slab.c 114.8 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52
/*
 * 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.
 *
A
Andrew Morton 已提交
53
 * The c_cpuarray may not be read with enabled local interrupts -
L
Linus Torvalds 已提交
54 55 56 57
 * it's changed with a smp_call_function().
 *
 * SMP synchronization:
 *  constructors and destructors are called without any locking.
58
 *  Several members in struct kmem_cache and struct slab never change, they
L
Linus Torvalds 已提交
59 60 61 62 63 64 65 66 67 68 69 70
 *	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
I
Ingo Molnar 已提交
71
 *	The global cache-chain is protected by the mutex 'cache_chain_mutex'.
L
Linus Torvalds 已提交
72 73 74 75 76 77
 *	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.
 *
78 79 80 81 82 83 84 85 86
 * 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.
L
Linus Torvalds 已提交
87 88 89 90
 */

#include	<linux/slab.h>
#include	<linux/mm.h>
91
#include	<linux/poison.h>
L
Linus Torvalds 已提交
92 93 94 95 96
#include	<linux/swap.h>
#include	<linux/cache.h>
#include	<linux/interrupt.h>
#include	<linux/init.h>
#include	<linux/compiler.h>
97
#include	<linux/cpuset.h>
L
Linus Torvalds 已提交
98 99 100 101 102 103 104
#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>
105
#include	<linux/string.h>
106
#include	<linux/uaccess.h>
107
#include	<linux/nodemask.h>
108
#include	<linux/mempolicy.h>
I
Ingo Molnar 已提交
109
#include	<linux/mutex.h>
110
#include	<linux/fault-inject.h>
I
Ingo Molnar 已提交
111
#include	<linux/rtmutex.h>
L
Linus Torvalds 已提交
112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175

#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 | \
176
			 SLAB_CACHE_DMA | \
L
Linus Torvalds 已提交
177 178
			 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
179
			 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
L
Linus Torvalds 已提交
180
#else
181
# define CREATE_MASK	(SLAB_HWCACHE_ALIGN | \
L
Linus Torvalds 已提交
182 183
			 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
184
			 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
L
Linus Torvalds 已提交
185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205
#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.
 */

206
typedef unsigned int kmem_bufctl_t;
L
Linus Torvalds 已提交
207 208
#define BUFCTL_END	(((kmem_bufctl_t)(~0U))-0)
#define BUFCTL_FREE	(((kmem_bufctl_t)(~0U))-1)
209 210
#define	BUFCTL_ACTIVE	(((kmem_bufctl_t)(~0U))-2)
#define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-3)
L
Linus Torvalds 已提交
211 212 213 214 215 216 217 218 219

/*
 * 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 {
P
Pekka Enberg 已提交
220 221 222 223 224 225
	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;
L
Linus Torvalds 已提交
226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244
};

/*
 * 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 {
P
Pekka Enberg 已提交
245
	struct rcu_head head;
246
	struct kmem_cache *cachep;
P
Pekka Enberg 已提交
247
	void *addr;
L
Linus Torvalds 已提交
248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266
};

/*
 * 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;
267
	spinlock_t lock;
A
Andrew Morton 已提交
268 269 270 271 272 273
	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 [].
			 */
L
Linus Torvalds 已提交
274 275
};

A
Andrew Morton 已提交
276 277 278
/*
 * bootstrap: The caches do not work without cpuarrays anymore, but the
 * cpuarrays are allocated from the generic caches...
L
Linus Torvalds 已提交
279 280 281 282
 */
#define BOOT_CPUCACHE_ENTRIES	1
struct arraycache_init {
	struct array_cache cache;
P
Pekka Enberg 已提交
283
	void *entries[BOOT_CPUCACHE_ENTRIES];
L
Linus Torvalds 已提交
284 285 286
};

/*
287
 * The slab lists for all objects.
L
Linus Torvalds 已提交
288 289
 */
struct kmem_list3 {
P
Pekka Enberg 已提交
290 291 292 293 294
	struct list_head slabs_partial;	/* partial list first, better asm code */
	struct list_head slabs_full;
	struct list_head slabs_free;
	unsigned long free_objects;
	unsigned int free_limit;
295
	unsigned int colour_next;	/* Per-node cache coloring */
P
Pekka Enberg 已提交
296 297 298
	spinlock_t list_lock;
	struct array_cache *shared;	/* shared per node */
	struct array_cache **alien;	/* on other nodes */
299 300
	unsigned long next_reap;	/* updated without locking */
	int free_touched;		/* updated without locking */
L
Linus Torvalds 已提交
301 302
};

303 304 305 306 307 308 309 310 311
/*
 * 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)

312 313 314 315
static int drain_freelist(struct kmem_cache *cache,
			struct kmem_list3 *l3, int tofree);
static void free_block(struct kmem_cache *cachep, void **objpp, int len,
			int node);
316
static int enable_cpucache(struct kmem_cache *cachep);
317
static void cache_reap(struct work_struct *unused);
318

319
/*
A
Andrew Morton 已提交
320 321
 * 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.
322
 */
323
static __always_inline int index_of(const size_t size)
324
{
325 326
	extern void __bad_size(void);

327 328 329 330 331 332 333 334 335 336
	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
337
		__bad_size();
338
	} else
339
		__bad_size();
340 341 342
	return 0;
}

343 344
static int slab_early_init = 1;

345 346
#define INDEX_AC index_of(sizeof(struct arraycache_init))
#define INDEX_L3 index_of(sizeof(struct kmem_list3))
L
Linus Torvalds 已提交
347

P
Pekka Enberg 已提交
348
static void kmem_list3_init(struct kmem_list3 *parent)
349 350 351 352 353 354
{
	INIT_LIST_HEAD(&parent->slabs_full);
	INIT_LIST_HEAD(&parent->slabs_partial);
	INIT_LIST_HEAD(&parent->slabs_free);
	parent->shared = NULL;
	parent->alien = NULL;
355
	parent->colour_next = 0;
356 357 358 359 360
	spin_lock_init(&parent->list_lock);
	parent->free_objects = 0;
	parent->free_touched = 0;
}

A
Andrew Morton 已提交
361 362 363 364
#define MAKE_LIST(cachep, listp, slab, nodeid)				\
	do {								\
		INIT_LIST_HEAD(listp);					\
		list_splice(&(cachep->nodelists[nodeid]->slab), listp);	\
365 366
	} while (0)

A
Andrew Morton 已提交
367 368
#define	MAKE_ALL_LISTS(cachep, ptr, nodeid)				\
	do {								\
369 370 371 372
	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)
L
Linus Torvalds 已提交
373 374

/*
375
 * struct kmem_cache
L
Linus Torvalds 已提交
376 377 378
 *
 * manages a cache.
 */
P
Pekka Enberg 已提交
379

380
struct kmem_cache {
L
Linus Torvalds 已提交
381
/* 1) per-cpu data, touched during every alloc/free */
P
Pekka Enberg 已提交
382
	struct array_cache *array[NR_CPUS];
383
/* 2) Cache tunables. Protected by cache_chain_mutex */
P
Pekka Enberg 已提交
384 385 386
	unsigned int batchcount;
	unsigned int limit;
	unsigned int shared;
387

388
	unsigned int buffer_size;
389
/* 3) touched by every alloc & free from the backend */
P
Pekka Enberg 已提交
390
	struct kmem_list3 *nodelists[MAX_NUMNODES];
391

A
Andrew Morton 已提交
392 393
	unsigned int flags;		/* constant flags */
	unsigned int num;		/* # of objs per slab */
L
Linus Torvalds 已提交
394

395
/* 4) cache_grow/shrink */
L
Linus Torvalds 已提交
396
	/* order of pgs per slab (2^n) */
P
Pekka Enberg 已提交
397
	unsigned int gfporder;
L
Linus Torvalds 已提交
398 399

	/* force GFP flags, e.g. GFP_DMA */
P
Pekka Enberg 已提交
400
	gfp_t gfpflags;
L
Linus Torvalds 已提交
401

A
Andrew Morton 已提交
402
	size_t colour;			/* cache colouring range */
P
Pekka Enberg 已提交
403
	unsigned int colour_off;	/* colour offset */
404
	struct kmem_cache *slabp_cache;
P
Pekka Enberg 已提交
405
	unsigned int slab_size;
A
Andrew Morton 已提交
406
	unsigned int dflags;		/* dynamic flags */
L
Linus Torvalds 已提交
407 408

	/* constructor func */
409
	void (*ctor) (void *, struct kmem_cache *, unsigned long);
L
Linus Torvalds 已提交
410 411

	/* de-constructor func */
412
	void (*dtor) (void *, struct kmem_cache *, unsigned long);
L
Linus Torvalds 已提交
413

414
/* 5) cache creation/removal */
P
Pekka Enberg 已提交
415 416
	const char *name;
	struct list_head next;
L
Linus Torvalds 已提交
417

418
/* 6) statistics */
L
Linus Torvalds 已提交
419
#if STATS
P
Pekka Enberg 已提交
420 421 422 423 424 425 426 427 428
	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;
429
	unsigned long node_overflow;
P
Pekka Enberg 已提交
430 431 432 433
	atomic_t allochit;
	atomic_t allocmiss;
	atomic_t freehit;
	atomic_t freemiss;
L
Linus Torvalds 已提交
434 435
#endif
#if DEBUG
436 437 438 439 440 441 442 443
	/*
	 * 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;
L
Linus Torvalds 已提交
444 445 446 447 448 449 450
#endif
};

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

#define BATCHREFILL_LIMIT	16
A
Andrew Morton 已提交
451 452 453
/*
 * Optimization question: fewer reaps means less probability for unnessary
 * cpucache drain/refill cycles.
L
Linus Torvalds 已提交
454
 *
A
Adrian Bunk 已提交
455
 * OTOH the cpuarrays can contain lots of objects,
L
Linus Torvalds 已提交
456 457 458 459 460 461 462 463 464 465
 * 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++)
466
#define	STATS_ADD_REAPED(x,y)	((x)->reaped += (y))
A
Andrew Morton 已提交
467 468 469 470 471
#define	STATS_SET_HIGH(x)						\
	do {								\
		if ((x)->num_active > (x)->high_mark)			\
			(x)->high_mark = (x)->num_active;		\
	} while (0)
L
Linus Torvalds 已提交
472 473
#define	STATS_INC_ERR(x)	((x)->errors++)
#define	STATS_INC_NODEALLOCS(x)	((x)->node_allocs++)
474
#define	STATS_INC_NODEFREES(x)	((x)->node_frees++)
475
#define STATS_INC_ACOVERFLOW(x)   ((x)->node_overflow++)
A
Andrew Morton 已提交
476 477 478 479 480
#define	STATS_SET_FREEABLE(x, i)					\
	do {								\
		if ((x)->max_freeable < i)				\
			(x)->max_freeable = i;				\
	} while (0)
L
Linus Torvalds 已提交
481 482 483 484 485 486 487 488 489
#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)
490
#define	STATS_ADD_REAPED(x,y)	do { } while (0)
L
Linus Torvalds 已提交
491 492 493
#define	STATS_SET_HIGH(x)	do { } while (0)
#define	STATS_INC_ERR(x)	do { } while (0)
#define	STATS_INC_NODEALLOCS(x)	do { } while (0)
494
#define	STATS_INC_NODEFREES(x)	do { } while (0)
495
#define STATS_INC_ACOVERFLOW(x)   do { } while (0)
A
Andrew Morton 已提交
496
#define	STATS_SET_FREEABLE(x, i) do { } while (0)
L
Linus Torvalds 已提交
497 498 499 500 501 502 503 504
#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

A
Andrew Morton 已提交
505 506
/*
 * memory layout of objects:
L
Linus Torvalds 已提交
507
 * 0		: objp
508
 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
L
Linus Torvalds 已提交
509 510
 * 		the end of an object is aligned with the end of the real
 * 		allocation. Catches writes behind the end of the allocation.
511
 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
L
Linus Torvalds 已提交
512
 * 		redzone word.
513 514
 * cachep->obj_offset: The real object.
 * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
A
Andrew Morton 已提交
515 516
 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
 *					[BYTES_PER_WORD long]
L
Linus Torvalds 已提交
517
 */
518
static int obj_offset(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
519
{
520
	return cachep->obj_offset;
L
Linus Torvalds 已提交
521 522
}

523
static int obj_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
524
{
525
	return cachep->obj_size;
L
Linus Torvalds 已提交
526 527
}

528
static unsigned long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
529 530
{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
531
	return (unsigned long*) (objp+obj_offset(cachep)-BYTES_PER_WORD);
L
Linus Torvalds 已提交
532 533
}

534
static unsigned long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
535 536 537
{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
	if (cachep->flags & SLAB_STORE_USER)
538
		return (unsigned long *)(objp + cachep->buffer_size -
P
Pekka Enberg 已提交
539
					 2 * BYTES_PER_WORD);
540
	return (unsigned long *)(objp + cachep->buffer_size - BYTES_PER_WORD);
L
Linus Torvalds 已提交
541 542
}

543
static void **dbg_userword(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
544 545
{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
546
	return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
L
Linus Torvalds 已提交
547 548 549 550
}

#else

551 552
#define obj_offset(x)			0
#define obj_size(cachep)		(cachep->buffer_size)
L
Linus Torvalds 已提交
553 554 555 556 557 558 559
#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

/*
A
Andrew Morton 已提交
560 561
 * Maximum size of an obj (in 2^order pages) and absolute limit for the gfp
 * order.
L
Linus Torvalds 已提交
562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580
 */
#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;

A
Andrew Morton 已提交
581 582 583 584
/*
 * 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
Linus Torvalds 已提交
585
 */
586 587 588 589 590 591 592
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)
{
593 594
	if (unlikely(PageCompound(page)))
		page = (struct page *)page_private(page);
595
	BUG_ON(!PageSlab(page));
596 597 598 599 600 601 602 603 604 605
	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)
{
606 607
	if (unlikely(PageCompound(page)))
		page = (struct page *)page_private(page);
608
	BUG_ON(!PageSlab(page));
609 610
	return (struct slab *)page->lru.prev;
}
L
Linus Torvalds 已提交
611

612 613 614 615 616 617 618 619 620 621 622 623
static inline struct kmem_cache *virt_to_cache(const void *obj)
{
	struct page *page = virt_to_page(obj);
	return page_get_cache(page);
}

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

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

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

A
Andrew Morton 已提交
636 637 638
/*
 * These are the default caches for kmalloc. Custom caches can have other sizes.
 */
L
Linus Torvalds 已提交
639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655
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>
P
Pekka Enberg 已提交
656
	{NULL,}
L
Linus Torvalds 已提交
657 658 659 660
#undef CACHE
};

static struct arraycache_init initarray_cache __initdata =
P
Pekka Enberg 已提交
661
    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
L
Linus Torvalds 已提交
662
static struct arraycache_init initarray_generic =
P
Pekka Enberg 已提交
663
    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
L
Linus Torvalds 已提交
664 665

/* internal cache of cache description objs */
666
static struct kmem_cache cache_cache = {
P
Pekka Enberg 已提交
667 668 669
	.batchcount = 1,
	.limit = BOOT_CPUCACHE_ENTRIES,
	.shared = 1,
670
	.buffer_size = sizeof(struct kmem_cache),
P
Pekka Enberg 已提交
671
	.name = "kmem_cache",
L
Linus Torvalds 已提交
672
#if DEBUG
673
	.obj_size = sizeof(struct kmem_cache),
L
Linus Torvalds 已提交
674 675 676
#endif
};

677 678
#define BAD_ALIEN_MAGIC 0x01020304ul

679 680 681 682 683 684 685 686
#ifdef CONFIG_LOCKDEP

/*
 * Slab sometimes uses the kmalloc slabs to store the slab headers
 * for other slabs "off slab".
 * The locking for this is tricky in that it nests within the locks
 * of all other slabs in a few places; to deal with this special
 * locking we put on-slab caches into a separate lock-class.
687 688 689 690
 *
 * We set lock class for alien array caches which are up during init.
 * The lock annotation will be lost if all cpus of a node goes down and
 * then comes back up during hotplug
691
 */
692 693 694 695
static struct lock_class_key on_slab_l3_key;
static struct lock_class_key on_slab_alc_key;

static inline void init_lock_keys(void)
696 697 698

{
	int q;
699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725
	struct cache_sizes *s = malloc_sizes;

	while (s->cs_size != ULONG_MAX) {
		for_each_node(q) {
			struct array_cache **alc;
			int r;
			struct kmem_list3 *l3 = s->cs_cachep->nodelists[q];
			if (!l3 || OFF_SLAB(s->cs_cachep))
				continue;
			lockdep_set_class(&l3->list_lock, &on_slab_l3_key);
			alc = l3->alien;
			/*
			 * FIXME: This check for BAD_ALIEN_MAGIC
			 * should go away when common slab code is taught to
			 * work even without alien caches.
			 * Currently, non NUMA code returns BAD_ALIEN_MAGIC
			 * for alloc_alien_cache,
			 */
			if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC)
				continue;
			for_each_node(r) {
				if (alc[r])
					lockdep_set_class(&alc[r]->lock,
					     &on_slab_alc_key);
			}
		}
		s++;
726 727 728
	}
}
#else
729
static inline void init_lock_keys(void)
730 731 732 733
{
}
#endif

734 735 736 737
/*
 * 1. Guard access to the cache-chain.
 * 2. Protect sanity of cpu_online_map against cpu hotplug events
 */
I
Ingo Molnar 已提交
738
static DEFINE_MUTEX(cache_chain_mutex);
L
Linus Torvalds 已提交
739 740 741 742 743 744 745 746
static struct list_head cache_chain;

/*
 * chicken and egg problem: delay the per-cpu array allocation
 * until the general caches are up.
 */
static enum {
	NONE,
747 748
	PARTIAL_AC,
	PARTIAL_L3,
L
Linus Torvalds 已提交
749 750 751
	FULL
} g_cpucache_up;

752 753 754 755 756 757 758 759
/*
 * used by boot code to determine if it can use slab based allocator
 */
int slab_is_available(void)
{
	return g_cpucache_up == FULL;
}

760
static DEFINE_PER_CPU(struct delayed_work, reap_work);
L
Linus Torvalds 已提交
761

762
static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
763 764 765 766
{
	return cachep->array[smp_processor_id()];
}

A
Andrew Morton 已提交
767 768
static inline struct kmem_cache *__find_general_cachep(size_t size,
							gfp_t gfpflags)
L
Linus Torvalds 已提交
769 770 771 772 773
{
	struct cache_sizes *csizep = malloc_sizes;

#if DEBUG
	/* This happens if someone tries to call
P
Pekka Enberg 已提交
774 775 776
	 * kmem_cache_create(), or __kmalloc(), before
	 * the generic caches are initialized.
	 */
777
	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
L
Linus Torvalds 已提交
778 779 780 781 782
#endif
	while (size > csizep->cs_size)
		csizep++;

	/*
783
	 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
L
Linus Torvalds 已提交
784 785 786 787 788 789 790 791
	 * 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;
}

A
Adrian Bunk 已提交
792
static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
793 794 795 796
{
	return __find_general_cachep(size, gfpflags);
}

797
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
L
Linus Torvalds 已提交
798
{
799 800
	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
}
L
Linus Torvalds 已提交
801

A
Andrew Morton 已提交
802 803 804
/*
 * Calculate the number of objects and left-over bytes for a given buffer size.
 */
805 806 807 808 809 810 811
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;
L
Linus Torvalds 已提交
812

813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860
	/*
	 * 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;
L
Linus Torvalds 已提交
861 862 863 864
}

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

A
Andrew Morton 已提交
865 866
static void __slab_error(const char *function, struct kmem_cache *cachep,
			char *msg)
L
Linus Torvalds 已提交
867 868
{
	printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
P
Pekka Enberg 已提交
869
	       function, cachep->name, msg);
L
Linus Torvalds 已提交
870 871 872
	dump_stack();
}

873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888
/*
 * By default on NUMA we use alien caches to stage the freeing of
 * objects allocated from other nodes. This causes massive memory
 * inefficiencies when using fake NUMA setup to split memory into a
 * large number of small nodes, so it can be disabled on the command
 * line
  */

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

889 890 891 892 893 894 895 896 897 898 899 900 901 902 903
#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)
904
		node = first_node(node_online_map);
905

906
	per_cpu(reap_node, cpu) = node;
907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929
}

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
930 931 932 933 934 935 936 937 938
/*
 * 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)
{
939
	struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
L
Linus Torvalds 已提交
940 941 942 943 944 945

	/*
	 * When this gets called from do_initcalls via cpucache_init(),
	 * init_workqueues() has already run, so keventd will be setup
	 * at that time.
	 */
946
	if (keventd_up() && reap_work->work.func == NULL) {
947
		init_reap_node(cpu);
948
		INIT_DELAYED_WORK(reap_work, cache_reap);
949 950
		schedule_delayed_work_on(cpu, reap_work,
					__round_jiffies_relative(HZ, cpu));
L
Linus Torvalds 已提交
951 952 953
	}
}

954
static struct array_cache *alloc_arraycache(int node, int entries,
P
Pekka Enberg 已提交
955
					    int batchcount)
L
Linus Torvalds 已提交
956
{
P
Pekka Enberg 已提交
957
	int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
L
Linus Torvalds 已提交
958 959
	struct array_cache *nc = NULL;

960
	nc = kmalloc_node(memsize, GFP_KERNEL, node);
L
Linus Torvalds 已提交
961 962 963 964 965
	if (nc) {
		nc->avail = 0;
		nc->limit = entries;
		nc->batchcount = batchcount;
		nc->touched = 0;
966
		spin_lock_init(&nc->lock);
L
Linus Torvalds 已提交
967 968 969 970
	}
	return nc;
}

971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994
/*
 * Transfer objects in one arraycache to another.
 * Locking must be handled by the caller.
 *
 * Return the number of entries transferred.
 */
static int transfer_objects(struct array_cache *to,
		struct array_cache *from, unsigned int max)
{
	/* Figure out how many entries to transfer */
	int nr = min(min(from->avail, max), to->limit - to->avail);

	if (!nr)
		return 0;

	memcpy(to->entry + to->avail, from->entry + from->avail -nr,
			sizeof(void *) *nr);

	from->avail -= nr;
	to->avail += nr;
	to->touched = 1;
	return nr;
}

995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019
#ifndef CONFIG_NUMA

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

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

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

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

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

1020
static inline void *____cache_alloc_node(struct kmem_cache *cachep,
1021 1022 1023 1024 1025 1026 1027
		 gfp_t flags, int nodeid)
{
	return NULL;
}

#else	/* CONFIG_NUMA */

1028
static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
1029
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
1030

P
Pekka Enberg 已提交
1031
static struct array_cache **alloc_alien_cache(int node, int limit)
1032 1033
{
	struct array_cache **ac_ptr;
P
Pekka Enberg 已提交
1034
	int memsize = sizeof(void *) * MAX_NUMNODES;
1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047
	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
1048
				for (i--; i <= 0; i--)
1049 1050 1051 1052 1053 1054 1055 1056 1057
					kfree(ac_ptr[i]);
				kfree(ac_ptr);
				return NULL;
			}
		}
	}
	return ac_ptr;
}

P
Pekka Enberg 已提交
1058
static void free_alien_cache(struct array_cache **ac_ptr)
1059 1060 1061 1062 1063 1064
{
	int i;

	if (!ac_ptr)
		return;
	for_each_node(i)
P
Pekka Enberg 已提交
1065
	    kfree(ac_ptr[i]);
1066 1067 1068
	kfree(ac_ptr);
}

1069
static void __drain_alien_cache(struct kmem_cache *cachep,
P
Pekka Enberg 已提交
1070
				struct array_cache *ac, int node)
1071 1072 1073 1074 1075
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
1076 1077 1078 1079 1080
		/*
		 * Stuff objects into the remote nodes shared array first.
		 * That way we could avoid the overhead of putting the objects
		 * into the free lists and getting them back later.
		 */
1081 1082
		if (rl3->shared)
			transfer_objects(rl3->shared, ac, ac->limit);
1083

1084
		free_block(cachep, ac->entry, ac->avail, node);
1085 1086 1087 1088 1089
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

1090 1091 1092 1093 1094 1095 1096 1097 1098
/*
 * 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];
1099 1100

		if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
1101 1102 1103 1104 1105 1106
			__drain_alien_cache(cachep, ac, node);
			spin_unlock_irq(&ac->lock);
		}
	}
}

A
Andrew Morton 已提交
1107 1108
static void drain_alien_cache(struct kmem_cache *cachep,
				struct array_cache **alien)
1109
{
P
Pekka Enberg 已提交
1110
	int i = 0;
1111 1112 1113 1114
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
1115
		ac = alien[i];
1116 1117 1118 1119 1120 1121 1122
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
1123

1124
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1125 1126 1127 1128 1129
{
	struct slab *slabp = virt_to_slab(objp);
	int nodeid = slabp->nodeid;
	struct kmem_list3 *l3;
	struct array_cache *alien = NULL;
P
Pekka Enberg 已提交
1130 1131 1132
	int node;

	node = numa_node_id();
1133 1134 1135 1136 1137

	/*
	 * Make sure we are not freeing a object from another node to the array
	 * cache on this cpu.
	 */
1138
	if (likely(slabp->nodeid == node) || unlikely(!use_alien_caches))
1139 1140
		return 0;

P
Pekka Enberg 已提交
1141
	l3 = cachep->nodelists[node];
1142 1143 1144
	STATS_INC_NODEFREES(cachep);
	if (l3->alien && l3->alien[nodeid]) {
		alien = l3->alien[nodeid];
1145
		spin_lock(&alien->lock);
1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158
		if (unlikely(alien->avail == alien->limit)) {
			STATS_INC_ACOVERFLOW(cachep);
			__drain_alien_cache(cachep, alien, nodeid);
		}
		alien->entry[alien->avail++] = objp;
		spin_unlock(&alien->lock);
	} else {
		spin_lock(&(cachep->nodelists[nodeid])->list_lock);
		free_block(cachep, &objp, 1, nodeid);
		spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
	}
	return 1;
}
1159 1160
#endif

1161
static int __cpuinit cpuup_callback(struct notifier_block *nfb,
P
Pekka Enberg 已提交
1162
				    unsigned long action, void *hcpu)
L
Linus Torvalds 已提交
1163 1164
{
	long cpu = (long)hcpu;
1165
	struct kmem_cache *cachep;
1166 1167 1168
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
	int memsize = sizeof(struct kmem_list3);
L
Linus Torvalds 已提交
1169 1170 1171

	switch (action) {
	case CPU_UP_PREPARE:
I
Ingo Molnar 已提交
1172
		mutex_lock(&cache_chain_mutex);
A
Andrew Morton 已提交
1173 1174
		/*
		 * We need to do this right in the beginning since
1175 1176 1177 1178 1179
		 * 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
1180
		list_for_each_entry(cachep, &cache_chain, next) {
A
Andrew Morton 已提交
1181 1182
			/*
			 * Set up the size64 kmemlist for cpu before we can
1183 1184 1185 1186
			 * 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
1187 1188
				l3 = kmalloc_node(memsize, GFP_KERNEL, node);
				if (!l3)
1189 1190 1191
					goto bad;
				kmem_list3_init(l3);
				l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
P
Pekka Enberg 已提交
1192
				    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1193

1194 1195 1196 1197 1198
				/*
				 * The l3s don't come and go as CPUs come and
				 * go.  cache_chain_mutex is sufficient
				 * protection here.
				 */
1199 1200
				cachep->nodelists[node] = l3;
			}
L
Linus Torvalds 已提交
1201

1202 1203
			spin_lock_irq(&cachep->nodelists[node]->list_lock);
			cachep->nodelists[node]->free_limit =
A
Andrew Morton 已提交
1204 1205
				(1 + nr_cpus_node(node)) *
				cachep->batchcount + cachep->num;
1206 1207 1208
			spin_unlock_irq(&cachep->nodelists[node]->list_lock);
		}

A
Andrew Morton 已提交
1209 1210 1211 1212
		/*
		 * Now we can go ahead with allocating the shared arrays and
		 * array caches
		 */
1213
		list_for_each_entry(cachep, &cache_chain, next) {
1214
			struct array_cache *nc;
1215
			struct array_cache *shared;
1216
			struct array_cache **alien = NULL;
1217

1218
			nc = alloc_arraycache(node, cachep->limit,
1219
						cachep->batchcount);
L
Linus Torvalds 已提交
1220 1221
			if (!nc)
				goto bad;
1222 1223 1224 1225 1226
			shared = alloc_arraycache(node,
					cachep->shared * cachep->batchcount,
					0xbaadf00d);
			if (!shared)
				goto bad;
1227

1228 1229 1230 1231 1232
			if (use_alien_caches) {
                                alien = alloc_alien_cache(node, cachep->limit);
                                if (!alien)
                                        goto bad;
                        }
L
Linus Torvalds 已提交
1233
			cachep->array[cpu] = nc;
1234 1235 1236
			l3 = cachep->nodelists[node];
			BUG_ON(!l3);

1237 1238 1239 1240 1241 1242 1243 1244
			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;
1245
			}
1246 1247 1248 1249 1250 1251 1252 1253 1254
#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
1255 1256 1257
		}
		break;
	case CPU_ONLINE:
1258
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1259 1260 1261
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
1262 1263 1264 1265 1266 1267
	case CPU_DOWN_PREPARE:
		mutex_lock(&cache_chain_mutex);
		break;
	case CPU_DOWN_FAILED:
		mutex_unlock(&cache_chain_mutex);
		break;
L
Linus Torvalds 已提交
1268
	case CPU_DEAD:
1269 1270 1271 1272 1273 1274 1275 1276
		/*
		 * 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
1277
		/* fall thru */
1278
#endif
L
Linus Torvalds 已提交
1279 1280 1281
	case CPU_UP_CANCELED:
		list_for_each_entry(cachep, &cache_chain, next) {
			struct array_cache *nc;
1282 1283
			struct array_cache *shared;
			struct array_cache **alien;
1284
			cpumask_t mask;
L
Linus Torvalds 已提交
1285

1286
			mask = node_to_cpumask(node);
L
Linus Torvalds 已提交
1287 1288 1289
			/* cpu is dead; no one can alloc from it. */
			nc = cachep->array[cpu];
			cachep->array[cpu] = NULL;
1290 1291 1292
			l3 = cachep->nodelists[node];

			if (!l3)
1293
				goto free_array_cache;
1294

1295
			spin_lock_irq(&l3->list_lock);
1296 1297 1298 1299

			/* Free limit for this kmem_list3 */
			l3->free_limit -= cachep->batchcount;
			if (nc)
1300
				free_block(cachep, nc->entry, nc->avail, node);
1301 1302

			if (!cpus_empty(mask)) {
1303
				spin_unlock_irq(&l3->list_lock);
1304
				goto free_array_cache;
P
Pekka Enberg 已提交
1305
			}
1306

1307 1308
			shared = l3->shared;
			if (shared) {
1309
				free_block(cachep, l3->shared->entry,
P
Pekka Enberg 已提交
1310
					   l3->shared->avail, node);
1311 1312 1313
				l3->shared = NULL;
			}

1314 1315 1316 1317 1318 1319 1320 1321 1322
			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);
1323
			}
1324
free_array_cache:
L
Linus Torvalds 已提交
1325 1326
			kfree(nc);
		}
1327 1328 1329 1330 1331 1332 1333 1334 1335
		/*
		 * 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;
1336
			drain_freelist(cachep, l3, l3->free_objects);
1337
		}
I
Ingo Molnar 已提交
1338
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1339 1340 1341
		break;
	}
	return NOTIFY_OK;
A
Andrew Morton 已提交
1342
bad:
L
Linus Torvalds 已提交
1343 1344 1345
	return NOTIFY_BAD;
}

1346 1347 1348
static struct notifier_block __cpuinitdata cpucache_notifier = {
	&cpuup_callback, NULL, 0
};
L
Linus Torvalds 已提交
1349

1350 1351 1352
/*
 * swap the static kmem_list3 with kmalloced memory
 */
A
Andrew Morton 已提交
1353 1354
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
			int nodeid)
1355 1356 1357 1358 1359 1360 1361 1362
{
	struct kmem_list3 *ptr;

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

	local_irq_disable();
	memcpy(ptr, list, sizeof(struct kmem_list3));
1363 1364 1365 1366 1367
	/*
	 * Do not assume that spinlocks can be initialized via memcpy:
	 */
	spin_lock_init(&ptr->list_lock);

1368 1369 1370 1371 1372
	MAKE_ALL_LISTS(cachep, ptr, nodeid);
	cachep->nodelists[nodeid] = ptr;
	local_irq_enable();
}

A
Andrew Morton 已提交
1373 1374 1375
/*
 * Initialisation.  Called after the page allocator have been initialised and
 * before smp_init().
L
Linus Torvalds 已提交
1376 1377 1378 1379 1380 1381
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1382
	int i;
1383
	int order;
P
Pekka Enberg 已提交
1384
	int node;
1385 1386 1387 1388 1389 1390

	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
1391 1392 1393 1394 1395 1396 1397 1398 1399 1400

	/*
	 * 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
1401 1402 1403
	 * 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.
1404 1405 1406
	 *    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
1407
	 * 2) Create the first kmalloc cache.
1408
	 *    The struct kmem_cache for the new cache is allocated normally.
1409 1410 1411
	 *    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
1412 1413
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1414 1415 1416
	 * 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
1417 1418
	 */

P
Pekka Enberg 已提交
1419 1420
	node = numa_node_id();

L
Linus Torvalds 已提交
1421 1422 1423 1424 1425
	/* 1) create the cache_cache */
	INIT_LIST_HEAD(&cache_chain);
	list_add(&cache_cache.next, &cache_chain);
	cache_cache.colour_off = cache_line_size();
	cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
P
Pekka Enberg 已提交
1426
	cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
L
Linus Torvalds 已提交
1427

A
Andrew Morton 已提交
1428 1429
	cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
					cache_line_size());
L
Linus Torvalds 已提交
1430

1431 1432 1433 1434 1435 1436
	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;
	}
1437
	BUG_ON(!cache_cache.num);
1438
	cache_cache.gfporder = order;
P
Pekka Enberg 已提交
1439 1440 1441
	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
1442 1443 1444 1445 1446

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

A
Andrew Morton 已提交
1447 1448 1449 1450
	/*
	 * Initialize the caches that provide memory for the array cache and the
	 * kmem_list3 structures first.  Without this, further allocations will
	 * bug.
1451 1452 1453
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
A
Andrew Morton 已提交
1454 1455 1456 1457
					sizes[INDEX_AC].cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
1458

A
Andrew Morton 已提交
1459
	if (INDEX_AC != INDEX_L3) {
1460
		sizes[INDEX_L3].cs_cachep =
A
Andrew Morton 已提交
1461 1462 1463 1464 1465 1466
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size,
				ARCH_KMALLOC_MINALIGN,
				ARCH_KMALLOC_FLAGS|SLAB_PANIC,
				NULL, NULL);
	}
1467

1468 1469
	slab_early_init = 0;

L
Linus Torvalds 已提交
1470
	while (sizes->cs_size != ULONG_MAX) {
1471 1472
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1473 1474 1475
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1476 1477
		 * allow tighter packing of the smaller caches.
		 */
A
Andrew Morton 已提交
1478
		if (!sizes->cs_cachep) {
1479
			sizes->cs_cachep = kmem_cache_create(names->name,
A
Andrew Morton 已提交
1480 1481 1482 1483 1484
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
					NULL, NULL);
		}
L
Linus Torvalds 已提交
1485 1486

		sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
A
Andrew Morton 已提交
1487 1488 1489 1490 1491
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
						SLAB_PANIC,
					NULL, NULL);
L
Linus Torvalds 已提交
1492 1493 1494 1495 1496
		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
1497
		struct array_cache *ptr;
1498

L
Linus Torvalds 已提交
1499
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1500

L
Linus Torvalds 已提交
1501
		local_irq_disable();
1502 1503
		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
		memcpy(ptr, cpu_cache_get(&cache_cache),
P
Pekka Enberg 已提交
1504
		       sizeof(struct arraycache_init));
1505 1506 1507 1508 1509
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

L
Linus Torvalds 已提交
1510 1511
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1512

L
Linus Torvalds 已提交
1513
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1514

L
Linus Torvalds 已提交
1515
		local_irq_disable();
1516
		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
P
Pekka Enberg 已提交
1517
		       != &initarray_generic.cache);
1518
		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
P
Pekka Enberg 已提交
1519
		       sizeof(struct arraycache_init));
1520 1521 1522 1523 1524
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

1525
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
P
Pekka Enberg 已提交
1526
		    ptr;
L
Linus Torvalds 已提交
1527 1528
		local_irq_enable();
	}
1529 1530
	/* 5) Replace the bootstrap kmem_list3's */
	{
P
Pekka Enberg 已提交
1531 1532
		int nid;

1533
		/* Replace the static kmem_list3 structures for the boot cpu */
P
Pekka Enberg 已提交
1534
		init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node);
1535

P
Pekka Enberg 已提交
1536
		for_each_online_node(nid) {
1537
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
P
Pekka Enberg 已提交
1538
				  &initkmem_list3[SIZE_AC + nid], nid);
1539 1540 1541

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
P
Pekka Enberg 已提交
1542
					  &initkmem_list3[SIZE_L3 + nid], nid);
1543 1544 1545
			}
		}
	}
L
Linus Torvalds 已提交
1546

1547
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1548
	{
1549
		struct kmem_cache *cachep;
I
Ingo Molnar 已提交
1550
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1551
		list_for_each_entry(cachep, &cache_chain, next)
1552 1553
			if (enable_cpucache(cachep))
				BUG();
I
Ingo Molnar 已提交
1554
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1555 1556
	}

1557 1558 1559 1560
	/* Annotate slab for lockdep -- annotate the malloc caches */
	init_lock_keys();


L
Linus Torvalds 已提交
1561 1562 1563
	/* Done! */
	g_cpucache_up = FULL;

A
Andrew Morton 已提交
1564 1565 1566
	/*
	 * Register a cpu startup notifier callback that initializes
	 * cpu_cache_get for all new cpus
L
Linus Torvalds 已提交
1567 1568 1569
	 */
	register_cpu_notifier(&cpucache_notifier);

A
Andrew Morton 已提交
1570 1571 1572
	/*
	 * 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
1573 1574 1575 1576 1577 1578 1579
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

A
Andrew Morton 已提交
1580 1581
	/*
	 * Register the timers that return unneeded pages to the page allocator
L
Linus Torvalds 已提交
1582
	 */
1583
	for_each_online_cpu(cpu)
A
Andrew Morton 已提交
1584
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595
	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.
 */
1596
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1597 1598
{
	struct page *page;
1599
	int nr_pages;
L
Linus Torvalds 已提交
1600 1601
	int i;

1602
#ifndef CONFIG_MMU
1603 1604 1605
	/*
	 * Nommu uses slab's for process anonymous memory allocations, and thus
	 * requires __GFP_COMP to properly refcount higher order allocations
1606
	 */
1607
	flags |= __GFP_COMP;
1608
#endif
1609

1610
	flags |= cachep->gfpflags;
1611 1612

	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1613 1614 1615
	if (!page)
		return NULL;

1616
	nr_pages = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1617
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1618 1619 1620 1621 1622
		add_zone_page_state(page_zone(page),
			NR_SLAB_RECLAIMABLE, nr_pages);
	else
		add_zone_page_state(page_zone(page),
			NR_SLAB_UNRECLAIMABLE, nr_pages);
1623 1624 1625
	for (i = 0; i < nr_pages; i++)
		__SetPageSlab(page + i);
	return page_address(page);
L
Linus Torvalds 已提交
1626 1627 1628 1629 1630
}

/*
 * Interface to system's page release.
 */
1631
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
L
Linus Torvalds 已提交
1632
{
P
Pekka Enberg 已提交
1633
	unsigned long i = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1634 1635 1636
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

1637 1638 1639 1640 1641 1642
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		sub_zone_page_state(page_zone(page),
				NR_SLAB_RECLAIMABLE, nr_freed);
	else
		sub_zone_page_state(page_zone(page),
				NR_SLAB_UNRECLAIMABLE, nr_freed);
L
Linus Torvalds 已提交
1643
	while (i--) {
N
Nick Piggin 已提交
1644 1645
		BUG_ON(!PageSlab(page));
		__ClearPageSlab(page);
L
Linus Torvalds 已提交
1646 1647 1648 1649 1650 1651 1652 1653 1654
		page++;
	}
	if (current->reclaim_state)
		current->reclaim_state->reclaimed_slab += nr_freed;
	free_pages((unsigned long)addr, cachep->gfporder);
}

static void kmem_rcu_free(struct rcu_head *head)
{
P
Pekka Enberg 已提交
1655
	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1656
	struct kmem_cache *cachep = slab_rcu->cachep;
L
Linus Torvalds 已提交
1657 1658 1659 1660 1661 1662 1663 1664 1665

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

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
1666
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
P
Pekka Enberg 已提交
1667
			    unsigned long caller)
L
Linus Torvalds 已提交
1668
{
1669
	int size = obj_size(cachep);
L
Linus Torvalds 已提交
1670

1671
	addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1672

P
Pekka Enberg 已提交
1673
	if (size < 5 * sizeof(unsigned long))
L
Linus Torvalds 已提交
1674 1675
		return;

P
Pekka Enberg 已提交
1676 1677 1678 1679
	*addr++ = 0x12345678;
	*addr++ = caller;
	*addr++ = smp_processor_id();
	size -= 3 * sizeof(unsigned long);
L
Linus Torvalds 已提交
1680 1681 1682 1683 1684 1685 1686
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
P
Pekka Enberg 已提交
1687
				*addr++ = svalue;
L
Linus Torvalds 已提交
1688 1689 1690 1691 1692 1693 1694
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
P
Pekka Enberg 已提交
1695
	*addr++ = 0x87654321;
L
Linus Torvalds 已提交
1696 1697 1698
}
#endif

1699
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
L
Linus Torvalds 已提交
1700
{
1701 1702
	int size = obj_size(cachep);
	addr = &((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1703 1704

	memset(addr, val, size);
P
Pekka Enberg 已提交
1705
	*(unsigned char *)(addr + size - 1) = POISON_END;
L
Linus Torvalds 已提交
1706 1707 1708 1709 1710
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
D
Dave Jones 已提交
1711 1712 1713
	unsigned char error = 0;
	int bad_count = 0;

L
Linus Torvalds 已提交
1714
	printk(KERN_ERR "%03x:", offset);
D
Dave Jones 已提交
1715 1716 1717 1718 1719
	for (i = 0; i < limit; i++) {
		if (data[offset + i] != POISON_FREE) {
			error = data[offset + i];
			bad_count++;
		}
P
Pekka Enberg 已提交
1720
		printk(" %02x", (unsigned char)data[offset + i]);
D
Dave Jones 已提交
1721
	}
L
Linus Torvalds 已提交
1722
	printk("\n");
D
Dave Jones 已提交
1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736

	if (bad_count == 1) {
		error ^= POISON_FREE;
		if (!(error & (error - 1))) {
			printk(KERN_ERR "Single bit error detected. Probably "
					"bad RAM.\n");
#ifdef CONFIG_X86
			printk(KERN_ERR "Run memtest86+ or a similar memory "
					"test tool.\n");
#else
			printk(KERN_ERR "Run a memory test tool.\n");
#endif
		}
	}
L
Linus Torvalds 已提交
1737 1738 1739 1740 1741
}
#endif

#if DEBUG

1742
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
L
Linus Torvalds 已提交
1743 1744 1745 1746 1747 1748
{
	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
1749 1750
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
1751 1752 1753 1754
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
A
Andrew Morton 已提交
1755
			*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1756
		print_symbol("(%s)",
A
Andrew Morton 已提交
1757
				(unsigned long)*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1758 1759
		printk("\n");
	}
1760 1761
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
P
Pekka Enberg 已提交
1762
	for (i = 0; i < size && lines; i += 16, lines--) {
L
Linus Torvalds 已提交
1763 1764
		int limit;
		limit = 16;
P
Pekka Enberg 已提交
1765 1766
		if (i + limit > size)
			limit = size - i;
L
Linus Torvalds 已提交
1767 1768 1769 1770
		dump_line(realobj, i, limit);
	}
}

1771
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
1772 1773 1774 1775 1776
{
	char *realobj;
	int size, i;
	int lines = 0;

1777 1778
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
L
Linus Torvalds 已提交
1779

P
Pekka Enberg 已提交
1780
	for (i = 0; i < size; i++) {
L
Linus Torvalds 已提交
1781
		char exp = POISON_FREE;
P
Pekka Enberg 已提交
1782
		if (i == size - 1)
L
Linus Torvalds 已提交
1783 1784 1785 1786 1787 1788
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
P
Pekka Enberg 已提交
1789
				printk(KERN_ERR
A
Andrew Morton 已提交
1790 1791
					"Slab corruption: start=%p, len=%d\n",
					realobj, size);
L
Linus Torvalds 已提交
1792 1793 1794
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
P
Pekka Enberg 已提交
1795
			i = (i / 16) * 16;
L
Linus Torvalds 已提交
1796
			limit = 16;
P
Pekka Enberg 已提交
1797 1798
			if (i + limit > size)
				limit = size - i;
L
Linus Torvalds 已提交
1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810
			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:
		 */
1811
		struct slab *slabp = virt_to_slab(objp);
1812
		unsigned int objnr;
L
Linus Torvalds 已提交
1813

1814
		objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
1815
		if (objnr) {
1816
			objp = index_to_obj(cachep, slabp, objnr - 1);
1817
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1818
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1819
			       realobj, size);
L
Linus Torvalds 已提交
1820 1821
			print_objinfo(cachep, objp, 2);
		}
P
Pekka Enberg 已提交
1822
		if (objnr + 1 < cachep->num) {
1823
			objp = index_to_obj(cachep, slabp, objnr + 1);
1824
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1825
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1826
			       realobj, size);
L
Linus Torvalds 已提交
1827 1828 1829 1830 1831 1832
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

1833 1834
#if DEBUG
/**
1835 1836 1837 1838 1839 1840
 * 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
1841
 */
1842
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
1843 1844 1845
{
	int i;
	for (i = 0; i < cachep->num; i++) {
1846
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
1847 1848 1849

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
1850 1851
			if (cachep->buffer_size % PAGE_SIZE == 0 &&
					OFF_SLAB(cachep))
P
Pekka Enberg 已提交
1852
				kernel_map_pages(virt_to_page(objp),
A
Andrew Morton 已提交
1853
					cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
1854 1855 1856 1857 1858 1859 1860 1861 1862
			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
1863
					   "was overwritten");
L
Linus Torvalds 已提交
1864 1865
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
P
Pekka Enberg 已提交
1866
					   "was overwritten");
L
Linus Torvalds 已提交
1867 1868
		}
		if (cachep->dtor && !(cachep->flags & SLAB_POISON))
1869
			(cachep->dtor) (objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
1870
	}
1871
}
L
Linus Torvalds 已提交
1872
#else
1873
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
1874
{
L
Linus Torvalds 已提交
1875 1876 1877
	if (cachep->dtor) {
		int i;
		for (i = 0; i < cachep->num; i++) {
1878
			void *objp = index_to_obj(cachep, slabp, i);
P
Pekka Enberg 已提交
1879
			(cachep->dtor) (objp, cachep, 0);
L
Linus Torvalds 已提交
1880 1881
		}
	}
1882
}
L
Linus Torvalds 已提交
1883 1884
#endif

1885 1886 1887 1888 1889
/**
 * slab_destroy - destroy and release all objects in a slab
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
1890
 * Destroy all the objs in a slab, and release the mem back to the system.
A
Andrew Morton 已提交
1891 1892
 * Before calling the slab must have been unlinked from the cache.  The
 * cache-lock is not held/needed.
1893
 */
1894
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1895 1896 1897 1898
{
	void *addr = slabp->s_mem - slabp->colouroff;

	slab_destroy_objs(cachep, slabp);
L
Linus Torvalds 已提交
1899 1900 1901
	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

P
Pekka Enberg 已提交
1902
		slab_rcu = (struct slab_rcu *)slabp;
L
Linus Torvalds 已提交
1903 1904 1905 1906 1907
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
1908 1909
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
L
Linus Torvalds 已提交
1910 1911 1912
	}
}

A
Andrew Morton 已提交
1913 1914 1915 1916
/*
 * For setting up all the kmem_list3s for cache whose buffer_size is same as
 * size of kmem_list3.
 */
1917
static void set_up_list3s(struct kmem_cache *cachep, int index)
1918 1919 1920 1921
{
	int node;

	for_each_online_node(node) {
P
Pekka Enberg 已提交
1922
		cachep->nodelists[node] = &initkmem_list3[index + node];
1923
		cachep->nodelists[node]->next_reap = jiffies +
P
Pekka Enberg 已提交
1924 1925
		    REAPTIMEOUT_LIST3 +
		    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1926 1927 1928
	}
}

1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949
static void __kmem_cache_destroy(struct kmem_cache *cachep)
{
	int i;
	struct kmem_list3 *l3;

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

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


1950
/**
1951 1952 1953 1954 1955 1956 1957
 * 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.
1958 1959 1960 1961 1962
 *
 * 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
1963
static size_t calculate_slab_order(struct kmem_cache *cachep,
R
Randy Dunlap 已提交
1964
			size_t size, size_t align, unsigned long flags)
1965
{
1966
	unsigned long offslab_limit;
1967
	size_t left_over = 0;
1968
	int gfporder;
1969

A
Andrew Morton 已提交
1970
	for (gfporder = 0; gfporder <= MAX_GFP_ORDER; gfporder++) {
1971 1972 1973
		unsigned int num;
		size_t remainder;

1974
		cache_estimate(gfporder, size, align, flags, &remainder, &num);
1975 1976
		if (!num)
			continue;
1977

1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989
		if (flags & CFLGS_OFF_SLAB) {
			/*
			 * Max number of objs-per-slab for caches which
			 * use off-slab slabs. Needed to avoid a possible
			 * looping condition in cache_grow().
			 */
			offslab_limit = size - sizeof(struct slab);
			offslab_limit /= sizeof(kmem_bufctl_t);

 			if (num > offslab_limit)
				break;
		}
1990

1991
		/* Found something acceptable - save it away */
1992
		cachep->num = num;
1993
		cachep->gfporder = gfporder;
1994 1995
		left_over = remainder;

1996 1997 1998 1999 2000 2001 2002 2003
		/*
		 * 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;

2004 2005 2006 2007
		/*
		 * Large number of objects is good, but very large slabs are
		 * currently bad for the gfp()s.
		 */
2008
		if (gfporder >= slab_break_gfp_order)
2009 2010
			break;

2011 2012 2013
		/*
		 * Acceptable internal fragmentation?
		 */
A
Andrew Morton 已提交
2014
		if (left_over * 8 <= (PAGE_SIZE << gfporder))
2015 2016 2017 2018 2019
			break;
	}
	return left_over;
}

2020
static int setup_cpu_cache(struct kmem_cache *cachep)
2021
{
2022 2023 2024
	if (g_cpucache_up == FULL)
		return enable_cpucache(cachep);

2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070
	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;
2071
	return 0;
2072 2073
}

L
Linus Torvalds 已提交
2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088
/**
 * 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
2089 2090
 * the module calling this has to destroy the cache before getting unloaded.
 *
L
Linus Torvalds 已提交
2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102
 * 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.
 */
2103
struct kmem_cache *
L
Linus Torvalds 已提交
2104
kmem_cache_create (const char *name, size_t size, size_t align,
A
Andrew Morton 已提交
2105 2106
	unsigned long flags,
	void (*ctor)(void*, struct kmem_cache *, unsigned long),
2107
	void (*dtor)(void*, struct kmem_cache *, unsigned long))
L
Linus Torvalds 已提交
2108 2109
{
	size_t left_over, slab_size, ralign;
2110
	struct kmem_cache *cachep = NULL, *pc;
L
Linus Torvalds 已提交
2111 2112 2113 2114

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
A
Andrew Morton 已提交
2115
	if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
P
Pekka Enberg 已提交
2116
	    (size > (1 << MAX_OBJ_ORDER) * PAGE_SIZE) || (dtor && !ctor)) {
A
Andrew Morton 已提交
2117 2118
		printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
				name);
P
Pekka Enberg 已提交
2119 2120
		BUG();
	}
L
Linus Torvalds 已提交
2121

2122
	/*
2123 2124
	 * We use cache_chain_mutex to ensure a consistent view of
	 * cpu_online_map as well.  Please see cpuup_callback
2125
	 */
I
Ingo Molnar 已提交
2126
	mutex_lock(&cache_chain_mutex);
2127

2128
	list_for_each_entry(pc, &cache_chain, next) {
2129 2130 2131 2132 2133 2134 2135 2136
		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.
		 */
2137
		res = probe_kernel_address(pc->name, tmp);
2138 2139
		if (res) {
			printk("SLAB: cache with size %d has lost its name\n",
2140
			       pc->buffer_size);
2141 2142 2143
			continue;
		}

P
Pekka Enberg 已提交
2144
		if (!strcmp(pc->name, name)) {
2145 2146 2147 2148 2149 2150
			printk("kmem_cache_create: duplicate cache %s\n", name);
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
2151 2152 2153 2154 2155
#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
2156
		       "requested - %s\n", __FUNCTION__, name);
L
Linus Torvalds 已提交
2157 2158 2159 2160 2161 2162 2163 2164 2165
		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
2166
	if (size < 4096 || fls(size - 1) == fls(size-1 + 3 * BYTES_PER_WORD))
P
Pekka Enberg 已提交
2167
		flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
L
Linus Torvalds 已提交
2168 2169 2170 2171 2172 2173 2174 2175 2176 2177
	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
2178 2179
	 * Always checks flags, a caller might be expecting debug support which
	 * isn't available.
L
Linus Torvalds 已提交
2180
	 */
2181
	BUG_ON(flags & ~CREATE_MASK);
L
Linus Torvalds 已提交
2182

A
Andrew Morton 已提交
2183 2184
	/*
	 * Check that size is in terms of words.  This is needed to avoid
L
Linus Torvalds 已提交
2185 2186 2187
	 * 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
2188 2189 2190
	if (size & (BYTES_PER_WORD - 1)) {
		size += (BYTES_PER_WORD - 1);
		size &= ~(BYTES_PER_WORD - 1);
L
Linus Torvalds 已提交
2191 2192
	}

A
Andrew Morton 已提交
2193 2194
	/* calculate the final buffer alignment: */

L
Linus Torvalds 已提交
2195 2196
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
A
Andrew Morton 已提交
2197 2198 2199 2200
		/*
		 * 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
2201 2202
		 */
		ralign = cache_line_size();
P
Pekka Enberg 已提交
2203
		while (size <= ralign / 2)
L
Linus Torvalds 已提交
2204 2205 2206 2207
			ralign /= 2;
	} else {
		ralign = BYTES_PER_WORD;
	}
2208 2209 2210 2211 2212 2213 2214 2215 2216

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

2217
	/* 2) arch mandated alignment */
L
Linus Torvalds 已提交
2218 2219 2220
	if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
	}
2221
	/* 3) caller mandated alignment */
L
Linus Torvalds 已提交
2222 2223 2224
	if (ralign < align) {
		ralign = align;
	}
2225 2226 2227
	/* disable debug if necessary */
	if (ralign > BYTES_PER_WORD)
		flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
A
Andrew Morton 已提交
2228
	/*
2229
	 * 4) Store it.
L
Linus Torvalds 已提交
2230 2231 2232 2233
	 */
	align = ralign;

	/* Get cache's description obj. */
2234
	cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
L
Linus Torvalds 已提交
2235
	if (!cachep)
2236
		goto oops;
L
Linus Torvalds 已提交
2237 2238

#if DEBUG
2239
	cachep->obj_size = size;
L
Linus Torvalds 已提交
2240

2241 2242 2243 2244
	/*
	 * Both debugging options require word-alignment which is calculated
	 * into align above.
	 */
L
Linus Torvalds 已提交
2245 2246
	if (flags & SLAB_RED_ZONE) {
		/* add space for red zone words */
2247
		cachep->obj_offset += BYTES_PER_WORD;
P
Pekka Enberg 已提交
2248
		size += 2 * BYTES_PER_WORD;
L
Linus Torvalds 已提交
2249 2250
	}
	if (flags & SLAB_STORE_USER) {
2251 2252
		/* user store requires one word storage behind the end of
		 * the real object.
L
Linus Torvalds 已提交
2253 2254 2255 2256
		 */
		size += BYTES_PER_WORD;
	}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
P
Pekka Enberg 已提交
2257
	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2258 2259
	    && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
		cachep->obj_offset += PAGE_SIZE - size;
L
Linus Torvalds 已提交
2260 2261 2262 2263 2264
		size = PAGE_SIZE;
	}
#endif
#endif

2265 2266 2267 2268 2269 2270
	/*
	 * Determine if the slab management is 'on' or 'off' slab.
	 * (bootstrapping cannot cope with offslab caches so don't do
	 * it too early on.)
	 */
	if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init)
L
Linus Torvalds 已提交
2271 2272 2273 2274 2275 2276 2277 2278
		/*
		 * 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);

2279
	left_over = calculate_slab_order(cachep, size, align, flags);
L
Linus Torvalds 已提交
2280 2281 2282 2283 2284

	if (!cachep->num) {
		printk("kmem_cache_create: couldn't create cache %s.\n", name);
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
2285
		goto oops;
L
Linus Torvalds 已提交
2286
	}
P
Pekka Enberg 已提交
2287 2288
	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
			  + sizeof(struct slab), align);
L
Linus Torvalds 已提交
2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300

	/*
	 * 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
2301 2302
		slab_size =
		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
L
Linus Torvalds 已提交
2303 2304 2305 2306 2307 2308
	}

	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
2309
	cachep->colour = left_over / cachep->colour_off;
L
Linus Torvalds 已提交
2310 2311 2312 2313 2314
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
	if (flags & SLAB_CACHE_DMA)
		cachep->gfpflags |= GFP_DMA;
2315
	cachep->buffer_size = size;
L
Linus Torvalds 已提交
2316

2317
	if (flags & CFLGS_OFF_SLAB) {
2318
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
2319 2320 2321 2322 2323 2324 2325 2326 2327
		/*
		 * This is a possibility for one of the malloc_sizes caches.
		 * But since we go off slab only for object size greater than
		 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
		 * this should not happen at all.
		 * But leave a BUG_ON for some lucky dude.
		 */
		BUG_ON(!cachep->slabp_cache);
	}
L
Linus Torvalds 已提交
2328 2329 2330 2331
	cachep->ctor = ctor;
	cachep->dtor = dtor;
	cachep->name = name;

2332 2333 2334 2335 2336
	if (setup_cpu_cache(cachep)) {
		__kmem_cache_destroy(cachep);
		cachep = NULL;
		goto oops;
	}
L
Linus Torvalds 已提交
2337 2338 2339

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
A
Andrew Morton 已提交
2340
oops:
L
Linus Torvalds 已提交
2341 2342
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
P
Pekka Enberg 已提交
2343
		      name);
I
Ingo Molnar 已提交
2344
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359
	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());
}

2360
static void check_spinlock_acquired(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2361 2362 2363
{
#ifdef CONFIG_SMP
	check_irq_off();
2364
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
2365 2366
#endif
}
2367

2368
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2369 2370 2371 2372 2373 2374 2375
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
2376 2377 2378 2379
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
2380
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
2381 2382
#endif

2383 2384 2385 2386
static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
			struct array_cache *ac,
			int force, int node);

L
Linus Torvalds 已提交
2387 2388
static void do_drain(void *arg)
{
A
Andrew Morton 已提交
2389
	struct kmem_cache *cachep = arg;
L
Linus Torvalds 已提交
2390
	struct array_cache *ac;
2391
	int node = numa_node_id();
L
Linus Torvalds 已提交
2392 2393

	check_irq_off();
2394
	ac = cpu_cache_get(cachep);
2395 2396 2397
	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
2398 2399 2400
	ac->avail = 0;
}

2401
static void drain_cpu_caches(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2402
{
2403 2404 2405
	struct kmem_list3 *l3;
	int node;

A
Andrew Morton 已提交
2406
	on_each_cpu(do_drain, cachep, 1, 1);
L
Linus Torvalds 已提交
2407
	check_irq_on();
P
Pekka Enberg 已提交
2408
	for_each_online_node(node) {
2409
		l3 = cachep->nodelists[node];
2410 2411 2412 2413 2414 2415 2416
		if (l3 && l3->alien)
			drain_alien_cache(cachep, l3->alien);
	}

	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (l3)
2417
			drain_array(cachep, l3, l3->shared, 1, node);
2418
	}
L
Linus Torvalds 已提交
2419 2420
}

2421 2422 2423 2424 2425 2426 2427 2428
/*
 * Remove slabs from the list of free slabs.
 * Specify the number of slabs to drain in tofree.
 *
 * Returns the actual number of slabs released.
 */
static int drain_freelist(struct kmem_cache *cache,
			struct kmem_list3 *l3, int tofree)
L
Linus Torvalds 已提交
2429
{
2430 2431
	struct list_head *p;
	int nr_freed;
L
Linus Torvalds 已提交
2432 2433
	struct slab *slabp;

2434 2435
	nr_freed = 0;
	while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
L
Linus Torvalds 已提交
2436

2437
		spin_lock_irq(&l3->list_lock);
2438
		p = l3->slabs_free.prev;
2439 2440 2441 2442
		if (p == &l3->slabs_free) {
			spin_unlock_irq(&l3->list_lock);
			goto out;
		}
L
Linus Torvalds 已提交
2443

2444
		slabp = list_entry(p, struct slab, list);
L
Linus Torvalds 已提交
2445
#if DEBUG
2446
		BUG_ON(slabp->inuse);
L
Linus Torvalds 已提交
2447 2448
#endif
		list_del(&slabp->list);
2449 2450 2451 2452 2453
		/*
		 * Safe to drop the lock. The slab is no longer linked
		 * to the cache.
		 */
		l3->free_objects -= cache->num;
2454
		spin_unlock_irq(&l3->list_lock);
2455 2456
		slab_destroy(cache, slabp);
		nr_freed++;
L
Linus Torvalds 已提交
2457
	}
2458 2459
out:
	return nr_freed;
L
Linus Torvalds 已提交
2460 2461
}

2462
/* Called with cache_chain_mutex held to protect against cpu hotplug */
2463
static int __cache_shrink(struct kmem_cache *cachep)
2464 2465 2466 2467 2468 2469 2470 2471 2472
{
	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];
2473 2474 2475 2476 2477 2478 2479
		if (!l3)
			continue;

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

		ret += !list_empty(&l3->slabs_full) ||
			!list_empty(&l3->slabs_partial);
2480 2481 2482 2483
	}
	return (ret ? 1 : 0);
}

L
Linus Torvalds 已提交
2484 2485 2486 2487 2488 2489 2490
/**
 * 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.
 */
2491
int kmem_cache_shrink(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2492
{
2493
	int ret;
2494
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2495

2496 2497 2498 2499
	mutex_lock(&cache_chain_mutex);
	ret = __cache_shrink(cachep);
	mutex_unlock(&cache_chain_mutex);
	return ret;
L
Linus Torvalds 已提交
2500 2501 2502 2503 2504 2505 2506
}
EXPORT_SYMBOL(kmem_cache_shrink);

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
2507
 * Remove a struct kmem_cache object from the slab cache.
L
Linus Torvalds 已提交
2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518
 *
 * 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().
 */
2519
void kmem_cache_destroy(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2520
{
2521
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2522 2523

	/* Find the cache in the chain of caches. */
I
Ingo Molnar 已提交
2524
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2525 2526 2527 2528 2529 2530
	/*
	 * the chain is never empty, cache_cache is never destroyed
	 */
	list_del(&cachep->next);
	if (__cache_shrink(cachep)) {
		slab_error(cachep, "Can't free all objects");
P
Pekka Enberg 已提交
2531
		list_add(&cachep->next, &cache_chain);
I
Ingo Molnar 已提交
2532
		mutex_unlock(&cache_chain_mutex);
2533
		return;
L
Linus Torvalds 已提交
2534 2535 2536
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2537
		synchronize_rcu();
L
Linus Torvalds 已提交
2538

2539
	__kmem_cache_destroy(cachep);
2540
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2541 2542 2543
}
EXPORT_SYMBOL(kmem_cache_destroy);

2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554
/*
 * Get the memory for a slab management obj.
 * For a slab cache when the slab descriptor is off-slab, slab descriptors
 * always come from malloc_sizes caches.  The slab descriptor cannot
 * come from the same cache which is getting created because,
 * when we are searching for an appropriate cache for these
 * descriptors in kmem_cache_create, we search through the malloc_sizes array.
 * If we are creating a malloc_sizes cache here it would not be visible to
 * kmem_find_general_cachep till the initialization is complete.
 * Hence we cannot have slabp_cache same as the original cache.
 */
2555
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
2556 2557
				   int colour_off, gfp_t local_flags,
				   int nodeid)
L
Linus Torvalds 已提交
2558 2559
{
	struct slab *slabp;
P
Pekka Enberg 已提交
2560

L
Linus Torvalds 已提交
2561 2562
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
2563
		slabp = kmem_cache_alloc_node(cachep->slabp_cache,
2564
					      local_flags & ~GFP_THISNODE, nodeid);
L
Linus Torvalds 已提交
2565 2566 2567
		if (!slabp)
			return NULL;
	} else {
P
Pekka Enberg 已提交
2568
		slabp = objp + colour_off;
L
Linus Torvalds 已提交
2569 2570 2571 2572
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
P
Pekka Enberg 已提交
2573
	slabp->s_mem = objp + colour_off;
2574
	slabp->nodeid = nodeid;
L
Linus Torvalds 已提交
2575 2576 2577 2578 2579
	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
P
Pekka Enberg 已提交
2580
	return (kmem_bufctl_t *) (slabp + 1);
L
Linus Torvalds 已提交
2581 2582
}

2583
static void cache_init_objs(struct kmem_cache *cachep,
P
Pekka Enberg 已提交
2584
			    struct slab *slabp, unsigned long ctor_flags)
L
Linus Torvalds 已提交
2585 2586 2587 2588
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2589
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601
#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
2602 2603 2604
		 * 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
2605 2606
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2607
			cachep->ctor(objp + obj_offset(cachep), cachep,
P
Pekka Enberg 已提交
2608
				     ctor_flags);
L
Linus Torvalds 已提交
2609 2610 2611 2612

		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
2613
					   " end of an object");
L
Linus Torvalds 已提交
2614 2615
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2616
					   " start of an object");
L
Linus Torvalds 已提交
2617
		}
A
Andrew Morton 已提交
2618 2619
		if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
			    OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
P
Pekka Enberg 已提交
2620
			kernel_map_pages(virt_to_page(objp),
2621
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2622 2623 2624 2625
#else
		if (cachep->ctor)
			cachep->ctor(objp, cachep, ctor_flags);
#endif
P
Pekka Enberg 已提交
2626
		slab_bufctl(slabp)[i] = i + 1;
L
Linus Torvalds 已提交
2627
	}
P
Pekka Enberg 已提交
2628
	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
L
Linus Torvalds 已提交
2629 2630 2631
	slabp->free = 0;
}

2632
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2633
{
C
Christoph Lameter 已提交
2634
	if (flags & GFP_DMA)
A
Andrew Morton 已提交
2635 2636 2637
		BUG_ON(!(cachep->gfpflags & GFP_DMA));
	else
		BUG_ON(cachep->gfpflags & GFP_DMA);
L
Linus Torvalds 已提交
2638 2639
}

A
Andrew Morton 已提交
2640 2641
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
				int nodeid)
2642
{
2643
	void *objp = index_to_obj(cachep, slabp, slabp->free);
2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656
	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
2657 2658
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
				void *objp, int nodeid)
2659
{
2660
	unsigned int objnr = obj_to_index(cachep, slabp, objp);
2661 2662 2663 2664 2665

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

2666
	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
2667
		printk(KERN_ERR "slab: double free detected in cache "
A
Andrew Morton 已提交
2668
				"'%s', objp %p\n", cachep->name, objp);
2669 2670 2671 2672 2673 2674 2675 2676
		BUG();
	}
#endif
	slab_bufctl(slabp)[objnr] = slabp->free;
	slabp->free = objnr;
	slabp->inuse--;
}

2677 2678 2679 2680 2681 2682 2683
/*
 * Map pages beginning at addr to the given cache and slab. This is required
 * for the slab allocator to be able to lookup the cache and slab of a
 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
 */
static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
			   void *addr)
L
Linus Torvalds 已提交
2684
{
2685
	int nr_pages;
L
Linus Torvalds 已提交
2686 2687
	struct page *page;

2688
	page = virt_to_page(addr);
2689

2690
	nr_pages = 1;
2691
	if (likely(!PageCompound(page)))
2692 2693
		nr_pages <<= cache->gfporder;

L
Linus Torvalds 已提交
2694
	do {
2695 2696
		page_set_cache(page, cache);
		page_set_slab(page, slab);
L
Linus Torvalds 已提交
2697
		page++;
2698
	} while (--nr_pages);
L
Linus Torvalds 已提交
2699 2700 2701 2702 2703 2704
}

/*
 * 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.
 */
2705 2706
static int cache_grow(struct kmem_cache *cachep,
		gfp_t flags, int nodeid, void *objp)
L
Linus Torvalds 已提交
2707
{
P
Pekka Enberg 已提交
2708 2709 2710 2711
	struct slab *slabp;
	size_t offset;
	gfp_t local_flags;
	unsigned long ctor_flags;
2712
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2713

A
Andrew Morton 已提交
2714 2715 2716
	/*
	 * 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
2717
	 */
C
Christoph Lameter 已提交
2718
	BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK | __GFP_NO_GROW));
2719
	if (flags & __GFP_NO_GROW)
L
Linus Torvalds 已提交
2720 2721 2722
		return 0;

	ctor_flags = SLAB_CTOR_CONSTRUCTOR;
2723
	local_flags = (flags & GFP_LEVEL_MASK);
L
Linus Torvalds 已提交
2724 2725 2726 2727 2728 2729 2730
	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;

2731
	/* Take the l3 list lock to change the colour_next on this node */
L
Linus Torvalds 已提交
2732
	check_irq_off();
2733 2734
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2735 2736

	/* Get colour for the slab, and cal the next value. */
2737 2738 2739 2740 2741
	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
2742

2743
	offset *= cachep->colour_off;
L
Linus Torvalds 已提交
2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755

	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
2756 2757 2758
	/*
	 * Get mem for the objs.  Attempt to allocate a physical page from
	 * 'nodeid'.
2759
	 */
2760 2761
	if (!objp)
		objp = kmem_getpages(cachep, flags, nodeid);
A
Andrew Morton 已提交
2762
	if (!objp)
L
Linus Torvalds 已提交
2763 2764 2765
		goto failed;

	/* Get slab management. */
2766 2767
	slabp = alloc_slabmgmt(cachep, objp, offset,
			local_flags & ~GFP_THISNODE, nodeid);
A
Andrew Morton 已提交
2768
	if (!slabp)
L
Linus Torvalds 已提交
2769 2770
		goto opps1;

2771
	slabp->nodeid = nodeid;
2772
	slab_map_pages(cachep, slabp, objp);
L
Linus Torvalds 已提交
2773 2774 2775 2776 2777 2778

	cache_init_objs(cachep, slabp, ctor_flags);

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2779
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2780 2781

	/* Make slab active. */
2782
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2783
	STATS_INC_GROWN(cachep);
2784 2785
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2786
	return 1;
A
Andrew Morton 已提交
2787
opps1:
L
Linus Torvalds 已提交
2788
	kmem_freepages(cachep, objp);
A
Andrew Morton 已提交
2789
failed:
L
Linus Torvalds 已提交
2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808
	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
2809 2810
		       (unsigned long)objp);
		BUG();
L
Linus Torvalds 已提交
2811 2812 2813
	}
	page = virt_to_page(objp);
	if (!PageSlab(page)) {
P
Pekka Enberg 已提交
2814 2815
		printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n",
		       (unsigned long)objp);
L
Linus Torvalds 已提交
2816 2817 2818 2819
		BUG();
	}
}

2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841
static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
{
	unsigned long redzone1, redzone2;

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

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

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

	printk(KERN_ERR "%p: redzone 1:0x%lx, redzone 2:0x%lx.\n",
			obj, redzone1, redzone2);
}

2842
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2843
				   void *caller)
L
Linus Torvalds 已提交
2844 2845 2846 2847 2848
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

2849
	objp -= obj_offset(cachep);
L
Linus Torvalds 已提交
2850 2851 2852
	kfree_debugcheck(objp);
	page = virt_to_page(objp);

2853
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2854 2855

	if (cachep->flags & SLAB_RED_ZONE) {
2856
		verify_redzone_free(cachep, objp);
L
Linus Torvalds 已提交
2857 2858 2859 2860 2861 2862
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

2863
	objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
2864 2865

	BUG_ON(objnr >= cachep->num);
2866
	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
L
Linus Torvalds 已提交
2867 2868

	if (cachep->flags & SLAB_DEBUG_INITIAL) {
A
Andrew Morton 已提交
2869 2870 2871 2872
		/*
		 * 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
2873
		 */
2874
		cachep->ctor(objp + obj_offset(cachep),
P
Pekka Enberg 已提交
2875
			     cachep, SLAB_CTOR_CONSTRUCTOR | SLAB_CTOR_VERIFY);
L
Linus Torvalds 已提交
2876 2877 2878 2879 2880
	}
	if (cachep->flags & SLAB_POISON && cachep->dtor) {
		/* we want to cache poison the object,
		 * call the destruction callback
		 */
2881
		cachep->dtor(objp + obj_offset(cachep), cachep, 0);
L
Linus Torvalds 已提交
2882
	}
2883 2884 2885
#ifdef CONFIG_DEBUG_SLAB_LEAK
	slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
#endif
L
Linus Torvalds 已提交
2886 2887
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
2888
		if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
L
Linus Torvalds 已提交
2889
			store_stackinfo(cachep, objp, (unsigned long)caller);
P
Pekka Enberg 已提交
2890
			kernel_map_pages(virt_to_page(objp),
2891
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2892 2893 2894 2895 2896 2897 2898 2899 2900 2901
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

2902
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
2903 2904 2905
{
	kmem_bufctl_t i;
	int entries = 0;
P
Pekka Enberg 已提交
2906

L
Linus Torvalds 已提交
2907 2908 2909 2910 2911 2912 2913
	/* 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
2914 2915 2916 2917
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
2918
		for (i = 0;
2919
		     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
P
Pekka Enberg 已提交
2920
		     i++) {
A
Andrew Morton 已提交
2921
			if (i % 16 == 0)
L
Linus Torvalds 已提交
2922
				printk("\n%03x:", i);
P
Pekka Enberg 已提交
2923
			printk(" %02x", ((unsigned char *)slabp)[i]);
L
Linus Torvalds 已提交
2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934
		}
		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

2935
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2936 2937 2938 2939
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;
P
Pekka Enberg 已提交
2940 2941 2942
	int node;

	node = numa_node_id();
L
Linus Torvalds 已提交
2943 2944

	check_irq_off();
2945
	ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
2946
retry:
L
Linus Torvalds 已提交
2947 2948
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
A
Andrew Morton 已提交
2949 2950 2951 2952
		/*
		 * 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
2953 2954 2955
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
P
Pekka Enberg 已提交
2956
	l3 = cachep->nodelists[node];
2957 2958 2959

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2960

2961 2962 2963 2964
	/* See if we can refill from the shared array */
	if (l3->shared && transfer_objects(ac, l3->shared, batchcount))
		goto alloc_done;

L
Linus Torvalds 已提交
2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984
	while (batchcount > 0) {
		struct list_head *entry;
		struct slab *slabp;
		/* Get slab alloc is to come from. */
		entry = l3->slabs_partial.next;
		if (entry == &l3->slabs_partial) {
			l3->free_touched = 1;
			entry = l3->slabs_free.next;
			if (entry == &l3->slabs_free)
				goto must_grow;
		}

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

2985
			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
P
Pekka Enberg 已提交
2986
							    node);
L
Linus Torvalds 已提交
2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997
		}
		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
2998
must_grow:
L
Linus Torvalds 已提交
2999
	l3->free_objects -= ac->avail;
A
Andrew Morton 已提交
3000
alloc_done:
3001
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3002 3003 3004

	if (unlikely(!ac->avail)) {
		int x;
3005
		x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
3006

A
Andrew Morton 已提交
3007
		/* cache_grow can reenable interrupts, then ac could change. */
3008
		ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
3009
		if (!x && ac->avail == 0)	/* no objects in sight? abort */
L
Linus Torvalds 已提交
3010 3011
			return NULL;

A
Andrew Morton 已提交
3012
		if (!ac->avail)		/* objects refilled by interrupt? */
L
Linus Torvalds 已提交
3013 3014 3015
			goto retry;
	}
	ac->touched = 1;
3016
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3017 3018
}

A
Andrew Morton 已提交
3019 3020
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
						gfp_t flags)
L
Linus Torvalds 已提交
3021 3022 3023 3024 3025 3026 3027 3028
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
A
Andrew Morton 已提交
3029 3030
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
				gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
3031
{
P
Pekka Enberg 已提交
3032
	if (!objp)
L
Linus Torvalds 已提交
3033
		return objp;
P
Pekka Enberg 已提交
3034
	if (cachep->flags & SLAB_POISON) {
L
Linus Torvalds 已提交
3035
#ifdef CONFIG_DEBUG_PAGEALLOC
3036
		if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
P
Pekka Enberg 已提交
3037
			kernel_map_pages(virt_to_page(objp),
3038
					 cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049
		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
3050 3051 3052 3053
		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
3054
			printk(KERN_ERR
A
Andrew Morton 已提交
3055 3056 3057
				"%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
3058 3059 3060 3061
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
3062 3063 3064 3065 3066 3067 3068 3069 3070 3071
#ifdef CONFIG_DEBUG_SLAB_LEAK
	{
		struct slab *slabp;
		unsigned objnr;

		slabp = page_get_slab(virt_to_page(objp));
		objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
	}
#endif
3072
	objp += obj_offset(cachep);
L
Linus Torvalds 已提交
3073
	if (cachep->ctor && cachep->flags & SLAB_POISON) {
P
Pekka Enberg 已提交
3074
		unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
L
Linus Torvalds 已提交
3075 3076 3077 3078 3079

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

		cachep->ctor(objp, cachep, ctor_flags);
P
Pekka Enberg 已提交
3080
	}
3081 3082 3083 3084 3085 3086
#if ARCH_SLAB_MINALIGN
	if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
		printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
		       objp, ARCH_SLAB_MINALIGN);
	}
#endif
L
Linus Torvalds 已提交
3087 3088 3089 3090 3091 3092
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105
#ifdef CONFIG_FAILSLAB

static struct failslab_attr {

	struct fault_attr attr;

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

} failslab = {
	.attr = FAULT_ATTR_INITIALIZER,
3106
	.ignore_gfp_wait = 1,
3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165
};

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

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

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

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

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

       	err = init_fault_attr_dentries(&failslab.attr, "failslab");
	if (err)
		return err;
	dir = failslab.attr.dentries.dir;

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

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

	return err;
}

late_initcall(failslab_debugfs);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#else /* CONFIG_FAILSLAB */

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

#endif /* CONFIG_FAILSLAB */

3166
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3167
{
P
Pekka Enberg 已提交
3168
	void *objp;
L
Linus Torvalds 已提交
3169 3170
	struct array_cache *ac;

3171
	check_irq_off();
3172 3173 3174 3175

	if (should_failslab(cachep, flags))
		return NULL;

3176
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3177 3178 3179
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
3180
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3181 3182 3183 3184
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
3185 3186 3187
	return objp;
}

A
Andrew Morton 已提交
3188 3189
static __always_inline void *__cache_alloc(struct kmem_cache *cachep,
						gfp_t flags, void *caller)
3190 3191
{
	unsigned long save_flags;
3192
	void *objp = NULL;
3193 3194 3195 3196

	cache_alloc_debugcheck_before(cachep, flags);

	local_irq_save(save_flags);
3197

3198 3199
	if (unlikely(NUMA_BUILD &&
			current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY)))
3200 3201 3202 3203
		objp = alternate_node_alloc(cachep, flags);

	if (!objp)
		objp = ____cache_alloc(cachep, flags);
3204 3205
	/*
	 * We may just have run out of memory on the local node.
3206
	 * ____cache_alloc_node() knows how to locate memory on other nodes
3207 3208
	 */
 	if (NUMA_BUILD && !objp)
3209
 		objp = ____cache_alloc_node(cachep, flags, numa_node_id());
L
Linus Torvalds 已提交
3210
	local_irq_restore(save_flags);
3211
	objp = cache_alloc_debugcheck_after(cachep, flags, objp,
3212
					    caller);
3213
	prefetchw(objp);
L
Linus Torvalds 已提交
3214 3215 3216
	return objp;
}

3217
#ifdef CONFIG_NUMA
3218
/*
3219
 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
3220 3221 3222 3223 3224 3225 3226 3227
 *
 * If we are in_interrupt, then process context, including cpusets and
 * mempolicy, may not apply and should not be used for allocation policy.
 */
static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
{
	int nid_alloc, nid_here;

3228
	if (in_interrupt() || (flags & __GFP_THISNODE))
3229 3230 3231 3232 3233 3234 3235
		return NULL;
	nid_alloc = nid_here = numa_node_id();
	if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
		nid_alloc = cpuset_mem_spread_node();
	else if (current->mempolicy)
		nid_alloc = slab_node(current->mempolicy);
	if (nid_alloc != nid_here)
3236
		return ____cache_alloc_node(cachep, flags, nid_alloc);
3237 3238 3239
	return NULL;
}

3240 3241
/*
 * Fallback function if there was no memory available and no objects on a
3242 3243 3244 3245 3246
 * certain node and fall back is permitted. First we scan all the
 * available nodelists for available objects. If that fails then we
 * perform an allocation without specifying a node. This allows the page
 * allocator to do its reclaim / fallback magic. We then insert the
 * slab into the proper nodelist and then allocate from it.
3247 3248 3249 3250 3251 3252 3253
 */
void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
{
	struct zonelist *zonelist = &NODE_DATA(slab_node(current->mempolicy))
					->node_zonelists[gfp_zone(flags)];
	struct zone **z;
	void *obj = NULL;
3254
	int nid;
3255
	gfp_t local_flags = (flags & GFP_LEVEL_MASK);
3256

3257 3258 3259 3260 3261
retry:
	/*
	 * Look through allowed nodes for objects available
	 * from existing per node queues.
	 */
3262
	for (z = zonelist->zones; *z && !obj; z++) {
3263
		nid = zone_to_nid(*z);
3264

3265
		if (cpuset_zone_allowed_hardwall(*z, flags) &&
3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278
			cache->nodelists[nid] &&
			cache->nodelists[nid]->free_objects)
				obj = ____cache_alloc_node(cache,
					flags | GFP_THISNODE, nid);
	}

	if (!obj) {
		/*
		 * This allocation will be performed within the constraints
		 * of the current cpuset / memory policy requirements.
		 * We may trigger various forms of reclaim on the allowed
		 * set and go into memory reserves if necessary.
		 */
3279 3280 3281
		if (local_flags & __GFP_WAIT)
			local_irq_enable();
		kmem_flagcheck(cache, flags);
3282
		obj = kmem_getpages(cache, flags, -1);
3283 3284
		if (local_flags & __GFP_WAIT)
			local_irq_disable();
3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304
		if (obj) {
			/*
			 * Insert into the appropriate per node queues
			 */
			nid = page_to_nid(virt_to_page(obj));
			if (cache_grow(cache, flags, nid, obj)) {
				obj = ____cache_alloc_node(cache,
					flags | GFP_THISNODE, nid);
				if (!obj)
					/*
					 * Another processor may allocate the
					 * objects in the slab since we are
					 * not holding any locks.
					 */
					goto retry;
			} else {
				kmem_freepages(cache, obj);
				obj = NULL;
			}
		}
3305
	}
3306 3307 3308
	return obj;
}

3309 3310
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
3311
 */
3312
static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
A
Andrew Morton 已提交
3313
				int nodeid)
3314 3315
{
	struct list_head *entry;
P
Pekka Enberg 已提交
3316 3317 3318 3319 3320 3321 3322 3323
	struct slab *slabp;
	struct kmem_list3 *l3;
	void *obj;
	int x;

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

A
Andrew Morton 已提交
3324
retry:
3325
	check_irq_off();
P
Pekka Enberg 已提交
3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344
	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);

3345
	obj = slab_get_obj(cachep, slabp, nodeid);
P
Pekka Enberg 已提交
3346 3347 3348 3349 3350
	check_slabp(cachep, slabp);
	l3->free_objects--;
	/* move slabp to correct slabp list: */
	list_del(&slabp->list);

A
Andrew Morton 已提交
3351
	if (slabp->free == BUFCTL_END)
P
Pekka Enberg 已提交
3352
		list_add(&slabp->list, &l3->slabs_full);
A
Andrew Morton 已提交
3353
	else
P
Pekka Enberg 已提交
3354
		list_add(&slabp->list, &l3->slabs_partial);
3355

P
Pekka Enberg 已提交
3356 3357
	spin_unlock(&l3->list_lock);
	goto done;
3358

A
Andrew Morton 已提交
3359
must_grow:
P
Pekka Enberg 已提交
3360
	spin_unlock(&l3->list_lock);
3361
	x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
3362 3363
	if (x)
		goto retry;
L
Linus Torvalds 已提交
3364

3365 3366 3367 3368 3369
	if (!(flags & __GFP_THISNODE))
		/* Unable to grow the cache. Fall back to other nodes. */
		return fallback_alloc(cachep, flags);

	return NULL;
3370

A
Andrew Morton 已提交
3371
done:
P
Pekka Enberg 已提交
3372
	return obj;
3373 3374 3375 3376 3377 3378
}
#endif

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
3379
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
P
Pekka Enberg 已提交
3380
		       int node)
L
Linus Torvalds 已提交
3381 3382
{
	int i;
3383
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3384 3385 3386 3387 3388

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

3389
		slabp = virt_to_slab(objp);
3390
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
3391
		list_del(&slabp->list);
3392
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
3393
		check_slabp(cachep, slabp);
3394
		slab_put_obj(cachep, slabp, objp, node);
L
Linus Torvalds 已提交
3395
		STATS_DEC_ACTIVE(cachep);
3396
		l3->free_objects++;
L
Linus Torvalds 已提交
3397 3398 3399 3400
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
3401 3402
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
3403 3404 3405 3406 3407 3408
				/* No need to drop any previously held
				 * lock here, even if we have a off-slab slab
				 * descriptor it is guaranteed to come from
				 * a different cache, refer to comments before
				 * alloc_slabmgmt.
				 */
L
Linus Torvalds 已提交
3409 3410
				slab_destroy(cachep, slabp);
			} else {
3411
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
3412 3413 3414 3415 3416 3417
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
3418
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
3419 3420 3421 3422
		}
	}
}

3423
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
L
Linus Torvalds 已提交
3424 3425
{
	int batchcount;
3426
	struct kmem_list3 *l3;
3427
	int node = numa_node_id();
L
Linus Torvalds 已提交
3428 3429 3430 3431 3432 3433

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
3434
	l3 = cachep->nodelists[node];
3435
	spin_lock(&l3->list_lock);
3436 3437
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
P
Pekka Enberg 已提交
3438
		int max = shared_array->limit - shared_array->avail;
L
Linus Torvalds 已提交
3439 3440 3441
		if (max) {
			if (batchcount > max)
				batchcount = max;
3442
			memcpy(&(shared_array->entry[shared_array->avail]),
P
Pekka Enberg 已提交
3443
			       ac->entry, sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
3444 3445 3446 3447 3448
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

3449
	free_block(cachep, ac->entry, batchcount, node);
A
Andrew Morton 已提交
3450
free_done:
L
Linus Torvalds 已提交
3451 3452 3453 3454 3455
#if STATS
	{
		int i = 0;
		struct list_head *p;

3456 3457
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468
			struct slab *slabp;

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

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
3469
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3470
	ac->avail -= batchcount;
A
Andrew Morton 已提交
3471
	memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
L
Linus Torvalds 已提交
3472 3473 3474
}

/*
A
Andrew Morton 已提交
3475 3476
 * 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
3477
 */
3478
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3479
{
3480
	struct array_cache *ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3481 3482 3483 3484

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

3485
	if (cache_free_alien(cachep, objp))
3486 3487
		return;

L
Linus Torvalds 已提交
3488 3489
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
3490
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3491 3492 3493 3494
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
3495
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506
	}
}

/**
 * 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.
 */
3507
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3508
{
3509
	return __cache_alloc(cachep, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3510 3511 3512
}
EXPORT_SYMBOL(kmem_cache_alloc);

3513
/**
3514
 * kmem_cache_zalloc - Allocate an object. The memory is set to zero.
3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529
 * @cache: The cache to allocate from.
 * @flags: See kmalloc().
 *
 * Allocate an object from this cache and set the allocated memory to zero.
 * The flags are only relevant if the cache has no available objects.
 */
void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags)
{
	void *ret = __cache_alloc(cache, flags, __builtin_return_address(0));
	if (ret)
		memset(ret, 0, obj_size(cache));
	return ret;
}
EXPORT_SYMBOL(kmem_cache_zalloc);

L
Linus Torvalds 已提交
3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543
/**
 * 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.
 */
C
Christoph Lameter 已提交
3544
int fastcall kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
L
Linus Torvalds 已提交
3545
{
P
Pekka Enberg 已提交
3546
	unsigned long addr = (unsigned long)ptr;
L
Linus Torvalds 已提交
3547
	unsigned long min_addr = PAGE_OFFSET;
P
Pekka Enberg 已提交
3548
	unsigned long align_mask = BYTES_PER_WORD - 1;
3549
	unsigned long size = cachep->buffer_size;
L
Linus Torvalds 已提交
3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564
	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;
3565
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
3566 3567
		goto out;
	return 1;
A
Andrew Morton 已提交
3568
out:
L
Linus Torvalds 已提交
3569 3570 3571 3572 3573 3574 3575 3576 3577 3578
	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.
 *
3579 3580 3581 3582
 * Identical to kmem_cache_alloc but it will allocate memory on the given
 * node, which can improve the performance for cpu bound structures.
 *
 * Fallback to other node is possible if __GFP_THISNODE is not set.
L
Linus Torvalds 已提交
3583
 */
3584 3585 3586
static __always_inline void *
__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
		int nodeid, void *caller)
L
Linus Torvalds 已提交
3587
{
3588
	unsigned long save_flags;
3589
	void *ptr = NULL;
L
Linus Torvalds 已提交
3590

3591 3592
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
3593

3594 3595
	if (unlikely(nodeid == -1))
		nodeid = numa_node_id();
3596

3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617
	if (likely(cachep->nodelists[nodeid])) {
		if (nodeid == numa_node_id()) {
			/*
			 * Use the locally cached objects if possible.
			 * However ____cache_alloc does not allow fallback
			 * to other nodes. It may fail while we still have
			 * objects on other nodes available.
			 */
			ptr = ____cache_alloc(cachep, flags);
		}
		if (!ptr) {
			/* ___cache_alloc_node can fall back to other nodes */
			ptr = ____cache_alloc_node(cachep, flags, nodeid);
		}
	} else {
		/* Node not bootstrapped yet */
		if (!(flags & __GFP_THISNODE))
			ptr = fallback_alloc(cachep, flags);
	}

	local_irq_restore(save_flags);
3618
	ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
L
Linus Torvalds 已提交
3619

3620
	return ptr;
L
Linus Torvalds 已提交
3621
}
3622 3623 3624 3625 3626 3627

void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
{
	return __cache_alloc_node(cachep, flags, nodeid,
			__builtin_return_address(0));
}
L
Linus Torvalds 已提交
3628 3629
EXPORT_SYMBOL(kmem_cache_alloc_node);

3630 3631
static __always_inline void *
__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
3632
{
3633
	struct kmem_cache *cachep;
3634 3635 3636 3637 3638 3639

	cachep = kmem_find_general_cachep(size, flags);
	if (unlikely(cachep == NULL))
		return NULL;
	return kmem_cache_alloc_node(cachep, flags, node);
}
3640 3641 3642 3643 3644 3645 3646

#ifdef CONFIG_DEBUG_SLAB
void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
	return __do_kmalloc_node(size, flags, node,
			__builtin_return_address(0));
}
3647
EXPORT_SYMBOL(__kmalloc_node);
3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662

void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
		int node, void *caller)
{
	return __do_kmalloc_node(size, flags, node, caller);
}
EXPORT_SYMBOL(__kmalloc_node_track_caller);
#else
void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
	return __do_kmalloc_node(size, flags, node, NULL);
}
EXPORT_SYMBOL(__kmalloc_node);
#endif /* CONFIG_DEBUG_SLAB */
#endif /* CONFIG_NUMA */
L
Linus Torvalds 已提交
3663 3664

/**
3665
 * __do_kmalloc - allocate memory
L
Linus Torvalds 已提交
3666
 * @size: how many bytes of memory are required.
3667
 * @flags: the type of memory to allocate (see kmalloc).
3668
 * @caller: function caller for debug tracking of the caller
L
Linus Torvalds 已提交
3669
 */
3670 3671
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
					  void *caller)
L
Linus Torvalds 已提交
3672
{
3673
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3674

3675 3676 3677 3678 3679 3680
	/* 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);
3681 3682
	if (unlikely(cachep == NULL))
		return NULL;
3683 3684 3685 3686
	return __cache_alloc(cachep, flags, caller);
}


3687
#ifdef CONFIG_DEBUG_SLAB
3688 3689
void *__kmalloc(size_t size, gfp_t flags)
{
3690
	return __do_kmalloc(size, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3691 3692 3693
}
EXPORT_SYMBOL(__kmalloc);

3694 3695 3696 3697 3698
void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
{
	return __do_kmalloc(size, flags, caller);
}
EXPORT_SYMBOL(__kmalloc_track_caller);
3699 3700 3701 3702 3703 3704 3705

#else
void *__kmalloc(size_t size, gfp_t flags)
{
	return __do_kmalloc(size, flags, NULL);
}
EXPORT_SYMBOL(__kmalloc);
3706 3707
#endif

L
Linus Torvalds 已提交
3708 3709 3710 3711 3712 3713 3714 3715
/**
 * 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.
 */
3716
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3717 3718 3719
{
	unsigned long flags;

3720 3721
	BUG_ON(virt_to_cache(objp) != cachep);

L
Linus Torvalds 已提交
3722
	local_irq_save(flags);
3723
	__cache_free(cachep, objp);
L
Linus Torvalds 已提交
3724 3725 3726 3727 3728 3729 3730 3731
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kmem_cache_free);

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3732 3733
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3734 3735 3736 3737 3738
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
3739
	struct kmem_cache *c;
L
Linus Torvalds 已提交
3740 3741 3742 3743 3744 3745
	unsigned long flags;

	if (unlikely(!objp))
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3746
	c = virt_to_cache(objp);
3747
	debug_check_no_locks_freed(objp, obj_size(c));
3748
	__cache_free(c, (void *)objp);
L
Linus Torvalds 已提交
3749 3750 3751 3752
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

3753
unsigned int kmem_cache_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3754
{
3755
	return obj_size(cachep);
L
Linus Torvalds 已提交
3756 3757 3758
}
EXPORT_SYMBOL(kmem_cache_size);

3759
const char *kmem_cache_name(struct kmem_cache *cachep)
3760 3761 3762 3763 3764
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3765
/*
3766
 * This initializes kmem_list3 or resizes varioius caches for all nodes.
3767
 */
3768
static int alloc_kmemlist(struct kmem_cache *cachep)
3769 3770 3771
{
	int node;
	struct kmem_list3 *l3;
3772
	struct array_cache *new_shared;
3773
	struct array_cache **new_alien = NULL;
3774 3775

	for_each_online_node(node) {
3776

3777 3778 3779 3780 3781
                if (use_alien_caches) {
                        new_alien = alloc_alien_cache(node, cachep->limit);
                        if (!new_alien)
                                goto fail;
                }
3782

3783 3784
		new_shared = alloc_arraycache(node,
				cachep->shared*cachep->batchcount,
A
Andrew Morton 已提交
3785
					0xbaadf00d);
3786 3787
		if (!new_shared) {
			free_alien_cache(new_alien);
3788
			goto fail;
3789
		}
3790

A
Andrew Morton 已提交
3791 3792
		l3 = cachep->nodelists[node];
		if (l3) {
3793 3794
			struct array_cache *shared = l3->shared;

3795 3796
			spin_lock_irq(&l3->list_lock);

3797
			if (shared)
3798 3799
				free_block(cachep, shared->entry,
						shared->avail, node);
3800

3801 3802
			l3->shared = new_shared;
			if (!l3->alien) {
3803 3804 3805
				l3->alien = new_alien;
				new_alien = NULL;
			}
P
Pekka Enberg 已提交
3806
			l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3807
					cachep->batchcount + cachep->num;
3808
			spin_unlock_irq(&l3->list_lock);
3809
			kfree(shared);
3810 3811 3812
			free_alien_cache(new_alien);
			continue;
		}
A
Andrew Morton 已提交
3813
		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
3814 3815 3816
		if (!l3) {
			free_alien_cache(new_alien);
			kfree(new_shared);
3817
			goto fail;
3818
		}
3819 3820 3821

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
A
Andrew Morton 已提交
3822
				((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3823
		l3->shared = new_shared;
3824
		l3->alien = new_alien;
P
Pekka Enberg 已提交
3825
		l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3826
					cachep->batchcount + cachep->num;
3827 3828
		cachep->nodelists[node] = l3;
	}
3829
	return 0;
3830

A
Andrew Morton 已提交
3831
fail:
3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846
	if (!cachep->next.next) {
		/* Cache is not active yet. Roll back what we did */
		node--;
		while (node >= 0) {
			if (cachep->nodelists[node]) {
				l3 = cachep->nodelists[node];

				kfree(l3->shared);
				free_alien_cache(l3->alien);
				kfree(l3);
				cachep->nodelists[node] = NULL;
			}
			node--;
		}
	}
3847
	return -ENOMEM;
3848 3849
}

L
Linus Torvalds 已提交
3850
struct ccupdate_struct {
3851
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3852 3853 3854 3855 3856
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
A
Andrew Morton 已提交
3857
	struct ccupdate_struct *new = info;
L
Linus Torvalds 已提交
3858 3859 3860
	struct array_cache *old;

	check_irq_off();
3861
	old = cpu_cache_get(new->cachep);
3862

L
Linus Torvalds 已提交
3863 3864 3865 3866
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}

3867
/* Always called with the cache_chain_mutex held */
A
Andrew Morton 已提交
3868 3869
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
				int batchcount, int shared)
L
Linus Torvalds 已提交
3870
{
3871
	struct ccupdate_struct *new;
3872
	int i;
L
Linus Torvalds 已提交
3873

3874 3875 3876 3877
	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		return -ENOMEM;

3878
	for_each_online_cpu(i) {
3879
		new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
A
Andrew Morton 已提交
3880
						batchcount);
3881
		if (!new->new[i]) {
P
Pekka Enberg 已提交
3882
			for (i--; i >= 0; i--)
3883 3884
				kfree(new->new[i]);
			kfree(new);
3885
			return -ENOMEM;
L
Linus Torvalds 已提交
3886 3887
		}
	}
3888
	new->cachep = cachep;
L
Linus Torvalds 已提交
3889

3890
	on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
3891

L
Linus Torvalds 已提交
3892 3893 3894
	check_irq_on();
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3895
	cachep->shared = shared;
L
Linus Torvalds 已提交
3896

3897
	for_each_online_cpu(i) {
3898
		struct array_cache *ccold = new->new[i];
L
Linus Torvalds 已提交
3899 3900
		if (!ccold)
			continue;
3901
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3902
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3903
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3904 3905
		kfree(ccold);
	}
3906
	kfree(new);
3907
	return alloc_kmemlist(cachep);
L
Linus Torvalds 已提交
3908 3909
}

3910
/* Called with cache_chain_mutex held always */
3911
static int enable_cpucache(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3912 3913 3914 3915
{
	int err;
	int limit, shared;

A
Andrew Morton 已提交
3916 3917
	/*
	 * The head array serves three purposes:
L
Linus Torvalds 已提交
3918 3919
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
A
Andrew Morton 已提交
3920
	 * - reduce the number of linked list operations on the slab and
L
Linus Torvalds 已提交
3921 3922 3923 3924
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
3925
	if (cachep->buffer_size > 131072)
L
Linus Torvalds 已提交
3926
		limit = 1;
3927
	else if (cachep->buffer_size > PAGE_SIZE)
L
Linus Torvalds 已提交
3928
		limit = 8;
3929
	else if (cachep->buffer_size > 1024)
L
Linus Torvalds 已提交
3930
		limit = 24;
3931
	else if (cachep->buffer_size > 256)
L
Linus Torvalds 已提交
3932 3933 3934 3935
		limit = 54;
	else
		limit = 120;

A
Andrew Morton 已提交
3936 3937
	/*
	 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
L
Linus Torvalds 已提交
3938 3939 3940 3941 3942 3943 3944 3945 3946
	 * 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
3947
	if (cachep->buffer_size <= PAGE_SIZE)
L
Linus Torvalds 已提交
3948 3949 3950 3951
		shared = 8;
#endif

#if DEBUG
A
Andrew Morton 已提交
3952 3953 3954
	/*
	 * With debugging enabled, large batchcount lead to excessively long
	 * periods with disabled local interrupts. Limit the batchcount
L
Linus Torvalds 已提交
3955 3956 3957 3958
	 */
	if (limit > 32)
		limit = 32;
#endif
P
Pekka Enberg 已提交
3959
	err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
L
Linus Torvalds 已提交
3960 3961
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
P
Pekka Enberg 已提交
3962
		       cachep->name, -err);
3963
	return err;
L
Linus Torvalds 已提交
3964 3965
}

3966 3967
/*
 * Drain an array if it contains any elements taking the l3 lock only if
3968 3969
 * necessary. Note that the l3 listlock also protects the array_cache
 * if drain_array() is used on the shared array.
3970 3971 3972
 */
void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
			 struct array_cache *ac, int force, int node)
L
Linus Torvalds 已提交
3973 3974 3975
{
	int tofree;

3976 3977
	if (!ac || !ac->avail)
		return;
L
Linus Torvalds 已提交
3978 3979
	if (ac->touched && !force) {
		ac->touched = 0;
3980
	} else {
3981
		spin_lock_irq(&l3->list_lock);
3982 3983 3984 3985 3986 3987 3988 3989 3990
		if (ac->avail) {
			tofree = force ? ac->avail : (ac->limit + 4) / 5;
			if (tofree > ac->avail)
				tofree = (ac->avail + 1) / 2;
			free_block(cachep, ac->entry, tofree, node);
			ac->avail -= tofree;
			memmove(ac->entry, &(ac->entry[tofree]),
				sizeof(void *) * ac->avail);
		}
3991
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3992 3993 3994 3995 3996
	}
}

/**
 * cache_reap - Reclaim memory from caches.
3997
 * @unused: unused parameter
L
Linus Torvalds 已提交
3998 3999 4000 4001 4002 4003
 *
 * 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
4004 4005
 * 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
4006
 */
4007
static void cache_reap(struct work_struct *unused)
L
Linus Torvalds 已提交
4008
{
4009
	struct kmem_cache *searchp;
4010
	struct kmem_list3 *l3;
4011
	int node = numa_node_id();
L
Linus Torvalds 已提交
4012

I
Ingo Molnar 已提交
4013
	if (!mutex_trylock(&cache_chain_mutex)) {
L
Linus Torvalds 已提交
4014
		/* Give up. Setup the next iteration. */
P
Pekka Enberg 已提交
4015
		schedule_delayed_work(&__get_cpu_var(reap_work),
4016
				      round_jiffies_relative(REAPTIMEOUT_CPUC));
L
Linus Torvalds 已提交
4017 4018 4019
		return;
	}

4020
	list_for_each_entry(searchp, &cache_chain, next) {
L
Linus Torvalds 已提交
4021 4022
		check_irq_on();

4023 4024 4025 4026 4027
		/*
		 * We only take the l3 lock if absolutely necessary and we
		 * have established with reasonable certainty that
		 * we can do some work if the lock was obtained.
		 */
4028
		l3 = searchp->nodelists[node];
4029

4030
		reap_alien(searchp, l3);
L
Linus Torvalds 已提交
4031

4032
		drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
L
Linus Torvalds 已提交
4033

4034 4035 4036 4037
		/*
		 * These are racy checks but it does not matter
		 * if we skip one check or scan twice.
		 */
4038
		if (time_after(l3->next_reap, jiffies))
4039
			goto next;
L
Linus Torvalds 已提交
4040

4041
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
4042

4043
		drain_array(searchp, l3, l3->shared, 0, node);
L
Linus Torvalds 已提交
4044

4045
		if (l3->free_touched)
4046
			l3->free_touched = 0;
4047 4048
		else {
			int freed;
L
Linus Torvalds 已提交
4049

4050 4051 4052 4053
			freed = drain_freelist(searchp, l3, (l3->free_limit +
				5 * searchp->num - 1) / (5 * searchp->num));
			STATS_ADD_REAPED(searchp, freed);
		}
4054
next:
L
Linus Torvalds 已提交
4055 4056 4057
		cond_resched();
	}
	check_irq_on();
I
Ingo Molnar 已提交
4058
	mutex_unlock(&cache_chain_mutex);
4059
	next_reap_node();
4060
	refresh_cpu_vm_stats(smp_processor_id());
A
Andrew Morton 已提交
4061
	/* Set up the next iteration */
4062 4063
	schedule_delayed_work(&__get_cpu_var(reap_work),
		round_jiffies_relative(REAPTIMEOUT_CPUC));
L
Linus Torvalds 已提交
4064 4065 4066 4067
}

#ifdef CONFIG_PROC_FS

4068
static void print_slabinfo_header(struct seq_file *m)
L
Linus Torvalds 已提交
4069
{
4070 4071 4072 4073
	/*
	 * Output format version, so at least we can change it
	 * without _too_ many complaints.
	 */
L
Linus Torvalds 已提交
4074
#if STATS
4075
	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
L
Linus Torvalds 已提交
4076
#else
4077
	seq_puts(m, "slabinfo - version: 2.1\n");
L
Linus Torvalds 已提交
4078
#endif
4079 4080 4081 4082
	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
4083
#if STATS
4084
	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
4085
		 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
4086
	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
L
Linus Torvalds 已提交
4087
#endif
4088 4089 4090 4091 4092 4093 4094 4095
	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
4096
	mutex_lock(&cache_chain_mutex);
4097 4098
	if (!n)
		print_slabinfo_header(m);
L
Linus Torvalds 已提交
4099 4100 4101 4102 4103 4104
	p = cache_chain.next;
	while (n--) {
		p = p->next;
		if (p == &cache_chain)
			return NULL;
	}
4105
	return list_entry(p, struct kmem_cache, next);
L
Linus Torvalds 已提交
4106 4107 4108 4109
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
4110
	struct kmem_cache *cachep = p;
L
Linus Torvalds 已提交
4111
	++*pos;
A
Andrew Morton 已提交
4112 4113
	return cachep->next.next == &cache_chain ?
		NULL : list_entry(cachep->next.next, struct kmem_cache, next);
L
Linus Torvalds 已提交
4114 4115 4116 4117
}

static void s_stop(struct seq_file *m, void *p)
{
I
Ingo Molnar 已提交
4118
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4119 4120 4121 4122
}

static int s_show(struct seq_file *m, void *p)
{
4123
	struct kmem_cache *cachep = p;
P
Pekka Enberg 已提交
4124 4125 4126 4127 4128
	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;
4129
	const char *name;
L
Linus Torvalds 已提交
4130
	char *error = NULL;
4131 4132
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
4133 4134 4135

	active_objs = 0;
	num_slabs = 0;
4136 4137 4138 4139 4140
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

4141 4142
		check_irq_on();
		spin_lock_irq(&l3->list_lock);
4143

4144
		list_for_each_entry(slabp, &l3->slabs_full, list) {
4145 4146 4147 4148 4149
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
4150
		list_for_each_entry(slabp, &l3->slabs_partial, list) {
4151 4152 4153 4154 4155 4156 4157
			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++;
		}
4158
		list_for_each_entry(slabp, &l3->slabs_free, list) {
4159 4160 4161 4162 4163
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
4164 4165
		if (l3->shared)
			shared_avail += l3->shared->avail;
4166

4167
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4168
	}
P
Pekka Enberg 已提交
4169 4170
	num_slabs += active_slabs;
	num_objs = num_slabs * cachep->num;
4171
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
4172 4173
		error = "free_objects accounting error";

P
Pekka Enberg 已提交
4174
	name = cachep->name;
L
Linus Torvalds 已提交
4175 4176 4177 4178
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
4179
		   name, active_objs, num_objs, cachep->buffer_size,
P
Pekka Enberg 已提交
4180
		   cachep->num, (1 << cachep->gfporder));
L
Linus Torvalds 已提交
4181
	seq_printf(m, " : tunables %4u %4u %4u",
P
Pekka Enberg 已提交
4182
		   cachep->limit, cachep->batchcount, cachep->shared);
4183
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
P
Pekka Enberg 已提交
4184
		   active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
4185
#if STATS
P
Pekka Enberg 已提交
4186
	{			/* list3 stats */
L
Linus Torvalds 已提交
4187 4188 4189 4190 4191 4192 4193
		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;
4194
		unsigned long node_frees = cachep->node_frees;
4195
		unsigned long overflows = cachep->node_overflow;
L
Linus Torvalds 已提交
4196

4197
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
4198
				%4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
A
Andrew Morton 已提交
4199
				reaped, errors, max_freeable, node_allocs,
4200
				node_frees, overflows);
L
Linus Torvalds 已提交
4201 4202 4203 4204 4205 4206 4207 4208 4209
	}
	/* 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
4210
			   allochit, allocmiss, freehit, freemiss);
L
Linus Torvalds 已提交
4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230
	}
#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
 */

4231
const struct seq_operations slabinfo_op = {
P
Pekka Enberg 已提交
4232 4233 4234 4235
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
L
Linus Torvalds 已提交
4236 4237 4238 4239 4240 4241 4242 4243 4244 4245
};

#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
4246 4247
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
		       size_t count, loff_t *ppos)
L
Linus Torvalds 已提交
4248
{
P
Pekka Enberg 已提交
4249
	char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
L
Linus Torvalds 已提交
4250
	int limit, batchcount, shared, res;
4251
	struct kmem_cache *cachep;
P
Pekka Enberg 已提交
4252

L
Linus Torvalds 已提交
4253 4254 4255 4256
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
P
Pekka Enberg 已提交
4257
	kbuf[MAX_SLABINFO_WRITE] = '\0';
L
Linus Torvalds 已提交
4258 4259 4260 4261 4262 4263 4264 4265 4266 4267

	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
4268
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4269
	res = -EINVAL;
4270
	list_for_each_entry(cachep, &cache_chain, next) {
L
Linus Torvalds 已提交
4271
		if (!strcmp(cachep->name, kbuf)) {
A
Andrew Morton 已提交
4272 4273
			if (limit < 1 || batchcount < 1 ||
					batchcount > limit || shared < 0) {
4274
				res = 0;
L
Linus Torvalds 已提交
4275
			} else {
4276
				res = do_tune_cpucache(cachep, limit,
P
Pekka Enberg 已提交
4277
						       batchcount, shared);
L
Linus Torvalds 已提交
4278 4279 4280 4281
			}
			break;
		}
	}
I
Ingo Molnar 已提交
4282
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4283 4284 4285 4286
	if (res >= 0)
		res = count;
	return res;
}
4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395

#ifdef CONFIG_DEBUG_SLAB_LEAK

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

	mutex_lock(&cache_chain_mutex);
	p = cache_chain.next;
	while (n--) {
		p = p->next;
		if (p == &cache_chain)
			return NULL;
	}
	return list_entry(p, struct kmem_cache, next);
}

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

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

static void show_symbol(struct seq_file *m, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
	char *modname;
	const char *name;
	unsigned long offset, size;
	char namebuf[KSYM_NAME_LEN+1];

	name = kallsyms_lookup(address, &size, &offset, &modname, namebuf);

	if (name) {
		seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
		if (modname)
			seq_printf(m, " [%s]", modname);
		return;
	}
#endif
	seq_printf(m, "%p", (void *)address);
}

static int leaks_show(struct seq_file *m, void *p)
{
	struct kmem_cache *cachep = p;
	struct slab *slabp;
	struct kmem_list3 *l3;
	const char *name;
	unsigned long *n = m->private;
	int node;
	int i;

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

	/* OK, we can do it */

	n[1] = 0;

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

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

4396
		list_for_each_entry(slabp, &l3->slabs_full, list)
4397
			handle_slab(n, cachep, slabp);
4398
		list_for_each_entry(slabp, &l3->slabs_partial, list)
4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424
			handle_slab(n, cachep, slabp);
		spin_unlock_irq(&l3->list_lock);
	}
	name = cachep->name;
	if (n[0] == n[1]) {
		/* Increase the buffer size */
		mutex_unlock(&cache_chain_mutex);
		m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
		if (!m->private) {
			/* Too bad, we are really out */
			m->private = n;
			mutex_lock(&cache_chain_mutex);
			return -ENOMEM;
		}
		*(unsigned long *)m->private = n[0] * 2;
		kfree(n);
		mutex_lock(&cache_chain_mutex);
		/* Now make sure this entry will be retried */
		m->count = m->size;
		return 0;
	}
	for (i = 0; i < n[1]; i++) {
		seq_printf(m, "%s: %lu ", name, n[2*i+3]);
		show_symbol(m, n[2*i+2]);
		seq_putc(m, '\n');
	}
4425

4426 4427 4428
	return 0;
}

4429
const struct seq_operations slabstats_op = {
4430 4431 4432 4433 4434 4435
	.start = leaks_start,
	.next = s_next,
	.stop = s_stop,
	.show = leaks_show,
};
#endif
L
Linus Torvalds 已提交
4436 4437
#endif

4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449
/**
 * 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
4450 4451
unsigned int ksize(const void *objp)
{
4452 4453
	if (unlikely(objp == NULL))
		return 0;
L
Linus Torvalds 已提交
4454

4455
	return obj_size(virt_to_cache(objp));
L
Linus Torvalds 已提交
4456
}