slab.c 116.3 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
/*
 * 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
S
Simon Arlott 已提交
29
 * slabs and you must pass objects with the same initializations to
L
Linus Torvalds 已提交
30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52
 * 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>
98
#include	<linux/proc_fs.h>
L
Linus Torvalds 已提交
99 100 101 102 103 104 105
#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>
106
#include	<linux/string.h>
107
#include	<linux/uaccess.h>
108
#include	<linux/nodemask.h>
109
#include	<linux/mempolicy.h>
I
Ingo Molnar 已提交
110
#include	<linux/mutex.h>
111
#include	<linux/fault-inject.h>
I
Ingo Molnar 已提交
112
#include	<linux/rtmutex.h>
113
#include	<linux/reciprocal_div.h>
114
#include	<linux/debugobjects.h>
L
Linus Torvalds 已提交
115 116 117 118 119 120

#include	<asm/cacheflush.h>
#include	<asm/tlbflush.h>
#include	<asm/page.h>

/*
121
 * DEBUG	- 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
L
Linus Torvalds 已提交
122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141
 *		  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 *)
D
David Woodhouse 已提交
142
#define	REDZONE_ALIGN		max(BYTES_PER_WORD, __alignof__(unsigned long long))
L
Linus Torvalds 已提交
143 144 145 146 147 148 149

#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
150 151 152
 * alignment larger than the alignment of a 64-bit integer.
 * ARCH_KMALLOC_MINALIGN allows that.
 * Note that increasing this value may disable some debug features.
L
Linus Torvalds 已提交
153
 */
154
#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
L
Linus Torvalds 已提交
155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173
#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
174
# define CREATE_MASK	(SLAB_RED_ZONE | \
L
Linus Torvalds 已提交
175
			 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
176
			 SLAB_CACHE_DMA | \
177
			 SLAB_STORE_USER | \
L
Linus Torvalds 已提交
178
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
179 180
			 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
			 SLAB_DEBUG_OBJECTS)
L
Linus Torvalds 已提交
181
#else
182
# define CREATE_MASK	(SLAB_HWCACHE_ALIGN | \
183
			 SLAB_CACHE_DMA | \
L
Linus Torvalds 已提交
184
			 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
185 186
			 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
			 SLAB_DEBUG_OBJECTS)
L
Linus Torvalds 已提交
187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
#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.
 */

208
typedef unsigned int kmem_bufctl_t;
L
Linus Torvalds 已提交
209 210
#define BUFCTL_END	(((kmem_bufctl_t)(~0U))-0)
#define BUFCTL_FREE	(((kmem_bufctl_t)(~0U))-1)
211 212
#define	BUFCTL_ACTIVE	(((kmem_bufctl_t)(~0U))-2)
#define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-3)
L
Linus Torvalds 已提交
213 214 215 216 217 218 219 220 221

/*
 * 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
222 223 224 225 226 227
	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
228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246
};

/*
 * 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
247
	struct rcu_head head;
248
	struct kmem_cache *cachep;
P
Pekka Enberg 已提交
249
	void *addr;
L
Linus Torvalds 已提交
250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268
};

/*
 * 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;
269
	spinlock_t lock;
270
	void *entry[];	/*
A
Andrew Morton 已提交
271 272 273 274
			 * Must have this definition in here for the proper
			 * alignment of array_cache. Also simplifies accessing
			 * the entries.
			 */
L
Linus Torvalds 已提交
275 276
};

A
Andrew Morton 已提交
277 278 279
/*
 * bootstrap: The caches do not work without cpuarrays anymore, but the
 * cpuarrays are allocated from the generic caches...
L
Linus Torvalds 已提交
280 281 282 283
 */
#define BOOT_CPUCACHE_ENTRIES	1
struct arraycache_init {
	struct array_cache cache;
P
Pekka Enberg 已提交
284
	void *entries[BOOT_CPUCACHE_ENTRIES];
L
Linus Torvalds 已提交
285 286 287
};

/*
288
 * The slab lists for all objects.
L
Linus Torvalds 已提交
289 290
 */
struct kmem_list3 {
P
Pekka Enberg 已提交
291 292 293 294 295
	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;
296
	unsigned int colour_next;	/* Per-node cache coloring */
P
Pekka Enberg 已提交
297 298 299
	spinlock_t list_lock;
	struct array_cache *shared;	/* shared per node */
	struct array_cache **alien;	/* on other nodes */
300 301
	unsigned long next_reap;	/* updated without locking */
	int free_touched;		/* updated without locking */
L
Linus Torvalds 已提交
302 303
};

304 305 306
/*
 * Need this for bootstrapping a per node allocator.
 */
307
#define NUM_INIT_LISTS (3 * MAX_NUMNODES)
308 309
struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
#define	CACHE_CACHE 0
310 311
#define	SIZE_AC MAX_NUMNODES
#define	SIZE_L3 (2 * MAX_NUMNODES)
312

313 314 315 316
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);
317
static int enable_cpucache(struct kmem_cache *cachep);
318
static void cache_reap(struct work_struct *unused);
319

320
/*
A
Andrew Morton 已提交
321 322
 * 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.
323
 */
324
static __always_inline int index_of(const size_t size)
325
{
326 327
	extern void __bad_size(void);

328 329 330 331 332 333 334 335
	if (__builtin_constant_p(size)) {
		int i = 0;

#define CACHE(x) \
	if (size <=x) \
		return i; \
	else \
		i++;
336
#include <linux/kmalloc_sizes.h>
337
#undef CACHE
338
		__bad_size();
339
	} else
340
		__bad_size();
341 342 343
	return 0;
}

344 345
static int slab_early_init = 1;

346 347
#define INDEX_AC index_of(sizeof(struct arraycache_init))
#define INDEX_L3 index_of(sizeof(struct kmem_list3))
L
Linus Torvalds 已提交
348

P
Pekka Enberg 已提交
349
static void kmem_list3_init(struct kmem_list3 *parent)
350 351 352 353 354 355
{
	INIT_LIST_HEAD(&parent->slabs_full);
	INIT_LIST_HEAD(&parent->slabs_partial);
	INIT_LIST_HEAD(&parent->slabs_free);
	parent->shared = NULL;
	parent->alien = NULL;
356
	parent->colour_next = 0;
357 358 359 360 361
	spin_lock_init(&parent->list_lock);
	parent->free_objects = 0;
	parent->free_touched = 0;
}

A
Andrew Morton 已提交
362 363 364 365
#define MAKE_LIST(cachep, listp, slab, nodeid)				\
	do {								\
		INIT_LIST_HEAD(listp);					\
		list_splice(&(cachep->nodelists[nodeid]->slab), listp);	\
366 367
	} while (0)

A
Andrew Morton 已提交
368 369
#define	MAKE_ALL_LISTS(cachep, ptr, nodeid)				\
	do {								\
370 371 372 373
	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
374 375

/*
376
 * struct kmem_cache
L
Linus Torvalds 已提交
377 378 379
 *
 * manages a cache.
 */
P
Pekka Enberg 已提交
380

381
struct kmem_cache {
L
Linus Torvalds 已提交
382
/* 1) per-cpu data, touched during every alloc/free */
P
Pekka Enberg 已提交
383
	struct array_cache *array[NR_CPUS];
384
/* 2) Cache tunables. Protected by cache_chain_mutex */
P
Pekka Enberg 已提交
385 386 387
	unsigned int batchcount;
	unsigned int limit;
	unsigned int shared;
388

389
	unsigned int buffer_size;
390
	u32 reciprocal_buffer_size;
391 392
/* 3) touched by every alloc & free from the backend */

A
Andrew Morton 已提交
393 394
	unsigned int flags;		/* constant flags */
	unsigned int num;		/* # of objs per slab */
L
Linus Torvalds 已提交
395

396
/* 4) cache_grow/shrink */
L
Linus Torvalds 已提交
397
	/* order of pgs per slab (2^n) */
P
Pekka Enberg 已提交
398
	unsigned int gfporder;
L
Linus Torvalds 已提交
399 400

	/* force GFP flags, e.g. GFP_DMA */
P
Pekka Enberg 已提交
401
	gfp_t gfpflags;
L
Linus Torvalds 已提交
402

A
Andrew Morton 已提交
403
	size_t colour;			/* cache colouring range */
P
Pekka Enberg 已提交
404
	unsigned int colour_off;	/* colour offset */
405
	struct kmem_cache *slabp_cache;
P
Pekka Enberg 已提交
406
	unsigned int slab_size;
A
Andrew Morton 已提交
407
	unsigned int dflags;		/* dynamic flags */
L
Linus Torvalds 已提交
408 409

	/* constructor func */
410
	void (*ctor)(void *obj);
L
Linus Torvalds 已提交
411

412
/* 5) cache creation/removal */
P
Pekka Enberg 已提交
413 414
	const char *name;
	struct list_head next;
L
Linus Torvalds 已提交
415

416
/* 6) statistics */
L
Linus Torvalds 已提交
417
#if STATS
P
Pekka Enberg 已提交
418 419 420 421 422 423 424 425 426
	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;
427
	unsigned long node_overflow;
P
Pekka Enberg 已提交
428 429 430 431
	atomic_t allochit;
	atomic_t allocmiss;
	atomic_t freehit;
	atomic_t freemiss;
L
Linus Torvalds 已提交
432 433
#endif
#if DEBUG
434 435 436 437 438 439 440 441
	/*
	 * 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
442
#endif
E
Eric Dumazet 已提交
443 444 445 446 447 448 449 450 451 452 453
	/*
	 * We put nodelists[] at the end of kmem_cache, because we want to size
	 * this array to nr_node_ids slots instead of MAX_NUMNODES
	 * (see kmem_cache_init())
	 * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache
	 * is statically defined, so we reserve the max number of nodes.
	 */
	struct kmem_list3 *nodelists[MAX_NUMNODES];
	/*
	 * Do not add fields after nodelists[]
	 */
L
Linus Torvalds 已提交
454 455 456 457 458 459
};

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

#define BATCHREFILL_LIMIT	16
A
Andrew Morton 已提交
460 461 462
/*
 * Optimization question: fewer reaps means less probability for unnessary
 * cpucache drain/refill cycles.
L
Linus Torvalds 已提交
463
 *
A
Adrian Bunk 已提交
464
 * OTOH the cpuarrays can contain lots of objects,
L
Linus Torvalds 已提交
465 466 467 468 469 470 471 472 473 474
 * 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++)
475
#define	STATS_ADD_REAPED(x,y)	((x)->reaped += (y))
A
Andrew Morton 已提交
476 477 478 479 480
#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
481 482
#define	STATS_INC_ERR(x)	((x)->errors++)
#define	STATS_INC_NODEALLOCS(x)	((x)->node_allocs++)
483
#define	STATS_INC_NODEFREES(x)	((x)->node_frees++)
484
#define STATS_INC_ACOVERFLOW(x)   ((x)->node_overflow++)
A
Andrew Morton 已提交
485 486 487 488 489
#define	STATS_SET_FREEABLE(x, i)					\
	do {								\
		if ((x)->max_freeable < i)				\
			(x)->max_freeable = i;				\
	} while (0)
L
Linus Torvalds 已提交
490 491 492 493 494 495 496 497 498
#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)
499
#define	STATS_ADD_REAPED(x,y)	do { } while (0)
L
Linus Torvalds 已提交
500 501 502
#define	STATS_SET_HIGH(x)	do { } while (0)
#define	STATS_INC_ERR(x)	do { } while (0)
#define	STATS_INC_NODEALLOCS(x)	do { } while (0)
503
#define	STATS_INC_NODEFREES(x)	do { } while (0)
504
#define STATS_INC_ACOVERFLOW(x)   do { } while (0)
A
Andrew Morton 已提交
505
#define	STATS_SET_FREEABLE(x, i) do { } while (0)
L
Linus Torvalds 已提交
506 507 508 509 510 511 512 513
#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
514 515
/*
 * memory layout of objects:
L
Linus Torvalds 已提交
516
 * 0		: objp
517
 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
L
Linus Torvalds 已提交
518 519
 * 		the end of an object is aligned with the end of the real
 * 		allocation. Catches writes behind the end of the allocation.
520
 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
L
Linus Torvalds 已提交
521
 * 		redzone word.
522 523
 * 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
524 525
 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
 *					[BYTES_PER_WORD long]
L
Linus Torvalds 已提交
526
 */
527
static int obj_offset(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
528
{
529
	return cachep->obj_offset;
L
Linus Torvalds 已提交
530 531
}

532
static int obj_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
533
{
534
	return cachep->obj_size;
L
Linus Torvalds 已提交
535 536
}

537
static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
538 539
{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
540 541
	return (unsigned long long*) (objp + obj_offset(cachep) -
				      sizeof(unsigned long long));
L
Linus Torvalds 已提交
542 543
}

544
static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
545 546 547
{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
	if (cachep->flags & SLAB_STORE_USER)
548 549
		return (unsigned long long *)(objp + cachep->buffer_size -
					      sizeof(unsigned long long) -
D
David Woodhouse 已提交
550
					      REDZONE_ALIGN);
551 552
	return (unsigned long long *) (objp + cachep->buffer_size -
				       sizeof(unsigned long long));
L
Linus Torvalds 已提交
553 554
}

555
static void **dbg_userword(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
556 557
{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
558
	return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
L
Linus Torvalds 已提交
559 560 561 562
}

#else

563 564
#define obj_offset(x)			0
#define obj_size(cachep)		(cachep->buffer_size)
565 566
#define dbg_redzone1(cachep, objp)	({BUG(); (unsigned long long *)NULL;})
#define dbg_redzone2(cachep, objp)	({BUG(); (unsigned long long *)NULL;})
L
Linus Torvalds 已提交
567 568 569 570 571 572 573 574 575 576 577
#define dbg_userword(cachep, objp)	({BUG(); (void **)NULL;})

#endif

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

A
Andrew Morton 已提交
578 579 580 581
/*
 * 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
582
 */
583 584 585 586 587 588 589
static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
{
	page->lru.next = (struct list_head *)cache;
}

static inline struct kmem_cache *page_get_cache(struct page *page)
{
590
	page = compound_head(page);
591
	BUG_ON(!PageSlab(page));
592 593 594 595 596 597 598 599 600 601
	return (struct kmem_cache *)page->lru.next;
}

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

static inline struct slab *page_get_slab(struct page *page)
{
602
	BUG_ON(!PageSlab(page));
603 604
	return (struct slab *)page->lru.prev;
}
L
Linus Torvalds 已提交
605

606 607
static inline struct kmem_cache *virt_to_cache(const void *obj)
{
608
	struct page *page = virt_to_head_page(obj);
609 610 611 612 613
	return page_get_cache(page);
}

static inline struct slab *virt_to_slab(const void *obj)
{
614
	struct page *page = virt_to_head_page(obj);
615 616 617
	return page_get_slab(page);
}

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

624 625 626 627 628 629 630 631
/*
 * We want to avoid an expensive divide : (offset / cache->buffer_size)
 *   Using the fact that buffer_size is a constant for a particular cache,
 *   we can replace (offset / cache->buffer_size) by
 *   reciprocal_divide(offset, cache->reciprocal_buffer_size)
 */
static inline unsigned int obj_to_index(const struct kmem_cache *cache,
					const struct slab *slab, void *obj)
632
{
633 634
	u32 offset = (obj - slab->s_mem);
	return reciprocal_divide(offset, cache->reciprocal_buffer_size);
635 636
}

A
Andrew Morton 已提交
637 638 639
/*
 * These are the default caches for kmalloc. Custom caches can have other sizes.
 */
L
Linus Torvalds 已提交
640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656
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
657
	{NULL,}
L
Linus Torvalds 已提交
658 659 660 661
#undef CACHE
};

static struct arraycache_init initarray_cache __initdata =
P
Pekka Enberg 已提交
662
    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
L
Linus Torvalds 已提交
663
static struct arraycache_init initarray_generic =
P
Pekka Enberg 已提交
664
    { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
L
Linus Torvalds 已提交
665 666

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

675 676
#define BAD_ALIEN_MAGIC 0x01020304ul

677 678 679 680 681 682 683 684
#ifdef CONFIG_LOCKDEP

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

static inline void init_lock_keys(void)
694 695 696

{
	int q;
697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723
	struct cache_sizes *s = malloc_sizes;

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

732
/*
733
 * Guard access to the cache-chain.
734
 */
I
Ingo Molnar 已提交
735
static DEFINE_MUTEX(cache_chain_mutex);
L
Linus Torvalds 已提交
736 737 738 739 740 741 742 743
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,
744 745
	PARTIAL_AC,
	PARTIAL_L3,
L
Linus Torvalds 已提交
746 747 748
	FULL
} g_cpucache_up;

749 750 751 752 753 754 755 756
/*
 * used by boot code to determine if it can use slab based allocator
 */
int slab_is_available(void)
{
	return g_cpucache_up == FULL;
}

757
static DEFINE_PER_CPU(struct delayed_work, reap_work);
L
Linus Torvalds 已提交
758

759
static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
760 761 762 763
{
	return cachep->array[smp_processor_id()];
}

A
Andrew Morton 已提交
764 765
static inline struct kmem_cache *__find_general_cachep(size_t size,
							gfp_t gfpflags)
L
Linus Torvalds 已提交
766 767 768 769 770
{
	struct cache_sizes *csizep = malloc_sizes;

#if DEBUG
	/* This happens if someone tries to call
P
Pekka Enberg 已提交
771 772 773
	 * kmem_cache_create(), or __kmalloc(), before
	 * the generic caches are initialized.
	 */
774
	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
L
Linus Torvalds 已提交
775
#endif
776 777 778
	if (!size)
		return ZERO_SIZE_PTR;

L
Linus Torvalds 已提交
779 780 781 782
	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
	 * has cs_{dma,}cachep==NULL. Thus no special case
	 * for large kmalloc calls required.
	 */
787
#ifdef CONFIG_ZONE_DMA
L
Linus Torvalds 已提交
788 789
	if (unlikely(gfpflags & GFP_DMA))
		return csizep->cs_dmacachep;
790
#endif
L
Linus Torvalds 已提交
791 792 793
	return csizep->cs_cachep;
}

A
Adrian Bunk 已提交
794
static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
795 796 797 798
{
	return __find_general_cachep(size, gfpflags);
}

799
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
L
Linus Torvalds 已提交
800
{
801 802
	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
}
L
Linus Torvalds 已提交
803

A
Andrew Morton 已提交
804 805 806
/*
 * Calculate the number of objects and left-over bytes for a given buffer size.
 */
807 808 809 810 811 812 813
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
814

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

865
#define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
L
Linus Torvalds 已提交
866

A
Andrew Morton 已提交
867 868
static void __slab_error(const char *function, struct kmem_cache *cachep,
			char *msg)
L
Linus Torvalds 已提交
869 870
{
	printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
P
Pekka Enberg 已提交
871
	       function, cachep->name, msg);
L
Linus Torvalds 已提交
872 873 874
	dump_stack();
}

875 876 877 878 879 880 881 882 883
/*
 * 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;
884
static int numa_platform __read_mostly = 1;
885 886 887 888 889 890 891
static int __init noaliencache_setup(char *s)
{
	use_alien_caches = 0;
	return 1;
}
__setup("noaliencache", noaliencache_setup);

892 893 894 895 896 897 898 899 900 901 902 903 904 905 906
#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)
907
		node = first_node(node_online_map);
908

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

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

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

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

L
Linus Torvalds 已提交
927 928 929 930 931 932 933
/*
 * 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.
 */
934
static void __cpuinit start_cpu_timer(int cpu)
L
Linus Torvalds 已提交
935
{
936
	struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
L
Linus Torvalds 已提交
937 938 939 940 941 942

	/*
	 * When this gets called from do_initcalls via cpucache_init(),
	 * init_workqueues() has already run, so keventd will be setup
	 * at that time.
	 */
943
	if (keventd_up() && reap_work->work.func == NULL) {
944
		init_reap_node(cpu);
945
		INIT_DELAYED_WORK(reap_work, cache_reap);
946 947
		schedule_delayed_work_on(cpu, reap_work,
					__round_jiffies_relative(HZ, cpu));
L
Linus Torvalds 已提交
948 949 950
	}
}

951
static struct array_cache *alloc_arraycache(int node, int entries,
P
Pekka Enberg 已提交
952
					    int batchcount)
L
Linus Torvalds 已提交
953
{
P
Pekka Enberg 已提交
954
	int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
L
Linus Torvalds 已提交
955 956
	struct array_cache *nc = NULL;

957
	nc = kmalloc_node(memsize, GFP_KERNEL, node);
L
Linus Torvalds 已提交
958 959 960 961 962
	if (nc) {
		nc->avail = 0;
		nc->limit = entries;
		nc->batchcount = batchcount;
		nc->touched = 0;
963
		spin_lock_init(&nc->lock);
L
Linus Torvalds 已提交
964 965 966 967
	}
	return nc;
}

968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991
/*
 * 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;
}

992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016
#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;
}

1017
static inline void *____cache_alloc_node(struct kmem_cache *cachep,
1018 1019 1020 1021 1022 1023 1024
		 gfp_t flags, int nodeid)
{
	return NULL;
}

#else	/* CONFIG_NUMA */

1025
static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
1026
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
1027

P
Pekka Enberg 已提交
1028
static struct array_cache **alloc_alien_cache(int node, int limit)
1029 1030
{
	struct array_cache **ac_ptr;
1031
	int memsize = sizeof(void *) * nr_node_ids;
1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044
	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]) {
1045
				for (i--; i >= 0; i--)
1046 1047 1048 1049 1050 1051 1052 1053 1054
					kfree(ac_ptr[i]);
				kfree(ac_ptr);
				return NULL;
			}
		}
	}
	return ac_ptr;
}

P
Pekka Enberg 已提交
1055
static void free_alien_cache(struct array_cache **ac_ptr)
1056 1057 1058 1059 1060 1061
{
	int i;

	if (!ac_ptr)
		return;
	for_each_node(i)
P
Pekka Enberg 已提交
1062
	    kfree(ac_ptr[i]);
1063 1064 1065
	kfree(ac_ptr);
}

1066
static void __drain_alien_cache(struct kmem_cache *cachep,
P
Pekka Enberg 已提交
1067
				struct array_cache *ac, int node)
1068 1069 1070 1071 1072
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
1073 1074 1075 1076 1077
		/*
		 * 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.
		 */
1078 1079
		if (rl3->shared)
			transfer_objects(rl3->shared, ac, ac->limit);
1080

1081
		free_block(cachep, ac->entry, ac->avail, node);
1082 1083 1084 1085 1086
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

1087 1088 1089 1090 1091 1092 1093 1094 1095
/*
 * 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];
1096 1097

		if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
1098 1099 1100 1101 1102 1103
			__drain_alien_cache(cachep, ac, node);
			spin_unlock_irq(&ac->lock);
		}
	}
}

A
Andrew Morton 已提交
1104 1105
static void drain_alien_cache(struct kmem_cache *cachep,
				struct array_cache **alien)
1106
{
P
Pekka Enberg 已提交
1107
	int i = 0;
1108 1109 1110 1111
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
1112
		ac = alien[i];
1113 1114 1115 1116 1117 1118 1119
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
1120

1121
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1122 1123 1124 1125 1126
{
	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
1127 1128 1129
	int node;

	node = numa_node_id();
1130 1131 1132 1133 1134

	/*
	 * Make sure we are not freeing a object from another node to the array
	 * cache on this cpu.
	 */
1135
	if (likely(slabp->nodeid == node))
1136 1137
		return 0;

P
Pekka Enberg 已提交
1138
	l3 = cachep->nodelists[node];
1139 1140 1141
	STATS_INC_NODEFREES(cachep);
	if (l3->alien && l3->alien[nodeid]) {
		alien = l3->alien[nodeid];
1142
		spin_lock(&alien->lock);
1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155
		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;
}
1156 1157
#endif

1158 1159 1160 1161 1162
static void __cpuinit cpuup_canceled(long cpu)
{
	struct kmem_cache *cachep;
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
1163
	node_to_cpumask_ptr(mask, node);
1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184

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

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

		if (!l3)
			goto free_array_cache;

		spin_lock_irq(&l3->list_lock);

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

1185
		if (!cpus_empty(*mask)) {
1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223
			spin_unlock_irq(&l3->list_lock);
			goto free_array_cache;
		}

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

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

		spin_unlock_irq(&l3->list_lock);

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

static int __cpuinit cpuup_prepare(long cpu)
L
Linus Torvalds 已提交
1224
{
1225
	struct kmem_cache *cachep;
1226 1227
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
1228
	const int memsize = sizeof(struct kmem_list3);
L
Linus Torvalds 已提交
1229

1230 1231 1232 1233 1234 1235 1236 1237
	/*
	 * We need to do this right in the beginning since
	 * alloc_arraycache's are going to use this list.
	 * kmalloc_node allows us to add the slab to the right
	 * kmem_list3 and not this cpu's kmem_list3
	 */

	list_for_each_entry(cachep, &cache_chain, next) {
A
Andrew Morton 已提交
1238
		/*
1239 1240 1241
		 * Set up the size64 kmemlist for cpu before we can
		 * begin anything. Make sure some other cpu on this
		 * node has not already allocated this
1242
		 */
1243 1244 1245 1246 1247 1248 1249
		if (!cachep->nodelists[node]) {
			l3 = kmalloc_node(memsize, GFP_KERNEL, node);
			if (!l3)
				goto bad;
			kmem_list3_init(l3);
			l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
			    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1250

A
Andrew Morton 已提交
1251
			/*
1252 1253 1254
			 * The l3s don't come and go as CPUs come and
			 * go.  cache_chain_mutex is sufficient
			 * protection here.
1255
			 */
1256
			cachep->nodelists[node] = l3;
1257 1258
		}

1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
		spin_lock_irq(&cachep->nodelists[node]->list_lock);
		cachep->nodelists[node]->free_limit =
			(1 + nr_cpus_node(node)) *
			cachep->batchcount + cachep->num;
		spin_unlock_irq(&cachep->nodelists[node]->list_lock);
	}

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

		nc = alloc_arraycache(node, cachep->limit,
					cachep->batchcount);
		if (!nc)
			goto bad;
		if (cachep->shared) {
			shared = alloc_arraycache(node,
				cachep->shared * cachep->batchcount,
				0xbaadf00d);
1283 1284
			if (!shared) {
				kfree(nc);
L
Linus Torvalds 已提交
1285
				goto bad;
1286
			}
1287 1288 1289
		}
		if (use_alien_caches) {
			alien = alloc_alien_cache(node, cachep->limit);
1290 1291 1292
			if (!alien) {
				kfree(shared);
				kfree(nc);
1293
				goto bad;
1294
			}
1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308
		}
		cachep->array[cpu] = nc;
		l3 = cachep->nodelists[node];
		BUG_ON(!l3);

		spin_lock_irq(&l3->list_lock);
		if (!l3->shared) {
			/*
			 * We are serialised from CPU_DEAD or
			 * CPU_UP_CANCELLED by the cpucontrol lock
			 */
			l3->shared = shared;
			shared = NULL;
		}
1309
#ifdef CONFIG_NUMA
1310 1311 1312
		if (!l3->alien) {
			l3->alien = alien;
			alien = NULL;
L
Linus Torvalds 已提交
1313
		}
1314 1315 1316 1317 1318 1319 1320
#endif
		spin_unlock_irq(&l3->list_lock);
		kfree(shared);
		free_alien_cache(alien);
	}
	return 0;
bad:
1321
	cpuup_canceled(cpu);
1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333
	return -ENOMEM;
}

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

	switch (action) {
	case CPU_UP_PREPARE:
	case CPU_UP_PREPARE_FROZEN:
1334
		mutex_lock(&cache_chain_mutex);
1335
		err = cpuup_prepare(cpu);
1336
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1337 1338
		break;
	case CPU_ONLINE:
1339
	case CPU_ONLINE_FROZEN:
L
Linus Torvalds 已提交
1340 1341 1342
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
1343
  	case CPU_DOWN_PREPARE:
1344
  	case CPU_DOWN_PREPARE_FROZEN:
1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355
		/*
		 * Shutdown cache reaper. Note that the cache_chain_mutex is
		 * held so that if cache_reap() is invoked it cannot do
		 * anything expensive but will only modify reap_work
		 * and reschedule the timer.
		*/
		cancel_rearming_delayed_work(&per_cpu(reap_work, cpu));
		/* Now the cache_reaper is guaranteed to be not running. */
		per_cpu(reap_work, cpu).work.func = NULL;
  		break;
  	case CPU_DOWN_FAILED:
1356
  	case CPU_DOWN_FAILED_FROZEN:
1357 1358
		start_cpu_timer(cpu);
  		break;
L
Linus Torvalds 已提交
1359
	case CPU_DEAD:
1360
	case CPU_DEAD_FROZEN:
1361 1362 1363 1364 1365 1366 1367 1368
		/*
		 * Even if all the cpus of a node are down, we don't free the
		 * kmem_list3 of any cache. This to avoid a race between
		 * cpu_down, and a kmalloc allocation from another cpu for
		 * memory from the node of the cpu going down.  The list3
		 * structure is usually allocated from kmem_cache_create() and
		 * gets destroyed at kmem_cache_destroy().
		 */
S
Simon Arlott 已提交
1369
		/* fall through */
1370
#endif
L
Linus Torvalds 已提交
1371
	case CPU_UP_CANCELED:
1372
	case CPU_UP_CANCELED_FROZEN:
1373
		mutex_lock(&cache_chain_mutex);
1374
		cpuup_canceled(cpu);
I
Ingo Molnar 已提交
1375
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1376 1377
		break;
	}
1378
	return err ? NOTIFY_BAD : NOTIFY_OK;
L
Linus Torvalds 已提交
1379 1380
}

1381 1382 1383
static struct notifier_block __cpuinitdata cpucache_notifier = {
	&cpuup_callback, NULL, 0
};
L
Linus Torvalds 已提交
1384

1385 1386 1387
/*
 * swap the static kmem_list3 with kmalloced memory
 */
A
Andrew Morton 已提交
1388 1389
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
			int nodeid)
1390 1391 1392 1393 1394 1395 1396 1397
{
	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));
1398 1399 1400 1401 1402
	/*
	 * Do not assume that spinlocks can be initialized via memcpy:
	 */
	spin_lock_init(&ptr->list_lock);

1403 1404 1405 1406 1407
	MAKE_ALL_LISTS(cachep, ptr, nodeid);
	cachep->nodelists[nodeid] = ptr;
	local_irq_enable();
}

1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423
/*
 * For setting up all the kmem_list3s for cache whose buffer_size is same as
 * size of kmem_list3.
 */
static void __init set_up_list3s(struct kmem_cache *cachep, int index)
{
	int node;

	for_each_online_node(node) {
		cachep->nodelists[node] = &initkmem_list3[index + node];
		cachep->nodelists[node]->next_reap = jiffies +
		    REAPTIMEOUT_LIST3 +
		    ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
	}
}

A
Andrew Morton 已提交
1424 1425 1426
/*
 * Initialisation.  Called after the page allocator have been initialised and
 * before smp_init().
L
Linus Torvalds 已提交
1427 1428 1429 1430 1431 1432
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1433
	int i;
1434
	int order;
P
Pekka Enberg 已提交
1435
	int node;
1436

1437
	if (num_possible_nodes() == 1) {
1438
		use_alien_caches = 0;
1439 1440
		numa_platform = 0;
	}
1441

1442 1443 1444 1445 1446
	for (i = 0; i < NUM_INIT_LISTS; i++) {
		kmem_list3_init(&initkmem_list3[i]);
		if (i < MAX_NUMNODES)
			cache_cache.nodelists[i] = NULL;
	}
1447
	set_up_list3s(&cache_cache, CACHE_CACHE);
L
Linus Torvalds 已提交
1448 1449 1450 1451 1452 1453 1454 1455 1456 1457

	/*
	 * 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
1458 1459 1460
	 * 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.
1461 1462 1463
	 *    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
1464
	 * 2) Create the first kmalloc cache.
1465
	 *    The struct kmem_cache for the new cache is allocated normally.
1466 1467 1468
	 *    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
1469 1470
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1471 1472 1473
	 * 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
1474 1475
	 */

P
Pekka Enberg 已提交
1476 1477
	node = numa_node_id();

L
Linus Torvalds 已提交
1478 1479 1480 1481 1482
	/* 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;
1483
	cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE + node];
L
Linus Torvalds 已提交
1484

E
Eric Dumazet 已提交
1485 1486 1487 1488 1489 1490 1491 1492 1493
	/*
	 * struct kmem_cache size depends on nr_node_ids, which
	 * can be less than MAX_NUMNODES.
	 */
	cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) +
				 nr_node_ids * sizeof(struct kmem_list3 *);
#if DEBUG
	cache_cache.obj_size = cache_cache.buffer_size;
#endif
A
Andrew Morton 已提交
1494 1495
	cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
					cache_line_size());
1496 1497
	cache_cache.reciprocal_buffer_size =
		reciprocal_value(cache_cache.buffer_size);
L
Linus Torvalds 已提交
1498

1499 1500 1501 1502 1503 1504
	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;
	}
1505
	BUG_ON(!cache_cache.num);
1506
	cache_cache.gfporder = order;
P
Pekka Enberg 已提交
1507 1508 1509
	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
1510 1511 1512 1513 1514

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

A
Andrew Morton 已提交
1515 1516 1517 1518
	/*
	 * Initialize the caches that provide memory for the array cache and the
	 * kmem_list3 structures first.  Without this, further allocations will
	 * bug.
1519 1520 1521
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
A
Andrew Morton 已提交
1522 1523 1524
					sizes[INDEX_AC].cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1525
					NULL);
1526

A
Andrew Morton 已提交
1527
	if (INDEX_AC != INDEX_L3) {
1528
		sizes[INDEX_L3].cs_cachep =
A
Andrew Morton 已提交
1529 1530 1531 1532
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size,
				ARCH_KMALLOC_MINALIGN,
				ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1533
				NULL);
A
Andrew Morton 已提交
1534
	}
1535

1536 1537
	slab_early_init = 0;

L
Linus Torvalds 已提交
1538
	while (sizes->cs_size != ULONG_MAX) {
1539 1540
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1541 1542 1543
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1544 1545
		 * allow tighter packing of the smaller caches.
		 */
A
Andrew Morton 已提交
1546
		if (!sizes->cs_cachep) {
1547
			sizes->cs_cachep = kmem_cache_create(names->name,
A
Andrew Morton 已提交
1548 1549 1550
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1551
					NULL);
A
Andrew Morton 已提交
1552
		}
1553 1554 1555
#ifdef CONFIG_ZONE_DMA
		sizes->cs_dmacachep = kmem_cache_create(
					names->name_dma,
A
Andrew Morton 已提交
1556 1557 1558 1559
					sizes->cs_size,
					ARCH_KMALLOC_MINALIGN,
					ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
						SLAB_PANIC,
1560
					NULL);
1561
#endif
L
Linus Torvalds 已提交
1562 1563 1564 1565 1566
		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
1567
		struct array_cache *ptr;
1568

L
Linus Torvalds 已提交
1569
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1570

L
Linus Torvalds 已提交
1571
		local_irq_disable();
1572 1573
		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
		memcpy(ptr, cpu_cache_get(&cache_cache),
P
Pekka Enberg 已提交
1574
		       sizeof(struct arraycache_init));
1575 1576 1577 1578 1579
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

L
Linus Torvalds 已提交
1580 1581
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1582

L
Linus Torvalds 已提交
1583
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1584

L
Linus Torvalds 已提交
1585
		local_irq_disable();
1586
		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
P
Pekka Enberg 已提交
1587
		       != &initarray_generic.cache);
1588
		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
P
Pekka Enberg 已提交
1589
		       sizeof(struct arraycache_init));
1590 1591 1592 1593 1594
		/*
		 * Do not assume that spinlocks can be initialized via memcpy:
		 */
		spin_lock_init(&ptr->lock);

1595
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
P
Pekka Enberg 已提交
1596
		    ptr;
L
Linus Torvalds 已提交
1597 1598
		local_irq_enable();
	}
1599 1600
	/* 5) Replace the bootstrap kmem_list3's */
	{
P
Pekka Enberg 已提交
1601 1602
		int nid;

1603
		for_each_online_node(nid) {
1604
			init_list(&cache_cache, &initkmem_list3[CACHE_CACHE + nid], nid);
1605

1606
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
P
Pekka Enberg 已提交
1607
				  &initkmem_list3[SIZE_AC + nid], nid);
1608 1609 1610

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
P
Pekka Enberg 已提交
1611
					  &initkmem_list3[SIZE_L3 + nid], nid);
1612 1613 1614
			}
		}
	}
L
Linus Torvalds 已提交
1615

1616
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1617
	{
1618
		struct kmem_cache *cachep;
I
Ingo Molnar 已提交
1619
		mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1620
		list_for_each_entry(cachep, &cache_chain, next)
1621 1622
			if (enable_cpucache(cachep))
				BUG();
I
Ingo Molnar 已提交
1623
		mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
1624 1625
	}

1626 1627 1628 1629
	/* Annotate slab for lockdep -- annotate the malloc caches */
	init_lock_keys();


L
Linus Torvalds 已提交
1630 1631 1632
	/* Done! */
	g_cpucache_up = FULL;

A
Andrew Morton 已提交
1633 1634 1635
	/*
	 * Register a cpu startup notifier callback that initializes
	 * cpu_cache_get for all new cpus
L
Linus Torvalds 已提交
1636 1637 1638
	 */
	register_cpu_notifier(&cpucache_notifier);

A
Andrew Morton 已提交
1639 1640 1641
	/*
	 * 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
1642 1643 1644 1645 1646 1647 1648
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

A
Andrew Morton 已提交
1649 1650
	/*
	 * Register the timers that return unneeded pages to the page allocator
L
Linus Torvalds 已提交
1651
	 */
1652
	for_each_online_cpu(cpu)
A
Andrew Morton 已提交
1653
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664
	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.
 */
1665
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1666 1667
{
	struct page *page;
1668
	int nr_pages;
L
Linus Torvalds 已提交
1669 1670
	int i;

1671
#ifndef CONFIG_MMU
1672 1673 1674
	/*
	 * Nommu uses slab's for process anonymous memory allocations, and thus
	 * requires __GFP_COMP to properly refcount higher order allocations
1675
	 */
1676
	flags |= __GFP_COMP;
1677
#endif
1678

1679
	flags |= cachep->gfpflags;
1680 1681
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		flags |= __GFP_RECLAIMABLE;
1682 1683

	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1684 1685 1686
	if (!page)
		return NULL;

1687
	nr_pages = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1688
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1689 1690 1691 1692 1693
		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);
1694 1695 1696
	for (i = 0; i < nr_pages; i++)
		__SetPageSlab(page + i);
	return page_address(page);
L
Linus Torvalds 已提交
1697 1698 1699 1700 1701
}

/*
 * Interface to system's page release.
 */
1702
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
L
Linus Torvalds 已提交
1703
{
P
Pekka Enberg 已提交
1704
	unsigned long i = (1 << cachep->gfporder);
L
Linus Torvalds 已提交
1705 1706 1707
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

1708 1709 1710 1711 1712 1713
	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
1714
	while (i--) {
N
Nick Piggin 已提交
1715 1716
		BUG_ON(!PageSlab(page));
		__ClearPageSlab(page);
L
Linus Torvalds 已提交
1717 1718 1719 1720 1721 1722 1723 1724 1725
		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
1726
	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1727
	struct kmem_cache *cachep = slab_rcu->cachep;
L
Linus Torvalds 已提交
1728 1729 1730 1731 1732 1733 1734 1735 1736

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

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
1737
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
P
Pekka Enberg 已提交
1738
			    unsigned long caller)
L
Linus Torvalds 已提交
1739
{
1740
	int size = obj_size(cachep);
L
Linus Torvalds 已提交
1741

1742
	addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1743

P
Pekka Enberg 已提交
1744
	if (size < 5 * sizeof(unsigned long))
L
Linus Torvalds 已提交
1745 1746
		return;

P
Pekka Enberg 已提交
1747 1748 1749 1750
	*addr++ = 0x12345678;
	*addr++ = caller;
	*addr++ = smp_processor_id();
	size -= 3 * sizeof(unsigned long);
L
Linus Torvalds 已提交
1751 1752 1753 1754 1755 1756 1757
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
P
Pekka Enberg 已提交
1758
				*addr++ = svalue;
L
Linus Torvalds 已提交
1759 1760 1761 1762 1763 1764 1765
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
P
Pekka Enberg 已提交
1766
	*addr++ = 0x87654321;
L
Linus Torvalds 已提交
1767 1768 1769
}
#endif

1770
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
L
Linus Torvalds 已提交
1771
{
1772 1773
	int size = obj_size(cachep);
	addr = &((char *)addr)[obj_offset(cachep)];
L
Linus Torvalds 已提交
1774 1775

	memset(addr, val, size);
P
Pekka Enberg 已提交
1776
	*(unsigned char *)(addr + size - 1) = POISON_END;
L
Linus Torvalds 已提交
1777 1778 1779 1780 1781
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
D
Dave Jones 已提交
1782 1783 1784
	unsigned char error = 0;
	int bad_count = 0;

L
Linus Torvalds 已提交
1785
	printk(KERN_ERR "%03x:", offset);
D
Dave Jones 已提交
1786 1787 1788 1789 1790
	for (i = 0; i < limit; i++) {
		if (data[offset + i] != POISON_FREE) {
			error = data[offset + i];
			bad_count++;
		}
P
Pekka Enberg 已提交
1791
		printk(" %02x", (unsigned char)data[offset + i]);
D
Dave Jones 已提交
1792
	}
L
Linus Torvalds 已提交
1793
	printk("\n");
D
Dave Jones 已提交
1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807

	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
1808 1809 1810 1811 1812
}
#endif

#if DEBUG

1813
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
L
Linus Torvalds 已提交
1814 1815 1816 1817 1818
{
	int i, size;
	char *realobj;

	if (cachep->flags & SLAB_RED_ZONE) {
1819
		printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n",
A
Andrew Morton 已提交
1820 1821
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
1822 1823 1824 1825
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
A
Andrew Morton 已提交
1826
			*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1827
		print_symbol("(%s)",
A
Andrew Morton 已提交
1828
				(unsigned long)*dbg_userword(cachep, objp));
L
Linus Torvalds 已提交
1829 1830
		printk("\n");
	}
1831 1832
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
P
Pekka Enberg 已提交
1833
	for (i = 0; i < size && lines; i += 16, lines--) {
L
Linus Torvalds 已提交
1834 1835
		int limit;
		limit = 16;
P
Pekka Enberg 已提交
1836 1837
		if (i + limit > size)
			limit = size - i;
L
Linus Torvalds 已提交
1838 1839 1840 1841
		dump_line(realobj, i, limit);
	}
}

1842
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
1843 1844 1845 1846 1847
{
	char *realobj;
	int size, i;
	int lines = 0;

1848 1849
	realobj = (char *)objp + obj_offset(cachep);
	size = obj_size(cachep);
L
Linus Torvalds 已提交
1850

P
Pekka Enberg 已提交
1851
	for (i = 0; i < size; i++) {
L
Linus Torvalds 已提交
1852
		char exp = POISON_FREE;
P
Pekka Enberg 已提交
1853
		if (i == size - 1)
L
Linus Torvalds 已提交
1854 1855 1856 1857 1858 1859
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
P
Pekka Enberg 已提交
1860
				printk(KERN_ERR
1861 1862
					"Slab corruption: %s start=%p, len=%d\n",
					cachep->name, realobj, size);
L
Linus Torvalds 已提交
1863 1864 1865
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
P
Pekka Enberg 已提交
1866
			i = (i / 16) * 16;
L
Linus Torvalds 已提交
1867
			limit = 16;
P
Pekka Enberg 已提交
1868 1869
			if (i + limit > size)
				limit = size - i;
L
Linus Torvalds 已提交
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881
			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:
		 */
1882
		struct slab *slabp = virt_to_slab(objp);
1883
		unsigned int objnr;
L
Linus Torvalds 已提交
1884

1885
		objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
1886
		if (objnr) {
1887
			objp = index_to_obj(cachep, slabp, objnr - 1);
1888
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1889
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1890
			       realobj, size);
L
Linus Torvalds 已提交
1891 1892
			print_objinfo(cachep, objp, 2);
		}
P
Pekka Enberg 已提交
1893
		if (objnr + 1 < cachep->num) {
1894
			objp = index_to_obj(cachep, slabp, objnr + 1);
1895
			realobj = (char *)objp + obj_offset(cachep);
L
Linus Torvalds 已提交
1896
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
P
Pekka Enberg 已提交
1897
			       realobj, size);
L
Linus Torvalds 已提交
1898 1899 1900 1901 1902 1903
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

1904
#if DEBUG
R
Rabin Vincent 已提交
1905
static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
1906 1907 1908
{
	int i;
	for (i = 0; i < cachep->num; i++) {
1909
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
1910 1911 1912

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
1913 1914
			if (cachep->buffer_size % PAGE_SIZE == 0 &&
					OFF_SLAB(cachep))
P
Pekka Enberg 已提交
1915
				kernel_map_pages(virt_to_page(objp),
A
Andrew Morton 已提交
1916
					cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
1917 1918 1919 1920 1921 1922 1923 1924 1925
			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
1926
					   "was overwritten");
L
Linus Torvalds 已提交
1927 1928
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
P
Pekka Enberg 已提交
1929
					   "was overwritten");
L
Linus Torvalds 已提交
1930 1931
		}
	}
1932
}
L
Linus Torvalds 已提交
1933
#else
R
Rabin Vincent 已提交
1934
static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
1935 1936
{
}
L
Linus Torvalds 已提交
1937 1938
#endif

1939 1940 1941 1942 1943
/**
 * slab_destroy - destroy and release all objects in a slab
 * @cachep: cache pointer being destroyed
 * @slabp: slab pointer being destroyed
 *
1944
 * Destroy all the objs in a slab, and release the mem back to the system.
A
Andrew Morton 已提交
1945 1946
 * Before calling the slab must have been unlinked from the cache.  The
 * cache-lock is not held/needed.
1947
 */
1948
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1949 1950 1951
{
	void *addr = slabp->s_mem - slabp->colouroff;

R
Rabin Vincent 已提交
1952
	slab_destroy_debugcheck(cachep, slabp);
L
Linus Torvalds 已提交
1953 1954 1955
	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

P
Pekka Enberg 已提交
1956
		slab_rcu = (struct slab_rcu *)slabp;
L
Linus Torvalds 已提交
1957 1958 1959 1960 1961
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
1962 1963
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
L
Linus Torvalds 已提交
1964 1965 1966
	}
}

1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987
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);
}


1988
/**
1989 1990 1991 1992 1993 1994 1995
 * 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.
1996 1997 1998 1999 2000
 *
 * 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
2001
static size_t calculate_slab_order(struct kmem_cache *cachep,
R
Randy Dunlap 已提交
2002
			size_t size, size_t align, unsigned long flags)
2003
{
2004
	unsigned long offslab_limit;
2005
	size_t left_over = 0;
2006
	int gfporder;
2007

2008
	for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
2009 2010 2011
		unsigned int num;
		size_t remainder;

2012
		cache_estimate(gfporder, size, align, flags, &remainder, &num);
2013 2014
		if (!num)
			continue;
2015

2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
		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;
		}
2028

2029
		/* Found something acceptable - save it away */
2030
		cachep->num = num;
2031
		cachep->gfporder = gfporder;
2032 2033
		left_over = remainder;

2034 2035 2036 2037 2038 2039 2040 2041
		/*
		 * 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;

2042 2043 2044 2045
		/*
		 * Large number of objects is good, but very large slabs are
		 * currently bad for the gfp()s.
		 */
2046
		if (gfporder >= slab_break_gfp_order)
2047 2048
			break;

2049 2050 2051
		/*
		 * Acceptable internal fragmentation?
		 */
A
Andrew Morton 已提交
2052
		if (left_over * 8 <= (PAGE_SIZE << gfporder))
2053 2054 2055 2056 2057
			break;
	}
	return left_over;
}

2058
static int __init_refok setup_cpu_cache(struct kmem_cache *cachep)
2059
{
2060 2061 2062
	if (g_cpucache_up == FULL)
		return enable_cpucache(cachep);

2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089
	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;
2090
			for_each_online_node(node) {
2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108
				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;
2109
	return 0;
2110 2111
}

L
Linus Torvalds 已提交
2112 2113 2114 2115 2116 2117 2118 2119 2120 2121
/**
 * kmem_cache_create - Create a cache.
 * @name: A string which is used in /proc/slabinfo to identify this cache.
 * @size: The size of objects to be created in this cache.
 * @align: The required alignment for the objects.
 * @flags: SLAB flags
 * @ctor: A constructor for the objects.
 *
 * Returns a ptr to the cache on success, NULL on failure.
 * Cannot be called within a int, but can be interrupted.
2122
 * The @ctor is run when new pages are allocated by the cache.
L
Linus Torvalds 已提交
2123 2124
 *
 * @name must be valid until the cache is destroyed. This implies that
A
Andrew Morton 已提交
2125 2126
 * the module calling this has to destroy the cache before getting unloaded.
 *
L
Linus Torvalds 已提交
2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138
 * 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.
 */
2139
struct kmem_cache *
L
Linus Torvalds 已提交
2140
kmem_cache_create (const char *name, size_t size, size_t align,
2141
	unsigned long flags, void (*ctor)(void *))
L
Linus Torvalds 已提交
2142 2143
{
	size_t left_over, slab_size, ralign;
2144
	struct kmem_cache *cachep = NULL, *pc;
L
Linus Torvalds 已提交
2145 2146 2147 2148

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
A
Andrew Morton 已提交
2149
	if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
2150
	    size > KMALLOC_MAX_SIZE) {
2151
		printk(KERN_ERR "%s: Early error in slab %s\n", __func__,
A
Andrew Morton 已提交
2152
				name);
P
Pekka Enberg 已提交
2153 2154
		BUG();
	}
L
Linus Torvalds 已提交
2155

2156
	/*
2157 2158
	 * We use cache_chain_mutex to ensure a consistent view of
	 * cpu_online_map as well.  Please see cpuup_callback
2159
	 */
2160
	get_online_cpus();
I
Ingo Molnar 已提交
2161
	mutex_lock(&cache_chain_mutex);
2162

2163
	list_for_each_entry(pc, &cache_chain, next) {
2164 2165 2166 2167 2168 2169 2170 2171
		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.
		 */
2172
		res = probe_kernel_address(pc->name, tmp);
2173
		if (res) {
2174 2175
			printk(KERN_ERR
			       "SLAB: cache with size %d has lost its name\n",
2176
			       pc->buffer_size);
2177 2178 2179
			continue;
		}

P
Pekka Enberg 已提交
2180
		if (!strcmp(pc->name, name)) {
2181 2182
			printk(KERN_ERR
			       "kmem_cache_create: duplicate cache %s\n", name);
2183 2184 2185 2186 2187
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
2188 2189 2190 2191 2192 2193 2194 2195 2196
#if DEBUG
	WARN_ON(strchr(name, ' '));	/* It confuses parsers */
#if FORCED_DEBUG
	/*
	 * Enable redzoning and last user accounting, except for caches with
	 * large objects, if the increased size would increase the object size
	 * above the next power of two: caches with object sizes just above a
	 * power of two have a significant amount of internal fragmentation.
	 */
D
David Woodhouse 已提交
2197 2198
	if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
						2 * sizeof(unsigned long long)))
P
Pekka Enberg 已提交
2199
		flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
L
Linus Torvalds 已提交
2200 2201 2202 2203 2204 2205 2206
	if (!(flags & SLAB_DESTROY_BY_RCU))
		flags |= SLAB_POISON;
#endif
	if (flags & SLAB_DESTROY_BY_RCU)
		BUG_ON(flags & SLAB_POISON);
#endif
	/*
A
Andrew Morton 已提交
2207 2208
	 * Always checks flags, a caller might be expecting debug support which
	 * isn't available.
L
Linus Torvalds 已提交
2209
	 */
2210
	BUG_ON(flags & ~CREATE_MASK);
L
Linus Torvalds 已提交
2211

A
Andrew Morton 已提交
2212 2213
	/*
	 * Check that size is in terms of words.  This is needed to avoid
L
Linus Torvalds 已提交
2214 2215 2216
	 * 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
2217 2218 2219
	if (size & (BYTES_PER_WORD - 1)) {
		size += (BYTES_PER_WORD - 1);
		size &= ~(BYTES_PER_WORD - 1);
L
Linus Torvalds 已提交
2220 2221
	}

A
Andrew Morton 已提交
2222 2223
	/* calculate the final buffer alignment: */

L
Linus Torvalds 已提交
2224 2225
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
A
Andrew Morton 已提交
2226 2227 2228 2229
		/*
		 * 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
2230 2231
		 */
		ralign = cache_line_size();
P
Pekka Enberg 已提交
2232
		while (size <= ralign / 2)
L
Linus Torvalds 已提交
2233 2234 2235 2236
			ralign /= 2;
	} else {
		ralign = BYTES_PER_WORD;
	}
2237 2238

	/*
D
David Woodhouse 已提交
2239 2240 2241
	 * Redzoning and user store require word alignment or possibly larger.
	 * Note this will be overridden by architecture or caller mandated
	 * alignment if either is greater than BYTES_PER_WORD.
2242
	 */
D
David Woodhouse 已提交
2243 2244 2245 2246 2247 2248 2249 2250 2251 2252
	if (flags & SLAB_STORE_USER)
		ralign = BYTES_PER_WORD;

	if (flags & SLAB_RED_ZONE) {
		ralign = REDZONE_ALIGN;
		/* If redzoning, ensure that the second redzone is suitably
		 * aligned, by adjusting the object size accordingly. */
		size += REDZONE_ALIGN - 1;
		size &= ~(REDZONE_ALIGN - 1);
	}
2253

2254
	/* 2) arch mandated alignment */
L
Linus Torvalds 已提交
2255 2256 2257
	if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
	}
2258
	/* 3) caller mandated alignment */
L
Linus Torvalds 已提交
2259 2260 2261
	if (ralign < align) {
		ralign = align;
	}
2262
	/* disable debug if necessary */
2263
	if (ralign > __alignof__(unsigned long long))
2264
		flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
A
Andrew Morton 已提交
2265
	/*
2266
	 * 4) Store it.
L
Linus Torvalds 已提交
2267 2268 2269 2270
	 */
	align = ralign;

	/* Get cache's description obj. */
2271
	cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
L
Linus Torvalds 已提交
2272
	if (!cachep)
2273
		goto oops;
L
Linus Torvalds 已提交
2274 2275

#if DEBUG
2276
	cachep->obj_size = size;
L
Linus Torvalds 已提交
2277

2278 2279 2280 2281
	/*
	 * Both debugging options require word-alignment which is calculated
	 * into align above.
	 */
L
Linus Torvalds 已提交
2282 2283
	if (flags & SLAB_RED_ZONE) {
		/* add space for red zone words */
2284 2285
		cachep->obj_offset += sizeof(unsigned long long);
		size += 2 * sizeof(unsigned long long);
L
Linus Torvalds 已提交
2286 2287
	}
	if (flags & SLAB_STORE_USER) {
2288
		/* user store requires one word storage behind the end of
D
David Woodhouse 已提交
2289 2290
		 * the real object. But if the second red zone needs to be
		 * aligned to 64 bits, we must allow that much space.
L
Linus Torvalds 已提交
2291
		 */
D
David Woodhouse 已提交
2292 2293 2294 2295
		if (flags & SLAB_RED_ZONE)
			size += REDZONE_ALIGN;
		else
			size += BYTES_PER_WORD;
L
Linus Torvalds 已提交
2296 2297
	}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
P
Pekka Enberg 已提交
2298
	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2299 2300
	    && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
		cachep->obj_offset += PAGE_SIZE - size;
L
Linus Torvalds 已提交
2301 2302 2303 2304 2305
		size = PAGE_SIZE;
	}
#endif
#endif

2306 2307 2308 2309 2310 2311
	/*
	 * 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
2312 2313 2314 2315 2316 2317 2318 2319
		/*
		 * 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);

2320
	left_over = calculate_slab_order(cachep, size, align, flags);
L
Linus Torvalds 已提交
2321 2322

	if (!cachep->num) {
2323 2324
		printk(KERN_ERR
		       "kmem_cache_create: couldn't create cache %s.\n", name);
L
Linus Torvalds 已提交
2325 2326
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
2327
		goto oops;
L
Linus Torvalds 已提交
2328
	}
P
Pekka Enberg 已提交
2329 2330
	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
			  + sizeof(struct slab), align);
L
Linus Torvalds 已提交
2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342

	/*
	 * 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
2343 2344
		slab_size =
		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
L
Linus Torvalds 已提交
2345 2346 2347 2348 2349 2350
	}

	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
2351
	cachep->colour = left_over / cachep->colour_off;
L
Linus Torvalds 已提交
2352 2353 2354
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
2355
	if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
L
Linus Torvalds 已提交
2356
		cachep->gfpflags |= GFP_DMA;
2357
	cachep->buffer_size = size;
2358
	cachep->reciprocal_buffer_size = reciprocal_value(size);
L
Linus Torvalds 已提交
2359

2360
	if (flags & CFLGS_OFF_SLAB) {
2361
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
2362 2363 2364 2365 2366 2367 2368
		/*
		 * 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.
		 */
2369
		BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));
2370
	}
L
Linus Torvalds 已提交
2371 2372 2373
	cachep->ctor = ctor;
	cachep->name = name;

2374 2375 2376 2377 2378
	if (setup_cpu_cache(cachep)) {
		__kmem_cache_destroy(cachep);
		cachep = NULL;
		goto oops;
	}
L
Linus Torvalds 已提交
2379 2380 2381

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
A
Andrew Morton 已提交
2382
oops:
L
Linus Torvalds 已提交
2383 2384
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
P
Pekka Enberg 已提交
2385
		      name);
I
Ingo Molnar 已提交
2386
	mutex_unlock(&cache_chain_mutex);
2387
	put_online_cpus();
L
Linus Torvalds 已提交
2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402
	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());
}

2403
static void check_spinlock_acquired(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2404 2405 2406
{
#ifdef CONFIG_SMP
	check_irq_off();
2407
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
2408 2409
#endif
}
2410

2411
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2412 2413 2414 2415 2416 2417 2418
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
2419 2420 2421 2422
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
2423
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
2424 2425
#endif

2426 2427 2428 2429
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
2430 2431
static void do_drain(void *arg)
{
A
Andrew Morton 已提交
2432
	struct kmem_cache *cachep = arg;
L
Linus Torvalds 已提交
2433
	struct array_cache *ac;
2434
	int node = numa_node_id();
L
Linus Torvalds 已提交
2435 2436

	check_irq_off();
2437
	ac = cpu_cache_get(cachep);
2438 2439 2440
	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
2441 2442 2443
	ac->avail = 0;
}

2444
static void drain_cpu_caches(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2445
{
2446 2447 2448
	struct kmem_list3 *l3;
	int node;

2449
	on_each_cpu(do_drain, cachep, 1);
L
Linus Torvalds 已提交
2450
	check_irq_on();
P
Pekka Enberg 已提交
2451
	for_each_online_node(node) {
2452
		l3 = cachep->nodelists[node];
2453 2454 2455 2456 2457 2458 2459
		if (l3 && l3->alien)
			drain_alien_cache(cachep, l3->alien);
	}

	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (l3)
2460
			drain_array(cachep, l3, l3->shared, 1, node);
2461
	}
L
Linus Torvalds 已提交
2462 2463
}

2464 2465 2466 2467 2468 2469 2470 2471
/*
 * 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
2472
{
2473 2474
	struct list_head *p;
	int nr_freed;
L
Linus Torvalds 已提交
2475 2476
	struct slab *slabp;

2477 2478
	nr_freed = 0;
	while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
L
Linus Torvalds 已提交
2479

2480
		spin_lock_irq(&l3->list_lock);
2481
		p = l3->slabs_free.prev;
2482 2483 2484 2485
		if (p == &l3->slabs_free) {
			spin_unlock_irq(&l3->list_lock);
			goto out;
		}
L
Linus Torvalds 已提交
2486

2487
		slabp = list_entry(p, struct slab, list);
L
Linus Torvalds 已提交
2488
#if DEBUG
2489
		BUG_ON(slabp->inuse);
L
Linus Torvalds 已提交
2490 2491
#endif
		list_del(&slabp->list);
2492 2493 2494 2495 2496
		/*
		 * Safe to drop the lock. The slab is no longer linked
		 * to the cache.
		 */
		l3->free_objects -= cache->num;
2497
		spin_unlock_irq(&l3->list_lock);
2498 2499
		slab_destroy(cache, slabp);
		nr_freed++;
L
Linus Torvalds 已提交
2500
	}
2501 2502
out:
	return nr_freed;
L
Linus Torvalds 已提交
2503 2504
}

2505
/* Called with cache_chain_mutex held to protect against cpu hotplug */
2506
static int __cache_shrink(struct kmem_cache *cachep)
2507 2508 2509 2510 2511 2512 2513 2514 2515
{
	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];
2516 2517 2518 2519 2520 2521 2522
		if (!l3)
			continue;

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

		ret += !list_empty(&l3->slabs_full) ||
			!list_empty(&l3->slabs_partial);
2523 2524 2525 2526
	}
	return (ret ? 1 : 0);
}

L
Linus Torvalds 已提交
2527 2528 2529 2530 2531 2532 2533
/**
 * 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.
 */
2534
int kmem_cache_shrink(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2535
{
2536
	int ret;
2537
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2538

2539
	get_online_cpus();
2540 2541 2542
	mutex_lock(&cache_chain_mutex);
	ret = __cache_shrink(cachep);
	mutex_unlock(&cache_chain_mutex);
2543
	put_online_cpus();
2544
	return ret;
L
Linus Torvalds 已提交
2545 2546 2547 2548 2549 2550 2551
}
EXPORT_SYMBOL(kmem_cache_shrink);

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
2552
 * Remove a &struct kmem_cache object from the slab cache.
L
Linus Torvalds 已提交
2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563
 *
 * 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().
 */
2564
void kmem_cache_destroy(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
2565
{
2566
	BUG_ON(!cachep || in_interrupt());
L
Linus Torvalds 已提交
2567 2568

	/* Find the cache in the chain of caches. */
2569
	get_online_cpus();
I
Ingo Molnar 已提交
2570
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
2571 2572 2573 2574 2575 2576
	/*
	 * 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
2577
		list_add(&cachep->next, &cache_chain);
I
Ingo Molnar 已提交
2578
		mutex_unlock(&cache_chain_mutex);
2579
		put_online_cpus();
2580
		return;
L
Linus Torvalds 已提交
2581 2582 2583
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2584
		synchronize_rcu();
L
Linus Torvalds 已提交
2585

2586
	__kmem_cache_destroy(cachep);
2587
	mutex_unlock(&cache_chain_mutex);
2588
	put_online_cpus();
L
Linus Torvalds 已提交
2589 2590 2591
}
EXPORT_SYMBOL(kmem_cache_destroy);

2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602
/*
 * 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.
 */
2603
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
2604 2605
				   int colour_off, gfp_t local_flags,
				   int nodeid)
L
Linus Torvalds 已提交
2606 2607
{
	struct slab *slabp;
P
Pekka Enberg 已提交
2608

L
Linus Torvalds 已提交
2609 2610
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
2611
		slabp = kmem_cache_alloc_node(cachep->slabp_cache,
2612
					      local_flags & ~GFP_THISNODE, nodeid);
L
Linus Torvalds 已提交
2613 2614 2615
		if (!slabp)
			return NULL;
	} else {
P
Pekka Enberg 已提交
2616
		slabp = objp + colour_off;
L
Linus Torvalds 已提交
2617 2618 2619 2620
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
P
Pekka Enberg 已提交
2621
	slabp->s_mem = objp + colour_off;
2622
	slabp->nodeid = nodeid;
2623
	slabp->free = 0;
L
Linus Torvalds 已提交
2624 2625 2626 2627 2628
	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
P
Pekka Enberg 已提交
2629
	return (kmem_bufctl_t *) (slabp + 1);
L
Linus Torvalds 已提交
2630 2631
}

2632
static void cache_init_objs(struct kmem_cache *cachep,
C
Christoph Lameter 已提交
2633
			    struct slab *slabp)
L
Linus Torvalds 已提交
2634 2635 2636 2637
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2638
		void *objp = index_to_obj(cachep, slabp, i);
L
Linus Torvalds 已提交
2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650
#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
2651 2652 2653
		 * 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
2654 2655
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2656
			cachep->ctor(objp + obj_offset(cachep));
L
Linus Torvalds 已提交
2657 2658 2659 2660

		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
2661
					   " end of an object");
L
Linus Torvalds 已提交
2662 2663
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
P
Pekka Enberg 已提交
2664
					   " start of an object");
L
Linus Torvalds 已提交
2665
		}
A
Andrew Morton 已提交
2666 2667
		if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
			    OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
P
Pekka Enberg 已提交
2668
			kernel_map_pages(virt_to_page(objp),
2669
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2670 2671
#else
		if (cachep->ctor)
2672
			cachep->ctor(objp);
L
Linus Torvalds 已提交
2673
#endif
P
Pekka Enberg 已提交
2674
		slab_bufctl(slabp)[i] = i + 1;
L
Linus Torvalds 已提交
2675
	}
P
Pekka Enberg 已提交
2676
	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
L
Linus Torvalds 已提交
2677 2678
}

2679
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2680
{
2681 2682 2683 2684 2685 2686
	if (CONFIG_ZONE_DMA_FLAG) {
		if (flags & GFP_DMA)
			BUG_ON(!(cachep->gfpflags & GFP_DMA));
		else
			BUG_ON(cachep->gfpflags & GFP_DMA);
	}
L
Linus Torvalds 已提交
2687 2688
}

A
Andrew Morton 已提交
2689 2690
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
				int nodeid)
2691
{
2692
	void *objp = index_to_obj(cachep, slabp, slabp->free);
2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705
	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
2706 2707
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
				void *objp, int nodeid)
2708
{
2709
	unsigned int objnr = obj_to_index(cachep, slabp, objp);
2710 2711 2712 2713 2714

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

2715
	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
2716
		printk(KERN_ERR "slab: double free detected in cache "
A
Andrew Morton 已提交
2717
				"'%s', objp %p\n", cachep->name, objp);
2718 2719 2720 2721 2722 2723 2724 2725
		BUG();
	}
#endif
	slab_bufctl(slabp)[objnr] = slabp->free;
	slabp->free = objnr;
	slabp->inuse--;
}

2726 2727 2728 2729 2730 2731 2732
/*
 * 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
2733
{
2734
	int nr_pages;
L
Linus Torvalds 已提交
2735 2736
	struct page *page;

2737
	page = virt_to_page(addr);
2738

2739
	nr_pages = 1;
2740
	if (likely(!PageCompound(page)))
2741 2742
		nr_pages <<= cache->gfporder;

L
Linus Torvalds 已提交
2743
	do {
2744 2745
		page_set_cache(page, cache);
		page_set_slab(page, slab);
L
Linus Torvalds 已提交
2746
		page++;
2747
	} while (--nr_pages);
L
Linus Torvalds 已提交
2748 2749 2750 2751 2752 2753
}

/*
 * 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.
 */
2754 2755
static int cache_grow(struct kmem_cache *cachep,
		gfp_t flags, int nodeid, void *objp)
L
Linus Torvalds 已提交
2756
{
P
Pekka Enberg 已提交
2757 2758 2759
	struct slab *slabp;
	size_t offset;
	gfp_t local_flags;
2760
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2761

A
Andrew Morton 已提交
2762 2763 2764
	/*
	 * 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
2765
	 */
C
Christoph Lameter 已提交
2766 2767
	BUG_ON(flags & GFP_SLAB_BUG_MASK);
	local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
L
Linus Torvalds 已提交
2768

2769
	/* Take the l3 list lock to change the colour_next on this node */
L
Linus Torvalds 已提交
2770
	check_irq_off();
2771 2772
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2773 2774

	/* Get colour for the slab, and cal the next value. */
2775 2776 2777 2778 2779
	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
2780

2781
	offset *= cachep->colour_off;
L
Linus Torvalds 已提交
2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793

	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
2794 2795 2796
	/*
	 * Get mem for the objs.  Attempt to allocate a physical page from
	 * 'nodeid'.
2797
	 */
2798
	if (!objp)
2799
		objp = kmem_getpages(cachep, local_flags, nodeid);
A
Andrew Morton 已提交
2800
	if (!objp)
L
Linus Torvalds 已提交
2801 2802 2803
		goto failed;

	/* Get slab management. */
2804
	slabp = alloc_slabmgmt(cachep, objp, offset,
C
Christoph Lameter 已提交
2805
			local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
A
Andrew Morton 已提交
2806
	if (!slabp)
L
Linus Torvalds 已提交
2807 2808
		goto opps1;

2809
	slab_map_pages(cachep, slabp, objp);
L
Linus Torvalds 已提交
2810

C
Christoph Lameter 已提交
2811
	cache_init_objs(cachep, slabp);
L
Linus Torvalds 已提交
2812 2813 2814 2815

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2816
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2817 2818

	/* Make slab active. */
2819
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2820
	STATS_INC_GROWN(cachep);
2821 2822
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2823
	return 1;
A
Andrew Morton 已提交
2824
opps1:
L
Linus Torvalds 已提交
2825
	kmem_freepages(cachep, objp);
A
Andrew Morton 已提交
2826
failed:
L
Linus Torvalds 已提交
2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842
	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	return 0;
}

#if DEBUG

/*
 * Perform extra freeing checks:
 * - detect bad pointers.
 * - POISON/RED_ZONE checking
 */
static void kfree_debugcheck(const void *objp)
{
	if (!virt_addr_valid(objp)) {
		printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
P
Pekka Enberg 已提交
2843 2844
		       (unsigned long)objp);
		BUG();
L
Linus Torvalds 已提交
2845 2846 2847
	}
}

2848 2849
static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
{
2850
	unsigned long long redzone1, redzone2;
2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865

	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");

2866
	printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
2867 2868 2869
			obj, redzone1, redzone2);
}

2870
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
P
Pekka Enberg 已提交
2871
				   void *caller)
L
Linus Torvalds 已提交
2872 2873 2874 2875 2876
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

2877 2878
	BUG_ON(virt_to_cache(objp) != cachep);

2879
	objp -= obj_offset(cachep);
L
Linus Torvalds 已提交
2880
	kfree_debugcheck(objp);
2881
	page = virt_to_head_page(objp);
L
Linus Torvalds 已提交
2882

2883
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2884 2885

	if (cachep->flags & SLAB_RED_ZONE) {
2886
		verify_redzone_free(cachep, objp);
L
Linus Torvalds 已提交
2887 2888 2889 2890 2891 2892
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

2893
	objnr = obj_to_index(cachep, slabp, objp);
L
Linus Torvalds 已提交
2894 2895

	BUG_ON(objnr >= cachep->num);
2896
	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
L
Linus Torvalds 已提交
2897

2898 2899 2900
#ifdef CONFIG_DEBUG_SLAB_LEAK
	slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
#endif
L
Linus Torvalds 已提交
2901 2902
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
A
Andrew Morton 已提交
2903
		if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
L
Linus Torvalds 已提交
2904
			store_stackinfo(cachep, objp, (unsigned long)caller);
P
Pekka Enberg 已提交
2905
			kernel_map_pages(virt_to_page(objp),
2906
					 cachep->buffer_size / PAGE_SIZE, 0);
L
Linus Torvalds 已提交
2907 2908 2909 2910 2911 2912 2913 2914 2915 2916
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

2917
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
L
Linus Torvalds 已提交
2918 2919 2920
{
	kmem_bufctl_t i;
	int entries = 0;
P
Pekka Enberg 已提交
2921

L
Linus Torvalds 已提交
2922 2923 2924 2925 2926 2927 2928
	/* 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
2929 2930 2931 2932
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
2933
		for (i = 0;
2934
		     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
P
Pekka Enberg 已提交
2935
		     i++) {
A
Andrew Morton 已提交
2936
			if (i % 16 == 0)
L
Linus Torvalds 已提交
2937
				printk("\n%03x:", i);
P
Pekka Enberg 已提交
2938
			printk(" %02x", ((unsigned char *)slabp)[i]);
L
Linus Torvalds 已提交
2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949
		}
		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

2950
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2951 2952 2953 2954
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;
P
Pekka Enberg 已提交
2955 2956
	int node;

2957
retry:
L
Linus Torvalds 已提交
2958
	check_irq_off();
2959
	node = numa_node_id();
2960
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
2961 2962
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
A
Andrew Morton 已提交
2963 2964 2965 2966
		/*
		 * 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
2967 2968 2969
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
P
Pekka Enberg 已提交
2970
	l3 = cachep->nodelists[node];
2971 2972 2973

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2974

2975 2976 2977 2978
	/* 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
2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993
	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);
2994 2995 2996 2997 2998 2999 3000 3001

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

L
Linus Torvalds 已提交
3002 3003 3004 3005 3006
		while (slabp->inuse < cachep->num && batchcount--) {
			STATS_INC_ALLOCED(cachep);
			STATS_INC_ACTIVE(cachep);
			STATS_SET_HIGH(cachep);

3007
			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
P
Pekka Enberg 已提交
3008
							    node);
L
Linus Torvalds 已提交
3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019
		}
		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
3020
must_grow:
L
Linus Torvalds 已提交
3021
	l3->free_objects -= ac->avail;
A
Andrew Morton 已提交
3022
alloc_done:
3023
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3024 3025 3026

	if (unlikely(!ac->avail)) {
		int x;
3027
		x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
3028

A
Andrew Morton 已提交
3029
		/* cache_grow can reenable interrupts, then ac could change. */
3030
		ac = cpu_cache_get(cachep);
A
Andrew Morton 已提交
3031
		if (!x && ac->avail == 0)	/* no objects in sight? abort */
L
Linus Torvalds 已提交
3032 3033
			return NULL;

A
Andrew Morton 已提交
3034
		if (!ac->avail)		/* objects refilled by interrupt? */
L
Linus Torvalds 已提交
3035 3036 3037
			goto retry;
	}
	ac->touched = 1;
3038
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3039 3040
}

A
Andrew Morton 已提交
3041 3042
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
						gfp_t flags)
L
Linus Torvalds 已提交
3043 3044 3045 3046 3047 3048 3049 3050
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
A
Andrew Morton 已提交
3051 3052
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
				gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
3053
{
P
Pekka Enberg 已提交
3054
	if (!objp)
L
Linus Torvalds 已提交
3055
		return objp;
P
Pekka Enberg 已提交
3056
	if (cachep->flags & SLAB_POISON) {
L
Linus Torvalds 已提交
3057
#ifdef CONFIG_DEBUG_PAGEALLOC
3058
		if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
P
Pekka Enberg 已提交
3059
			kernel_map_pages(virt_to_page(objp),
3060
					 cachep->buffer_size / PAGE_SIZE, 1);
L
Linus Torvalds 已提交
3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071
		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
3072 3073 3074 3075
		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
3076
			printk(KERN_ERR
3077
				"%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
A
Andrew Morton 已提交
3078 3079
				objp, *dbg_redzone1(cachep, objp),
				*dbg_redzone2(cachep, objp));
L
Linus Torvalds 已提交
3080 3081 3082 3083
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
3084 3085 3086 3087 3088
#ifdef CONFIG_DEBUG_SLAB_LEAK
	{
		struct slab *slabp;
		unsigned objnr;

3089
		slabp = page_get_slab(virt_to_head_page(objp));
3090 3091 3092 3093
		objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
	}
#endif
3094
	objp += obj_offset(cachep);
3095
	if (cachep->ctor && cachep->flags & SLAB_POISON)
3096
		cachep->ctor(objp);
3097 3098 3099 3100 3101 3102
#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
3103 3104 3105 3106 3107 3108
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121
#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,
3122
	.ignore_gfp_wait = 1,
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
};

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;

3151
	err = init_fault_attr_dentries(&failslab.attr, "failslab");
3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181
	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 */

3182
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3183
{
P
Pekka Enberg 已提交
3184
	void *objp;
L
Linus Torvalds 已提交
3185 3186
	struct array_cache *ac;

3187
	check_irq_off();
3188

3189
	ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3190 3191 3192
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
3193
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
3194 3195 3196 3197
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
3198 3199 3200
	return objp;
}

3201
#ifdef CONFIG_NUMA
3202
/*
3203
 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
3204 3205 3206 3207 3208 3209 3210 3211
 *
 * 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;

3212
	if (in_interrupt() || (flags & __GFP_THISNODE))
3213 3214 3215 3216 3217 3218 3219
		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)
3220
		return ____cache_alloc_node(cachep, flags, nid_alloc);
3221 3222 3223
	return NULL;
}

3224 3225
/*
 * Fallback function if there was no memory available and no objects on a
3226 3227 3228 3229 3230
 * 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.
3231
 */
3232
static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
3233
{
3234 3235
	struct zonelist *zonelist;
	gfp_t local_flags;
3236
	struct zoneref *z;
3237 3238
	struct zone *zone;
	enum zone_type high_zoneidx = gfp_zone(flags);
3239
	void *obj = NULL;
3240
	int nid;
3241 3242 3243 3244

	if (flags & __GFP_THISNODE)
		return NULL;

3245
	zonelist = node_zonelist(slab_node(current->mempolicy), flags);
C
Christoph Lameter 已提交
3246
	local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
3247

3248 3249 3250 3251 3252
retry:
	/*
	 * Look through allowed nodes for objects available
	 * from existing per node queues.
	 */
3253 3254
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
		nid = zone_to_nid(zone);
3255

3256
		if (cpuset_zone_allowed_hardwall(zone, flags) &&
3257
			cache->nodelists[nid] &&
3258
			cache->nodelists[nid]->free_objects) {
3259 3260
				obj = ____cache_alloc_node(cache,
					flags | GFP_THISNODE, nid);
3261 3262 3263
				if (obj)
					break;
		}
3264 3265
	}

3266
	if (!obj) {
3267 3268 3269 3270 3271 3272
		/*
		 * 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.
		 */
3273 3274 3275
		if (local_flags & __GFP_WAIT)
			local_irq_enable();
		kmem_flagcheck(cache, flags);
3276
		obj = kmem_getpages(cache, local_flags, -1);
3277 3278
		if (local_flags & __GFP_WAIT)
			local_irq_disable();
3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294
		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 {
3295
				/* cache_grow already freed obj */
3296 3297 3298
				obj = NULL;
			}
		}
3299
	}
3300 3301 3302
	return obj;
}

3303 3304
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
3305
 */
3306
static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
A
Andrew Morton 已提交
3307
				int nodeid)
3308 3309
{
	struct list_head *entry;
P
Pekka Enberg 已提交
3310 3311 3312 3313 3314 3315 3316 3317
	struct slab *slabp;
	struct kmem_list3 *l3;
	void *obj;
	int x;

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

A
Andrew Morton 已提交
3318
retry:
3319
	check_irq_off();
P
Pekka Enberg 已提交
3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338
	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);

3339
	obj = slab_get_obj(cachep, slabp, nodeid);
P
Pekka Enberg 已提交
3340 3341 3342 3343 3344
	check_slabp(cachep, slabp);
	l3->free_objects--;
	/* move slabp to correct slabp list: */
	list_del(&slabp->list);

A
Andrew Morton 已提交
3345
	if (slabp->free == BUFCTL_END)
P
Pekka Enberg 已提交
3346
		list_add(&slabp->list, &l3->slabs_full);
A
Andrew Morton 已提交
3347
	else
P
Pekka Enberg 已提交
3348
		list_add(&slabp->list, &l3->slabs_partial);
3349

P
Pekka Enberg 已提交
3350 3351
	spin_unlock(&l3->list_lock);
	goto done;
3352

A
Andrew Morton 已提交
3353
must_grow:
P
Pekka Enberg 已提交
3354
	spin_unlock(&l3->list_lock);
3355
	x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
3356 3357
	if (x)
		goto retry;
L
Linus Torvalds 已提交
3358

3359
	return fallback_alloc(cachep, flags);
3360

A
Andrew Morton 已提交
3361
done:
P
Pekka Enberg 已提交
3362
	return obj;
3363
}
3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383

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

3384 3385 3386
	if (should_failslab(cachep, flags))
		return NULL;

3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);

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

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

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

3416 3417 3418
	if (unlikely((flags & __GFP_ZERO) && ptr))
		memset(ptr, 0, obj_size(cachep));

3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459
	return ptr;
}

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

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

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

  out:
	return objp;
}
#else

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

#endif /* CONFIG_NUMA */

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

3460 3461 3462
	if (should_failslab(cachep, flags))
		return NULL;

3463 3464 3465 3466 3467 3468 3469
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
	objp = __do_cache_alloc(cachep, flags);
	local_irq_restore(save_flags);
	objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
	prefetchw(objp);

3470 3471 3472
	if (unlikely((flags & __GFP_ZERO) && objp))
		memset(objp, 0, obj_size(cachep));

3473 3474
	return objp;
}
3475 3476 3477 3478

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
3479
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
P
Pekka Enberg 已提交
3480
		       int node)
L
Linus Torvalds 已提交
3481 3482
{
	int i;
3483
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3484 3485 3486 3487 3488

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

3489
		slabp = virt_to_slab(objp);
3490
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
3491
		list_del(&slabp->list);
3492
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
3493
		check_slabp(cachep, slabp);
3494
		slab_put_obj(cachep, slabp, objp, node);
L
Linus Torvalds 已提交
3495
		STATS_DEC_ACTIVE(cachep);
3496
		l3->free_objects++;
L
Linus Torvalds 已提交
3497 3498 3499 3500
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
3501 3502
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
3503 3504 3505 3506 3507 3508
				/* 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
3509 3510
				slab_destroy(cachep, slabp);
			} else {
3511
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
3512 3513 3514 3515 3516 3517
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
3518
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
3519 3520 3521 3522
		}
	}
}

3523
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
L
Linus Torvalds 已提交
3524 3525
{
	int batchcount;
3526
	struct kmem_list3 *l3;
3527
	int node = numa_node_id();
L
Linus Torvalds 已提交
3528 3529 3530 3531 3532 3533

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
3534
	l3 = cachep->nodelists[node];
3535
	spin_lock(&l3->list_lock);
3536 3537
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
P
Pekka Enberg 已提交
3538
		int max = shared_array->limit - shared_array->avail;
L
Linus Torvalds 已提交
3539 3540 3541
		if (max) {
			if (batchcount > max)
				batchcount = max;
3542
			memcpy(&(shared_array->entry[shared_array->avail]),
P
Pekka Enberg 已提交
3543
			       ac->entry, sizeof(void *) * batchcount);
L
Linus Torvalds 已提交
3544 3545 3546 3547 3548
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

3549
	free_block(cachep, ac->entry, batchcount, node);
A
Andrew Morton 已提交
3550
free_done:
L
Linus Torvalds 已提交
3551 3552 3553 3554 3555
#if STATS
	{
		int i = 0;
		struct list_head *p;

3556 3557
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568
			struct slab *slabp;

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

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
3569
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3570
	ac->avail -= batchcount;
A
Andrew Morton 已提交
3571
	memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
L
Linus Torvalds 已提交
3572 3573 3574
}

/*
A
Andrew Morton 已提交
3575 3576
 * 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
3577
 */
3578
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3579
{
3580
	struct array_cache *ac = cpu_cache_get(cachep);
L
Linus Torvalds 已提交
3581 3582 3583 3584

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

3585 3586 3587 3588 3589 3590 3591 3592
	/*
	 * Skip calling cache_free_alien() when the platform is not numa.
	 * This will avoid cache misses that happen while accessing slabp (which
	 * is per page memory  reference) to get nodeid. Instead use a global
	 * variable to skip the call, which is mostly likely to be present in
	 * the cache.
	 */
	if (numa_platform && cache_free_alien(cachep, objp))
3593 3594
		return;

L
Linus Torvalds 已提交
3595 3596
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
3597
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3598 3599 3600 3601
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
3602
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613
	}
}

/**
 * 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.
 */
3614
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
L
Linus Torvalds 已提交
3615
{
3616
	return __cache_alloc(cachep, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3617 3618 3619 3620
}
EXPORT_SYMBOL(kmem_cache_alloc);

/**
3621
 * kmem_ptr_validate - check if an untrusted pointer might be a slab entry.
L
Linus Torvalds 已提交
3622 3623 3624
 * @cachep: the cache we're checking against
 * @ptr: pointer to validate
 *
3625
 * This verifies that the untrusted pointer looks sane;
L
Linus Torvalds 已提交
3626 3627 3628 3629 3630 3631 3632
 * 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.
 */
3633
int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
L
Linus Torvalds 已提交
3634
{
P
Pekka Enberg 已提交
3635
	unsigned long addr = (unsigned long)ptr;
L
Linus Torvalds 已提交
3636
	unsigned long min_addr = PAGE_OFFSET;
P
Pekka Enberg 已提交
3637
	unsigned long align_mask = BYTES_PER_WORD - 1;
3638
	unsigned long size = cachep->buffer_size;
L
Linus Torvalds 已提交
3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653
	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;
3654
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
3655 3656
		goto out;
	return 1;
A
Andrew Morton 已提交
3657
out:
L
Linus Torvalds 已提交
3658 3659 3660 3661
	return 0;
}

#ifdef CONFIG_NUMA
3662 3663 3664 3665 3666
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
3667 3668
EXPORT_SYMBOL(kmem_cache_alloc_node);

3669 3670
static __always_inline void *
__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
3671
{
3672
	struct kmem_cache *cachep;
3673 3674

	cachep = kmem_find_general_cachep(size, flags);
3675 3676
	if (unlikely(ZERO_OR_NULL_PTR(cachep)))
		return cachep;
3677 3678
	return kmem_cache_alloc_node(cachep, flags, node);
}
3679 3680 3681 3682 3683 3684 3685

#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));
}
3686
EXPORT_SYMBOL(__kmalloc_node);
3687 3688

void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
3689
		int node, unsigned long caller)
3690
{
3691
	return __do_kmalloc_node(size, flags, node, (void *)caller);
3692 3693 3694 3695 3696 3697 3698 3699 3700 3701
}
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
3702 3703

/**
3704
 * __do_kmalloc - allocate memory
L
Linus Torvalds 已提交
3705
 * @size: how many bytes of memory are required.
3706
 * @flags: the type of memory to allocate (see kmalloc).
3707
 * @caller: function caller for debug tracking of the caller
L
Linus Torvalds 已提交
3708
 */
3709 3710
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
					  void *caller)
L
Linus Torvalds 已提交
3711
{
3712
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3713

3714 3715 3716 3717 3718 3719
	/* 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);
3720 3721
	if (unlikely(ZERO_OR_NULL_PTR(cachep)))
		return cachep;
3722 3723 3724 3725
	return __cache_alloc(cachep, flags, caller);
}


3726
#ifdef CONFIG_DEBUG_SLAB
3727 3728
void *__kmalloc(size_t size, gfp_t flags)
{
3729
	return __do_kmalloc(size, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
3730 3731 3732
}
EXPORT_SYMBOL(__kmalloc);

3733
void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller)
3734
{
3735
	return __do_kmalloc(size, flags, (void *)caller);
3736 3737
}
EXPORT_SYMBOL(__kmalloc_track_caller);
3738 3739 3740 3741 3742 3743 3744

#else
void *__kmalloc(size_t size, gfp_t flags)
{
	return __do_kmalloc(size, flags, NULL);
}
EXPORT_SYMBOL(__kmalloc);
3745 3746
#endif

L
Linus Torvalds 已提交
3747 3748 3749 3750 3751 3752 3753 3754
/**
 * 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.
 */
3755
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
L
Linus Torvalds 已提交
3756 3757 3758 3759
{
	unsigned long flags;

	local_irq_save(flags);
3760
	debug_check_no_locks_freed(objp, obj_size(cachep));
3761 3762
	if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
		debug_check_no_obj_freed(objp, obj_size(cachep));
3763
	__cache_free(cachep, objp);
L
Linus Torvalds 已提交
3764 3765 3766 3767 3768 3769 3770 3771
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kmem_cache_free);

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3772 3773
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3774 3775 3776 3777 3778
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
3779
	struct kmem_cache *c;
L
Linus Torvalds 已提交
3780 3781
	unsigned long flags;

3782
	if (unlikely(ZERO_OR_NULL_PTR(objp)))
L
Linus Torvalds 已提交
3783 3784 3785
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3786
	c = virt_to_cache(objp);
3787
	debug_check_no_locks_freed(objp, obj_size(c));
3788
	debug_check_no_obj_freed(objp, obj_size(c));
3789
	__cache_free(c, (void *)objp);
L
Linus Torvalds 已提交
3790 3791 3792 3793
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

3794
unsigned int kmem_cache_size(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3795
{
3796
	return obj_size(cachep);
L
Linus Torvalds 已提交
3797 3798 3799
}
EXPORT_SYMBOL(kmem_cache_size);

3800
const char *kmem_cache_name(struct kmem_cache *cachep)
3801 3802 3803 3804 3805
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3806
/*
S
Simon Arlott 已提交
3807
 * This initializes kmem_list3 or resizes various caches for all nodes.
3808
 */
3809
static int alloc_kmemlist(struct kmem_cache *cachep)
3810 3811 3812
{
	int node;
	struct kmem_list3 *l3;
3813
	struct array_cache *new_shared;
3814
	struct array_cache **new_alien = NULL;
3815

3816
	for_each_online_node(node) {
3817

3818 3819 3820 3821 3822
                if (use_alien_caches) {
                        new_alien = alloc_alien_cache(node, cachep->limit);
                        if (!new_alien)
                                goto fail;
                }
3823

3824 3825 3826
		new_shared = NULL;
		if (cachep->shared) {
			new_shared = alloc_arraycache(node,
3827
				cachep->shared*cachep->batchcount,
A
Andrew Morton 已提交
3828
					0xbaadf00d);
3829 3830 3831 3832
			if (!new_shared) {
				free_alien_cache(new_alien);
				goto fail;
			}
3833
		}
3834

A
Andrew Morton 已提交
3835 3836
		l3 = cachep->nodelists[node];
		if (l3) {
3837 3838
			struct array_cache *shared = l3->shared;

3839 3840
			spin_lock_irq(&l3->list_lock);

3841
			if (shared)
3842 3843
				free_block(cachep, shared->entry,
						shared->avail, node);
3844

3845 3846
			l3->shared = new_shared;
			if (!l3->alien) {
3847 3848 3849
				l3->alien = new_alien;
				new_alien = NULL;
			}
P
Pekka Enberg 已提交
3850
			l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3851
					cachep->batchcount + cachep->num;
3852
			spin_unlock_irq(&l3->list_lock);
3853
			kfree(shared);
3854 3855 3856
			free_alien_cache(new_alien);
			continue;
		}
A
Andrew Morton 已提交
3857
		l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
3858 3859 3860
		if (!l3) {
			free_alien_cache(new_alien);
			kfree(new_shared);
3861
			goto fail;
3862
		}
3863 3864 3865

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
A
Andrew Morton 已提交
3866
				((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3867
		l3->shared = new_shared;
3868
		l3->alien = new_alien;
P
Pekka Enberg 已提交
3869
		l3->free_limit = (1 + nr_cpus_node(node)) *
A
Andrew Morton 已提交
3870
					cachep->batchcount + cachep->num;
3871 3872
		cachep->nodelists[node] = l3;
	}
3873
	return 0;
3874

A
Andrew Morton 已提交
3875
fail:
3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890
	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--;
		}
	}
3891
	return -ENOMEM;
3892 3893
}

L
Linus Torvalds 已提交
3894
struct ccupdate_struct {
3895
	struct kmem_cache *cachep;
L
Linus Torvalds 已提交
3896 3897 3898 3899 3900
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
A
Andrew Morton 已提交
3901
	struct ccupdate_struct *new = info;
L
Linus Torvalds 已提交
3902 3903 3904
	struct array_cache *old;

	check_irq_off();
3905
	old = cpu_cache_get(new->cachep);
3906

L
Linus Torvalds 已提交
3907 3908 3909 3910
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}

3911
/* Always called with the cache_chain_mutex held */
A
Andrew Morton 已提交
3912 3913
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
				int batchcount, int shared)
L
Linus Torvalds 已提交
3914
{
3915
	struct ccupdate_struct *new;
3916
	int i;
L
Linus Torvalds 已提交
3917

3918 3919 3920 3921
	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		return -ENOMEM;

3922
	for_each_online_cpu(i) {
3923
		new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
A
Andrew Morton 已提交
3924
						batchcount);
3925
		if (!new->new[i]) {
P
Pekka Enberg 已提交
3926
			for (i--; i >= 0; i--)
3927 3928
				kfree(new->new[i]);
			kfree(new);
3929
			return -ENOMEM;
L
Linus Torvalds 已提交
3930 3931
		}
	}
3932
	new->cachep = cachep;
L
Linus Torvalds 已提交
3933

3934
	on_each_cpu(do_ccupdate_local, (void *)new, 1);
3935

L
Linus Torvalds 已提交
3936 3937 3938
	check_irq_on();
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3939
	cachep->shared = shared;
L
Linus Torvalds 已提交
3940

3941
	for_each_online_cpu(i) {
3942
		struct array_cache *ccold = new->new[i];
L
Linus Torvalds 已提交
3943 3944
		if (!ccold)
			continue;
3945
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3946
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3947
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3948 3949
		kfree(ccold);
	}
3950
	kfree(new);
3951
	return alloc_kmemlist(cachep);
L
Linus Torvalds 已提交
3952 3953
}

3954
/* Called with cache_chain_mutex held always */
3955
static int enable_cpucache(struct kmem_cache *cachep)
L
Linus Torvalds 已提交
3956 3957 3958 3959
{
	int err;
	int limit, shared;

A
Andrew Morton 已提交
3960 3961
	/*
	 * The head array serves three purposes:
L
Linus Torvalds 已提交
3962 3963
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
A
Andrew Morton 已提交
3964
	 * - reduce the number of linked list operations on the slab and
L
Linus Torvalds 已提交
3965 3966 3967 3968
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
3969
	if (cachep->buffer_size > 131072)
L
Linus Torvalds 已提交
3970
		limit = 1;
3971
	else if (cachep->buffer_size > PAGE_SIZE)
L
Linus Torvalds 已提交
3972
		limit = 8;
3973
	else if (cachep->buffer_size > 1024)
L
Linus Torvalds 已提交
3974
		limit = 24;
3975
	else if (cachep->buffer_size > 256)
L
Linus Torvalds 已提交
3976 3977 3978 3979
		limit = 54;
	else
		limit = 120;

A
Andrew Morton 已提交
3980 3981
	/*
	 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
L
Linus Torvalds 已提交
3982 3983 3984 3985 3986 3987 3988 3989
	 * 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;
3990
	if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1)
L
Linus Torvalds 已提交
3991 3992 3993
		shared = 8;

#if DEBUG
A
Andrew Morton 已提交
3994 3995 3996
	/*
	 * With debugging enabled, large batchcount lead to excessively long
	 * periods with disabled local interrupts. Limit the batchcount
L
Linus Torvalds 已提交
3997 3998 3999 4000
	 */
	if (limit > 32)
		limit = 32;
#endif
P
Pekka Enberg 已提交
4001
	err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
L
Linus Torvalds 已提交
4002 4003
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
P
Pekka Enberg 已提交
4004
		       cachep->name, -err);
4005
	return err;
L
Linus Torvalds 已提交
4006 4007
}

4008 4009
/*
 * Drain an array if it contains any elements taking the l3 lock only if
4010 4011
 * necessary. Note that the l3 listlock also protects the array_cache
 * if drain_array() is used on the shared array.
4012 4013 4014
 */
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
4015 4016 4017
{
	int tofree;

4018 4019
	if (!ac || !ac->avail)
		return;
L
Linus Torvalds 已提交
4020 4021
	if (ac->touched && !force) {
		ac->touched = 0;
4022
	} else {
4023
		spin_lock_irq(&l3->list_lock);
4024 4025 4026 4027 4028 4029 4030 4031 4032
		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);
		}
4033
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4034 4035 4036 4037 4038
	}
}

/**
 * cache_reap - Reclaim memory from caches.
4039
 * @w: work descriptor
L
Linus Torvalds 已提交
4040 4041 4042 4043 4044 4045
 *
 * 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
4046 4047
 * 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
4048
 */
4049
static void cache_reap(struct work_struct *w)
L
Linus Torvalds 已提交
4050
{
4051
	struct kmem_cache *searchp;
4052
	struct kmem_list3 *l3;
4053
	int node = numa_node_id();
4054 4055
	struct delayed_work *work =
		container_of(w, struct delayed_work, work);
L
Linus Torvalds 已提交
4056

4057
	if (!mutex_trylock(&cache_chain_mutex))
L
Linus Torvalds 已提交
4058
		/* Give up. Setup the next iteration. */
4059
		goto out;
L
Linus Torvalds 已提交
4060

4061
	list_for_each_entry(searchp, &cache_chain, next) {
L
Linus Torvalds 已提交
4062 4063
		check_irq_on();

4064 4065 4066 4067 4068
		/*
		 * 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.
		 */
4069
		l3 = searchp->nodelists[node];
4070

4071
		reap_alien(searchp, l3);
L
Linus Torvalds 已提交
4072

4073
		drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
L
Linus Torvalds 已提交
4074

4075 4076 4077 4078
		/*
		 * These are racy checks but it does not matter
		 * if we skip one check or scan twice.
		 */
4079
		if (time_after(l3->next_reap, jiffies))
4080
			goto next;
L
Linus Torvalds 已提交
4081

4082
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
4083

4084
		drain_array(searchp, l3, l3->shared, 0, node);
L
Linus Torvalds 已提交
4085

4086
		if (l3->free_touched)
4087
			l3->free_touched = 0;
4088 4089
		else {
			int freed;
L
Linus Torvalds 已提交
4090

4091 4092 4093 4094
			freed = drain_freelist(searchp, l3, (l3->free_limit +
				5 * searchp->num - 1) / (5 * searchp->num));
			STATS_ADD_REAPED(searchp, freed);
		}
4095
next:
L
Linus Torvalds 已提交
4096 4097 4098
		cond_resched();
	}
	check_irq_on();
I
Ingo Molnar 已提交
4099
	mutex_unlock(&cache_chain_mutex);
4100
	next_reap_node();
4101
out:
A
Andrew Morton 已提交
4102
	/* Set up the next iteration */
4103
	schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
L
Linus Torvalds 已提交
4104 4105
}

4106
#ifdef CONFIG_SLABINFO
L
Linus Torvalds 已提交
4107

4108
static void print_slabinfo_header(struct seq_file *m)
L
Linus Torvalds 已提交
4109
{
4110 4111 4112 4113
	/*
	 * Output format version, so at least we can change it
	 * without _too_ many complaints.
	 */
L
Linus Torvalds 已提交
4114
#if STATS
4115
	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
L
Linus Torvalds 已提交
4116
#else
4117
	seq_puts(m, "slabinfo - version: 2.1\n");
L
Linus Torvalds 已提交
4118
#endif
4119 4120 4121 4122
	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
4123
#if STATS
4124
	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
4125
		 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
4126
	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
L
Linus Torvalds 已提交
4127
#endif
4128 4129 4130 4131 4132 4133 4134
	seq_putc(m, '\n');
}

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

I
Ingo Molnar 已提交
4135
	mutex_lock(&cache_chain_mutex);
4136 4137
	if (!n)
		print_slabinfo_header(m);
4138 4139

	return seq_list_start(&cache_chain, *pos);
L
Linus Torvalds 已提交
4140 4141 4142 4143
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
4144
	return seq_list_next(p, &cache_chain, pos);
L
Linus Torvalds 已提交
4145 4146 4147 4148
}

static void s_stop(struct seq_file *m, void *p)
{
I
Ingo Molnar 已提交
4149
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4150 4151 4152 4153
}

static int s_show(struct seq_file *m, void *p)
{
4154
	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
P
Pekka Enberg 已提交
4155 4156 4157 4158 4159
	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;
4160
	const char *name;
L
Linus Torvalds 已提交
4161
	char *error = NULL;
4162 4163
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
4164 4165 4166

	active_objs = 0;
	num_slabs = 0;
4167 4168 4169 4170 4171
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

4172 4173
		check_irq_on();
		spin_lock_irq(&l3->list_lock);
4174

4175
		list_for_each_entry(slabp, &l3->slabs_full, list) {
4176 4177 4178 4179 4180
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
4181
		list_for_each_entry(slabp, &l3->slabs_partial, list) {
4182 4183 4184 4185 4186 4187 4188
			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++;
		}
4189
		list_for_each_entry(slabp, &l3->slabs_free, list) {
4190 4191 4192 4193 4194
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
4195 4196
		if (l3->shared)
			shared_avail += l3->shared->avail;
4197

4198
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
4199
	}
P
Pekka Enberg 已提交
4200 4201
	num_slabs += active_slabs;
	num_objs = num_slabs * cachep->num;
4202
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
4203 4204
		error = "free_objects accounting error";

P
Pekka Enberg 已提交
4205
	name = cachep->name;
L
Linus Torvalds 已提交
4206 4207 4208 4209
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
4210
		   name, active_objs, num_objs, cachep->buffer_size,
P
Pekka Enberg 已提交
4211
		   cachep->num, (1 << cachep->gfporder));
L
Linus Torvalds 已提交
4212
	seq_printf(m, " : tunables %4u %4u %4u",
P
Pekka Enberg 已提交
4213
		   cachep->limit, cachep->batchcount, cachep->shared);
4214
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
P
Pekka Enberg 已提交
4215
		   active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
4216
#if STATS
P
Pekka Enberg 已提交
4217
	{			/* list3 stats */
L
Linus Torvalds 已提交
4218 4219 4220 4221 4222 4223 4224
		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;
4225
		unsigned long node_frees = cachep->node_frees;
4226
		unsigned long overflows = cachep->node_overflow;
L
Linus Torvalds 已提交
4227

4228
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
4229
				%4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
A
Andrew Morton 已提交
4230
				reaped, errors, max_freeable, node_allocs,
4231
				node_frees, overflows);
L
Linus Torvalds 已提交
4232 4233 4234 4235 4236 4237 4238 4239 4240
	}
	/* 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
4241
			   allochit, allocmiss, freehit, freemiss);
L
Linus Torvalds 已提交
4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261
	}
#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
 */

4262
static const struct seq_operations slabinfo_op = {
P
Pekka Enberg 已提交
4263 4264 4265 4266
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
L
Linus Torvalds 已提交
4267 4268 4269 4270 4271 4272 4273 4274 4275 4276
};

#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
4277 4278
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
		       size_t count, loff_t *ppos)
L
Linus Torvalds 已提交
4279
{
P
Pekka Enberg 已提交
4280
	char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
L
Linus Torvalds 已提交
4281
	int limit, batchcount, shared, res;
4282
	struct kmem_cache *cachep;
P
Pekka Enberg 已提交
4283

L
Linus Torvalds 已提交
4284 4285 4286 4287
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
P
Pekka Enberg 已提交
4288
	kbuf[MAX_SLABINFO_WRITE] = '\0';
L
Linus Torvalds 已提交
4289 4290 4291 4292 4293 4294 4295 4296 4297 4298

	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
4299
	mutex_lock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4300
	res = -EINVAL;
4301
	list_for_each_entry(cachep, &cache_chain, next) {
L
Linus Torvalds 已提交
4302
		if (!strcmp(cachep->name, kbuf)) {
A
Andrew Morton 已提交
4303 4304
			if (limit < 1 || batchcount < 1 ||
					batchcount > limit || shared < 0) {
4305
				res = 0;
L
Linus Torvalds 已提交
4306
			} else {
4307
				res = do_tune_cpucache(cachep, limit,
P
Pekka Enberg 已提交
4308
						       batchcount, shared);
L
Linus Torvalds 已提交
4309 4310 4311 4312
			}
			break;
		}
	}
I
Ingo Molnar 已提交
4313
	mutex_unlock(&cache_chain_mutex);
L
Linus Torvalds 已提交
4314 4315 4316 4317
	if (res >= 0)
		res = count;
	return res;
}
4318

4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331
static int slabinfo_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &slabinfo_op);
}

static const struct file_operations proc_slabinfo_operations = {
	.open		= slabinfo_open,
	.read		= seq_read,
	.write		= slabinfo_write,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

4332 4333 4334 4335 4336
#ifdef CONFIG_DEBUG_SLAB_LEAK

static void *leaks_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&cache_chain_mutex);
4337
	return seq_list_start(&cache_chain, *pos);
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
}

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

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

static void show_symbol(struct seq_file *m, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
	unsigned long offset, size;
4388
	char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN];
4389

4390
	if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) {
4391
		seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
4392
		if (modname[0])
4393 4394 4395 4396 4397 4398 4399 4400 4401
			seq_printf(m, " [%s]", modname);
		return;
	}
#endif
	seq_printf(m, "%p", (void *)address);
}

static int leaks_show(struct seq_file *m, void *p)
{
4402
	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426
	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);

4427
		list_for_each_entry(slabp, &l3->slabs_full, list)
4428
			handle_slab(n, cachep, slabp);
4429
		list_for_each_entry(slabp, &l3->slabs_partial, list)
4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455
			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');
	}
4456

4457 4458 4459
	return 0;
}

4460
static const struct seq_operations slabstats_op = {
4461 4462 4463 4464 4465
	.start = leaks_start,
	.next = s_next,
	.stop = s_stop,
	.show = leaks_show,
};
4466 4467 4468 4469 4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493

static int slabstats_open(struct inode *inode, struct file *file)
{
	unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL);
	int ret = -ENOMEM;
	if (n) {
		ret = seq_open(file, &slabstats_op);
		if (!ret) {
			struct seq_file *m = file->private_data;
			*n = PAGE_SIZE / (2 * sizeof(unsigned long));
			m->private = n;
			n = NULL;
		}
		kfree(n);
	}
	return ret;
}

static const struct file_operations proc_slabstats_operations = {
	.open		= slabstats_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release_private,
};
#endif

static int __init slab_proc_init(void)
{
4494
	proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
4495 4496
#ifdef CONFIG_DEBUG_SLAB_LEAK
	proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations);
4497
#endif
4498 4499 4500
	return 0;
}
module_init(slab_proc_init);
L
Linus Torvalds 已提交
4501 4502
#endif

4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514
/**
 * ksize - get the actual amount of memory allocated for a given object
 * @objp: Pointer to the object
 *
 * kmalloc may internally round up allocations and return more memory
 * than requested. ksize() can be used to determine the actual amount of
 * memory allocated. The caller may use this additional memory, even though
 * a smaller amount of memory was initially specified with the kmalloc call.
 * The caller must guarantee that objp points to a valid object previously
 * allocated with either kmalloc() or kmem_cache_alloc(). The object
 * must not be freed during the duration of the call.
 */
P
Pekka Enberg 已提交
4515
size_t ksize(const void *objp)
L
Linus Torvalds 已提交
4516
{
4517 4518
	BUG_ON(!objp);
	if (unlikely(objp == ZERO_SIZE_PTR))
4519
		return 0;
L
Linus Torvalds 已提交
4520

4521
	return obj_size(virt_to_cache(objp));
L
Linus Torvalds 已提交
4522
}