slab.c 101.0 KB
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/*
 * linux/mm/slab.c
 * Written by Mark Hemment, 1996/97.
 * (markhe@nextd.demon.co.uk)
 *
 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
 *
 * Major cleanup, different bufctl logic, per-cpu arrays
 *	(c) 2000 Manfred Spraul
 *
 * Cleanup, make the head arrays unconditional, preparation for NUMA
 * 	(c) 2002 Manfred Spraul
 *
 * An implementation of the Slab Allocator as described in outline in;
 *	UNIX Internals: The New Frontiers by Uresh Vahalia
 *	Pub: Prentice Hall	ISBN 0-13-101908-2
 * or with a little more detail in;
 *	The Slab Allocator: An Object-Caching Kernel Memory Allocator
 *	Jeff Bonwick (Sun Microsystems).
 *	Presented at: USENIX Summer 1994 Technical Conference
 *
 * The memory is organized in caches, one cache for each object type.
 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
 * Each cache consists out of many slabs (they are small (usually one
 * page long) and always contiguous), and each slab contains multiple
 * initialized objects.
 *
 * This means, that your constructor is used only for newly allocated
 * slabs and you must pass objects with the same intializations to
 * kmem_cache_free.
 *
 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
 * normal). If you need a special memory type, then must create a new
 * cache for that memory type.
 *
 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
 *   full slabs with 0 free objects
 *   partial slabs
 *   empty slabs with no allocated objects
 *
 * If partial slabs exist, then new allocations come from these slabs,
 * otherwise from empty slabs or new slabs are allocated.
 *
 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
 *
 * Each cache has a short per-cpu head array, most allocs
 * and frees go into that array, and if that array overflows, then 1/2
 * of the entries in the array are given back into the global cache.
 * The head array is strictly LIFO and should improve the cache hit rates.
 * On SMP, it additionally reduces the spinlock operations.
 *
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 * The c_cpuarray may not be read with enabled local interrupts -
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 * it's changed with a smp_call_function().
 *
 * SMP synchronization:
 *  constructors and destructors are called without any locking.
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 *  Several members in struct kmem_cache and struct slab never change, they
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 *	are accessed without any locking.
 *  The per-cpu arrays are never accessed from the wrong cpu, no locking,
 *  	and local interrupts are disabled so slab code is preempt-safe.
 *  The non-constant members are protected with a per-cache irq spinlock.
 *
 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
 * in 2000 - many ideas in the current implementation are derived from
 * his patch.
 *
 * Further notes from the original documentation:
 *
 * 11 April '97.  Started multi-threading - markhe
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 *	The global cache-chain is protected by the mutex 'cache_chain_mutex'.
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 *	The sem is only needed when accessing/extending the cache-chain, which
 *	can never happen inside an interrupt (kmem_cache_create(),
 *	kmem_cache_shrink() and kmem_cache_reap()).
 *
 *	At present, each engine can be growing a cache.  This should be blocked.
 *
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 * 15 March 2005. NUMA slab allocator.
 *	Shai Fultheim <shai@scalex86.org>.
 *	Shobhit Dayal <shobhit@calsoftinc.com>
 *	Alok N Kataria <alokk@calsoftinc.com>
 *	Christoph Lameter <christoph@lameter.com>
 *
 *	Modified the slab allocator to be node aware on NUMA systems.
 *	Each node has its own list of partial, free and full slabs.
 *	All object allocations for a node occur from node specific slab lists.
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 */

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

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

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

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

#ifndef cache_line_size
#define cache_line_size()	L1_CACHE_BYTES
#endif

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

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

#ifndef ARCH_KMALLOC_FLAGS
#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
#endif

/* Legal flag mask for kmem_cache_create(). */
#if DEBUG
# define CREATE_MASK	(SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
			 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
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			 SLAB_CACHE_DMA | \
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			 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
			 SLAB_DESTROY_BY_RCU)
#else
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# define CREATE_MASK	(SLAB_HWCACHE_ALIGN | \
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			 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
			 SLAB_DESTROY_BY_RCU)
#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)
#define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-2)

/* Max number of objs-per-slab for caches which use off-slab slabs.
 * Needed to avoid a possible looping condition in cache_grow().
 */
static unsigned long offslab_limit;

/*
 * struct slab
 *
 * Manages the objs in a slab. Placed either at the beginning of mem allocated
 * for a slab, or allocated from an general cache.
 * Slabs are chained into three list: fully used, partial, fully free slabs.
 */
struct slab {
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	struct list_head list;
	unsigned long colouroff;
	void *s_mem;		/* including colour offset */
	unsigned int inuse;	/* num of objs active in slab */
	kmem_bufctl_t free;
	unsigned short nodeid;
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};

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

/*
 * struct array_cache
 *
 * Purpose:
 * - LIFO ordering, to hand out cache-warm objects from _alloc
 * - reduce the number of linked list operations
 * - reduce spinlock operations
 *
 * The limit is stored in the per-cpu structure to reduce the data cache
 * footprint.
 *
 */
struct array_cache {
	unsigned int avail;
	unsigned int limit;
	unsigned int batchcount;
	unsigned int touched;
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	spinlock_t lock;
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	void *entry[0];	/*
			 * Must have this definition in here for the proper
			 * alignment of array_cache. Also simplifies accessing
			 * the entries.
			 * [0] is for gcc 2.95. It should really be [].
			 */
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};

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

/*
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 * The slab lists for all objects.
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 */
struct kmem_list3 {
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	struct list_head slabs_partial;	/* partial list first, better asm code */
	struct list_head slabs_full;
	struct list_head slabs_free;
	unsigned long free_objects;
	unsigned long next_reap;
	int free_touched;
	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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};

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

/*
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 * This function must be completely optimized away if a constant is passed to
 * it.  Mostly the same as what is in linux/slab.h except it returns an index.
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 */
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static __always_inline int index_of(const size_t size)
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{
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	extern void __bad_size(void);

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

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

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

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

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

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

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

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

#if DEBUG
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/*
 * Magic nums for obj red zoning.
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 * Placed in the first word before and the first word after an obj.
 */
#define	RED_INACTIVE	0x5A2CF071UL	/* when obj is inactive */
#define	RED_ACTIVE	0x170FC2A5UL	/* when obj is active */

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

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

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

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

534
static unsigned long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
	if (cachep->flags & SLAB_STORE_USER)
538
		return (unsigned long *)(objp + cachep->buffer_size -
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					 2 * BYTES_PER_WORD);
540
	return (unsigned long *)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

543
static void **dbg_userword(struct kmem_cache *cachep, void *objp)
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{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
546
	return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
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}

#else

551 552
#define obj_offset(x)			0
#define obj_size(cachep)		(cachep->buffer_size)
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#define dbg_redzone1(cachep, objp)	({BUG(); (unsigned long *)NULL;})
#define dbg_redzone2(cachep, objp)	({BUG(); (unsigned long *)NULL;})
#define dbg_userword(cachep, objp)	({BUG(); (void **)NULL;})

#endif

/*
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 * Maximum size of an obj (in 2^order pages) and absolute limit for the gfp
 * order.
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 */
#if defined(CONFIG_LARGE_ALLOCS)
#define	MAX_OBJ_ORDER	13	/* up to 32Mb */
#define	MAX_GFP_ORDER	13	/* up to 32Mb */
#elif defined(CONFIG_MMU)
#define	MAX_OBJ_ORDER	5	/* 32 pages */
#define	MAX_GFP_ORDER	5	/* 32 pages */
#else
#define	MAX_OBJ_ORDER	8	/* up to 1Mb */
#define	MAX_GFP_ORDER	8	/* up to 1Mb */
#endif

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

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/*
 * Functions for storing/retrieving the cachep and or slab from the page
 * allocator.  These are used to find the slab an obj belongs to.  With kfree(),
 * these are used to find the cache which an obj belongs to.
L
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 */
586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604
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)
{
	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)
{
	return (struct slab *)page->lru.prev;
}
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606 607 608 609 610 611 612 613 614 615 616 617
static inline struct kmem_cache *virt_to_cache(const void *obj)
{
	struct page *page = virt_to_page(obj);
	return page_get_cache(page);
}

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

618 619 620 621 622 623 624 625 626 627 628 629
static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
				 unsigned int idx)
{
	return slab->s_mem + cache->buffer_size * idx;
}

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

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/*
 * These are the default caches for kmalloc. Custom caches can have other sizes.
 */
L
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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 =
P
Pekka Enberg 已提交
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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 */
660
static struct kmem_cache cache_cache = {
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	.batchcount = 1,
	.limit = BOOT_CPUCACHE_ENTRIES,
	.shared = 1,
664
	.buffer_size = sizeof(struct kmem_cache),
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	.name = "kmem_cache",
L
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#if DEBUG
667
	.obj_size = sizeof(struct kmem_cache),
L
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668 669 670 671
#endif
};

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

/*
A
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676 677
 * vm_enough_memory() looks at this to determine how many slab-allocated pages
 * are possibly freeable under pressure
L
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 *
 * SLAB_RECLAIM_ACCOUNT turns this on per-slab
 */
atomic_t slab_reclaim_pages;

/*
 * chicken and egg problem: delay the per-cpu array allocation
 * until the general caches are up.
 */
static enum {
	NONE,
689 690
	PARTIAL_AC,
	PARTIAL_L3,
L
Linus Torvalds 已提交
691 692 693 694 695
	FULL
} g_cpucache_up;

static DEFINE_PER_CPU(struct work_struct, reap_work);

A
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static void free_block(struct kmem_cache *cachep, void **objpp, int len,
			int node);
698
static void enable_cpucache(struct kmem_cache *cachep);
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699
static void cache_reap(void *unused);
700
static int __node_shrink(struct kmem_cache *cachep, int node);
L
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701

702
static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
L
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703 704 705 706
{
	return cachep->array[smp_processor_id()];
}

A
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static inline struct kmem_cache *__find_general_cachep(size_t size,
							gfp_t gfpflags)
L
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709 710 711 712 713
{
	struct cache_sizes *csizep = malloc_sizes;

#if DEBUG
	/* This happens if someone tries to call
P
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714 715 716
	 * kmem_cache_create(), or __kmalloc(), before
	 * the generic caches are initialized.
	 */
717
	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
L
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#endif
	while (size > csizep->cs_size)
		csizep++;

	/*
723
	 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
L
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724 725 726 727 728 729 730 731
	 * has cs_{dma,}cachep==NULL. Thus no special case
	 * for large kmalloc calls required.
	 */
	if (unlikely(gfpflags & GFP_DMA))
		return csizep->cs_dmacachep;
	return csizep->cs_cachep;
}

732
struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
733 734 735 736 737
{
	return __find_general_cachep(size, gfpflags);
}
EXPORT_SYMBOL(kmem_find_general_cachep);

738
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
L
Linus Torvalds 已提交
739
{
740 741
	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
}
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742

A
Andrew Morton 已提交
743 744 745
/*
 * Calculate the number of objects and left-over bytes for a given buffer size.
 */
746 747 748 749 750 751 752
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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754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801
	/*
	 * The slab management structure can be either off the slab or
	 * on it. For the latter case, the memory allocated for a
	 * slab is used for:
	 *
	 * - The struct slab
	 * - One kmem_bufctl_t for each object
	 * - Padding to respect alignment of @align
	 * - @buffer_size bytes for each object
	 *
	 * If the slab management structure is off the slab, then the
	 * alignment will already be calculated into the size. Because
	 * the slabs are all pages aligned, the objects will be at the
	 * correct alignment when allocated.
	 */
	if (flags & CFLGS_OFF_SLAB) {
		mgmt_size = 0;
		nr_objs = slab_size / buffer_size;

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

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

		if (nr_objs > SLAB_LIMIT)
			nr_objs = SLAB_LIMIT;

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

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

A
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static void __slab_error(const char *function, struct kmem_cache *cachep,
			char *msg)
L
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808 809
{
	printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
P
Pekka Enberg 已提交
810
	       function, cachep->name, msg);
L
Linus Torvalds 已提交
811 812 813
	dump_stack();
}

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
#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)
		node = 0;

	__get_cpu_var(reap_node) = node;
}

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

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

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

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

L
Linus Torvalds 已提交
855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871
/*
 * Initiate the reap timer running on the target CPU.  We run at around 1 to 2Hz
 * via the workqueue/eventd.
 * Add the CPU number into the expiration time to minimize the possibility of
 * the CPUs getting into lockstep and contending for the global cache chain
 * lock.
 */
static void __devinit start_cpu_timer(int cpu)
{
	struct work_struct *reap_work = &per_cpu(reap_work, cpu);

	/*
	 * When this gets called from do_initcalls via cpucache_init(),
	 * init_workqueues() has already run, so keventd will be setup
	 * at that time.
	 */
	if (keventd_up() && reap_work->func == NULL) {
872
		init_reap_node(cpu);
L
Linus Torvalds 已提交
873 874 875 876 877
		INIT_WORK(reap_work, cache_reap, NULL);
		schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
	}
}

878
static struct array_cache *alloc_arraycache(int node, int entries,
P
Pekka Enberg 已提交
879
					    int batchcount)
L
Linus Torvalds 已提交
880
{
P
Pekka Enberg 已提交
881
	int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
L
Linus Torvalds 已提交
882 883
	struct array_cache *nc = NULL;

884
	nc = kmalloc_node(memsize, GFP_KERNEL, node);
L
Linus Torvalds 已提交
885 886 887 888 889
	if (nc) {
		nc->avail = 0;
		nc->limit = entries;
		nc->batchcount = batchcount;
		nc->touched = 0;
890
		spin_lock_init(&nc->lock);
L
Linus Torvalds 已提交
891 892 893 894
	}
	return nc;
}

895
#ifdef CONFIG_NUMA
896
static void *__cache_alloc_node(struct kmem_cache *, gfp_t, int);
897

P
Pekka Enberg 已提交
898
static struct array_cache **alloc_alien_cache(int node, int limit)
899 900
{
	struct array_cache **ac_ptr;
P
Pekka Enberg 已提交
901
	int memsize = sizeof(void *) * MAX_NUMNODES;
902 903 904 905 906 907 908 909 910 911 912 913 914
	int i;

	if (limit > 1)
		limit = 12;
	ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node);
	if (ac_ptr) {
		for_each_node(i) {
			if (i == node || !node_online(i)) {
				ac_ptr[i] = NULL;
				continue;
			}
			ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d);
			if (!ac_ptr[i]) {
P
Pekka Enberg 已提交
915
				for (i--; i <= 0; i--)
916 917 918 919 920 921 922 923 924
					kfree(ac_ptr[i]);
				kfree(ac_ptr);
				return NULL;
			}
		}
	}
	return ac_ptr;
}

P
Pekka Enberg 已提交
925
static void free_alien_cache(struct array_cache **ac_ptr)
926 927 928 929 930 931
{
	int i;

	if (!ac_ptr)
		return;
	for_each_node(i)
P
Pekka Enberg 已提交
932
	    kfree(ac_ptr[i]);
933 934 935
	kfree(ac_ptr);
}

936
static void __drain_alien_cache(struct kmem_cache *cachep,
P
Pekka Enberg 已提交
937
				struct array_cache *ac, int node)
938 939 940 941 942
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
943
		free_block(cachep, ac->entry, ac->avail, node);
944 945 946 947 948
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965
/*
 * 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];
		if (ac && ac->avail) {
			spin_lock_irq(&ac->lock);
			__drain_alien_cache(cachep, ac, node);
			spin_unlock_irq(&ac->lock);
		}
	}
}

A
Andrew Morton 已提交
966 967
static void drain_alien_cache(struct kmem_cache *cachep,
				struct array_cache **alien)
968
{
P
Pekka Enberg 已提交
969
	int i = 0;
970 971 972 973
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
974
		ac = alien[i];
975 976 977 978 979 980 981 982
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
#else
983

984
#define drain_alien_cache(cachep, alien) do { } while (0)
985
#define reap_alien(cachep, l3) do { } while (0)
986

987 988 989 990 991
static inline struct array_cache **alloc_alien_cache(int node, int limit)
{
	return (struct array_cache **) 0x01020304ul;
}

992 993 994
static inline void free_alien_cache(struct array_cache **ac_ptr)
{
}
995

996 997
#endif

L
Linus Torvalds 已提交
998
static int __devinit cpuup_callback(struct notifier_block *nfb,
P
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999
				    unsigned long action, void *hcpu)
L
Linus Torvalds 已提交
1000 1001
{
	long cpu = (long)hcpu;
1002
	struct kmem_cache *cachep;
1003 1004 1005
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
	int memsize = sizeof(struct kmem_list3);
L
Linus Torvalds 已提交
1006 1007 1008

	switch (action) {
	case CPU_UP_PREPARE:
I
Ingo Molnar 已提交
1009
		mutex_lock(&cache_chain_mutex);
A
Andrew Morton 已提交
1010 1011
		/*
		 * We need to do this right in the beginning since
1012 1013 1014 1015 1016
		 * 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
1017
		list_for_each_entry(cachep, &cache_chain, next) {
A
Andrew Morton 已提交
1018 1019
			/*
			 * Set up the size64 kmemlist for cpu before we can
1020 1021 1022 1023
			 * 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
1024 1025
				l3 = kmalloc_node(memsize, GFP_KERNEL, node);
				if (!l3)
1026 1027 1028
					goto bad;
				kmem_list3_init(l3);
				l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
P
Pekka Enberg 已提交
1029
				    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1030

1031 1032 1033 1034 1035
				/*
				 * The l3s don't come and go as CPUs come and
				 * go.  cache_chain_mutex is sufficient
				 * protection here.
				 */
1036 1037
				cachep->nodelists[node] = l3;
			}
L
Linus Torvalds 已提交
1038

1039 1040
			spin_lock_irq(&cachep->nodelists[node]->list_lock);
			cachep->nodelists[node]->free_limit =
A
Andrew Morton 已提交
1041 1042
				(1 + nr_cpus_node(node)) *
				cachep->batchcount + cachep->num;
1043 1044 1045
			spin_unlock_irq(&cachep->nodelists[node]->list_lock);
		}

A
Andrew Morton 已提交
1046 1047 1048 1049
		/*
		 * Now we can go ahead with allocating the shared arrays and
		 * array caches
		 */
1050
		list_for_each_entry(cachep, &cache_chain, next) {
1051
			struct array_cache *nc;
1052 1053
			struct array_cache *shared;
			struct array_cache **alien;
1054

1055
			nc = alloc_arraycache(node, cachep->limit,
1056
						cachep->batchcount);
L
Linus Torvalds 已提交
1057 1058
			if (!nc)
				goto bad;
1059 1060 1061 1062 1063
			shared = alloc_arraycache(node,
					cachep->shared * cachep->batchcount,
					0xbaadf00d);
			if (!shared)
				goto bad;
1064

1065 1066 1067
			alien = alloc_alien_cache(node, cachep->limit);
			if (!alien)
				goto bad;
L
Linus Torvalds 已提交
1068
			cachep->array[cpu] = nc;
1069 1070 1071
			l3 = cachep->nodelists[node];
			BUG_ON(!l3);

1072 1073 1074 1075 1076 1077 1078 1079
			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;
1080
			}
1081 1082 1083 1084 1085 1086 1087 1088 1089
#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
1090
		}
I
Ingo Molnar 已提交
1091
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1092 1093 1094 1095 1096 1097
		break;
	case CPU_ONLINE:
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
	case CPU_DEAD:
1098 1099 1100 1101 1102 1103 1104 1105
		/*
		 * 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
1106 1107
		/* fall thru */
	case CPU_UP_CANCELED:
I
Ingo Molnar 已提交
1108
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1109 1110
		list_for_each_entry(cachep, &cache_chain, next) {
			struct array_cache *nc;
1111 1112
			struct array_cache *shared;
			struct array_cache **alien;
1113
			cpumask_t mask;
L
Linus Torvalds 已提交
1114

1115
			mask = node_to_cpumask(node);
L
Linus Torvalds 已提交
1116 1117 1118
			/* cpu is dead; no one can alloc from it. */
			nc = cachep->array[cpu];
			cachep->array[cpu] = NULL;
1119 1120 1121
			l3 = cachep->nodelists[node];

			if (!l3)
1122
				goto free_array_cache;
1123

1124
			spin_lock_irq(&l3->list_lock);
1125 1126 1127 1128

			/* Free limit for this kmem_list3 */
			l3->free_limit -= cachep->batchcount;
			if (nc)
1129
				free_block(cachep, nc->entry, nc->avail, node);
1130 1131

			if (!cpus_empty(mask)) {
1132
				spin_unlock_irq(&l3->list_lock);
1133
				goto free_array_cache;
P
Pekka Enberg 已提交
1134
			}
1135

1136 1137
			shared = l3->shared;
			if (shared) {
1138
				free_block(cachep, l3->shared->entry,
P
Pekka Enberg 已提交
1139
					   l3->shared->avail, node);
1140 1141 1142
				l3->shared = NULL;
			}

1143 1144 1145 1146 1147 1148 1149 1150 1151
			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);
1152
			}
1153
free_array_cache:
L
Linus Torvalds 已提交
1154 1155
			kfree(nc);
		}
1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169
		/*
		 * In the previous loop, all the objects were freed to
		 * the respective cache's slabs,  now we can go ahead and
		 * shrink each nodelist to its limit.
		 */
		list_for_each_entry(cachep, &cache_chain, next) {
			l3 = cachep->nodelists[node];
			if (!l3)
				continue;
			spin_lock_irq(&l3->list_lock);
			/* free slabs belonging to this node */
			__node_shrink(cachep, node);
			spin_unlock_irq(&l3->list_lock);
		}
I
Ingo Molnar 已提交
1170
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1171 1172 1173 1174
		break;
#endif
	}
	return NOTIFY_OK;
A
Andrew Morton 已提交
1175
bad:
I
Ingo Molnar 已提交
1176
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1177 1178 1179 1180 1181
	return NOTIFY_BAD;
}

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

1182 1183 1184
/*
 * swap the static kmem_list3 with kmalloced memory
 */
A
Andrew Morton 已提交
1185 1186
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
			int nodeid)
1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200
{
	struct kmem_list3 *ptr;

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

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

A
Andrew Morton 已提交
1201 1202 1203
/*
 * Initialisation.  Called after the page allocator have been initialised and
 * before smp_init().
L
Linus Torvalds 已提交
1204 1205 1206 1207 1208 1209
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1210
	int i;
1211
	int order;
1212 1213 1214 1215 1216 1217

	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
1218 1219 1220 1221 1222 1223 1224 1225 1226 1227

	/*
	 * 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
1228 1229 1230
	 * 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.
1231 1232 1233
	 *    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
1234
	 * 2) Create the first kmalloc cache.
1235
	 *    The struct kmem_cache for the new cache is allocated normally.
1236 1237 1238
	 *    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
1239 1240
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1241 1242 1243
	 * 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
1244 1245 1246 1247 1248 1249 1250
	 */

	/* 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;
1251
	cache_cache.nodelists[numa_node_id()] = &initkmem_list3[CACHE_CACHE];
L
Linus Torvalds 已提交
1252

A
Andrew Morton 已提交
1253 1254
	cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
					cache_line_size());
L
Linus Torvalds 已提交
1255

1256 1257 1258 1259 1260 1261
	for (order = 0; order < MAX_ORDER; order++) {
		cache_estimate(order, cache_cache.buffer_size,
			cache_line_size(), 0, &left_over, &cache_cache.num);
		if (cache_cache.num)
			break;
	}
L
Linus Torvalds 已提交
1262 1263
	if (!cache_cache.num)
		BUG();
1264
	cache_cache.gfporder = order;
P
Pekka Enberg 已提交
1265 1266 1267
	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
1268 1269 1270 1271 1272

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

A
Andrew Morton 已提交
1273 1274 1275 1276
	/*
	 * Initialize the caches that provide memory for the array cache and the
	 * kmem_list3 structures first.  Without this, further allocations will
	 * bug.
1277 1278 1279
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
A
Andrew Morton 已提交
1280 1281 1282 1283
					sizes[INDEX_AC].cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
1284

A
Andrew Morton 已提交
1285
	if (INDEX_AC != INDEX_L3) {
1286
		sizes[INDEX_L3].cs_cachep =
A
Andrew Morton 已提交
1287 1288 1289 1290 1291 1292
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size,
				ARCH_KMALLOC_MINALIGN,
				ARCH_KMALLOC_FLAGS|SLAB_PANIC,
				NULL, NULL);
	}
1293

L
Linus Torvalds 已提交
1294
	while (sizes->cs_size != ULONG_MAX) {
1295 1296
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1297 1298 1299
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1300 1301
		 * allow tighter packing of the smaller caches.
		 */
A
Andrew Morton 已提交
1302
		if (!sizes->cs_cachep) {
1303
			sizes->cs_cachep = kmem_cache_create(names->name,
A
Andrew Morton 已提交
1304 1305 1306 1307 1308
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
		}
L
Linus Torvalds 已提交
1309 1310 1311

		/* Inc off-slab bufctl limit until the ceiling is hit. */
		if (!(OFF_SLAB(sizes->cs_cachep))) {
P
Pekka Enberg 已提交
1312
			offslab_limit = sizes->cs_size - sizeof(struct slab);
L
Linus Torvalds 已提交
1313 1314 1315 1316
			offslab_limit /= sizeof(kmem_bufctl_t);
		}

		sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
A
Andrew Morton 已提交
1317 1318 1319 1320 1321
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
						SLAB_PANIC,
					NULL, NULL);
L
Linus Torvalds 已提交
1322 1323 1324 1325 1326
		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
P
Pekka Enberg 已提交
1327
		void *ptr;
1328

L
Linus Torvalds 已提交
1329
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1330

L
Linus Torvalds 已提交
1331
		local_irq_disable();
1332 1333
		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
		memcpy(ptr, cpu_cache_get(&cache_cache),
P
Pekka Enberg 已提交
1334
		       sizeof(struct arraycache_init));
L
Linus Torvalds 已提交
1335 1336
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1337

L
Linus Torvalds 已提交
1338
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1339

L
Linus Torvalds 已提交
1340
		local_irq_disable();
1341
		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
P
Pekka Enberg 已提交
1342
		       != &initarray_generic.cache);
1343
		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
P
Pekka Enberg 已提交
1344
		       sizeof(struct arraycache_init));
1345
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
P
Pekka Enberg 已提交
1346
		    ptr;
L
Linus Torvalds 已提交
1347 1348
		local_irq_enable();
	}
1349 1350 1351 1352 1353
	/* 5) Replace the bootstrap kmem_list3's */
	{
		int node;
		/* Replace the static kmem_list3 structures for the boot cpu */
		init_list(&cache_cache, &initkmem_list3[CACHE_CACHE],
P
Pekka Enberg 已提交
1354
			  numa_node_id());
1355 1356 1357

		for_each_online_node(node) {
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
P
Pekka Enberg 已提交
1358
				  &initkmem_list3[SIZE_AC + node], node);
1359 1360 1361

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
P
Pekka Enberg 已提交
1362 1363
					  &initkmem_list3[SIZE_L3 + node],
					  node);
1364 1365 1366
			}
		}
	}
L
Linus Torvalds 已提交
1367

1368
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1369
	{
1370
		struct kmem_cache *cachep;
I
Ingo Molnar 已提交
1371
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1372
		list_for_each_entry(cachep, &cache_chain, next)
A
Andrew Morton 已提交
1373
			enable_cpucache(cachep);
I
Ingo Molnar 已提交
1374
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1375 1376 1377 1378 1379
	}

	/* Done! */
	g_cpucache_up = FULL;

A
Andrew Morton 已提交
1380 1381 1382
	/*
	 * Register a cpu startup notifier callback that initializes
	 * cpu_cache_get for all new cpus
L
Linus Torvalds 已提交
1383 1384 1385
	 */
	register_cpu_notifier(&cpucache_notifier);

A
Andrew Morton 已提交
1386 1387 1388
	/*
	 * 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
1389 1390 1391 1392 1393 1394 1395
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

A
Andrew Morton 已提交
1396 1397
	/*
	 * Register the timers that return unneeded pages to the page allocator
L
Linus Torvalds 已提交
1398
	 */
1399
	for_each_online_cpu(cpu)
A
Andrew Morton 已提交
1400
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411
	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.
 */
1412
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1413 1414 1415 1416 1417 1418
{
	struct page *page;
	void *addr;
	int i;

	flags |= cachep->gfpflags;
1419
	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1420 1421 1422 1423 1424 1425 1426 1427 1428
	if (!page)
		return NULL;
	addr = page_address(page);

	i = (1 << cachep->gfporder);
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		atomic_add(i, &slab_reclaim_pages);
	add_page_state(nr_slab, i);
	while (i--) {
N
Nick Piggin 已提交
1429
		__SetPageSlab(page);
L
Linus Torvalds 已提交
1430 1431 1432 1433 1434 1435 1436 1437
		page++;
	}
	return addr;
}

/*
 * Interface to system's page release.
 */
1438
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
L
Linus Torvalds 已提交
1439
{
P
Pekka Enberg 已提交
1440
	unsigned long i = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1441 1442 1443 1444
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

	while (i--) {
N
Nick Piggin 已提交
1445 1446
		BUG_ON(!PageSlab(page));
		__ClearPageSlab(page);
L
Linus Torvalds 已提交
1447 1448 1449 1450 1451 1452
		page++;
	}
	sub_page_state(nr_slab, nr_freed);
	if (current->reclaim_state)
		current->reclaim_state->reclaimed_slab += nr_freed;
	free_pages((unsigned long)addr, cachep->gfporder);
P
Pekka Enberg 已提交
1453 1454
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		atomic_sub(1 << cachep->gfporder, &slab_reclaim_pages);
L
Linus Torvalds 已提交
1455 1456 1457 1458
}

static void kmem_rcu_free(struct rcu_head *head)
{
P
Pekka Enberg 已提交
1459
	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1460
	struct kmem_cache *cachep = slab_rcu->cachep;
L
Linus Torvalds 已提交
1461 1462 1463 1464 1465 1466 1467 1468 1469

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

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
1470
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
P
Pekka Enberg 已提交
1471
			    unsigned long caller)
L
Linus Torvalds 已提交
1472
{
1473
	int size = obj_size(cachep);
L
Linus Torvalds 已提交
1474

1475
	addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1476

P
Pekka Enberg 已提交
1477
	if (size < 5 * sizeof(unsigned long))
L
Linus Torvalds 已提交
1478 1479
		return;

P
Pekka Enberg 已提交
1480 1481 1482 1483
	*addr++ = 0x12345678;
	*addr++ = caller;
	*addr++ = smp_processor_id();
	size -= 3 * sizeof(unsigned long);
L
Linus Torvalds 已提交
1484 1485 1486 1487 1488 1489 1490
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
P
Pekka Enberg 已提交
1491
				*addr++ = svalue;
L
Linus Torvalds 已提交
1492 1493 1494 1495 1496 1497 1498
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
P
Pekka Enberg 已提交
1499
	*addr++ = 0x87654321;
L
Linus Torvalds 已提交
1500 1501 1502
}
#endif

1503
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
L
Linus Torvalds 已提交
1504
{
1505 1506
	int size = obj_size(cachep);
	addr = &((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1507 1508

	memset(addr, val, size);
P
Pekka Enberg 已提交
1509
	*(unsigned char *)(addr + size - 1) = POISON_END;
L
Linus Torvalds 已提交
1510 1511 1512 1513 1514 1515
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
	printk(KERN_ERR "%03x:", offset);
A
Andrew Morton 已提交
1516
	for (i = 0; i < limit; i++)
P
Pekka Enberg 已提交
1517
		printk(" %02x", (unsigned char)data[offset + i]);
L
Linus Torvalds 已提交
1518 1519 1520 1521 1522 1523
	printk("\n");
}
#endif

#if DEBUG

1524
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
L
Linus Torvalds 已提交
1525 1526 1527 1528 1529 1530
{
	int i, size;
	char *realobj;

	if (cachep->flags & SLAB_RED_ZONE) {
		printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n",
A
Andrew Morton 已提交
1531 1532
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
1533 1534 1535 1536
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
A
Andrew Morton 已提交
1537
			*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1538
		print_symbol("(%s)",
A
Andrew Morton 已提交
1539
				(unsigned long)*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1540 1541
		printk("\n");
	}
1542 1543
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
P
Pekka Enberg 已提交
1544
	for (i = 0; i < size && lines; i += 16, lines--) {
L
Linus Torvalds 已提交
1545 1546
		int limit;
		limit = 16;
P
Pekka Enberg 已提交
1547 1548
		if (i + limit > size)
			limit = size - i;
L
Linus Torvalds 已提交
1549 1550 1551 1552
		dump_line(realobj, i, limit);
	}
}

1553
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
1554 1555 1556 1557 1558
{
	char *realobj;
	int size, i;
	int lines = 0;

1559 1560
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
L
Linus Torvalds 已提交
1561

P
Pekka Enberg 已提交
1562
	for (i = 0; i < size; i++) {
L
Linus Torvalds 已提交
1563
		char exp = POISON_FREE;
P
Pekka Enberg 已提交
1564
		if (i == size - 1)
L
Linus Torvalds 已提交
1565 1566 1567 1568 1569 1570
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
P
Pekka Enberg 已提交
1571
				printk(KERN_ERR
A
Andrew Morton 已提交
1572 1573
					"Slab corruption: start=%p, len=%d\n",
					realobj, size);
L
Linus Torvalds 已提交
1574 1575 1576
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
P
Pekka Enberg 已提交
1577
			i = (i / 16) * 16;
L
Linus Torvalds 已提交
1578
			limit = 16;
P
Pekka Enberg 已提交
1579 1580
			if (i + limit > size)
				limit = size - i;
L
Linus Torvalds 已提交
1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592
			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:
		 */
1593
		struct slab *slabp = virt_to_slab(objp);
1594
		unsigned int objnr;
L
Linus Torvalds 已提交
1595

1596
		objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
1597
		if (objnr) {
1598
			objp = index_to_obj(cachep, slabp, objnr - 1);
1599
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1600
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1601
			       realobj, size);
L
Linus Torvalds 已提交
1602 1603
			print_objinfo(cachep, objp, 2);
		}
P
Pekka Enberg 已提交
1604
		if (objnr + 1 < cachep->num) {
1605
			objp = index_to_obj(cachep, slabp, objnr + 1);
1606
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1607
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1608
			       realobj, size);
L
Linus Torvalds 已提交
1609 1610 1611 1612 1613 1614
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

1615 1616
#if DEBUG
/**
1617 1618 1619 1620 1621 1622
 * 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
1623
 */
1624
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
1625 1626 1627
{
	int i;
	for (i = 0; i < cachep->num; i++) {
1628
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
1629 1630 1631

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
1632 1633
			if (cachep->buffer_size % PAGE_SIZE == 0 &&
					OFF_SLAB(cachep))
P
Pekka Enberg 已提交
1634
				kernel_map_pages(virt_to_page(objp),
A
Andrew Morton 已提交
1635
					cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
1636 1637 1638 1639 1640 1641 1642 1643 1644
			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
1645
					   "was overwritten");
L
Linus Torvalds 已提交
1646 1647
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
P
Pekka Enberg 已提交
1648
					   "was overwritten");
L
Linus Torvalds 已提交
1649 1650
		}
		if (cachep->dtor && !(cachep->flags & SLAB_POISON))
1651
			(cachep->dtor) (objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
1652
	}
1653
}
L
Linus Torvalds 已提交
1654
#else
1655
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
1656
{
L
Linus Torvalds 已提交
1657 1658 1659
	if (cachep->dtor) {
		int i;
		for (i = 0; i < cachep->num; i++) {
1660
			void *objp = index_to_obj(cachep, slabp, i);
P
Pekka Enberg 已提交
1661
			(cachep->dtor) (objp, cachep, 0);
L
Linus Torvalds 已提交
1662 1663
		}
	}
1664
}
L
Linus Torvalds 已提交
1665 1666
#endif

1667 1668 1669 1670 1671
/**
 * slab_destroy - destroy and release all objects in a slab
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
1672
 * Destroy all the objs in a slab, and release the mem back to the system.
A
Andrew Morton 已提交
1673 1674
 * Before calling the slab must have been unlinked from the cache.  The
 * cache-lock is not held/needed.
1675
 */
1676
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1677 1678 1679 1680
{
	void *addr = slabp->s_mem - slabp->colouroff;

	slab_destroy_objs(cachep, slabp);
L
Linus Torvalds 已提交
1681 1682 1683
	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

P
Pekka Enberg 已提交
1684
		slab_rcu = (struct slab_rcu *)slabp;
L
Linus Torvalds 已提交
1685 1686 1687 1688 1689 1690 1691 1692 1693 1694
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
	}
}

A
Andrew Morton 已提交
1695 1696 1697 1698
/*
 * For setting up all the kmem_list3s for cache whose buffer_size is same as
 * size of kmem_list3.
 */
1699
static void set_up_list3s(struct kmem_cache *cachep, int index)
1700 1701 1702 1703
{
	int node;

	for_each_online_node(node) {
P
Pekka Enberg 已提交
1704
		cachep->nodelists[node] = &initkmem_list3[index + node];
1705
		cachep->nodelists[node]->next_reap = jiffies +
P
Pekka Enberg 已提交
1706 1707
		    REAPTIMEOUT_LIST3 +
		    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1708 1709 1710
	}
}

1711
/**
1712 1713 1714 1715 1716 1717 1718
 * 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.
1719 1720 1721 1722 1723
 *
 * 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
1724
static size_t calculate_slab_order(struct kmem_cache *cachep,
R
Randy Dunlap 已提交
1725
			size_t size, size_t align, unsigned long flags)
1726 1727
{
	size_t left_over = 0;
1728
	int gfporder;
1729

A
Andrew Morton 已提交
1730
	for (gfporder = 0; gfporder <= MAX_GFP_ORDER; gfporder++) {
1731 1732 1733
		unsigned int num;
		size_t remainder;

1734
		cache_estimate(gfporder, size, align, flags, &remainder, &num);
1735 1736
		if (!num)
			continue;
1737

1738
		/* More than offslab_limit objects will cause problems */
1739
		if ((flags & CFLGS_OFF_SLAB) && num > offslab_limit)
1740 1741
			break;

1742
		/* Found something acceptable - save it away */
1743
		cachep->num = num;
1744
		cachep->gfporder = gfporder;
1745 1746
		left_over = remainder;

1747 1748 1749 1750 1751 1752 1753 1754
		/*
		 * 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;

1755 1756 1757 1758
		/*
		 * Large number of objects is good, but very large slabs are
		 * currently bad for the gfp()s.
		 */
1759
		if (gfporder >= slab_break_gfp_order)
1760 1761
			break;

1762 1763 1764
		/*
		 * Acceptable internal fragmentation?
		 */
A
Andrew Morton 已提交
1765
		if (left_over * 8 <= (PAGE_SIZE << gfporder))
1766 1767 1768 1769 1770
			break;
	}
	return left_over;
}

1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824
static void setup_cpu_cache(struct kmem_cache *cachep)
{
	if (g_cpucache_up == FULL) {
		enable_cpucache(cachep);
		return;
	}
	if (g_cpucache_up == NONE) {
		/*
		 * Note: the first kmem_cache_create must create the cache
		 * that's used by kmalloc(24), otherwise the creation of
		 * further caches will BUG().
		 */
		cachep->array[smp_processor_id()] = &initarray_generic.cache;

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

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

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

L
Linus Torvalds 已提交
1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839
/**
 * kmem_cache_create - Create a cache.
 * @name: A string which is used in /proc/slabinfo to identify this cache.
 * @size: The size of objects to be created in this cache.
 * @align: The required alignment for the objects.
 * @flags: SLAB flags
 * @ctor: A constructor for the objects.
 * @dtor: A destructor for the objects.
 *
 * Returns a ptr to the cache on success, NULL on failure.
 * Cannot be called within a int, but can be interrupted.
 * The @ctor is run when new pages are allocated by the cache
 * and the @dtor is run before the pages are handed back.
 *
 * @name must be valid until the cache is destroyed. This implies that
A
Andrew Morton 已提交
1840 1841
 * the module calling this has to destroy the cache before getting unloaded.
 *
L
Linus Torvalds 已提交
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853
 * 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.
 */
1854
struct kmem_cache *
L
Linus Torvalds 已提交
1855
kmem_cache_create (const char *name, size_t size, size_t align,
A
Andrew Morton 已提交
1856 1857
	unsigned long flags,
	void (*ctor)(void*, struct kmem_cache *, unsigned long),
1858
	void (*dtor)(void*, struct kmem_cache *, unsigned long))
L
Linus Torvalds 已提交
1859 1860
{
	size_t left_over, slab_size, ralign;
1861
	struct kmem_cache *cachep = NULL;
1862
	struct list_head *p;
L
Linus Torvalds 已提交
1863 1864 1865 1866

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
A
Andrew Morton 已提交
1867
	if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
P
Pekka Enberg 已提交
1868
	    (size > (1 << MAX_OBJ_ORDER) * PAGE_SIZE) || (dtor && !ctor)) {
A
Andrew Morton 已提交
1869 1870
		printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
				name);
P
Pekka Enberg 已提交
1871 1872
		BUG();
	}
L
Linus Torvalds 已提交
1873

1874 1875 1876 1877 1878 1879
	/*
	 * Prevent CPUs from coming and going.
	 * lock_cpu_hotplug() nests outside cache_chain_mutex
	 */
	lock_cpu_hotplug();

I
Ingo Molnar 已提交
1880
	mutex_lock(&cache_chain_mutex);
1881 1882

	list_for_each(p, &cache_chain) {
1883
		struct kmem_cache *pc = list_entry(p, struct kmem_cache, next);
1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897
		mm_segment_t old_fs = get_fs();
		char tmp;
		int res;

		/*
		 * This happens when the module gets unloaded and doesn't
		 * destroy its slab cache and no-one else reuses the vmalloc
		 * area of the module.  Print a warning.
		 */
		set_fs(KERNEL_DS);
		res = __get_user(tmp, pc->name);
		set_fs(old_fs);
		if (res) {
			printk("SLAB: cache with size %d has lost its name\n",
1898
			       pc->buffer_size);
1899 1900 1901
			continue;
		}

P
Pekka Enberg 已提交
1902
		if (!strcmp(pc->name, name)) {
1903 1904 1905 1906 1907 1908
			printk("kmem_cache_create: duplicate cache %s\n", name);
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
1909 1910 1911 1912 1913
#if DEBUG
	WARN_ON(strchr(name, ' '));	/* It confuses parsers */
	if ((flags & SLAB_DEBUG_INITIAL) && !ctor) {
		/* No constructor, but inital state check requested */
		printk(KERN_ERR "%s: No con, but init state check "
P
Pekka Enberg 已提交
1914
		       "requested - %s\n", __FUNCTION__, name);
L
Linus Torvalds 已提交
1915 1916 1917 1918 1919 1920 1921 1922 1923
		flags &= ~SLAB_DEBUG_INITIAL;
	}
#if FORCED_DEBUG
	/*
	 * Enable redzoning and last user accounting, except for caches with
	 * large objects, if the increased size would increase the object size
	 * above the next power of two: caches with object sizes just above a
	 * power of two have a significant amount of internal fragmentation.
	 */
A
Andrew Morton 已提交
1924
	if (size < 4096 || fls(size - 1) == fls(size-1 + 3 * BYTES_PER_WORD))
P
Pekka Enberg 已提交
1925
		flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
L
Linus Torvalds 已提交
1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
	if (!(flags & SLAB_DESTROY_BY_RCU))
		flags |= SLAB_POISON;
#endif
	if (flags & SLAB_DESTROY_BY_RCU)
		BUG_ON(flags & SLAB_POISON);
#endif
	if (flags & SLAB_DESTROY_BY_RCU)
		BUG_ON(dtor);

	/*
A
Andrew Morton 已提交
1936 1937
	 * Always checks flags, a caller might be expecting debug support which
	 * isn't available.
L
Linus Torvalds 已提交
1938 1939 1940 1941
	 */
	if (flags & ~CREATE_MASK)
		BUG();

A
Andrew Morton 已提交
1942 1943
	/*
	 * Check that size is in terms of words.  This is needed to avoid
L
Linus Torvalds 已提交
1944 1945 1946
	 * 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
1947 1948 1949
	if (size & (BYTES_PER_WORD - 1)) {
		size += (BYTES_PER_WORD - 1);
		size &= ~(BYTES_PER_WORD - 1);
L
Linus Torvalds 已提交
1950 1951
	}

A
Andrew Morton 已提交
1952 1953
	/* calculate the final buffer alignment: */

L
Linus Torvalds 已提交
1954 1955
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
A
Andrew Morton 已提交
1956 1957 1958 1959
		/*
		 * 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
1960 1961
		 */
		ralign = cache_line_size();
P
Pekka Enberg 已提交
1962
		while (size <= ralign / 2)
L
Linus Torvalds 已提交
1963 1964 1965 1966 1967 1968 1969 1970
			ralign /= 2;
	} else {
		ralign = BYTES_PER_WORD;
	}
	/* 2) arch mandated alignment: disables debug if necessary */
	if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
		if (ralign > BYTES_PER_WORD)
P
Pekka Enberg 已提交
1971
			flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
L
Linus Torvalds 已提交
1972 1973 1974 1975 1976
	}
	/* 3) caller mandated alignment: disables debug if necessary */
	if (ralign < align) {
		ralign = align;
		if (ralign > BYTES_PER_WORD)
P
Pekka Enberg 已提交
1977
			flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
L
Linus Torvalds 已提交
1978
	}
A
Andrew Morton 已提交
1979 1980
	/*
	 * 4) Store it. Note that the debug code below can reduce
L
Linus Torvalds 已提交
1981 1982 1983 1984 1985
	 *    the alignment to BYTES_PER_WORD.
	 */
	align = ralign;

	/* Get cache's description obj. */
1986
	cachep = kmem_cache_alloc(&cache_cache, SLAB_KERNEL);
L
Linus Torvalds 已提交
1987
	if (!cachep)
1988
		goto oops;
1989
	memset(cachep, 0, sizeof(struct kmem_cache));
L
Linus Torvalds 已提交
1990 1991

#if DEBUG
1992
	cachep->obj_size = size;
L
Linus Torvalds 已提交
1993 1994 1995 1996 1997 1998

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

		/* add space for red zone words */
1999
		cachep->obj_offset += BYTES_PER_WORD;
P
Pekka Enberg 已提交
2000
		size += 2 * BYTES_PER_WORD;
L
Linus Torvalds 已提交
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
	}
	if (flags & SLAB_STORE_USER) {
		/* user store requires word alignment and
		 * one word storage behind the end of the real
		 * object.
		 */
		align = BYTES_PER_WORD;
		size += BYTES_PER_WORD;
	}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
P
Pekka Enberg 已提交
2011
	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2012 2013
	    && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
		cachep->obj_offset += PAGE_SIZE - size;
L
Linus Torvalds 已提交
2014 2015 2016 2017 2018 2019
		size = PAGE_SIZE;
	}
#endif
#endif

	/* Determine if the slab management is 'on' or 'off' slab. */
P
Pekka Enberg 已提交
2020
	if (size >= (PAGE_SIZE >> 3))
L
Linus Torvalds 已提交
2021 2022 2023 2024 2025 2026 2027 2028
		/*
		 * 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);

2029
	left_over = calculate_slab_order(cachep, size, align, flags);
L
Linus Torvalds 已提交
2030 2031 2032 2033 2034

	if (!cachep->num) {
		printk("kmem_cache_create: couldn't create cache %s.\n", name);
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
2035
		goto oops;
L
Linus Torvalds 已提交
2036
	}
P
Pekka Enberg 已提交
2037 2038
	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
			  + sizeof(struct slab), align);
L
Linus Torvalds 已提交
2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050

	/*
	 * 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
2051 2052
		slab_size =
		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
L
Linus Torvalds 已提交
2053 2054 2055 2056 2057 2058
	}

	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
2059
	cachep->colour = left_over / cachep->colour_off;
L
Linus Torvalds 已提交
2060 2061 2062 2063 2064
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
	if (flags & SLAB_CACHE_DMA)
		cachep->gfpflags |= GFP_DMA;
2065
	cachep->buffer_size = size;
L
Linus Torvalds 已提交
2066 2067

	if (flags & CFLGS_OFF_SLAB)
2068
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
L
Linus Torvalds 已提交
2069 2070 2071 2072 2073
	cachep->ctor = ctor;
	cachep->dtor = dtor;
	cachep->name = name;


2074
	setup_cpu_cache(cachep);
L
Linus Torvalds 已提交
2075 2076 2077

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
A
Andrew Morton 已提交
2078
oops:
L
Linus Torvalds 已提交
2079 2080
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
P
Pekka Enberg 已提交
2081
		      name);
I
Ingo Molnar 已提交
2082
	mutex_unlock(&cache_chain_mutex);
2083
	unlock_cpu_hotplug();
L
Linus Torvalds 已提交
2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098
	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());
}

2099
static void check_spinlock_acquired(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2100 2101 2102
{
#ifdef CONFIG_SMP
	check_irq_off();
2103
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
2104 2105
#endif
}
2106

2107
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2108 2109 2110 2111 2112 2113 2114
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
2115 2116 2117 2118
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
2119
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
2120 2121 2122 2123 2124
#endif

/*
 * Waits for all CPUs to execute func().
 */
P
Pekka Enberg 已提交
2125
static void smp_call_function_all_cpus(void (*func)(void *arg), void *arg)
L
Linus Torvalds 已提交
2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138
{
	check_irq_on();
	preempt_disable();
	local_irq_disable();
	func(arg);
	local_irq_enable();

	if (smp_call_function(func, arg, 1, 1))
		BUG();

	preempt_enable();
}

A
Andrew Morton 已提交
2139 2140
static void drain_array_locked(struct kmem_cache *cachep,
			struct array_cache *ac, int force, int node);
L
Linus Torvalds 已提交
2141 2142 2143

static void do_drain(void *arg)
{
A
Andrew Morton 已提交
2144
	struct kmem_cache *cachep = arg;
L
Linus Torvalds 已提交
2145
	struct array_cache *ac;
2146
	int node = numa_node_id();
L
Linus Torvalds 已提交
2147 2148

	check_irq_off();
2149
	ac = cpu_cache_get(cachep);
2150 2151 2152
	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
2153 2154 2155
	ac->avail = 0;
}

2156
static void drain_cpu_caches(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2157
{
2158 2159 2160
	struct kmem_list3 *l3;
	int node;

L
Linus Torvalds 已提交
2161 2162
	smp_call_function_all_cpus(do_drain, cachep);
	check_irq_on();
P
Pekka Enberg 已提交
2163
	for_each_online_node(node) {
2164 2165
		l3 = cachep->nodelists[node];
		if (l3) {
2166
			spin_lock_irq(&l3->list_lock);
2167
			drain_array_locked(cachep, l3->shared, 1, node);
2168
			spin_unlock_irq(&l3->list_lock);
2169
			if (l3->alien)
2170
				drain_alien_cache(cachep, l3->alien);
2171 2172
		}
	}
L
Linus Torvalds 已提交
2173 2174
}

2175
static int __node_shrink(struct kmem_cache *cachep, int node)
L
Linus Torvalds 已提交
2176 2177
{
	struct slab *slabp;
2178
	struct kmem_list3 *l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
2179 2180
	int ret;

2181
	for (;;) {
L
Linus Torvalds 已提交
2182 2183
		struct list_head *p;

2184 2185
		p = l3->slabs_free.prev;
		if (p == &l3->slabs_free)
L
Linus Torvalds 已提交
2186 2187
			break;

2188
		slabp = list_entry(l3->slabs_free.prev, struct slab, list);
L
Linus Torvalds 已提交
2189 2190 2191 2192 2193 2194
#if DEBUG
		if (slabp->inuse)
			BUG();
#endif
		list_del(&slabp->list);

2195 2196
		l3->free_objects -= cachep->num;
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
2197
		slab_destroy(cachep, slabp);
2198
		spin_lock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
2199
	}
P
Pekka Enberg 已提交
2200
	ret = !list_empty(&l3->slabs_full) || !list_empty(&l3->slabs_partial);
L
Linus Torvalds 已提交
2201 2202 2203
	return ret;
}

2204
static int __cache_shrink(struct kmem_cache *cachep)
2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222
{
	int ret = 0, i = 0;
	struct kmem_list3 *l3;

	drain_cpu_caches(cachep);

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

L
Linus Torvalds 已提交
2223 2224 2225 2226 2227 2228 2229
/**
 * 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.
 */
2230
int kmem_cache_shrink(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242
{
	if (!cachep || in_interrupt())
		BUG();

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

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
2243
 * Remove a struct kmem_cache object from the slab cache.
L
Linus Torvalds 已提交
2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255
 * Returns 0 on success.
 *
 * It is expected this function will be called by a module when it is
 * unloaded.  This will remove the cache completely, and avoid a duplicate
 * cache being allocated each time a module is loaded and unloaded, if the
 * module doesn't have persistent in-kernel storage across loads and unloads.
 *
 * The cache must be empty before calling this function.
 *
 * The caller must guarantee that noone will allocate memory from the cache
 * during the kmem_cache_destroy().
 */
2256
int kmem_cache_destroy(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2257 2258
{
	int i;
2259
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2260 2261 2262 2263 2264 2265 2266 2267

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

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

	/* Find the cache in the chain of caches. */
I
Ingo Molnar 已提交
2268
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2269 2270 2271 2272
	/*
	 * the chain is never empty, cache_cache is never destroyed
	 */
	list_del(&cachep->next);
I
Ingo Molnar 已提交
2273
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2274 2275 2276

	if (__cache_shrink(cachep)) {
		slab_error(cachep, "Can't free all objects");
I
Ingo Molnar 已提交
2277
		mutex_lock(&cache_chain_mutex);
P
Pekka Enberg 已提交
2278
		list_add(&cachep->next, &cache_chain);
I
Ingo Molnar 已提交
2279
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2280 2281 2282 2283 2284
		unlock_cpu_hotplug();
		return 1;
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2285
		synchronize_rcu();
L
Linus Torvalds 已提交
2286

2287
	for_each_online_cpu(i)
P
Pekka Enberg 已提交
2288
	    kfree(cachep->array[i]);
L
Linus Torvalds 已提交
2289 2290

	/* NUMA: free the list3 structures */
2291
	for_each_online_node(i) {
A
Andrew Morton 已提交
2292 2293
		l3 = cachep->nodelists[i];
		if (l3) {
2294 2295 2296 2297 2298
			kfree(l3->shared);
			free_alien_cache(l3->alien);
			kfree(l3);
		}
	}
L
Linus Torvalds 已提交
2299 2300 2301 2302 2303 2304 2305
	kmem_cache_free(&cache_cache, cachep);
	unlock_cpu_hotplug();
	return 0;
}
EXPORT_SYMBOL(kmem_cache_destroy);

/* Get the memory for a slab management obj. */
2306
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2307
				   int colour_off, gfp_t local_flags)
L
Linus Torvalds 已提交
2308 2309
{
	struct slab *slabp;
P
Pekka Enberg 已提交
2310

L
Linus Torvalds 已提交
2311 2312 2313 2314 2315 2316
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
		slabp = kmem_cache_alloc(cachep->slabp_cache, local_flags);
		if (!slabp)
			return NULL;
	} else {
P
Pekka Enberg 已提交
2317
		slabp = objp + colour_off;
L
Linus Torvalds 已提交
2318 2319 2320 2321
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
P
Pekka Enberg 已提交
2322
	slabp->s_mem = objp + colour_off;
L
Linus Torvalds 已提交
2323 2324 2325 2326 2327
	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
P
Pekka Enberg 已提交
2328
	return (kmem_bufctl_t *) (slabp + 1);
L
Linus Torvalds 已提交
2329 2330
}

2331
static void cache_init_objs(struct kmem_cache *cachep,
P
Pekka Enberg 已提交
2332
			    struct slab *slabp, unsigned long ctor_flags)
L
Linus Torvalds 已提交
2333 2334 2335 2336
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2337
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349
#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
2350 2351 2352
		 * 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
2353 2354
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2355
			cachep->ctor(objp + obj_offset(cachep), cachep,
P
Pekka Enberg 已提交
2356
				     ctor_flags);
L
Linus Torvalds 已提交
2357 2358 2359 2360

		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
2361
					   " end of an object");
L
Linus Torvalds 已提交
2362 2363
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2364
					   " start of an object");
L
Linus Torvalds 已提交
2365
		}
A
Andrew Morton 已提交
2366 2367
		if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
			    OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
P
Pekka Enberg 已提交
2368
			kernel_map_pages(virt_to_page(objp),
2369
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2370 2371 2372 2373
#else
		if (cachep->ctor)
			cachep->ctor(objp, cachep, ctor_flags);
#endif
P
Pekka Enberg 已提交
2374
		slab_bufctl(slabp)[i] = i + 1;
L
Linus Torvalds 已提交
2375
	}
P
Pekka Enberg 已提交
2376
	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
L
Linus Torvalds 已提交
2377 2378 2379
	slabp->free = 0;
}

2380
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2381
{
A
Andrew Morton 已提交
2382 2383 2384 2385
	if (flags & SLAB_DMA)
		BUG_ON(!(cachep->gfpflags & GFP_DMA));
	else
		BUG_ON(cachep->gfpflags & GFP_DMA);
L
Linus Torvalds 已提交
2386 2387
}

A
Andrew Morton 已提交
2388 2389
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
				int nodeid)
2390
{
2391
	void *objp = index_to_obj(cachep, slabp, slabp->free);
2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404
	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
2405 2406
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
				void *objp, int nodeid)
2407
{
2408
	unsigned int objnr = obj_to_index(cachep, slabp, objp);
2409 2410 2411 2412 2413 2414 2415

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

	if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
		printk(KERN_ERR "slab: double free detected in cache "
A
Andrew Morton 已提交
2416
				"'%s', objp %p\n", cachep->name, objp);
2417 2418 2419 2420 2421 2422 2423 2424
		BUG();
	}
#endif
	slab_bufctl(slabp)[objnr] = slabp->free;
	slabp->free = objnr;
	slabp->inuse--;
}

A
Andrew Morton 已提交
2425 2426
static void set_slab_attr(struct kmem_cache *cachep, struct slab *slabp,
			void *objp)
L
Linus Torvalds 已提交
2427 2428 2429 2430 2431 2432 2433 2434
{
	int i;
	struct page *page;

	/* Nasty!!!!!! I hope this is OK. */
	i = 1 << cachep->gfporder;
	page = virt_to_page(objp);
	do {
2435 2436
		page_set_cache(page, cachep);
		page_set_slab(page, slabp);
L
Linus Torvalds 已提交
2437 2438 2439 2440 2441 2442 2443 2444
		page++;
	} while (--i);
}

/*
 * Grow (by 1) the number of slabs within a cache.  This is called by
 * kmem_cache_alloc() when there are no active objs left in a cache.
 */
2445
static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
2446
{
P
Pekka Enberg 已提交
2447 2448 2449 2450 2451
	struct slab *slabp;
	void *objp;
	size_t offset;
	gfp_t local_flags;
	unsigned long ctor_flags;
2452
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2453

A
Andrew Morton 已提交
2454 2455 2456
	/*
	 * 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
2457
	 */
P
Pekka Enberg 已提交
2458
	if (flags & ~(SLAB_DMA | SLAB_LEVEL_MASK | SLAB_NO_GROW))
L
Linus Torvalds 已提交
2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471
		BUG();
	if (flags & SLAB_NO_GROW)
		return 0;

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

2472
	/* Take the l3 list lock to change the colour_next on this node */
L
Linus Torvalds 已提交
2473
	check_irq_off();
2474 2475
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2476 2477

	/* Get colour for the slab, and cal the next value. */
2478 2479 2480 2481 2482
	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
2483

2484
	offset *= cachep->colour_off;
L
Linus Torvalds 已提交
2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496

	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
2497 2498 2499
	/*
	 * Get mem for the objs.  Attempt to allocate a physical page from
	 * 'nodeid'.
2500
	 */
A
Andrew Morton 已提交
2501 2502
	objp = kmem_getpages(cachep, flags, nodeid);
	if (!objp)
L
Linus Torvalds 已提交
2503 2504 2505
		goto failed;

	/* Get slab management. */
A
Andrew Morton 已提交
2506 2507
	slabp = alloc_slabmgmt(cachep, objp, offset, local_flags);
	if (!slabp)
L
Linus Torvalds 已提交
2508 2509
		goto opps1;

2510
	slabp->nodeid = nodeid;
L
Linus Torvalds 已提交
2511 2512 2513 2514 2515 2516 2517
	set_slab_attr(cachep, slabp, objp);

	cache_init_objs(cachep, slabp, ctor_flags);

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2518
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2519 2520

	/* Make slab active. */
2521
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2522
	STATS_INC_GROWN(cachep);
2523 2524
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2525
	return 1;
A
Andrew Morton 已提交
2526
opps1:
L
Linus Torvalds 已提交
2527
	kmem_freepages(cachep, objp);
A
Andrew Morton 已提交
2528
failed:
L
Linus Torvalds 已提交
2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547
	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	return 0;
}

#if DEBUG

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

	if (!virt_addr_valid(objp)) {
		printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
P
Pekka Enberg 已提交
2548 2549
		       (unsigned long)objp);
		BUG();
L
Linus Torvalds 已提交
2550 2551 2552
	}
	page = virt_to_page(objp);
	if (!PageSlab(page)) {
P
Pekka Enberg 已提交
2553 2554
		printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n",
		       (unsigned long)objp);
L
Linus Torvalds 已提交
2555 2556 2557 2558
		BUG();
	}
}

2559
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2560
				   void *caller)
L
Linus Torvalds 已提交
2561 2562 2563 2564 2565
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

2566
	objp -= obj_offset(cachep);
L
Linus Torvalds 已提交
2567 2568 2569
	kfree_debugcheck(objp);
	page = virt_to_page(objp);

2570
	if (page_get_cache(page) != cachep) {
A
Andrew Morton 已提交
2571 2572
		printk(KERN_ERR "mismatch in kmem_cache_free: expected "
				"cache %p, got %p\n",
P
Pekka Enberg 已提交
2573
		       page_get_cache(page), cachep);
L
Linus Torvalds 已提交
2574
		printk(KERN_ERR "%p is %s.\n", cachep, cachep->name);
P
Pekka Enberg 已提交
2575 2576
		printk(KERN_ERR "%p is %s.\n", page_get_cache(page),
		       page_get_cache(page)->name);
L
Linus Torvalds 已提交
2577 2578
		WARN_ON(1);
	}
2579
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2580 2581

	if (cachep->flags & SLAB_RED_ZONE) {
A
Andrew Morton 已提交
2582 2583 2584 2585 2586 2587
		if (*dbg_redzone1(cachep, objp) != RED_ACTIVE ||
				*dbg_redzone2(cachep, objp) != RED_ACTIVE) {
			slab_error(cachep, "double free, or memory outside"
						" object was overwritten");
			printk(KERN_ERR "%p: redzone 1:0x%lx, "
					"redzone 2:0x%lx.\n",
P
Pekka Enberg 已提交
2588 2589
			       objp, *dbg_redzone1(cachep, objp),
			       *dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
2590 2591 2592 2593 2594 2595 2596
		}
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

2597
	objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
2598 2599

	BUG_ON(objnr >= cachep->num);
2600
	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
L
Linus Torvalds 已提交
2601 2602

	if (cachep->flags & SLAB_DEBUG_INITIAL) {
A
Andrew Morton 已提交
2603 2604 2605 2606
		/*
		 * Need to call the slab's constructor so the caller can
		 * perform a verify of its state (debugging).  Called without
		 * the cache-lock held.
L
Linus Torvalds 已提交
2607
		 */
2608
		cachep->ctor(objp + obj_offset(cachep),
P
Pekka Enberg 已提交
2609
			     cachep, SLAB_CTOR_CONSTRUCTOR | SLAB_CTOR_VERIFY);
L
Linus Torvalds 已提交
2610 2611 2612 2613 2614
	}
	if (cachep->flags & SLAB_POISON && cachep->dtor) {
		/* we want to cache poison the object,
		 * call the destruction callback
		 */
2615
		cachep->dtor(objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
2616 2617 2618
	}
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
2619
		if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
L
Linus Torvalds 已提交
2620
			store_stackinfo(cachep, objp, (unsigned long)caller);
P
Pekka Enberg 已提交
2621
			kernel_map_pages(virt_to_page(objp),
2622
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

2633
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
2634 2635 2636
{
	kmem_bufctl_t i;
	int entries = 0;
P
Pekka Enberg 已提交
2637

L
Linus Torvalds 已提交
2638 2639 2640 2641 2642 2643 2644
	/* 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
2645 2646 2647 2648
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
2649
		for (i = 0;
2650
		     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
P
Pekka Enberg 已提交
2651
		     i++) {
A
Andrew Morton 已提交
2652
			if (i % 16 == 0)
L
Linus Torvalds 已提交
2653
				printk("\n%03x:", i);
P
Pekka Enberg 已提交
2654
			printk(" %02x", ((unsigned char *)slabp)[i]);
L
Linus Torvalds 已提交
2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665
		}
		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

2666
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2667 2668 2669 2670 2671 2672
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;

	check_irq_off();
2673
	ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2674
retry:
L
Linus Torvalds 已提交
2675 2676
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
A
Andrew Morton 已提交
2677 2678 2679 2680
		/*
		 * 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
2681 2682 2683
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
2684 2685 2686 2687
	l3 = cachep->nodelists[numa_node_id()];

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2688 2689 2690 2691 2692 2693 2694 2695

	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
		if (shared_array->avail) {
			if (batchcount > shared_array->avail)
				batchcount = shared_array->avail;
			shared_array->avail -= batchcount;
			ac->avail = batchcount;
2696
			memcpy(ac->entry,
P
Pekka Enberg 已提交
2697 2698
			       &(shared_array->entry[shared_array->avail]),
			       sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722
			shared_array->touched = 1;
			goto alloc_done;
		}
	}
	while (batchcount > 0) {
		struct list_head *entry;
		struct slab *slabp;
		/* Get slab alloc is to come from. */
		entry = l3->slabs_partial.next;
		if (entry == &l3->slabs_partial) {
			l3->free_touched = 1;
			entry = l3->slabs_free.next;
			if (entry == &l3->slabs_free)
				goto must_grow;
		}

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

2723 2724
			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
							    numa_node_id());
L
Linus Torvalds 已提交
2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735
		}
		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
2736
must_grow:
L
Linus Torvalds 已提交
2737
	l3->free_objects -= ac->avail;
A
Andrew Morton 已提交
2738
alloc_done:
2739
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2740 2741 2742

	if (unlikely(!ac->avail)) {
		int x;
2743 2744
		x = cache_grow(cachep, flags, numa_node_id());

A
Andrew Morton 已提交
2745
		/* cache_grow can reenable interrupts, then ac could change. */
2746
		ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2747
		if (!x && ac->avail == 0)	/* no objects in sight? abort */
L
Linus Torvalds 已提交
2748 2749
			return NULL;

A
Andrew Morton 已提交
2750
		if (!ac->avail)		/* objects refilled by interrupt? */
L
Linus Torvalds 已提交
2751 2752 2753
			goto retry;
	}
	ac->touched = 1;
2754
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
2755 2756
}

A
Andrew Morton 已提交
2757 2758
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
						gfp_t flags)
L
Linus Torvalds 已提交
2759 2760 2761 2762 2763 2764 2765 2766
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
A
Andrew Morton 已提交
2767 2768
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
				gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
2769
{
P
Pekka Enberg 已提交
2770
	if (!objp)
L
Linus Torvalds 已提交
2771
		return objp;
P
Pekka Enberg 已提交
2772
	if (cachep->flags & SLAB_POISON) {
L
Linus Torvalds 已提交
2773
#ifdef CONFIG_DEBUG_PAGEALLOC
2774
		if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
P
Pekka Enberg 已提交
2775
			kernel_map_pages(virt_to_page(objp),
2776
					 cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787
		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
2788 2789 2790 2791
		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
2792
			printk(KERN_ERR
A
Andrew Morton 已提交
2793 2794 2795
				"%p: redzone 1:0x%lx, redzone 2:0x%lx\n",
				objp, *dbg_redzone1(cachep, objp),
				*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
2796 2797 2798 2799
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
2800
	objp += obj_offset(cachep);
L
Linus Torvalds 已提交
2801
	if (cachep->ctor && cachep->flags & SLAB_POISON) {
P
Pekka Enberg 已提交
2802
		unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
L
Linus Torvalds 已提交
2803 2804 2805 2806 2807

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

		cachep->ctor(objp, cachep, ctor_flags);
P
Pekka Enberg 已提交
2808
	}
L
Linus Torvalds 已提交
2809 2810 2811 2812 2813 2814
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

2815
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2816
{
P
Pekka Enberg 已提交
2817
	void *objp;
L
Linus Torvalds 已提交
2818 2819
	struct array_cache *ac;

2820
#ifdef CONFIG_NUMA
2821
	if (unlikely(current->mempolicy && !in_interrupt())) {
2822 2823 2824 2825 2826 2827 2828
		int nid = slab_node(current->mempolicy);

		if (nid != numa_node_id())
			return __cache_alloc_node(cachep, flags, nid);
	}
#endif

2829
	check_irq_off();
2830
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
2831 2832 2833
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
2834
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
2835 2836 2837 2838
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
2839 2840 2841
	return objp;
}

A
Andrew Morton 已提交
2842 2843
static __always_inline void *__cache_alloc(struct kmem_cache *cachep,
						gfp_t flags, void *caller)
2844 2845
{
	unsigned long save_flags;
P
Pekka Enberg 已提交
2846
	void *objp;
2847 2848 2849 2850 2851

	cache_alloc_debugcheck_before(cachep, flags);

	local_irq_save(save_flags);
	objp = ____cache_alloc(cachep, flags);
L
Linus Torvalds 已提交
2852
	local_irq_restore(save_flags);
2853
	objp = cache_alloc_debugcheck_after(cachep, flags, objp,
2854
					    caller);
2855
	prefetchw(objp);
L
Linus Torvalds 已提交
2856 2857 2858
	return objp;
}

2859 2860 2861
#ifdef CONFIG_NUMA
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
2862
 */
A
Andrew Morton 已提交
2863 2864
static void *__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
				int nodeid)
2865 2866
{
	struct list_head *entry;
P
Pekka Enberg 已提交
2867 2868 2869 2870 2871 2872 2873 2874
	struct slab *slabp;
	struct kmem_list3 *l3;
	void *obj;
	int x;

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

A
Andrew Morton 已提交
2875
retry:
2876
	check_irq_off();
P
Pekka Enberg 已提交
2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895
	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);

2896
	obj = slab_get_obj(cachep, slabp, nodeid);
P
Pekka Enberg 已提交
2897 2898 2899 2900 2901
	check_slabp(cachep, slabp);
	l3->free_objects--;
	/* move slabp to correct slabp list: */
	list_del(&slabp->list);

A
Andrew Morton 已提交
2902
	if (slabp->free == BUFCTL_END)
P
Pekka Enberg 已提交
2903
		list_add(&slabp->list, &l3->slabs_full);
A
Andrew Morton 已提交
2904
	else
P
Pekka Enberg 已提交
2905
		list_add(&slabp->list, &l3->slabs_partial);
2906

P
Pekka Enberg 已提交
2907 2908
	spin_unlock(&l3->list_lock);
	goto done;
2909

A
Andrew Morton 已提交
2910
must_grow:
P
Pekka Enberg 已提交
2911 2912
	spin_unlock(&l3->list_lock);
	x = cache_grow(cachep, flags, nodeid);
L
Linus Torvalds 已提交
2913

P
Pekka Enberg 已提交
2914 2915
	if (!x)
		return NULL;
2916

P
Pekka Enberg 已提交
2917
	goto retry;
A
Andrew Morton 已提交
2918
done:
P
Pekka Enberg 已提交
2919
	return obj;
2920 2921 2922 2923 2924 2925
}
#endif

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
2926
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
P
Pekka Enberg 已提交
2927
		       int node)
L
Linus Torvalds 已提交
2928 2929
{
	int i;
2930
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2931 2932 2933 2934 2935

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

2936
		slabp = virt_to_slab(objp);
2937
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
2938
		list_del(&slabp->list);
2939
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
2940
		check_slabp(cachep, slabp);
2941
		slab_put_obj(cachep, slabp, objp, node);
L
Linus Torvalds 已提交
2942
		STATS_DEC_ACTIVE(cachep);
2943
		l3->free_objects++;
L
Linus Torvalds 已提交
2944 2945 2946 2947
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
2948 2949
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
L
Linus Torvalds 已提交
2950 2951
				slab_destroy(cachep, slabp);
			} else {
2952
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
2953 2954 2955 2956 2957 2958
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
2959
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
2960 2961 2962 2963
		}
	}
}

2964
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
L
Linus Torvalds 已提交
2965 2966
{
	int batchcount;
2967
	struct kmem_list3 *l3;
2968
	int node = numa_node_id();
L
Linus Torvalds 已提交
2969 2970 2971 2972 2973 2974

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
2975
	l3 = cachep->nodelists[node];
2976 2977 2978
	spin_lock(&l3->list_lock);
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
P
Pekka Enberg 已提交
2979
		int max = shared_array->limit - shared_array->avail;
L
Linus Torvalds 已提交
2980 2981 2982
		if (max) {
			if (batchcount > max)
				batchcount = max;
2983
			memcpy(&(shared_array->entry[shared_array->avail]),
P
Pekka Enberg 已提交
2984
			       ac->entry, sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
2985 2986 2987 2988 2989
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

2990
	free_block(cachep, ac->entry, batchcount, node);
A
Andrew Morton 已提交
2991
free_done:
L
Linus Torvalds 已提交
2992 2993 2994 2995 2996
#if STATS
	{
		int i = 0;
		struct list_head *p;

2997 2998
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009
			struct slab *slabp;

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

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
3010
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3011
	ac->avail -= batchcount;
A
Andrew Morton 已提交
3012
	memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
L
Linus Torvalds 已提交
3013 3014 3015
}

/*
A
Andrew Morton 已提交
3016 3017
 * 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
3018
 */
3019
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3020
{
3021
	struct array_cache *ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3022 3023 3024 3025

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

3026 3027 3028 3029 3030 3031
	/* Make sure we are not freeing a object from another
	 * node to the array cache on this cpu.
	 */
#ifdef CONFIG_NUMA
	{
		struct slab *slabp;
3032
		slabp = virt_to_slab(objp);
3033 3034 3035
		if (unlikely(slabp->nodeid != numa_node_id())) {
			struct array_cache *alien = NULL;
			int nodeid = slabp->nodeid;
A
Andrew Morton 已提交
3036
			struct kmem_list3 *l3;
3037

A
Andrew Morton 已提交
3038
			l3 = cachep->nodelists[numa_node_id()];
3039 3040 3041 3042 3043 3044
			STATS_INC_NODEFREES(cachep);
			if (l3->alien && l3->alien[nodeid]) {
				alien = l3->alien[nodeid];
				spin_lock(&alien->lock);
				if (unlikely(alien->avail == alien->limit))
					__drain_alien_cache(cachep,
P
Pekka Enberg 已提交
3045
							    alien, nodeid);
3046 3047 3048 3049
				alien->entry[alien->avail++] = objp;
				spin_unlock(&alien->lock);
			} else {
				spin_lock(&(cachep->nodelists[nodeid])->
P
Pekka Enberg 已提交
3050
					  list_lock);
3051
				free_block(cachep, &objp, 1, nodeid);
3052
				spin_unlock(&(cachep->nodelists[nodeid])->
P
Pekka Enberg 已提交
3053
					    list_lock);
3054 3055 3056 3057 3058
			}
			return;
		}
	}
#endif
L
Linus Torvalds 已提交
3059 3060
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
3061
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3062 3063 3064 3065
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
3066
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077
	}
}

/**
 * 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.
 */
3078
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3079
{
3080
	return __cache_alloc(cachep, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097
}
EXPORT_SYMBOL(kmem_cache_alloc);

/**
 * kmem_ptr_validate - check if an untrusted pointer might
 *	be a slab entry.
 * @cachep: the cache we're checking against
 * @ptr: pointer to validate
 *
 * This verifies that the untrusted pointer looks sane:
 * it is _not_ a guarantee that the pointer is actually
 * part of the slab cache in question, but it at least
 * validates that the pointer can be dereferenced and
 * looks half-way sane.
 *
 * Currently only used for dentry validation.
 */
3098
int fastcall kmem_ptr_validate(struct kmem_cache *cachep, void *ptr)
L
Linus Torvalds 已提交
3099
{
P
Pekka Enberg 已提交
3100
	unsigned long addr = (unsigned long)ptr;
L
Linus Torvalds 已提交
3101
	unsigned long min_addr = PAGE_OFFSET;
P
Pekka Enberg 已提交
3102
	unsigned long align_mask = BYTES_PER_WORD - 1;
3103
	unsigned long size = cachep->buffer_size;
L
Linus Torvalds 已提交
3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118
	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;
3119
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
3120 3121
		goto out;
	return 1;
A
Andrew Morton 已提交
3122
out:
L
Linus Torvalds 已提交
3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135
	return 0;
}

#ifdef CONFIG_NUMA
/**
 * kmem_cache_alloc_node - Allocate an object on the specified node
 * @cachep: The cache to allocate from.
 * @flags: See kmalloc().
 * @nodeid: node number of the target node.
 *
 * Identical to kmem_cache_alloc, except that this function is slow
 * and can sleep. And it will allocate memory on the given node, which
 * can improve the performance for cpu bound structures.
3136 3137
 * New and improved: it will now make sure that the object gets
 * put on the correct node list so that there is no false sharing.
L
Linus Torvalds 已提交
3138
 */
3139
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
3140
{
3141 3142
	unsigned long save_flags;
	void *ptr;
L
Linus Torvalds 已提交
3143

3144 3145
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
3146 3147

	if (nodeid == -1 || nodeid == numa_node_id() ||
A
Andrew Morton 已提交
3148
			!cachep->nodelists[nodeid])
3149 3150 3151
		ptr = ____cache_alloc(cachep, flags);
	else
		ptr = __cache_alloc_node(cachep, flags, nodeid);
3152
	local_irq_restore(save_flags);
3153 3154 3155

	ptr = cache_alloc_debugcheck_after(cachep, flags, ptr,
					   __builtin_return_address(0));
L
Linus Torvalds 已提交
3156

3157
	return ptr;
L
Linus Torvalds 已提交
3158 3159 3160
}
EXPORT_SYMBOL(kmem_cache_alloc_node);

A
Al Viro 已提交
3161
void *kmalloc_node(size_t size, gfp_t flags, int node)
3162
{
3163
	struct kmem_cache *cachep;
3164 3165 3166 3167 3168 3169 3170

	cachep = kmem_find_general_cachep(size, flags);
	if (unlikely(cachep == NULL))
		return NULL;
	return kmem_cache_alloc_node(cachep, flags, node);
}
EXPORT_SYMBOL(kmalloc_node);
L
Linus Torvalds 已提交
3171 3172 3173 3174 3175 3176
#endif

/**
 * kmalloc - allocate memory
 * @size: how many bytes of memory are required.
 * @flags: the type of memory to allocate.
3177
 * @caller: function caller for debug tracking of the caller
L
Linus Torvalds 已提交
3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194
 *
 * kmalloc is the normal method of allocating memory
 * in the kernel.
 *
 * The @flags argument may be one of:
 *
 * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 *
 * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 *
 * %GFP_ATOMIC - Allocation will not sleep.  Use inside interrupt handlers.
 *
 * Additionally, the %GFP_DMA flag may be set to indicate the memory
 * must be suitable for DMA.  This can mean different things on different
 * platforms.  For example, on i386, it means that the memory must come
 * from the first 16MB.
 */
3195 3196
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
					  void *caller)
L
Linus Torvalds 已提交
3197
{
3198
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3199

3200 3201 3202 3203 3204 3205
	/* 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);
3206 3207
	if (unlikely(cachep == NULL))
		return NULL;
3208 3209 3210 3211 3212 3213 3214 3215
	return __cache_alloc(cachep, flags, caller);
}

#ifndef CONFIG_DEBUG_SLAB

void *__kmalloc(size_t size, gfp_t flags)
{
	return __do_kmalloc(size, flags, NULL);
L
Linus Torvalds 已提交
3216 3217 3218
}
EXPORT_SYMBOL(__kmalloc);

3219 3220 3221 3222 3223 3224 3225 3226 3227 3228
#else

void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
{
	return __do_kmalloc(size, flags, caller);
}
EXPORT_SYMBOL(__kmalloc_track_caller);

#endif

L
Linus Torvalds 已提交
3229 3230 3231 3232 3233 3234 3235 3236
#ifdef CONFIG_SMP
/**
 * __alloc_percpu - allocate one copy of the object for every present
 * cpu in the system, zeroing them.
 * Objects should be dereferenced using the per_cpu_ptr macro only.
 *
 * @size: how many bytes of memory are required.
 */
3237
void *__alloc_percpu(size_t size)
L
Linus Torvalds 已提交
3238 3239
{
	int i;
P
Pekka Enberg 已提交
3240
	struct percpu_data *pdata = kmalloc(sizeof(*pdata), GFP_KERNEL);
L
Linus Torvalds 已提交
3241 3242 3243 3244

	if (!pdata)
		return NULL;

3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256
	/*
	 * Cannot use for_each_online_cpu since a cpu may come online
	 * and we have no way of figuring out how to fix the array
	 * that we have allocated then....
	 */
	for_each_cpu(i) {
		int node = cpu_to_node(i);

		if (node_online(node))
			pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node);
		else
			pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
L
Linus Torvalds 已提交
3257 3258 3259 3260 3261 3262 3263

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

	/* Catch derefs w/o wrappers */
P
Pekka Enberg 已提交
3264
	return (void *)(~(unsigned long)pdata);
L
Linus Torvalds 已提交
3265

A
Andrew Morton 已提交
3266
unwind_oom:
L
Linus Torvalds 已提交
3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285
	while (--i >= 0) {
		if (!cpu_possible(i))
			continue;
		kfree(pdata->ptrs[i]);
	}
	kfree(pdata);
	return NULL;
}
EXPORT_SYMBOL(__alloc_percpu);
#endif

/**
 * kmem_cache_free - Deallocate an object
 * @cachep: The cache the allocation was from.
 * @objp: The previously allocated object.
 *
 * Free an object which was previously allocated from this
 * cache.
 */
3286
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299
{
	unsigned long flags;

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

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3300 3301
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3302 3303 3304 3305 3306
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
3307
	struct kmem_cache *c;
L
Linus Torvalds 已提交
3308 3309 3310 3311 3312 3313
	unsigned long flags;

	if (unlikely(!objp))
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3314
	c = virt_to_cache(objp);
3315
	mutex_debug_check_no_locks_freed(objp, obj_size(c));
P
Pekka Enberg 已提交
3316
	__cache_free(c, (void *)objp);
L
Linus Torvalds 已提交
3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

#ifdef CONFIG_SMP
/**
 * free_percpu - free previously allocated percpu memory
 * @objp: pointer returned by alloc_percpu.
 *
 * Don't free memory not originally allocated by alloc_percpu()
 * The complemented objp is to check for that.
 */
P
Pekka Enberg 已提交
3329
void free_percpu(const void *objp)
L
Linus Torvalds 已提交
3330 3331
{
	int i;
P
Pekka Enberg 已提交
3332
	struct percpu_data *p = (struct percpu_data *)(~(unsigned long)objp);
L
Linus Torvalds 已提交
3333

3334 3335 3336 3337
	/*
	 * We allocate for all cpus so we cannot use for online cpu here.
	 */
	for_each_cpu(i)
P
Pekka Enberg 已提交
3338
	    kfree(p->ptrs[i]);
L
Linus Torvalds 已提交
3339 3340 3341 3342 3343
	kfree(p);
}
EXPORT_SYMBOL(free_percpu);
#endif

3344
unsigned int kmem_cache_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3345
{
3346
	return obj_size(cachep);
L
Linus Torvalds 已提交
3347 3348 3349
}
EXPORT_SYMBOL(kmem_cache_size);

3350
const char *kmem_cache_name(struct kmem_cache *cachep)
3351 3352 3353 3354 3355
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3356 3357 3358
/*
 * This initializes kmem_list3 for all nodes.
 */
3359
static int alloc_kmemlist(struct kmem_cache *cachep)
3360 3361 3362 3363 3364 3365 3366 3367 3368
{
	int node;
	struct kmem_list3 *l3;
	int err = 0;

	for_each_online_node(node) {
		struct array_cache *nc = NULL, *new;
		struct array_cache **new_alien = NULL;
#ifdef CONFIG_NUMA
A
Andrew Morton 已提交
3369 3370
		new_alien = alloc_alien_cache(node, cachep->limit);
		if (!new_alien)
3371 3372
			goto fail;
#endif
A
Andrew Morton 已提交
3373 3374 3375
		new = alloc_arraycache(node, cachep->shared*cachep->batchcount,
					0xbaadf00d);
		if (!new)
3376
			goto fail;
A
Andrew Morton 已提交
3377 3378
		l3 = cachep->nodelists[node];
		if (l3) {
3379 3380
			spin_lock_irq(&l3->list_lock);

A
Andrew Morton 已提交
3381 3382
			nc = cachep->nodelists[node]->shared;
			if (nc)
P
Pekka Enberg 已提交
3383
				free_block(cachep, nc->entry, nc->avail, node);
3384 3385 3386 3387 3388 3389

			l3->shared = new;
			if (!cachep->nodelists[node]->alien) {
				l3->alien = new_alien;
				new_alien = NULL;
			}
P
Pekka Enberg 已提交
3390
			l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3391
					cachep->batchcount + cachep->num;
3392 3393 3394 3395 3396
			spin_unlock_irq(&l3->list_lock);
			kfree(nc);
			free_alien_cache(new_alien);
			continue;
		}
A
Andrew Morton 已提交
3397 3398
		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
		if (!l3)
3399 3400 3401 3402
			goto fail;

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
A
Andrew Morton 已提交
3403
				((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3404 3405
		l3->shared = new;
		l3->alien = new_alien;
P
Pekka Enberg 已提交
3406
		l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3407
					cachep->batchcount + cachep->num;
3408 3409 3410
		cachep->nodelists[node] = l3;
	}
	return err;
A
Andrew Morton 已提交
3411
fail:
3412 3413 3414 3415
	err = -ENOMEM;
	return err;
}

L
Linus Torvalds 已提交
3416
struct ccupdate_struct {
3417
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3418 3419 3420 3421 3422
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
A
Andrew Morton 已提交
3423
	struct ccupdate_struct *new = info;
L
Linus Torvalds 已提交
3424 3425 3426
	struct array_cache *old;

	check_irq_off();
3427
	old = cpu_cache_get(new->cachep);
3428

L
Linus Torvalds 已提交
3429 3430 3431 3432
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}

3433
/* Always called with the cache_chain_mutex held */
A
Andrew Morton 已提交
3434 3435
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
				int batchcount, int shared)
L
Linus Torvalds 已提交
3436 3437
{
	struct ccupdate_struct new;
3438
	int i, err;
L
Linus Torvalds 已提交
3439

P
Pekka Enberg 已提交
3440
	memset(&new.new, 0, sizeof(new.new));
3441
	for_each_online_cpu(i) {
A
Andrew Morton 已提交
3442 3443
		new.new[i] = alloc_arraycache(cpu_to_node(i), limit,
						batchcount);
3444
		if (!new.new[i]) {
P
Pekka Enberg 已提交
3445 3446
			for (i--; i >= 0; i--)
				kfree(new.new[i]);
3447
			return -ENOMEM;
L
Linus Torvalds 已提交
3448 3449 3450 3451 3452
		}
	}
	new.cachep = cachep;

	smp_call_function_all_cpus(do_ccupdate_local, (void *)&new);
3453

L
Linus Torvalds 已提交
3454 3455 3456
	check_irq_on();
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3457
	cachep->shared = shared;
L
Linus Torvalds 已提交
3458

3459
	for_each_online_cpu(i) {
L
Linus Torvalds 已提交
3460 3461 3462
		struct array_cache *ccold = new.new[i];
		if (!ccold)
			continue;
3463
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3464
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3465
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3466 3467 3468
		kfree(ccold);
	}

3469 3470 3471
	err = alloc_kmemlist(cachep);
	if (err) {
		printk(KERN_ERR "alloc_kmemlist failed for %s, error %d.\n",
P
Pekka Enberg 已提交
3472
		       cachep->name, -err);
3473
		BUG();
L
Linus Torvalds 已提交
3474 3475 3476 3477
	}
	return 0;
}

3478
/* Called with cache_chain_mutex held always */
3479
static void enable_cpucache(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3480 3481 3482 3483
{
	int err;
	int limit, shared;

A
Andrew Morton 已提交
3484 3485
	/*
	 * The head array serves three purposes:
L
Linus Torvalds 已提交
3486 3487
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
A
Andrew Morton 已提交
3488
	 * - reduce the number of linked list operations on the slab and
L
Linus Torvalds 已提交
3489 3490 3491 3492
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
3493
	if (cachep->buffer_size > 131072)
L
Linus Torvalds 已提交
3494
		limit = 1;
3495
	else if (cachep->buffer_size > PAGE_SIZE)
L
Linus Torvalds 已提交
3496
		limit = 8;
3497
	else if (cachep->buffer_size > 1024)
L
Linus Torvalds 已提交
3498
		limit = 24;
3499
	else if (cachep->buffer_size > 256)
L
Linus Torvalds 已提交
3500 3501 3502 3503
		limit = 54;
	else
		limit = 120;

A
Andrew Morton 已提交
3504 3505
	/*
	 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
L
Linus Torvalds 已提交
3506 3507 3508 3509 3510 3511 3512 3513 3514
	 * allocation behaviour: Most allocs on one cpu, most free operations
	 * on another cpu. For these cases, an efficient object passing between
	 * cpus is necessary. This is provided by a shared array. The array
	 * replaces Bonwick's magazine layer.
	 * On uniprocessor, it's functionally equivalent (but less efficient)
	 * to a larger limit. Thus disabled by default.
	 */
	shared = 0;
#ifdef CONFIG_SMP
3515
	if (cachep->buffer_size <= PAGE_SIZE)
L
Linus Torvalds 已提交
3516 3517 3518 3519
		shared = 8;
#endif

#if DEBUG
A
Andrew Morton 已提交
3520 3521 3522
	/*
	 * With debugging enabled, large batchcount lead to excessively long
	 * periods with disabled local interrupts. Limit the batchcount
L
Linus Torvalds 已提交
3523 3524 3525 3526
	 */
	if (limit > 32)
		limit = 32;
#endif
P
Pekka Enberg 已提交
3527
	err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
L
Linus Torvalds 已提交
3528 3529
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
P
Pekka Enberg 已提交
3530
		       cachep->name, -err);
L
Linus Torvalds 已提交
3531 3532
}

A
Andrew Morton 已提交
3533 3534
static void drain_array_locked(struct kmem_cache *cachep,
				struct array_cache *ac, int force, int node)
L
Linus Torvalds 已提交
3535 3536 3537
{
	int tofree;

3538
	check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
3539 3540 3541
	if (ac->touched && !force) {
		ac->touched = 0;
	} else if (ac->avail) {
P
Pekka Enberg 已提交
3542
		tofree = force ? ac->avail : (ac->limit + 4) / 5;
A
Andrew Morton 已提交
3543
		if (tofree > ac->avail)
P
Pekka Enberg 已提交
3544
			tofree = (ac->avail + 1) / 2;
3545
		free_block(cachep, ac->entry, tofree, node);
L
Linus Torvalds 已提交
3546
		ac->avail -= tofree;
3547
		memmove(ac->entry, &(ac->entry[tofree]),
P
Pekka Enberg 已提交
3548
			sizeof(void *) * ac->avail);
L
Linus Torvalds 已提交
3549 3550 3551 3552 3553
	}
}

/**
 * cache_reap - Reclaim memory from caches.
3554
 * @unused: unused parameter
L
Linus Torvalds 已提交
3555 3556 3557 3558 3559 3560
 *
 * 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
3561 3562
 * 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
3563 3564 3565 3566
 */
static void cache_reap(void *unused)
{
	struct list_head *walk;
3567
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3568

I
Ingo Molnar 已提交
3569
	if (!mutex_trylock(&cache_chain_mutex)) {
L
Linus Torvalds 已提交
3570
		/* Give up. Setup the next iteration. */
P
Pekka Enberg 已提交
3571 3572
		schedule_delayed_work(&__get_cpu_var(reap_work),
				      REAPTIMEOUT_CPUC);
L
Linus Torvalds 已提交
3573 3574 3575 3576
		return;
	}

	list_for_each(walk, &cache_chain) {
3577
		struct kmem_cache *searchp;
P
Pekka Enberg 已提交
3578
		struct list_head *p;
L
Linus Torvalds 已提交
3579 3580 3581
		int tofree;
		struct slab *slabp;

3582
		searchp = list_entry(walk, struct kmem_cache, next);
L
Linus Torvalds 已提交
3583 3584
		check_irq_on();

3585
		l3 = searchp->nodelists[numa_node_id()];
3586
		reap_alien(searchp, l3);
3587
		spin_lock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3588

3589
		drain_array_locked(searchp, cpu_cache_get(searchp), 0,
P
Pekka Enberg 已提交
3590
				   numa_node_id());
L
Linus Torvalds 已提交
3591

3592
		if (time_after(l3->next_reap, jiffies))
L
Linus Torvalds 已提交
3593 3594
			goto next_unlock;

3595
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
3596

3597 3598
		if (l3->shared)
			drain_array_locked(searchp, l3->shared, 0,
P
Pekka Enberg 已提交
3599
					   numa_node_id());
L
Linus Torvalds 已提交
3600

3601 3602
		if (l3->free_touched) {
			l3->free_touched = 0;
L
Linus Torvalds 已提交
3603 3604 3605
			goto next_unlock;
		}

A
Andrew Morton 已提交
3606 3607
		tofree = (l3->free_limit + 5 * searchp->num - 1) /
				(5 * searchp->num);
L
Linus Torvalds 已提交
3608
		do {
3609 3610
			p = l3->slabs_free.next;
			if (p == &(l3->slabs_free))
L
Linus Torvalds 已提交
3611 3612 3613 3614 3615 3616 3617
				break;

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

A
Andrew Morton 已提交
3618 3619 3620
			/*
			 * Safe to drop the lock. The slab is no longer linked
			 * to the cache. searchp cannot disappear, we hold
L
Linus Torvalds 已提交
3621 3622
			 * cache_chain_lock
			 */
3623 3624
			l3->free_objects -= searchp->num;
			spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3625
			slab_destroy(searchp, slabp);
3626
			spin_lock_irq(&l3->list_lock);
P
Pekka Enberg 已提交
3627
		} while (--tofree > 0);
A
Andrew Morton 已提交
3628
next_unlock:
3629
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3630 3631 3632
		cond_resched();
	}
	check_irq_on();
I
Ingo Molnar 已提交
3633
	mutex_unlock(&cache_chain_mutex);
3634
	next_reap_node();
A
Andrew Morton 已提交
3635
	/* Set up the next iteration */
3636
	schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
L
Linus Torvalds 已提交
3637 3638 3639 3640
}

#ifdef CONFIG_PROC_FS

3641
static void print_slabinfo_header(struct seq_file *m)
L
Linus Torvalds 已提交
3642
{
3643 3644 3645 3646
	/*
	 * Output format version, so at least we can change it
	 * without _too_ many complaints.
	 */
L
Linus Torvalds 已提交
3647
#if STATS
3648
	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
L
Linus Torvalds 已提交
3649
#else
3650
	seq_puts(m, "slabinfo - version: 2.1\n");
L
Linus Torvalds 已提交
3651
#endif
3652 3653 3654 3655
	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
3656
#if STATS
3657 3658 3659
	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
		 "<error> <maxfreeable> <nodeallocs> <remotefrees>");
	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
L
Linus Torvalds 已提交
3660
#endif
3661 3662 3663 3664 3665 3666 3667 3668
	seq_putc(m, '\n');
}

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

I
Ingo Molnar 已提交
3669
	mutex_lock(&cache_chain_mutex);
3670 3671
	if (!n)
		print_slabinfo_header(m);
L
Linus Torvalds 已提交
3672 3673 3674 3675 3676 3677
	p = cache_chain.next;
	while (n--) {
		p = p->next;
		if (p == &cache_chain)
			return NULL;
	}
3678
	return list_entry(p, struct kmem_cache, next);
L
Linus Torvalds 已提交
3679 3680 3681 3682
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
3683
	struct kmem_cache *cachep = p;
L
Linus Torvalds 已提交
3684
	++*pos;
A
Andrew Morton 已提交
3685 3686
	return cachep->next.next == &cache_chain ?
		NULL : list_entry(cachep->next.next, struct kmem_cache, next);
L
Linus Torvalds 已提交
3687 3688 3689 3690
}

static void s_stop(struct seq_file *m, void *p)
{
I
Ingo Molnar 已提交
3691
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
3692 3693 3694 3695
}

static int s_show(struct seq_file *m, void *p)
{
3696
	struct kmem_cache *cachep = p;
L
Linus Torvalds 已提交
3697
	struct list_head *q;
P
Pekka Enberg 已提交
3698 3699 3700 3701 3702
	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;
3703
	const char *name;
L
Linus Torvalds 已提交
3704
	char *error = NULL;
3705 3706
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3707 3708 3709

	active_objs = 0;
	num_slabs = 0;
3710 3711 3712 3713 3714
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

3715 3716
		check_irq_on();
		spin_lock_irq(&l3->list_lock);
3717

P
Pekka Enberg 已提交
3718
		list_for_each(q, &l3->slabs_full) {
3719 3720 3721 3722 3723 3724
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
P
Pekka Enberg 已提交
3725
		list_for_each(q, &l3->slabs_partial) {
3726 3727 3728 3729 3730 3731 3732 3733
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse == cachep->num && !error)
				error = "slabs_partial inuse accounting error";
			if (!slabp->inuse && !error)
				error = "slabs_partial/inuse accounting error";
			active_objs += slabp->inuse;
			active_slabs++;
		}
P
Pekka Enberg 已提交
3734
		list_for_each(q, &l3->slabs_free) {
3735 3736 3737 3738 3739 3740
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
3741 3742
		if (l3->shared)
			shared_avail += l3->shared->avail;
3743

3744
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3745
	}
P
Pekka Enberg 已提交
3746 3747
	num_slabs += active_slabs;
	num_objs = num_slabs * cachep->num;
3748
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
3749 3750
		error = "free_objects accounting error";

P
Pekka Enberg 已提交
3751
	name = cachep->name;
L
Linus Torvalds 已提交
3752 3753 3754 3755
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
3756
		   name, active_objs, num_objs, cachep->buffer_size,
P
Pekka Enberg 已提交
3757
		   cachep->num, (1 << cachep->gfporder));
L
Linus Torvalds 已提交
3758
	seq_printf(m, " : tunables %4u %4u %4u",
P
Pekka Enberg 已提交
3759
		   cachep->limit, cachep->batchcount, cachep->shared);
3760
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
P
Pekka Enberg 已提交
3761
		   active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
3762
#if STATS
P
Pekka Enberg 已提交
3763
	{			/* list3 stats */
L
Linus Torvalds 已提交
3764 3765 3766 3767 3768 3769 3770
		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;
3771
		unsigned long node_frees = cachep->node_frees;
L
Linus Torvalds 已提交
3772

3773
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
A
Andrew Morton 已提交
3774 3775 3776
				%4lu %4lu %4lu %4lu", allocs, high, grown,
				reaped, errors, max_freeable, node_allocs,
				node_frees);
L
Linus Torvalds 已提交
3777 3778 3779 3780 3781 3782 3783 3784 3785
	}
	/* 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
3786
			   allochit, allocmiss, freehit, freemiss);
L
Linus Torvalds 已提交
3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807
	}
#endif
	seq_putc(m, '\n');
	return 0;
}

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

struct seq_operations slabinfo_op = {
P
Pekka Enberg 已提交
3808 3809 3810 3811
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
L
Linus Torvalds 已提交
3812 3813 3814 3815 3816 3817 3818 3819 3820 3821
};

#define MAX_SLABINFO_WRITE 128
/**
 * slabinfo_write - Tuning for the slab allocator
 * @file: unused
 * @buffer: user buffer
 * @count: data length
 * @ppos: unused
 */
P
Pekka Enberg 已提交
3822 3823
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
		       size_t count, loff_t *ppos)
L
Linus Torvalds 已提交
3824
{
P
Pekka Enberg 已提交
3825
	char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
L
Linus Torvalds 已提交
3826 3827
	int limit, batchcount, shared, res;
	struct list_head *p;
P
Pekka Enberg 已提交
3828

L
Linus Torvalds 已提交
3829 3830 3831 3832
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
P
Pekka Enberg 已提交
3833
	kbuf[MAX_SLABINFO_WRITE] = '\0';
L
Linus Torvalds 已提交
3834 3835 3836 3837 3838 3839 3840 3841 3842 3843

	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
3844
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
3845
	res = -EINVAL;
P
Pekka Enberg 已提交
3846
	list_for_each(p, &cache_chain) {
A
Andrew Morton 已提交
3847
		struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3848

A
Andrew Morton 已提交
3849
		cachep = list_entry(p, struct kmem_cache, next);
L
Linus Torvalds 已提交
3850
		if (!strcmp(cachep->name, kbuf)) {
A
Andrew Morton 已提交
3851 3852
			if (limit < 1 || batchcount < 1 ||
					batchcount > limit || shared < 0) {
3853
				res = 0;
L
Linus Torvalds 已提交
3854
			} else {
3855
				res = do_tune_cpucache(cachep, limit,
P
Pekka Enberg 已提交
3856
						       batchcount, shared);
L
Linus Torvalds 已提交
3857 3858 3859 3860
			}
			break;
		}
	}
I
Ingo Molnar 已提交
3861
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
3862 3863 3864 3865 3866 3867
	if (res >= 0)
		res = count;
	return res;
}
#endif

3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879
/**
 * 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.
 */
L
Linus Torvalds 已提交
3880 3881
unsigned int ksize(const void *objp)
{
3882 3883
	if (unlikely(objp == NULL))
		return 0;
L
Linus Torvalds 已提交
3884

3885
	return obj_size(virt_to_cache(objp));
L
Linus Torvalds 已提交
3886
}