD - 1;
3619
	unsigned long size = cachep->buffer_size;
L
Linus Torvalds 已提交
3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634
	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;
3635
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
3636 3637
		goto out;
	return 1;
A
Andrew Morton 已提交
3638
out:
L
Linus Torvalds 已提交
3639 3640 3641 3642
	return 0;
}

#ifdef CONFIG_NUMA
3643 3644 3645 3646 3647
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
3648 3649
EXPORT_SYMBOL(kmem_cache_alloc_node);

3650 3651
static __always_inline void *
__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
3652
{
3653
	struct kmem_cache *cachep;
3654 3655 3656 3657 3658 3659

	cachep = kmem_find_general_cachep(size, flags);
	if (unlikely(cachep == NULL))
		return NULL;
	return kmem_cache_alloc_node(cachep, flags, node);
}
3660 3661 3662 3663 3664 3665 3666

#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));
}
3667
EXPORT_SYMBOL(__kmalloc_node);
3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682

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
3683 3684

/**
3685
 * __do_kmalloc - allocate memory
L
Linus Torvalds 已提交
3686
 * @size: how many bytes of memory are required.
3687
 * @flags: the type of memory to allocate (see kmalloc).
3688
 * @caller: function caller for debug tracking of the caller
L
Linus Torvalds 已提交
3689
 */
3690 3691
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
					  void *caller)
L
Linus Torvalds 已提交
3692
{
3693
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3694

3695 3696 3697 3698 3699 3700
	/* 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);
3701 3702
	if (unlikely(cachep == NULL))
		return NULL;
3703 3704 3705 3706
	return __cache_alloc(cachep, flags, caller);
}


3707
#ifdef CONFIG_DEBUG_SLAB
3708 3709
void *__kmalloc(size_t size, gfp_t flags)
{
3710
	return __do_kmalloc(size, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3711 3712 3713
}
EXPORT_SYMBOL(__kmalloc);

3714 3715 3716 3717 3718
void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
{
	return __do_kmalloc(size, flags, caller);
}
EXPORT_SYMBOL(__kmalloc_track_caller);
3719 3720 3721 3722 3723 3724 3725

#else
void *__kmalloc(size_t size, gfp_t flags)
{
	return __do_kmalloc(size, flags, NULL);
}
EXPORT_SYMBOL(__kmalloc);
3726 3727
#endif

L
Linus Torvalds 已提交
3728 3729 3730 3731 3732 3733 3734 3735
/**
 * 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.
 */
3736
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3737 3738 3739
{
	unsigned long flags;

3740 3741
	BUG_ON(virt_to_cache(objp) != cachep);

L
Linus Torvalds 已提交
3742
	local_irq_save(flags);
3743
	debug_check_no_locks_freed(objp, obj_size(cachep));
3744
	__cache_free(cachep, objp);
L
Linus Torvalds 已提交
3745 3746 3747 3748 3749 3750 3751 3752
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kmem_cache_free);

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3753 3754
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3755 3756 3757 3758 3759
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
3760
	struct kmem_cache *c;
L
Linus Torvalds 已提交
3761 3762 3763 3764 3765 3766
	unsigned long flags;

	if (unlikely(!objp))
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3767
	c = virt_to_cache(objp);
3768
	debug_check_no_locks_freed(objp, obj_size(c));
3769
	__cache_free(c, (void *)objp);
L
Linus Torvalds 已提交
3770 3771 3772 3773
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

3774
unsigned int kmem_cache_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3775
{
3776
	return obj_size(cachep);
L
Linus Torvalds 已提交
3777 3778 3779
}
EXPORT_SYMBOL(kmem_cache_size);

3780
const char *kmem_cache_name(struct kmem_cache *cachep)
3781 3782 3783 3784 3785
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3786
/*
3787
 * This initializes kmem_list3 or resizes varioius caches for all nodes.
3788
 */
3789
static int alloc_kmemlist(struct kmem_cache *cachep)
3790 3791 3792
{
	int node;
	struct kmem_list3 *l3;
3793
	struct array_cache *new_shared;
3794
	struct array_cache **new_alien = NULL;
3795 3796

	for_each_online_node(node) {
3797

3798 3799 3800 3801 3802
                if (use_alien_caches) {
                        new_alien = alloc_alien_cache(node, cachep->limit);
                        if (!new_alien)
                                goto fail;
                }
3803

3804 3805 3806
		new_shared = NULL;
		if (cachep->shared) {
			new_shared = alloc_arraycache(node,
3807
				cachep->shared*cachep->batchcount,
A
Andrew Morton 已提交
3808
					0xbaadf00d);
3809 3810 3811 3812
			if (!new_shared) {
				free_alien_cache(new_alien);
				goto fail;
			}
3813
		}
3814

A
Andrew Morton 已提交
3815 3816
		l3 = cachep->nodelists[node];
		if (l3) {
3817 3818
			struct array_cache *shared = l3->shared;

3819 3820
			spin_lock_irq(&l3->list_lock);

3821
			if (shared)
3822 3823
				free_block(cachep, shared->entry,
						shared->avail, node);
3824

3825 3826
			l3->shared = new_shared;
			if (!l3->alien) {
3827 3828 3829
				l3->alien = new_alien;
				new_alien = NULL;
			}
P
Pekka Enberg 已提交
3830
			l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3831
					cachep->batchcount + cachep->num;
3832
			spin_unlock_irq(&l3->list_lock);
3833
			kfree(shared);
3834 3835 3836
			free_alien_cache(new_alien);
			continue;
		}
A
Andrew Morton 已提交
3837
		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
3838 3839 3840
		if (!l3) {
			free_alien_cache(new_alien);
			kfree(new_shared);
3841
			goto fail;
3842
		}
3843 3844 3845

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
A
Andrew Morton 已提交
3846
				((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3847
		l3->shared = new_shared;
3848
		l3->alien = new_alien;
P
Pekka Enberg 已提交
3849
		l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3850
					cachep->batchcount + cachep->num;
3851 3852
		cachep->nodelists[node] = l3;
	}
3853
	return 0;
3854

A
Andrew Morton 已提交
3855
fail:
3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870
	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--;
		}
	}
3871
	return -ENOMEM;
3872 3873
}

L
Linus Torvalds 已提交
3874
struct ccupdate_struct {
3875
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3876 3877 3878 3879 3880
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
A
Andrew Morton 已提交
3881
	struct ccupdate_struct *new = info;
L
Linus Torvalds 已提交
3882 3883 3884
	struct array_cache *old;

	check_irq_off();
3885
	old = cpu_cache_get(new->cachep);
3886

L
Linus Torvalds 已提交
3887 3888 3889 3890
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}

3891
/* Always called with the cache_chain_mutex held */
A
Andrew Morton 已提交
3892 3893
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
				int batchcount, int shared)
L
Linus Torvalds 已提交
3894
{
3895
	struct ccupdate_struct *new;
3896
	int i;
L
Linus Torvalds 已提交
3897

3898 3899 3900 3901
	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		return -ENOMEM;

3902
	for_each_online_cpu(i) {
3903
		new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
A
Andrew Morton 已提交
3904
						batchcount);
3905
		if (!new->new[i]) {
P
Pekka Enberg 已提交
3906
			for (i--; i >= 0; i--)
3907 3908
				kfree(new->new[i]);
			kfree(new);
3909
			return -ENOMEM;
L
Linus Torvalds 已提交
3910 3911
		}
	}
3912
	new->cachep = cachep;
L
Linus Torvalds 已提交
3913

3914
	on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
3915

L
Linus Torvalds 已提交
3916 3917 3918
	check_irq_on();
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3919
	cachep->shared = shared;
L
Linus Torvalds 已提交
3920

3921
	for_each_online_cpu(i) {
3922
		struct array_cache *ccold = new->new[i];
L
Linus Torvalds 已提交
3923 3924
		if (!ccold)
			continue;
3925
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3926
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3927
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3928 3929
		kfree(ccold);
	}
3930
	kfree(new);
3931
	return alloc_kmemlist(cachep);
L
Linus Torvalds 已提交
3932 3933
}

3934
/* Called with cache_chain_mutex held always */
3935
static int enable_cpucache(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3936 3937 3938 3939
{
	int err;
	int limit, shared;

A
Andrew Morton 已提交
3940 3941
	/*
	 * The head array serves three purposes:
L
Linus Torvalds 已提交
3942 3943
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
A
Andrew Morton 已提交
3944
	 * - reduce the number of linked list operations on the slab and
L
Linus Torvalds 已提交
3945 3946 3947 3948
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
3949
	if (cachep->buffer_size > 131072)
L
Linus Torvalds 已提交
3950
		limit = 1;
3951
	else if (cachep->buffer_size > PAGE_SIZE)
L
Linus Torvalds 已提交
3952
		limit = 8;
3953
	else if (cachep->buffer_size > 1024)
L
Linus Torvalds 已提交
3954
		limit = 24;
3955
	else if (cachep->buffer_size > 256)
L
Linus Torvalds 已提交
3956 3957 3958 3959
		limit = 54;
	else
		limit = 120;

A
Andrew Morton 已提交
3960 3961
	/*
	 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
L
Linus Torvalds 已提交
3962 3963 3964 3965 3966 3967 3968 3969
	 * 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;
3970
	if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1)
L
Linus Torvalds 已提交
3971 3972 3973
		shared = 8;

#if DEBUG
A
Andrew Morton 已提交
3974 3975 3976
	/*
	 * With debugging enabled, large batchcount lead to excessively long
	 * periods with disabled local interrupts. Limit the batchcount
L
Linus Torvalds 已提交
3977 3978 3979 3980
	 */
	if (limit > 32)
		limit = 32;
#endif
P
Pekka Enberg 已提交
3981
	err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
L
Linus Torvalds 已提交
3982 3983
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
P
Pekka Enberg 已提交
3984
		       cachep->name, -err);
3985
	return err;
L
Linus Torvalds 已提交
3986 3987
}

3988 3989
/*
 * Drain an array if it contains any elements taking the l3 lock only if
3990 3991
 * necessary. Note that the l3 listlock also protects the array_cache
 * if drain_array() is used on the shared array.
3992 3993 3994
 */
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
3995 3996 3997
{
	int tofree;

3998 3999
	if (!ac || !ac->avail)
		return;
L
Linus Torvalds 已提交
4000 4001
	if (ac->touched && !force) {
		ac->touched = 0;
4002
	} else {
4003
		spin_lock_irq(&l3->list_lock);
4004 4005 4006 4007 4008 4009 4010 4011 4012
		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);
		}
4013
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4014 4015 4016 4017 4018
	}
}

/**
 * cache_reap - Reclaim memory from caches.
4019
 * @w: work descriptor
L
Linus Torvalds 已提交
4020 4021 4022 4023 4024 4025
 *
 * 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
4026 4027
 * 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
4028
 */
4029
static void cache_reap(struct work_struct *w)
L
Linus Torvalds 已提交
4030
{
4031
	struct kmem_cache *searchp;
4032
	struct kmem_list3 *l3;
4033
	int node = numa_node_id();
4034 4035
	struct delayed_work *work =
		container_of(w, struct delayed_work, work);
L
Linus Torvalds 已提交
4036

4037
	if (!mutex_trylock(&cache_chain_mutex))
L
Linus Torvalds 已提交
4038
		/* Give up. Setup the next iteration. */
4039
		goto out;
L
Linus Torvalds 已提交
4040

4041
	list_for_each_entry(searchp, &cache_chain, next) {
L
Linus Torvalds 已提交
4042 4043
		check_irq_on();

4044 4045 4046 4047 4048
		/*
		 * 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.
		 */
4049
		l3 = searchp->nodelists[node];
4050

4051
		reap_alien(searchp, l3);
L
Linus Torvalds 已提交
4052

4053
		drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
L
Linus Torvalds 已提交
4054

4055 4056 4057 4058
		/*
		 * These are racy checks but it does not matter
		 * if we skip one check or scan twice.
		 */
4059
		if (time_after(l3->next_reap, jiffies))
4060
			goto next;
L
Linus Torvalds 已提交
4061

4062
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
4063

4064
		drain_array(searchp, l3, l3->shared, 0, node);
L
Linus Torvalds 已提交
4065

4066
		if (l3->free_touched)
4067
			l3->free_touched = 0;
4068 4069
		else {
			int freed;
L
Linus Torvalds 已提交
4070

4071 4072 4073 4074
			freed = drain_freelist(searchp, l3, (l3->free_limit +
				5 * searchp->num - 1) / (5 * searchp->num));
			STATS_ADD_REAPED(searchp, freed);
		}
4075
next:
L
Linus Torvalds 已提交
4076 4077 4078
		cond_resched();
	}
	check_irq_on();
I
Ingo Molnar 已提交
4079
	mutex_unlock(&cache_chain_mutex);
4080
	next_reap_node();
4081
out:
A
Andrew Morton 已提交
4082
	/* Set up the next iteration */
4083
	schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
L
Linus Torvalds 已提交
4084 4085 4086 4087
}

#ifdef CONFIG_PROC_FS

4088
static void print_slabinfo_header(struct seq_file *m)
L
Linus Torvalds 已提交
4089
{
4090 4091 4092 4093
	/*
	 * Output format version, so at least we can change it
	 * without _too_ many complaints.
	 */
L
Linus Torvalds 已提交
4094
#if STATS
4095
	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
L
Linus Torvalds 已提交
4096
#else
4097
	seq_puts(m, "slabinfo - version: 2.1\n");
L
Linus Torvalds 已提交
4098
#endif
4099 4100 4101 4102
	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
4103
#if STATS
4104
	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
4105
		 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
4106
	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
L
Linus Torvalds 已提交
4107
#endif
4108 4109 4110 4111 4112 4113 4114
	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
4115
	mutex_lock(&cache_chain_mutex);
4116 4117
	if (!n)
		print_slabinfo_header(m);
4118 4119

	return seq_list_start(&cache_chain, *pos);
L
Linus Torvalds 已提交
4120 4121 4122 4123
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
4124
	return seq_list_next(p, &cache_chain, pos);
L
Linus Torvalds 已提交
4125 4126 4127 4128
}

static void s_stop(struct seq_file *m, void *p)
{
I
Ingo Molnar 已提交
4129
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4130 4131 4132 4133
}

static int s_show(struct seq_file *m, void *p)
{
4134
	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
P
Pekka Enberg 已提交
4135 4136 4137 4138 4139
	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;
4140
	const char *name;
L
Linus Torvalds 已提交
4141
	char *error = NULL;
4142 4143
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
4144 4145 4146

	active_objs = 0;
	num_slabs = 0;
4147 4148 4149 4150 4151
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

4152 4153
		check_irq_on();
		spin_lock_irq(&l3->list_lock);
4154

4155
		list_for_each_entry(slabp, &l3->slabs_full, list) {
4156 4157 4158 4159 4160
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
4161
		list_for_each_entry(slabp, &l3->slabs_partial, list) {
4162 4163 4164 4165 4166 4167 4168
			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++;
		}
4169
		list_for_each_entry(slabp, &l3->slabs_free, list) {
4170 4171 4172 4173 4174
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
4175 4176
		if (l3->shared)
			shared_avail += l3->shared->avail;
4177

4178
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4179
	}
P
Pekka Enberg 已提交
4180 4181
	num_slabs += active_slabs;
	num_objs = num_slabs * cachep->num;
4182
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
4183 4184
		error = "free_objects accounting error";

P
Pekka Enberg 已提交
4185
	name = cachep->name;
L
Linus Torvalds 已提交
4186 4187 4188 4189
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
4190
		   name, active_objs, num_objs, cachep->buffer_size,
P
Pekka Enberg 已提交
4191
		   cachep->num, (1 << cachep->gfporder));
L
Linus Torvalds 已提交
4192
	seq_printf(m, " : tunables %4u %4u %4u",
P
Pekka Enberg 已提交
4193
		   cachep->limit, cachep->batchcount, cachep->shared);
4194
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
P
Pekka Enberg 已提交
4195
		   active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
4196
#if STATS
P
Pekka Enberg 已提交
4197
	{			/* list3 stats */
L
Linus Torvalds 已提交
4198 4199 4200 4201 4202 4203 4204
		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;
4205
		unsigned long node_frees = cachep->node_frees;
4206
		unsigned long overflows = cachep->node_overflow;
L
Linus Torvalds 已提交
4207

4208
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
4209
				%4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
A
Andrew Morton 已提交
4210
				reaped, errors, max_freeable, node_allocs,
4211
				node_frees, overflows);
L
Linus Torvalds 已提交
4212 4213 4214 4215 4216 4217 4218 4219 4220
	}
	/* 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
4221
			   allochit, allocmiss, freehit, freemiss);
L
Linus Torvalds 已提交
4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241
	}
#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
 */

4242
const struct seq_operations slabinfo_op = {
P
Pekka Enberg 已提交
4243 4244 4245 4246
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
L
Linus Torvalds 已提交
4247 4248 4249 4250 4251 4252 4253 4254 4255 4256
};

#define MAX_SLABINFO_WRITE 128
/**
 * slabinfo_write - Tuning for the slab allocator
 * @file: unused
 * @buffer: user buffer
 * @count: data length
 * @ppos: unused
 */
P
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4257 4258
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
		       size_t count, loff_t *ppos)
L
Linus Torvalds 已提交
4259
{
P
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4260
	char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
L
Linus Torvalds 已提交
4261
	int limit, batchcount, shared, res;
4262
	struct kmem_cache *cachep;
P
Pekka Enberg 已提交
4263

L
Linus Torvalds 已提交
4264 4265 4266 4267
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
P
Pekka Enberg 已提交
4268
	kbuf[MAX_SLABINFO_WRITE] = '\0';
L
Linus Torvalds 已提交
4269 4270 4271 4272 4273 4274 4275 4276 4277 4278

	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
4279
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4280
	res = -EINVAL;
4281
	list_for_each_entry(cachep, &cache_chain, next) {
L
Linus Torvalds 已提交
4282
		if (!strcmp(cachep->name, kbuf)) {
A
Andrew Morton 已提交
4283 4284
			if (limit < 1 || batchcount < 1 ||
					batchcount > limit || shared < 0) {
4285
				res = 0;
L
Linus Torvalds 已提交
4286
			} else {
4287
				res = do_tune_cpucache(cachep, limit,
P
Pekka Enberg 已提交
4288
						       batchcount, shared);
L
Linus Torvalds 已提交
4289 4290 4291 4292
			}
			break;
		}
	}
I
Ingo Molnar 已提交
4293
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4294 4295 4296 4297
	if (res >= 0)
		res = count;
	return res;
}
4298 4299 4300 4301 4302 4303

#ifdef CONFIG_DEBUG_SLAB_LEAK

static void *leaks_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&cache_chain_mutex);
4304
	return seq_list_start(&cache_chain, *pos);
4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 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
}

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;
4355
	char modname[MODULE_NAME_LEN + 1], name[KSYM_NAME_LEN + 1];
4356

4357
	if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) {
4358
		seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
4359
		if (modname[0])
4360 4361 4362 4363 4364 4365 4366 4367 4368
			seq_printf(m, " [%s]", modname);
		return;
	}
#endif
	seq_printf(m, "%p", (void *)address);
}

static int leaks_show(struct seq_file *m, void *p)
{
4369
	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393
	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);

4394
		list_for_each_entry(slabp, &l3->slabs_full, list)
4395
			handle_slab(n, cachep, slabp);
4396
		list_for_each_entry(slabp, &l3->slabs_partial, list)
4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422
			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');
	}
4423

4424 4425 4426
	return 0;
}

4427
const struct seq_operations slabstats_op = {
4428 4429 4430 4431 4432 4433
	.start = leaks_start,
	.next = s_next,
	.stop = s_stop,
	.show = leaks_show,
};
#endif
L
Linus Torvalds 已提交
4434 4435
#endif

4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447
/**
 * 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
4448
size_t ksize(const void *objp)
L
Linus Torvalds 已提交
4449
{
4450 4451
	if (unlikely(objp == NULL))
		return 0;
L
Linus Torvalds 已提交
4452

4453
	return obj_size(virt_to_cache(objp));
L
Linus Torvalds 已提交
4454
}