slab.c 94.4 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77
/*
 * linux/mm/slab.c
 * Written by Mark Hemment, 1996/97.
 * (markhe@nextd.demon.co.uk)
 *
 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
 *
 * Major cleanup, different bufctl logic, per-cpu arrays
 *	(c) 2000 Manfred Spraul
 *
 * Cleanup, make the head arrays unconditional, preparation for NUMA
 * 	(c) 2002 Manfred Spraul
 *
 * An implementation of the Slab Allocator as described in outline in;
 *	UNIX Internals: The New Frontiers by Uresh Vahalia
 *	Pub: Prentice Hall	ISBN 0-13-101908-2
 * or with a little more detail in;
 *	The Slab Allocator: An Object-Caching Kernel Memory Allocator
 *	Jeff Bonwick (Sun Microsystems).
 *	Presented at: USENIX Summer 1994 Technical Conference
 *
 * The memory is organized in caches, one cache for each object type.
 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
 * Each cache consists out of many slabs (they are small (usually one
 * page long) and always contiguous), and each slab contains multiple
 * initialized objects.
 *
 * This means, that your constructor is used only for newly allocated
 * slabs and you must pass objects with the same intializations to
 * kmem_cache_free.
 *
 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
 * normal). If you need a special memory type, then must create a new
 * cache for that memory type.
 *
 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
 *   full slabs with 0 free objects
 *   partial slabs
 *   empty slabs with no allocated objects
 *
 * If partial slabs exist, then new allocations come from these slabs,
 * otherwise from empty slabs or new slabs are allocated.
 *
 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
 *
 * Each cache has a short per-cpu head array, most allocs
 * and frees go into that array, and if that array overflows, then 1/2
 * of the entries in the array are given back into the global cache.
 * The head array is strictly LIFO and should improve the cache hit rates.
 * On SMP, it additionally reduces the spinlock operations.
 *
 * The c_cpuarray may not be read with enabled local interrupts - 
 * it's changed with a smp_call_function().
 *
 * SMP synchronization:
 *  constructors and destructors are called without any locking.
 *  Several members in kmem_cache_t and struct slab never change, they
 *	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
 *	The global cache-chain is protected by the semaphore 'cache_chain_sem'.
 *	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 91 92 93 94 95 96 97 98 99 100 101 102 103
 */

#include	<linux/config.h>
#include	<linux/slab.h>
#include	<linux/mm.h>
#include	<linux/swap.h>
#include	<linux/cache.h>
#include	<linux/interrupt.h>
#include	<linux/init.h>
#include	<linux/compiler.h>
#include	<linux/seq_file.h>
#include	<linux/notifier.h>
#include	<linux/kallsyms.h>
#include	<linux/cpu.h>
#include	<linux/sysctl.h>
#include	<linux/module.h>
#include	<linux/rcupdate.h>
104
#include	<linux/string.h>
105
#include	<linux/nodemask.h>
L
Linus Torvalds 已提交
106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201

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

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

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


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

#ifndef cache_line_size
#define cache_line_size()	L1_CACHE_BYTES
#endif

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

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

#ifndef ARCH_KMALLOC_FLAGS
#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
#endif

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

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

202
typedef unsigned int kmem_bufctl_t;
L
Linus Torvalds 已提交
203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224
#define BUFCTL_END	(((kmem_bufctl_t)(~0U))-0)
#define BUFCTL_FREE	(((kmem_bufctl_t)(~0U))-1)
#define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-2)

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

/*
 * struct slab
 *
 * Manages the objs in a slab. Placed either at the beginning of mem allocated
 * for a slab, or allocated from an general cache.
 * Slabs are chained into three list: fully used, partial, fully free slabs.
 */
struct slab {
	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;
225
	unsigned short          nodeid;
L
Linus Torvalds 已提交
226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266
};

/*
 * 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 {
	struct rcu_head		head;
	kmem_cache_t		*cachep;
	void			*addr;
};

/*
 * struct array_cache
 *
 * Purpose:
 * - LIFO ordering, to hand out cache-warm objects from _alloc
 * - reduce the number of linked list operations
 * - reduce spinlock operations
 *
 * The limit is stored in the per-cpu structure to reduce the data cache
 * footprint.
 *
 */
struct array_cache {
	unsigned int avail;
	unsigned int limit;
	unsigned int batchcount;
	unsigned int touched;
267 268 269 270 271 272 273
	spinlock_t lock;
	void *entry[0];		/*
				 * Must have this definition in here for the proper
				 * alignment of array_cache. Also simplifies accessing
				 * the entries.
				 * [0] is for gcc 2.95. It should really be [].
				 */
L
Linus Torvalds 已提交
274 275 276 277 278 279 280 281 282 283 284 285
};

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

/*
286
 * The slab lists for all objects.
L
Linus Torvalds 已提交
287 288 289 290 291 292 293
 */
struct kmem_list3 {
	struct list_head	slabs_partial;	/* partial list first, better asm code */
	struct list_head	slabs_full;
	struct list_head	slabs_free;
	unsigned long	free_objects;
	unsigned long	next_reap;
294 295 296 297 298
	int		free_touched;
	unsigned int 	free_limit;
	spinlock_t      list_lock;
	struct array_cache	*shared;	/* shared per node */
	struct array_cache	**alien;	/* on other nodes */
L
Linus Torvalds 已提交
299 300
};

301 302 303 304 305 306 307 308 309 310
/*
 * Need this for bootstrapping a per node allocator.
 */
#define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
#define	CACHE_CACHE 0
#define	SIZE_AC 1
#define	SIZE_L3 (1 + MAX_NUMNODES)

/*
311
 * This function must be completely optimized away if
312 313 314 315
 * a constant is passed to it. Mostly the same as
 * what is in linux/slab.h except it returns an
 * index.
 */
316
static __always_inline int index_of(const size_t size)
317 318 319 320 321 322 323 324 325 326 327 328 329 330 331
{
	if (__builtin_constant_p(size)) {
		int i = 0;

#define CACHE(x) \
	if (size <=x) \
		return i; \
	else \
		i++;
#include "linux/kmalloc_sizes.h"
#undef CACHE
		{
			extern void __bad_size(void);
			__bad_size();
		}
332 333
	} else
		BUG();
334 335 336 337 338
	return 0;
}

#define INDEX_AC index_of(sizeof(struct arraycache_init))
#define INDEX_L3 index_of(sizeof(struct kmem_list3))
L
Linus Torvalds 已提交
339

340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363
static inline void kmem_list3_init(struct kmem_list3 *parent)
{
	INIT_LIST_HEAD(&parent->slabs_full);
	INIT_LIST_HEAD(&parent->slabs_partial);
	INIT_LIST_HEAD(&parent->slabs_free);
	parent->shared = NULL;
	parent->alien = NULL;
	spin_lock_init(&parent->list_lock);
	parent->free_objects = 0;
	parent->free_touched = 0;
}

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

#define	MAKE_ALL_LISTS(cachep, ptr, nodeid)			\
	do {					\
	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
364 365 366 367 368 369 370

/*
 * kmem_cache_t
 *
 * manages a cache.
 */
	
371
struct kmem_cache {
L
Linus Torvalds 已提交
372 373 374 375
/* 1) per-cpu data, touched during every alloc/free */
	struct array_cache	*array[NR_CPUS];
	unsigned int		batchcount;
	unsigned int		limit;
376
	unsigned int 		shared;
L
Linus Torvalds 已提交
377
	unsigned int		objsize;
378 379
/* 2) touched by every alloc & free from the backend */
	struct kmem_list3	*nodelists[MAX_NUMNODES];
L
Linus Torvalds 已提交
380 381 382 383 384 385 386 387 388
	unsigned int	 	flags;	/* constant flags */
	unsigned int		num;	/* # of objs per slab */
	spinlock_t		spinlock;

/* 3) cache_grow/shrink */
	/* order of pgs per slab (2^n) */
	unsigned int		gfporder;

	/* force GFP flags, e.g. GFP_DMA */
A
Al Viro 已提交
389
	gfp_t			gfpflags;
L
Linus Torvalds 已提交
390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417

	size_t			colour;		/* cache colouring range */
	unsigned int		colour_off;	/* colour offset */
	unsigned int		colour_next;	/* cache colouring */
	kmem_cache_t		*slabp_cache;
	unsigned int		slab_size;
	unsigned int		dflags;		/* dynamic flags */

	/* constructor func */
	void (*ctor)(void *, kmem_cache_t *, unsigned long);

	/* de-constructor func */
	void (*dtor)(void *, kmem_cache_t *, unsigned long);

/* 4) cache creation/removal */
	const char		*name;
	struct list_head	next;

/* 5) statistics */
#if STATS
	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;
418
	unsigned long		node_frees;
L
Linus Torvalds 已提交
419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436
	atomic_t		allochit;
	atomic_t		allocmiss;
	atomic_t		freehit;
	atomic_t		freemiss;
#endif
#if DEBUG
	int			dbghead;
	int			reallen;
#endif
};

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

#define BATCHREFILL_LIMIT	16
/* Optimization question: fewer reaps means less 
 * probability for unnessary cpucache drain/refill cycles.
 *
A
Adrian Bunk 已提交
437
 * OTOH the cpuarrays can contain lots of objects,
L
Linus Torvalds 已提交
438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453
 * which could lock up otherwise freeable slabs.
 */
#define REAPTIMEOUT_CPUC	(2*HZ)
#define REAPTIMEOUT_LIST3	(4*HZ)

#if STATS
#define	STATS_INC_ACTIVE(x)	((x)->num_active++)
#define	STATS_DEC_ACTIVE(x)	((x)->num_active--)
#define	STATS_INC_ALLOCED(x)	((x)->num_allocations++)
#define	STATS_INC_GROWN(x)	((x)->grown++)
#define	STATS_INC_REAPED(x)	((x)->reaped++)
#define	STATS_SET_HIGH(x)	do { if ((x)->num_active > (x)->high_mark) \
					(x)->high_mark = (x)->num_active; \
				} while (0)
#define	STATS_INC_ERR(x)	((x)->errors++)
#define	STATS_INC_NODEALLOCS(x)	((x)->node_allocs++)
454
#define	STATS_INC_NODEFREES(x)	((x)->node_frees++)
L
Linus Torvalds 已提交
455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472
#define	STATS_SET_FREEABLE(x, i) \
				do { if ((x)->max_freeable < i) \
					(x)->max_freeable = i; \
				} while (0)

#define STATS_INC_ALLOCHIT(x)	atomic_inc(&(x)->allochit)
#define STATS_INC_ALLOCMISS(x)	atomic_inc(&(x)->allocmiss)
#define STATS_INC_FREEHIT(x)	atomic_inc(&(x)->freehit)
#define STATS_INC_FREEMISS(x)	atomic_inc(&(x)->freemiss)
#else
#define	STATS_INC_ACTIVE(x)	do { } while (0)
#define	STATS_DEC_ACTIVE(x)	do { } while (0)
#define	STATS_INC_ALLOCED(x)	do { } while (0)
#define	STATS_INC_GROWN(x)	do { } while (0)
#define	STATS_INC_REAPED(x)	do { } while (0)
#define	STATS_SET_HIGH(x)	do { } while (0)
#define	STATS_INC_ERR(x)	do { } while (0)
#define	STATS_INC_NODEALLOCS(x)	do { } while (0)
473
#define	STATS_INC_NODEFREES(x)	do { } while (0)
L
Linus Torvalds 已提交
474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567
#define	STATS_SET_FREEABLE(x, i) \
				do { } while (0)

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

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

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

static int obj_reallen(kmem_cache_t *cachep)
{
	return cachep->reallen;
}

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

static unsigned long *dbg_redzone2(kmem_cache_t *cachep, void *objp)
{
	BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
	if (cachep->flags & SLAB_STORE_USER)
		return (unsigned long*) (objp+cachep->objsize-2*BYTES_PER_WORD);
	return (unsigned long*) (objp+cachep->objsize-BYTES_PER_WORD);
}

static void **dbg_userword(kmem_cache_t *cachep, void *objp)
{
	BUG_ON(!(cachep->flags & SLAB_STORE_USER));
	return (void**)(objp+cachep->objsize-BYTES_PER_WORD);
}

#else

#define obj_dbghead(x)			0
#define obj_reallen(cachep)		(cachep->objsize)
#define dbg_redzone1(cachep, objp)	({BUG(); (unsigned long *)NULL;})
#define dbg_redzone2(cachep, objp)	({BUG(); (unsigned long *)NULL;})
#define dbg_userword(cachep, objp)	({BUG(); (void **)NULL;})

#endif

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

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

568
/* Functions for storing/retrieving the cachep and or slab from the
L
Linus Torvalds 已提交
569 570 571
 * global 'mem_map'. 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.
 */
572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590
static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
{
	page->lru.next = (struct list_head *)cache;
}

static inline struct kmem_cache *page_get_cache(struct page *page)
{
	return (struct kmem_cache *)page->lru.next;
}

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

static inline struct slab *page_get_slab(struct page *page)
{
	return (struct slab *)page->lru.prev;
}
L
Linus Torvalds 已提交
591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622

/* These are the default caches for kmalloc. Custom caches can have other sizes. */
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>
	{ NULL, }
#undef CACHE
};

static struct arraycache_init initarray_cache __initdata =
	{ { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
static struct arraycache_init initarray_generic =
	{ { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} };

/* internal cache of cache description objs */
static kmem_cache_t cache_cache = {
	.batchcount	= 1,
	.limit		= BOOT_CPUCACHE_ENTRIES,
623
	.shared		= 1,
L
Linus Torvalds 已提交
624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650
	.objsize	= sizeof(kmem_cache_t),
	.flags		= SLAB_NO_REAP,
	.spinlock	= SPIN_LOCK_UNLOCKED,
	.name		= "kmem_cache",
#if DEBUG
	.reallen	= sizeof(kmem_cache_t),
#endif
};

/* Guard access to the cache-chain. */
static struct semaphore	cache_chain_sem;
static struct list_head cache_chain;

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

/*
 * chicken and egg problem: delay the per-cpu array allocation
 * until the general caches are up.
 */
static enum {
	NONE,
651 652
	PARTIAL_AC,
	PARTIAL_L3,
L
Linus Torvalds 已提交
653 654 655 656 657
	FULL
} g_cpucache_up;

static DEFINE_PER_CPU(struct work_struct, reap_work);

658
static void free_block(kmem_cache_t* cachep, void** objpp, int len, int node);
L
Linus Torvalds 已提交
659 660
static void enable_cpucache (kmem_cache_t *cachep);
static void cache_reap (void *unused);
661
static int __node_shrink(kmem_cache_t *cachep, int node);
L
Linus Torvalds 已提交
662 663 664 665 666 667

static inline struct array_cache *ac_data(kmem_cache_t *cachep)
{
	return cachep->array[smp_processor_id()];
}

A
Al Viro 已提交
668
static inline kmem_cache_t *__find_general_cachep(size_t size, gfp_t gfpflags)
L
Linus Torvalds 已提交
669 670 671 672 673 674 675 676
{
	struct cache_sizes *csizep = malloc_sizes;

#if DEBUG
	/* This happens if someone tries to call
 	* kmem_cache_create(), or __kmalloc(), before
 	* the generic caches are initialized.
 	*/
677
	BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
L
Linus Torvalds 已提交
678 679 680 681 682
#endif
	while (size > csizep->cs_size)
		csizep++;

	/*
683
	 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
L
Linus Torvalds 已提交
684 685 686 687 688 689 690 691
	 * has cs_{dma,}cachep==NULL. Thus no special case
	 * for large kmalloc calls required.
	 */
	if (unlikely(gfpflags & GFP_DMA))
		return csizep->cs_dmacachep;
	return csizep->cs_cachep;
}

A
Al Viro 已提交
692
kmem_cache_t *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
693 694 695 696 697
{
	return __find_general_cachep(size, gfpflags);
}
EXPORT_SYMBOL(kmem_find_general_cachep);

L
Linus Torvalds 已提交
698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756
/* Cal the num objs, wastage, and bytes left over for a given slab size. */
static void cache_estimate(unsigned long gfporder, size_t size, size_t align,
		 int flags, size_t *left_over, unsigned int *num)
{
	int i;
	size_t wastage = PAGE_SIZE<<gfporder;
	size_t extra = 0;
	size_t base = 0;

	if (!(flags & CFLGS_OFF_SLAB)) {
		base = sizeof(struct slab);
		extra = sizeof(kmem_bufctl_t);
	}
	i = 0;
	while (i*size + ALIGN(base+i*extra, align) <= wastage)
		i++;
	if (i > 0)
		i--;

	if (i > SLAB_LIMIT)
		i = SLAB_LIMIT;

	*num = i;
	wastage -= i*size;
	wastage -= ALIGN(base+i*extra, align);
	*left_over = wastage;
}

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

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

/*
 * Initiate the reap timer running on the target CPU.  We run at around 1 to 2Hz
 * via the workqueue/eventd.
 * Add the CPU number into the expiration time to minimize the possibility of
 * the CPUs getting into lockstep and contending for the global cache chain
 * lock.
 */
static void __devinit start_cpu_timer(int cpu)
{
	struct work_struct *reap_work = &per_cpu(reap_work, cpu);

	/*
	 * When this gets called from do_initcalls via cpucache_init(),
	 * init_workqueues() has already run, so keventd will be setup
	 * at that time.
	 */
	if (keventd_up() && reap_work->func == NULL) {
		INIT_WORK(reap_work, cache_reap, NULL);
		schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
	}
}

757
static struct array_cache *alloc_arraycache(int node, int entries,
L
Linus Torvalds 已提交
758 759 760 761 762
						int batchcount)
{
	int memsize = sizeof(void*)*entries+sizeof(struct array_cache);
	struct array_cache *nc = NULL;

763
	nc = kmalloc_node(memsize, GFP_KERNEL, node);
L
Linus Torvalds 已提交
764 765 766 767 768
	if (nc) {
		nc->avail = 0;
		nc->limit = entries;
		nc->batchcount = batchcount;
		nc->touched = 0;
769
		spin_lock_init(&nc->lock);
L
Linus Torvalds 已提交
770 771 772 773
	}
	return nc;
}

774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820
#ifdef CONFIG_NUMA
static inline struct array_cache **alloc_alien_cache(int node, int limit)
{
	struct array_cache **ac_ptr;
	int memsize = sizeof(void*)*MAX_NUMNODES;
	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]) {
				for (i--; i <=0; i--)
					kfree(ac_ptr[i]);
				kfree(ac_ptr);
				return NULL;
			}
		}
	}
	return ac_ptr;
}

static inline void free_alien_cache(struct array_cache **ac_ptr)
{
	int i;

	if (!ac_ptr)
		return;

	for_each_node(i)
		kfree(ac_ptr[i]);

	kfree(ac_ptr);
}

static inline void __drain_alien_cache(kmem_cache_t *cachep, struct array_cache *ac, int node)
{
	struct kmem_list3 *rl3 = cachep->nodelists[node];

	if (ac->avail) {
		spin_lock(&rl3->list_lock);
821
		free_block(cachep, ac->entry, ac->avail, node);
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
		ac->avail = 0;
		spin_unlock(&rl3->list_lock);
	}
}

static void drain_alien_cache(kmem_cache_t *cachep, struct kmem_list3 *l3)
{
	int i=0;
	struct array_cache *ac;
	unsigned long flags;

	for_each_online_node(i) {
		ac = l3->alien[i];
		if (ac) {
			spin_lock_irqsave(&ac->lock, flags);
			__drain_alien_cache(cachep, ac, i);
			spin_unlock_irqrestore(&ac->lock, flags);
		}
	}
}
#else
#define alloc_alien_cache(node, limit) do { } while (0)
#define free_alien_cache(ac_ptr) do { } while (0)
#define drain_alien_cache(cachep, l3) do { } while (0)
#endif

L
Linus Torvalds 已提交
848 849 850 851 852
static int __devinit cpuup_callback(struct notifier_block *nfb,
				  unsigned long action, void *hcpu)
{
	long cpu = (long)hcpu;
	kmem_cache_t* cachep;
853 854 855 856
	struct kmem_list3 *l3 = NULL;
	int node = cpu_to_node(cpu);
	int memsize = sizeof(struct kmem_list3);
	struct array_cache *nc = NULL;
L
Linus Torvalds 已提交
857 858 859 860

	switch (action) {
	case CPU_UP_PREPARE:
		down(&cache_chain_sem);
861 862 863 864 865 866
		/* 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
		 */

L
Linus Torvalds 已提交
867
		list_for_each_entry(cachep, &cache_chain, next) {
868 869 870 871 872 873 874 875 876 877 878 879 880 881
			/* setup the size64 kmemlist for cpu before we can
			 * begin anything. Make sure some other cpu on this
			 * node has not already allocated this
			 */
			if (!cachep->nodelists[node]) {
				if (!(l3 = kmalloc_node(memsize,
						GFP_KERNEL, node)))
					goto bad;
				kmem_list3_init(l3);
				l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
				  ((unsigned long)cachep)%REAPTIMEOUT_LIST3;

				cachep->nodelists[node] = l3;
			}
L
Linus Torvalds 已提交
882

883 884 885 886 887 888 889 890 891 892 893 894
			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 array's
		  & array cache's */
		list_for_each_entry(cachep, &cache_chain, next) {
			nc = alloc_arraycache(node, cachep->limit,
					cachep->batchcount);
L
Linus Torvalds 已提交
895 896 897 898
			if (!nc)
				goto bad;
			cachep->array[cpu] = nc;

899 900 901 902 903 904 905 906 907 908 909 910
			l3 = cachep->nodelists[node];
			BUG_ON(!l3);
			if (!l3->shared) {
				if (!(nc = alloc_arraycache(node,
					cachep->shared*cachep->batchcount,
					0xbaadf00d)))
					goto  bad;

				/* we are serialised from CPU_DEAD or
				  CPU_UP_CANCELLED by the cpucontrol lock */
				l3->shared = nc;
			}
L
Linus Torvalds 已提交
911 912 913 914 915 916 917 918 919 920 921 922 923 924
		}
		up(&cache_chain_sem);
		break;
	case CPU_ONLINE:
		start_cpu_timer(cpu);
		break;
#ifdef CONFIG_HOTPLUG_CPU
	case CPU_DEAD:
		/* fall thru */
	case CPU_UP_CANCELED:
		down(&cache_chain_sem);

		list_for_each_entry(cachep, &cache_chain, next) {
			struct array_cache *nc;
925
			cpumask_t mask;
L
Linus Torvalds 已提交
926

927
			mask = node_to_cpumask(node);
L
Linus Torvalds 已提交
928 929 930 931
			spin_lock_irq(&cachep->spinlock);
			/* cpu is dead; no one can alloc from it. */
			nc = cachep->array[cpu];
			cachep->array[cpu] = NULL;
932 933 934 935 936 937 938 939 940 941
			l3 = cachep->nodelists[node];

			if (!l3)
				goto unlock_cache;

			spin_lock(&l3->list_lock);

			/* Free limit for this kmem_list3 */
			l3->free_limit -= cachep->batchcount;
			if (nc)
942
				free_block(cachep, nc->entry, nc->avail, node);
943 944 945 946 947 948 949 950

			if (!cpus_empty(mask)) {
                                spin_unlock(&l3->list_lock);
                                goto unlock_cache;
                        }

			if (l3->shared) {
				free_block(cachep, l3->shared->entry,
951
						l3->shared->avail, node);
952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969
				kfree(l3->shared);
				l3->shared = NULL;
			}
			if (l3->alien) {
				drain_alien_cache(cachep, l3);
				free_alien_cache(l3->alien);
				l3->alien = NULL;
			}

			/* free slabs belonging to this node */
			if (__node_shrink(cachep, node)) {
				cachep->nodelists[node] = NULL;
				spin_unlock(&l3->list_lock);
				kfree(l3);
			} else {
				spin_unlock(&l3->list_lock);
			}
unlock_cache:
L
Linus Torvalds 已提交
970 971 972 973 974 975 976 977 978 979 980 981 982 983 984
			spin_unlock_irq(&cachep->spinlock);
			kfree(nc);
		}
		up(&cache_chain_sem);
		break;
#endif
	}
	return NOTIFY_OK;
bad:
	up(&cache_chain_sem);
	return NOTIFY_BAD;
}

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

985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
/*
 * swap the static kmem_list3 with kmalloced memory
 */
static void init_list(kmem_cache_t *cachep, struct kmem_list3 *list,
		int nodeid)
{
	struct kmem_list3 *ptr;

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

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

L
Linus Torvalds 已提交
1004 1005 1006 1007 1008 1009 1010 1011
/* Initialisation.
 * Called after the gfp() functions have been enabled, and before smp_init().
 */
void __init kmem_cache_init(void)
{
	size_t left_over;
	struct cache_sizes *sizes;
	struct cache_names *names;
1012 1013 1014 1015 1016 1017 1018
	int i;

	for (i = 0; i < NUM_INIT_LISTS; i++) {
		kmem_list3_init(&initkmem_list3[i]);
		if (i < MAX_NUMNODES)
			cache_cache.nodelists[i] = NULL;
	}
L
Linus Torvalds 已提交
1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031

	/*
	 * 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:
	 * 1) initialize the cache_cache cache: it contains the kmem_cache_t
	 *    structures of all caches, except cache_cache itself: cache_cache
	 *    is statically allocated.
1032 1033 1034
	 *    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
1035
	 * 2) Create the first kmalloc cache.
1036 1037 1038 1039
	 *    The kmem_cache_t for the new cache is allocated normally.
	 *    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
1040 1041
	 * 4) Replace the __init data head arrays for cache_cache and the first
	 *    kmalloc cache with kmalloc allocated arrays.
1042 1043 1044
	 * 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
1045 1046 1047 1048 1049 1050 1051 1052
	 */

	/* 1) create the cache_cache */
	init_MUTEX(&cache_chain_sem);
	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;
1053
	cache_cache.nodelists[numa_node_id()] = &initkmem_list3[CACHE_CACHE];
L
Linus Torvalds 已提交
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070

	cache_cache.objsize = ALIGN(cache_cache.objsize, cache_line_size());

	cache_estimate(0, cache_cache.objsize, cache_line_size(), 0,
				&left_over, &cache_cache.num);
	if (!cache_cache.num)
		BUG();

	cache_cache.colour = left_over/cache_cache.colour_off;
	cache_cache.colour_next = 0;
	cache_cache.slab_size = ALIGN(cache_cache.num*sizeof(kmem_bufctl_t) +
				sizeof(struct slab), cache_line_size());

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

1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085
	/* Initialize the caches that provide memory for the array cache
	 * and the kmem_list3 structures first.
	 * Without this, further allocations will bug
	 */

	sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
				sizes[INDEX_AC].cs_size, ARCH_KMALLOC_MINALIGN,
				(ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL);

	if (INDEX_AC != INDEX_L3)
		sizes[INDEX_L3].cs_cachep =
			kmem_cache_create(names[INDEX_L3].name,
				sizes[INDEX_L3].cs_size, ARCH_KMALLOC_MINALIGN,
				(ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL);

L
Linus Torvalds 已提交
1086
	while (sizes->cs_size != ULONG_MAX) {
1087 1088
		/*
		 * For performance, all the general caches are L1 aligned.
L
Linus Torvalds 已提交
1089 1090 1091
		 * This should be particularly beneficial on SMP boxes, as it
		 * eliminates "false sharing".
		 * Note for systems short on memory removing the alignment will
1092 1093 1094 1095 1096 1097
		 * allow tighter packing of the smaller caches.
		 */
		if(!sizes->cs_cachep)
			sizes->cs_cachep = kmem_cache_create(names->name,
				sizes->cs_size, ARCH_KMALLOC_MINALIGN,
				(ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL);
L
Linus Torvalds 已提交
1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115

		/* Inc off-slab bufctl limit until the ceiling is hit. */
		if (!(OFF_SLAB(sizes->cs_cachep))) {
			offslab_limit = sizes->cs_size-sizeof(struct slab);
			offslab_limit /= sizeof(kmem_bufctl_t);
		}

		sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
			sizes->cs_size, ARCH_KMALLOC_MINALIGN,
			(ARCH_KMALLOC_FLAGS | SLAB_CACHE_DMA | SLAB_PANIC),
			NULL, NULL);

		sizes++;
		names++;
	}
	/* 4) Replace the bootstrap head arrays */
	{
		void * ptr;
1116

L
Linus Torvalds 已提交
1117
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1118

L
Linus Torvalds 已提交
1119 1120
		local_irq_disable();
		BUG_ON(ac_data(&cache_cache) != &initarray_cache.cache);
1121 1122
		memcpy(ptr, ac_data(&cache_cache),
				sizeof(struct arraycache_init));
L
Linus Torvalds 已提交
1123 1124
		cache_cache.array[smp_processor_id()] = ptr;
		local_irq_enable();
1125

L
Linus Torvalds 已提交
1126
		ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1127

L
Linus Torvalds 已提交
1128
		local_irq_disable();
1129 1130 1131
		BUG_ON(ac_data(malloc_sizes[INDEX_AC].cs_cachep)
				!= &initarray_generic.cache);
		memcpy(ptr, ac_data(malloc_sizes[INDEX_AC].cs_cachep),
L
Linus Torvalds 已提交
1132
				sizeof(struct arraycache_init));
1133 1134
		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
						ptr;
L
Linus Torvalds 已提交
1135 1136
		local_irq_enable();
	}
1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
	/* 5) Replace the bootstrap kmem_list3's */
	{
		int node;
		/* Replace the static kmem_list3 structures for the boot cpu */
		init_list(&cache_cache, &initkmem_list3[CACHE_CACHE],
				numa_node_id());

		for_each_online_node(node) {
			init_list(malloc_sizes[INDEX_AC].cs_cachep,
					&initkmem_list3[SIZE_AC+node], node);

			if (INDEX_AC != INDEX_L3) {
				init_list(malloc_sizes[INDEX_L3].cs_cachep,
						&initkmem_list3[SIZE_L3+node],
						node);
			}
		}
	}
L
Linus Torvalds 已提交
1155

1156
	/* 6) resize the head arrays to their final sizes */
L
Linus Torvalds 已提交
1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
	{
		kmem_cache_t *cachep;
		down(&cache_chain_sem);
		list_for_each_entry(cachep, &cache_chain, next)
			enable_cpucache(cachep);
		up(&cache_chain_sem);
	}

	/* Done! */
	g_cpucache_up = FULL;

	/* Register a cpu startup notifier callback
	 * that initializes ac_data for all new cpus
	 */
	register_cpu_notifier(&cpucache_notifier);

	/* The reap timers are started later, with a module init call:
	 * That part of the kernel is not yet operational.
	 */
}

static int __init cpucache_init(void)
{
	int cpu;

	/* 
	 * Register the timers that return unneeded
	 * pages to gfp.
	 */
1186 1187
	for_each_online_cpu(cpu)
		start_cpu_timer(cpu);
L
Linus Torvalds 已提交
1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200

	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.
 */
A
Al Viro 已提交
1201
static void *kmem_getpages(kmem_cache_t *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
1202 1203 1204 1205 1206 1207
{
	struct page *page;
	void *addr;
	int i;

	flags |= cachep->gfpflags;
1208
	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
L
Linus Torvalds 已提交
1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 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 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381
	if (!page)
		return NULL;
	addr = page_address(page);

	i = (1 << cachep->gfporder);
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
		atomic_add(i, &slab_reclaim_pages);
	add_page_state(nr_slab, i);
	while (i--) {
		SetPageSlab(page);
		page++;
	}
	return addr;
}

/*
 * Interface to system's page release.
 */
static void kmem_freepages(kmem_cache_t *cachep, void *addr)
{
	unsigned long i = (1<<cachep->gfporder);
	struct page *page = virt_to_page(addr);
	const unsigned long nr_freed = i;

	while (i--) {
		if (!TestClearPageSlab(page))
			BUG();
		page++;
	}
	sub_page_state(nr_slab, nr_freed);
	if (current->reclaim_state)
		current->reclaim_state->reclaimed_slab += nr_freed;
	free_pages((unsigned long)addr, cachep->gfporder);
	if (cachep->flags & SLAB_RECLAIM_ACCOUNT) 
		atomic_sub(1<<cachep->gfporder, &slab_reclaim_pages);
}

static void kmem_rcu_free(struct rcu_head *head)
{
	struct slab_rcu *slab_rcu = (struct slab_rcu *) head;
	kmem_cache_t *cachep = slab_rcu->cachep;

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

#if DEBUG

#ifdef CONFIG_DEBUG_PAGEALLOC
static void store_stackinfo(kmem_cache_t *cachep, unsigned long *addr,
				unsigned long caller)
{
	int size = obj_reallen(cachep);

	addr = (unsigned long *)&((char*)addr)[obj_dbghead(cachep)];

	if (size < 5*sizeof(unsigned long))
		return;

	*addr++=0x12345678;
	*addr++=caller;
	*addr++=smp_processor_id();
	size -= 3*sizeof(unsigned long);
	{
		unsigned long *sptr = &caller;
		unsigned long svalue;

		while (!kstack_end(sptr)) {
			svalue = *sptr++;
			if (kernel_text_address(svalue)) {
				*addr++=svalue;
				size -= sizeof(unsigned long);
				if (size <= sizeof(unsigned long))
					break;
			}
		}

	}
	*addr++=0x87654321;
}
#endif

static void poison_obj(kmem_cache_t *cachep, void *addr, unsigned char val)
{
	int size = obj_reallen(cachep);
	addr = &((char*)addr)[obj_dbghead(cachep)];

	memset(addr, val, size);
	*(unsigned char *)(addr+size-1) = POISON_END;
}

static void dump_line(char *data, int offset, int limit)
{
	int i;
	printk(KERN_ERR "%03x:", offset);
	for (i=0;i<limit;i++) {
		printk(" %02x", (unsigned char)data[offset+i]);
	}
	printk("\n");
}
#endif

#if DEBUG

static void print_objinfo(kmem_cache_t *cachep, void *objp, int lines)
{
	int i, size;
	char *realobj;

	if (cachep->flags & SLAB_RED_ZONE) {
		printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n",
			*dbg_redzone1(cachep, objp),
			*dbg_redzone2(cachep, objp));
	}

	if (cachep->flags & SLAB_STORE_USER) {
		printk(KERN_ERR "Last user: [<%p>]",
				*dbg_userword(cachep, objp));
		print_symbol("(%s)",
				(unsigned long)*dbg_userword(cachep, objp));
		printk("\n");
	}
	realobj = (char*)objp+obj_dbghead(cachep);
	size = obj_reallen(cachep);
	for (i=0; i<size && lines;i+=16, lines--) {
		int limit;
		limit = 16;
		if (i+limit > size)
			limit = size-i;
		dump_line(realobj, i, limit);
	}
}

static void check_poison_obj(kmem_cache_t *cachep, void *objp)
{
	char *realobj;
	int size, i;
	int lines = 0;

	realobj = (char*)objp+obj_dbghead(cachep);
	size = obj_reallen(cachep);

	for (i=0;i<size;i++) {
		char exp = POISON_FREE;
		if (i == size-1)
			exp = POISON_END;
		if (realobj[i] != exp) {
			int limit;
			/* Mismatch ! */
			/* Print header */
			if (lines == 0) {
				printk(KERN_ERR "Slab corruption: start=%p, len=%d\n",
						realobj, size);
				print_objinfo(cachep, objp, 0);
			}
			/* Hexdump the affected line */
			i = (i/16)*16;
			limit = 16;
			if (i+limit > size)
				limit = size-i;
			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:
		 */
1382
		struct slab *slabp = page_get_slab(virt_to_page(objp));
L
Linus Torvalds 已提交
1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461
		int objnr;

		objnr = (objp-slabp->s_mem)/cachep->objsize;
		if (objnr) {
			objp = slabp->s_mem+(objnr-1)*cachep->objsize;
			realobj = (char*)objp+obj_dbghead(cachep);
			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
						realobj, size);
			print_objinfo(cachep, objp, 2);
		}
		if (objnr+1 < cachep->num) {
			objp = slabp->s_mem+(objnr+1)*cachep->objsize;
			realobj = (char*)objp+obj_dbghead(cachep);
			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
						realobj, size);
			print_objinfo(cachep, objp, 2);
		}
	}
}
#endif

/* Destroy all the objs in a slab, and release the mem back to the system.
 * Before calling the slab must have been unlinked from the cache.
 * The cache-lock is not held/needed.
 */
static void slab_destroy (kmem_cache_t *cachep, struct slab *slabp)
{
	void *addr = slabp->s_mem - slabp->colouroff;

#if DEBUG
	int i;
	for (i = 0; i < cachep->num; i++) {
		void *objp = slabp->s_mem + cachep->objsize * i;

		if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
			if ((cachep->objsize%PAGE_SIZE)==0 && OFF_SLAB(cachep))
				kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE,1);
			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 "
							"was overwritten");
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "end of a freed object "
							"was overwritten");
		}
		if (cachep->dtor && !(cachep->flags & SLAB_POISON))
			(cachep->dtor)(objp+obj_dbghead(cachep), cachep, 0);
	}
#else
	if (cachep->dtor) {
		int i;
		for (i = 0; i < cachep->num; i++) {
			void* objp = slabp->s_mem+cachep->objsize*i;
			(cachep->dtor)(objp, cachep, 0);
		}
	}
#endif

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
		struct slab_rcu *slab_rcu;

		slab_rcu = (struct slab_rcu *) slabp;
		slab_rcu->cachep = cachep;
		slab_rcu->addr = addr;
		call_rcu(&slab_rcu->head, kmem_rcu_free);
	} else {
		kmem_freepages(cachep, addr);
		if (OFF_SLAB(cachep))
			kmem_cache_free(cachep->slabp_cache, slabp);
	}
}

1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475
/* For setting up all the kmem_list3s for cache whose objsize is same
   as size of kmem_list3. */
static inline void set_up_list3s(kmem_cache_t *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;
	}
}

L
Linus Torvalds 已提交
1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515
/**
 * kmem_cache_create - Create a cache.
 * @name: A string which is used in /proc/slabinfo to identify this cache.
 * @size: The size of objects to be created in this cache.
 * @align: The required alignment for the objects.
 * @flags: SLAB flags
 * @ctor: A constructor for the objects.
 * @dtor: A destructor for the objects.
 *
 * Returns a ptr to the cache on success, NULL on failure.
 * Cannot be called within a int, but can be interrupted.
 * The @ctor is run when new pages are allocated by the cache
 * and the @dtor is run before the pages are handed back.
 *
 * @name must be valid until the cache is destroyed. This implies that
 * the module calling this has to destroy the cache before getting 
 * unloaded.
 * 
 * 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_NO_REAP - Don't automatically reap this cache when we're under
 * memory pressure.
 *
 * %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.
 */
kmem_cache_t *
kmem_cache_create (const char *name, size_t size, size_t align,
	unsigned long flags, void (*ctor)(void*, kmem_cache_t *, unsigned long),
	void (*dtor)(void*, kmem_cache_t *, unsigned long))
{
	size_t left_over, slab_size, ralign;
	kmem_cache_t *cachep = NULL;
1516
	struct list_head *p;
L
Linus Torvalds 已提交
1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530

	/*
	 * Sanity checks... these are all serious usage bugs.
	 */
	if ((!name) ||
		in_interrupt() ||
		(size < BYTES_PER_WORD) ||
		(size > (1<<MAX_OBJ_ORDER)*PAGE_SIZE) ||
		(dtor && !ctor)) {
			printk(KERN_ERR "%s: Early error in slab %s\n",
					__FUNCTION__, name);
			BUG();
		}

1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559
	down(&cache_chain_sem);

	list_for_each(p, &cache_chain) {
		kmem_cache_t *pc = list_entry(p, kmem_cache_t, next);
		mm_segment_t old_fs = get_fs();
		char tmp;
		int res;

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

		if (!strcmp(pc->name,name)) {
			printk("kmem_cache_create: duplicate cache %s\n", name);
			dump_stack();
			goto oops;
		}
	}

L
Linus Torvalds 已提交
1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635
#if DEBUG
	WARN_ON(strchr(name, ' '));	/* It confuses parsers */
	if ((flags & SLAB_DEBUG_INITIAL) && !ctor) {
		/* No constructor, but inital state check requested */
		printk(KERN_ERR "%s: No con, but init state check "
				"requested - %s\n", __FUNCTION__, name);
		flags &= ~SLAB_DEBUG_INITIAL;
	}

#if FORCED_DEBUG
	/*
	 * Enable redzoning and last user accounting, except for caches with
	 * large objects, if the increased size would increase the object size
	 * above the next power of two: caches with object sizes just above a
	 * power of two have a significant amount of internal fragmentation.
	 */
	if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD)))
		flags |= SLAB_RED_ZONE|SLAB_STORE_USER;
	if (!(flags & SLAB_DESTROY_BY_RCU))
		flags |= SLAB_POISON;
#endif
	if (flags & SLAB_DESTROY_BY_RCU)
		BUG_ON(flags & SLAB_POISON);
#endif
	if (flags & SLAB_DESTROY_BY_RCU)
		BUG_ON(dtor);

	/*
	 * Always checks flags, a caller might be expecting debug
	 * support which isn't available.
	 */
	if (flags & ~CREATE_MASK)
		BUG();

	/* Check that size is in terms of words.  This is needed to avoid
	 * unaligned accesses for some archs when redzoning is used, and makes
	 * sure any on-slab bufctl's are also correctly aligned.
	 */
	if (size & (BYTES_PER_WORD-1)) {
		size += (BYTES_PER_WORD-1);
		size &= ~(BYTES_PER_WORD-1);
	}

	/* calculate out the final buffer alignment: */
	/* 1) arch recommendation: can be overridden for debug */
	if (flags & SLAB_HWCACHE_ALIGN) {
		/* Default alignment: as specified by the arch code.
		 * Except if an object is really small, then squeeze multiple
		 * objects into one cacheline.
		 */
		ralign = cache_line_size();
		while (size <= ralign/2)
			ralign /= 2;
	} else {
		ralign = BYTES_PER_WORD;
	}
	/* 2) arch mandated alignment: disables debug if necessary */
	if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
		if (ralign > BYTES_PER_WORD)
			flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER);
	}
	/* 3) caller mandated alignment: disables debug if necessary */
	if (ralign < align) {
		ralign = align;
		if (ralign > BYTES_PER_WORD)
			flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER);
	}
	/* 4) Store it. Note that the debug code below can reduce
	 *    the alignment to BYTES_PER_WORD.
	 */
	align = ralign;

	/* Get cache's description obj. */
	cachep = (kmem_cache_t *) kmem_cache_alloc(&cache_cache, SLAB_KERNEL);
	if (!cachep)
1636
		goto oops;
L
Linus Torvalds 已提交
1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658
	memset(cachep, 0, sizeof(kmem_cache_t));

#if DEBUG
	cachep->reallen = size;

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

		/* add space for red zone words */
		cachep->dbghead += BYTES_PER_WORD;
		size += 2*BYTES_PER_WORD;
	}
	if (flags & SLAB_STORE_USER) {
		/* user store requires word alignment and
		 * one word storage behind the end of the real
		 * object.
		 */
		align = BYTES_PER_WORD;
		size += BYTES_PER_WORD;
	}
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
1659
	if (size >= malloc_sizes[INDEX_L3+1].cs_size && cachep->reallen > cache_line_size() && size < PAGE_SIZE) {
L
Linus Torvalds 已提交
1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729
		cachep->dbghead += PAGE_SIZE - size;
		size = PAGE_SIZE;
	}
#endif
#endif

	/* Determine if the slab management is 'on' or 'off' slab. */
	if (size >= (PAGE_SIZE>>3))
		/*
		 * 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);

	if ((flags & SLAB_RECLAIM_ACCOUNT) && size <= PAGE_SIZE) {
		/*
		 * 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.
		 */
		cachep->gfporder = 0;
		cache_estimate(cachep->gfporder, size, align, flags,
					&left_over, &cachep->num);
	} else {
		/*
		 * Calculate size (in pages) of slabs, and the num of objs per
		 * slab.  This could be made much more intelligent.  For now,
		 * try to avoid using high page-orders for slabs.  When the
		 * gfp() funcs are more friendly towards high-order requests,
		 * this should be changed.
		 */
		do {
			unsigned int break_flag = 0;
cal_wastage:
			cache_estimate(cachep->gfporder, size, align, flags,
						&left_over, &cachep->num);
			if (break_flag)
				break;
			if (cachep->gfporder >= MAX_GFP_ORDER)
				break;
			if (!cachep->num)
				goto next;
			if (flags & CFLGS_OFF_SLAB &&
					cachep->num > offslab_limit) {
				/* This num of objs will cause problems. */
				cachep->gfporder--;
				break_flag++;
				goto cal_wastage;
			}

			/*
			 * Large num of objs is good, but v. large slabs are
			 * currently bad for the gfp()s.
			 */
			if (cachep->gfporder >= slab_break_gfp_order)
				break;

			if ((left_over*8) <= (PAGE_SIZE<<cachep->gfporder))
				break;	/* Acceptable internal fragmentation. */
next:
			cachep->gfporder++;
		} while (1);
	}

	if (!cachep->num) {
		printk("kmem_cache_create: couldn't create cache %s.\n", name);
		kmem_cache_free(&cache_cache, cachep);
		cachep = NULL;
1730
		goto oops;
L
Linus Torvalds 已提交
1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762
	}
	slab_size = ALIGN(cachep->num*sizeof(kmem_bufctl_t)
				+ sizeof(struct slab), align);

	/*
	 * 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 */
		slab_size = cachep->num*sizeof(kmem_bufctl_t)+sizeof(struct slab);
	}

	cachep->colour_off = cache_line_size();
	/* Offset must be a multiple of the alignment. */
	if (cachep->colour_off < align)
		cachep->colour_off = align;
	cachep->colour = left_over/cachep->colour_off;
	cachep->slab_size = slab_size;
	cachep->flags = flags;
	cachep->gfpflags = 0;
	if (flags & SLAB_CACHE_DMA)
		cachep->gfpflags |= GFP_DMA;
	spin_lock_init(&cachep->spinlock);
	cachep->objsize = size;

	if (flags & CFLGS_OFF_SLAB)
1763
		cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
L
Linus Torvalds 已提交
1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778
	cachep->ctor = ctor;
	cachep->dtor = dtor;
	cachep->name = name;

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

	if (g_cpucache_up == FULL) {
		enable_cpucache(cachep);
	} else {
		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().
			 */
1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791
			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;
L
Linus Torvalds 已提交
1792
		} else {
1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810
			cachep->array[smp_processor_id()] =
				kmalloc(sizeof(struct arraycache_init),
						GFP_KERNEL);

			if (g_cpucache_up == PARTIAL_AC) {
				set_up_list3s(cachep, SIZE_L3);
				g_cpucache_up = PARTIAL_L3;
			} else {
				int node;
				for_each_online_node(node) {

					cachep->nodelists[node] =
						kmalloc_node(sizeof(struct kmem_list3),
								GFP_KERNEL, node);
					BUG_ON(!cachep->nodelists[node]);
					kmem_list3_init(cachep->nodelists[node]);
				}
			}
L
Linus Torvalds 已提交
1811
		}
1812 1813 1814 1815
		cachep->nodelists[numa_node_id()]->next_reap =
			jiffies + REAPTIMEOUT_LIST3 +
			((unsigned long)cachep)%REAPTIMEOUT_LIST3;

L
Linus Torvalds 已提交
1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827
		BUG_ON(!ac_data(cachep));
		ac_data(cachep)->avail = 0;
		ac_data(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
		ac_data(cachep)->batchcount = 1;
		ac_data(cachep)->touched = 0;
		cachep->batchcount = 1;
		cachep->limit = BOOT_CPUCACHE_ENTRIES;
	} 

	/* cache setup completed, link it into the list */
	list_add(&cachep->next, &cache_chain);
	unlock_cpu_hotplug();
1828
oops:
L
Linus Torvalds 已提交
1829 1830 1831
	if (!cachep && (flags & SLAB_PANIC))
		panic("kmem_cache_create(): failed to create slab `%s'\n",
			name);
1832
	up(&cache_chain_sem);
L
Linus Torvalds 已提交
1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851
	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());
}

static void check_spinlock_acquired(kmem_cache_t *cachep)
{
#ifdef CONFIG_SMP
	check_irq_off();
1852
	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
L
Linus Torvalds 已提交
1853 1854
#endif
}
1855 1856 1857 1858 1859 1860 1861 1862 1863

static inline void check_spinlock_acquired_node(kmem_cache_t *cachep, int node)
{
#ifdef CONFIG_SMP
	check_irq_off();
	assert_spin_locked(&cachep->nodelists[node]->list_lock);
#endif
}

L
Linus Torvalds 已提交
1864 1865 1866 1867
#else
#define check_irq_off()	do { } while(0)
#define check_irq_on()	do { } while(0)
#define check_spinlock_acquired(x) do { } while(0)
1868
#define check_spinlock_acquired_node(x, y) do { } while(0)
L
Linus Torvalds 已提交
1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889
#endif

/*
 * Waits for all CPUs to execute func().
 */
static void smp_call_function_all_cpus(void (*func) (void *arg), void *arg)
{
	check_irq_on();
	preempt_disable();

	local_irq_disable();
	func(arg);
	local_irq_enable();

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

	preempt_enable();
}

static void drain_array_locked(kmem_cache_t* cachep,
1890
				struct array_cache *ac, int force, int node);
L
Linus Torvalds 已提交
1891 1892 1893 1894 1895

static void do_drain(void *arg)
{
	kmem_cache_t *cachep = (kmem_cache_t*)arg;
	struct array_cache *ac;
1896
	int node = numa_node_id();
L
Linus Torvalds 已提交
1897 1898 1899

	check_irq_off();
	ac = ac_data(cachep);
1900 1901 1902
	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
1903 1904 1905 1906 1907
	ac->avail = 0;
}

static void drain_cpu_caches(kmem_cache_t *cachep)
{
1908 1909 1910
	struct kmem_list3 *l3;
	int node;

L
Linus Torvalds 已提交
1911 1912 1913
	smp_call_function_all_cpus(do_drain, cachep);
	check_irq_on();
	spin_lock_irq(&cachep->spinlock);
1914 1915 1916 1917 1918 1919 1920 1921 1922 1923
	for_each_online_node(node)  {
		l3 = cachep->nodelists[node];
		if (l3) {
			spin_lock(&l3->list_lock);
			drain_array_locked(cachep, l3->shared, 1, node);
			spin_unlock(&l3->list_lock);
			if (l3->alien)
				drain_alien_cache(cachep, l3);
		}
	}
L
Linus Torvalds 已提交
1924 1925 1926
	spin_unlock_irq(&cachep->spinlock);
}

1927
static int __node_shrink(kmem_cache_t *cachep, int node)
L
Linus Torvalds 已提交
1928 1929
{
	struct slab *slabp;
1930
	struct kmem_list3 *l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
1931 1932
	int ret;

1933
	for (;;) {
L
Linus Torvalds 已提交
1934 1935
		struct list_head *p;

1936 1937
		p = l3->slabs_free.prev;
		if (p == &l3->slabs_free)
L
Linus Torvalds 已提交
1938 1939
			break;

1940
		slabp = list_entry(l3->slabs_free.prev, struct slab, list);
L
Linus Torvalds 已提交
1941 1942 1943 1944 1945 1946
#if DEBUG
		if (slabp->inuse)
			BUG();
#endif
		list_del(&slabp->list);

1947 1948
		l3->free_objects -= cachep->num;
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
1949
		slab_destroy(cachep, slabp);
1950
		spin_lock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
1951
	}
1952 1953
	ret = !list_empty(&l3->slabs_full) ||
		!list_empty(&l3->slabs_partial);
L
Linus Torvalds 已提交
1954 1955 1956
	return ret;
}

1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975
static int __cache_shrink(kmem_cache_t *cachep)
{
	int ret = 0, i = 0;
	struct kmem_list3 *l3;

	drain_cpu_caches(cachep);

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

L
Linus Torvalds 已提交
1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
/**
 * 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.
 */
int kmem_cache_shrink(kmem_cache_t *cachep)
{
	if (!cachep || in_interrupt())
		BUG();

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

/**
 * kmem_cache_destroy - delete a cache
 * @cachep: the cache to destroy
 *
 * Remove a kmem_cache_t object from the slab cache.
 * Returns 0 on success.
 *
 * It is expected this function will be called by a module when it is
 * unloaded.  This will remove the cache completely, and avoid a duplicate
 * cache being allocated each time a module is loaded and unloaded, if the
 * module doesn't have persistent in-kernel storage across loads and unloads.
 *
 * The cache must be empty before calling this function.
 *
 * The caller must guarantee that noone will allocate memory from the cache
 * during the kmem_cache_destroy().
 */
int kmem_cache_destroy(kmem_cache_t * cachep)
{
	int i;
2012
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037

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

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

	/* Find the cache in the chain of caches. */
	down(&cache_chain_sem);
	/*
	 * the chain is never empty, cache_cache is never destroyed
	 */
	list_del(&cachep->next);
	up(&cache_chain_sem);

	if (__cache_shrink(cachep)) {
		slab_error(cachep, "Can't free all objects");
		down(&cache_chain_sem);
		list_add(&cachep->next,&cache_chain);
		up(&cache_chain_sem);
		unlock_cpu_hotplug();
		return 1;
	}

	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2038
		synchronize_rcu();
L
Linus Torvalds 已提交
2039

2040
	for_each_online_cpu(i)
L
Linus Torvalds 已提交
2041 2042 2043
		kfree(cachep->array[i]);

	/* NUMA: free the list3 structures */
2044 2045 2046 2047 2048 2049 2050
	for_each_online_node(i) {
		if ((l3 = cachep->nodelists[i])) {
			kfree(l3->shared);
			free_alien_cache(l3->alien);
			kfree(l3);
		}
	}
L
Linus Torvalds 已提交
2051 2052 2053 2054 2055 2056 2057 2058 2059
	kmem_cache_free(&cache_cache, cachep);

	unlock_cpu_hotplug();

	return 0;
}
EXPORT_SYMBOL(kmem_cache_destroy);

/* Get the memory for a slab management obj. */
2060
static struct slab* alloc_slabmgmt(kmem_cache_t *cachep, void *objp,
A
Al Viro 已提交
2061
			int colour_off, gfp_t local_flags)
L
Linus Torvalds 已提交
2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091
{
	struct slab *slabp;
	
	if (OFF_SLAB(cachep)) {
		/* Slab management obj is off-slab. */
		slabp = kmem_cache_alloc(cachep->slabp_cache, local_flags);
		if (!slabp)
			return NULL;
	} else {
		slabp = objp+colour_off;
		colour_off += cachep->slab_size;
	}
	slabp->inuse = 0;
	slabp->colouroff = colour_off;
	slabp->s_mem = objp+colour_off;

	return slabp;
}

static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
{
	return (kmem_bufctl_t *)(slabp+1);
}

static void cache_init_objs(kmem_cache_t *cachep,
			struct slab *slabp, unsigned long ctor_flags)
{
	int i;

	for (i = 0; i < cachep->num; i++) {
2092
		void *objp = slabp->s_mem+cachep->objsize*i;
L
Linus Torvalds 已提交
2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131
#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;
		}
		/*
		 * Constructors are not allowed to allocate memory from
		 * the same cache which they are a constructor for.
		 * Otherwise, deadlock. They must also be threaded.
		 */
		if (cachep->ctor && !(cachep->flags & SLAB_POISON))
			cachep->ctor(objp+obj_dbghead(cachep), cachep, ctor_flags);

		if (cachep->flags & SLAB_RED_ZONE) {
			if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
							" end of an object");
			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
				slab_error(cachep, "constructor overwrote the"
							" start of an object");
		}
		if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
	       		kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0);
#else
		if (cachep->ctor)
			cachep->ctor(objp, cachep, ctor_flags);
#endif
		slab_bufctl(slabp)[i] = i+1;
	}
	slab_bufctl(slabp)[i-1] = BUFCTL_END;
	slabp->free = 0;
}

A
Al Viro 已提交
2132
static void kmem_flagcheck(kmem_cache_t *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151
{
	if (flags & SLAB_DMA) {
		if (!(cachep->gfpflags & GFP_DMA))
			BUG();
	} else {
		if (cachep->gfpflags & GFP_DMA)
			BUG();
	}
}

static void set_slab_attr(kmem_cache_t *cachep, struct slab *slabp, void *objp)
{
	int i;
	struct page *page;

	/* Nasty!!!!!! I hope this is OK. */
	i = 1 << cachep->gfporder;
	page = virt_to_page(objp);
	do {
2152 2153
		page_set_cache(page, cachep);
		page_set_slab(page, slabp);
L
Linus Torvalds 已提交
2154 2155 2156 2157 2158 2159 2160 2161
		page++;
	} while (--i);
}

/*
 * Grow (by 1) the number of slabs within a cache.  This is called by
 * kmem_cache_alloc() when there are no active objs left in a cache.
 */
A
Al Viro 已提交
2162
static int cache_grow(kmem_cache_t *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
2163 2164 2165 2166
{
	struct slab	*slabp;
	void		*objp;
	size_t		 offset;
A
Al Viro 已提交
2167
	gfp_t	 	 local_flags;
L
Linus Torvalds 已提交
2168
	unsigned long	 ctor_flags;
2169
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200

	/* Be lazy and only check for valid flags here,
 	 * keeping it out of the critical path in kmem_cache_alloc().
	 */
	if (flags & ~(SLAB_DMA|SLAB_LEVEL_MASK|SLAB_NO_GROW))
		BUG();
	if (flags & SLAB_NO_GROW)
		return 0;

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

	/* About to mess with non-constant members - lock. */
	check_irq_off();
	spin_lock(&cachep->spinlock);

	/* Get colour for the slab, and cal the next value. */
	offset = cachep->colour_next;
	cachep->colour_next++;
	if (cachep->colour_next >= cachep->colour)
		cachep->colour_next = 0;
	offset *= cachep->colour_off;

	spin_unlock(&cachep->spinlock);

2201
	check_irq_off();
L
Linus Torvalds 已提交
2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212
	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);

2213 2214 2215
	/* Get mem for the objs.
	 * Attempt to allocate a physical page from 'nodeid',
	 */
L
Linus Torvalds 已提交
2216 2217 2218 2219 2220 2221 2222
	if (!(objp = kmem_getpages(cachep, flags, nodeid)))
		goto failed;

	/* Get slab management. */
	if (!(slabp = alloc_slabmgmt(cachep, objp, offset, local_flags)))
		goto opps1;

2223
	slabp->nodeid = nodeid;
L
Linus Torvalds 已提交
2224 2225 2226 2227 2228 2229 2230
	set_slab_attr(cachep, slabp, objp);

	cache_init_objs(cachep, slabp, ctor_flags);

	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	check_irq_off();
2231 2232
	l3 = cachep->nodelists[nodeid];
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2233 2234

	/* Make slab active. */
2235
	list_add_tail(&slabp->list, &(l3->slabs_free));
L
Linus Torvalds 已提交
2236
	STATS_INC_GROWN(cachep);
2237 2238
	l3->free_objects += cachep->num;
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282
	return 1;
opps1:
	kmem_freepages(cachep, objp);
failed:
	if (local_flags & __GFP_WAIT)
		local_irq_disable();
	return 0;
}

#if DEBUG

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

	if (!virt_addr_valid(objp)) {
		printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
			(unsigned long)objp);	
		BUG();	
	}
	page = virt_to_page(objp);
	if (!PageSlab(page)) {
		printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n", (unsigned long)objp);
		BUG();
	}
}

static void *cache_free_debugcheck(kmem_cache_t *cachep, void *objp,
					void *caller)
{
	struct page *page;
	unsigned int objnr;
	struct slab *slabp;

	objp -= obj_dbghead(cachep);
	kfree_debugcheck(objp);
	page = virt_to_page(objp);

2283
	if (page_get_cache(page) != cachep) {
L
Linus Torvalds 已提交
2284
		printk(KERN_ERR "mismatch in kmem_cache_free: expected cache %p, got %p\n",
2285
				page_get_cache(page),cachep);
L
Linus Torvalds 已提交
2286
		printk(KERN_ERR "%p is %s.\n", cachep, cachep->name);
2287
		printk(KERN_ERR "%p is %s.\n", page_get_cache(page), page_get_cache(page)->name);
L
Linus Torvalds 已提交
2288 2289
		WARN_ON(1);
	}
2290
	slabp = page_get_slab(page);
L
Linus Torvalds 已提交
2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368

	if (cachep->flags & SLAB_RED_ZONE) {
		if (*dbg_redzone1(cachep, objp) != RED_ACTIVE || *dbg_redzone2(cachep, objp) != RED_ACTIVE) {
			slab_error(cachep, "double free, or memory outside"
						" object was overwritten");
			printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n",
					objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp));
		}
		*dbg_redzone1(cachep, objp) = RED_INACTIVE;
		*dbg_redzone2(cachep, objp) = RED_INACTIVE;
	}
	if (cachep->flags & SLAB_STORE_USER)
		*dbg_userword(cachep, objp) = caller;

	objnr = (objp-slabp->s_mem)/cachep->objsize;

	BUG_ON(objnr >= cachep->num);
	BUG_ON(objp != slabp->s_mem + objnr*cachep->objsize);

	if (cachep->flags & SLAB_DEBUG_INITIAL) {
		/* Need to call the slab's constructor so the
		 * caller can perform a verify of its state (debugging).
		 * Called without the cache-lock held.
		 */
		cachep->ctor(objp+obj_dbghead(cachep),
					cachep, SLAB_CTOR_CONSTRUCTOR|SLAB_CTOR_VERIFY);
	}
	if (cachep->flags & SLAB_POISON && cachep->dtor) {
		/* we want to cache poison the object,
		 * call the destruction callback
		 */
		cachep->dtor(objp+obj_dbghead(cachep), cachep, 0);
	}
	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
		if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) {
			store_stackinfo(cachep, objp, (unsigned long)caller);
	       		kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0);
		} else {
			poison_obj(cachep, objp, POISON_FREE);
		}
#else
		poison_obj(cachep, objp, POISON_FREE);
#endif
	}
	return objp;
}

static void check_slabp(kmem_cache_t *cachep, struct slab *slabp)
{
	kmem_bufctl_t i;
	int entries = 0;
	
	/* 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) {
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);
		for (i=0;i<sizeof(slabp)+cachep->num*sizeof(kmem_bufctl_t);i++) {
			if ((i%16)==0)
				printk("\n%03x:", i);
			printk(" %02x", ((unsigned char*)slabp)[i]);
		}
		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

A
Al Viro 已提交
2369
static void *cache_alloc_refill(kmem_cache_t *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385
{
	int batchcount;
	struct kmem_list3 *l3;
	struct array_cache *ac;

	check_irq_off();
	ac = ac_data(cachep);
retry:
	batchcount = ac->batchcount;
	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
		/* if there was little recent activity on this
		 * cache, then perform only a partial refill.
		 * Otherwise we could generate refill bouncing.
		 */
		batchcount = BATCHREFILL_LIMIT;
	}
2386 2387 2388 2389
	l3 = cachep->nodelists[numa_node_id()];

	BUG_ON(ac->avail > 0 || !l3);
	spin_lock(&l3->list_lock);
L
Linus Torvalds 已提交
2390 2391 2392 2393 2394 2395 2396 2397

	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
		if (shared_array->avail) {
			if (batchcount > shared_array->avail)
				batchcount = shared_array->avail;
			shared_array->avail -= batchcount;
			ac->avail = batchcount;
2398 2399 2400
			memcpy(ac->entry,
				&(shared_array->entry[shared_array->avail]),
				sizeof(void*)*batchcount);
L
Linus Torvalds 已提交
2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426
			shared_array->touched = 1;
			goto alloc_done;
		}
	}
	while (batchcount > 0) {
		struct list_head *entry;
		struct slab *slabp;
		/* Get slab alloc is to come from. */
		entry = l3->slabs_partial.next;
		if (entry == &l3->slabs_partial) {
			l3->free_touched = 1;
			entry = l3->slabs_free.next;
			if (entry == &l3->slabs_free)
				goto must_grow;
		}

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

			/* get obj pointer */
2427 2428
			ac->entry[ac->avail++] = slabp->s_mem +
				slabp->free*cachep->objsize;
L
Linus Torvalds 已提交
2429 2430 2431 2432 2433

			slabp->inuse++;
			next = slab_bufctl(slabp)[slabp->free];
#if DEBUG
			slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
2434
			WARN_ON(numa_node_id() != slabp->nodeid);
L
Linus Torvalds 已提交
2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450
#endif
		       	slabp->free = next;
		}
		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);
	}

must_grow:
	l3->free_objects -= ac->avail;
alloc_done:
2451
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2452 2453 2454

	if (unlikely(!ac->avail)) {
		int x;
2455 2456
		x = cache_grow(cachep, flags, numa_node_id());

L
Linus Torvalds 已提交
2457 2458 2459 2460 2461 2462 2463 2464 2465
		// cache_grow can reenable interrupts, then ac could change.
		ac = ac_data(cachep);
		if (!x && ac->avail == 0)	// no objects in sight? abort
			return NULL;

		if (!ac->avail)		// objects refilled by interrupt?
			goto retry;
	}
	ac->touched = 1;
2466
	return ac->entry[--ac->avail];
L
Linus Torvalds 已提交
2467 2468 2469
}

static inline void
A
Al Viro 已提交
2470
cache_alloc_debugcheck_before(kmem_cache_t *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2471 2472 2473 2474 2475 2476 2477 2478 2479 2480
{
	might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
	kmem_flagcheck(cachep, flags);
#endif
}

#if DEBUG
static void *
cache_alloc_debugcheck_after(kmem_cache_t *cachep,
A
Al Viro 已提交
2481
			gfp_t flags, void *objp, void *caller)
L
Linus Torvalds 已提交
2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523
{
	if (!objp)	
		return objp;
 	if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
		if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
			kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 1);
		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) {
		if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
			slab_error(cachep, "double free, or memory outside"
						" object was overwritten");
			printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n",
					objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp));
		}
		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
	}
	objp += obj_dbghead(cachep);
	if (cachep->ctor && cachep->flags & SLAB_POISON) {
		unsigned long	ctor_flags = SLAB_CTOR_CONSTRUCTOR;

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

		cachep->ctor(objp, cachep, ctor_flags);
	}	
	return objp;
}
#else
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

A
Al Viro 已提交
2524
static inline void *____cache_alloc(kmem_cache_t *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2525 2526 2527 2528
{
	void* objp;
	struct array_cache *ac;

2529
	check_irq_off();
L
Linus Torvalds 已提交
2530 2531 2532 2533
	ac = ac_data(cachep);
	if (likely(ac->avail)) {
		STATS_INC_ALLOCHIT(cachep);
		ac->touched = 1;
2534
		objp = ac->entry[--ac->avail];
L
Linus Torvalds 已提交
2535 2536 2537 2538
	} else {
		STATS_INC_ALLOCMISS(cachep);
		objp = cache_alloc_refill(cachep, flags);
	}
2539 2540 2541
	return objp;
}

A
Al Viro 已提交
2542
static inline void *__cache_alloc(kmem_cache_t *cachep, gfp_t flags)
2543 2544 2545 2546 2547 2548 2549 2550
{
	unsigned long save_flags;
	void* objp;

	cache_alloc_debugcheck_before(cachep, flags);

	local_irq_save(save_flags);
	objp = ____cache_alloc(cachep, flags);
L
Linus Torvalds 已提交
2551
	local_irq_restore(save_flags);
2552 2553 2554
	objp = cache_alloc_debugcheck_after(cachep, flags, objp,
					__builtin_return_address(0));
	prefetchw(objp);
L
Linus Torvalds 已提交
2555 2556 2557
	return objp;
}

2558 2559 2560
#ifdef CONFIG_NUMA
/*
 * A interface to enable slab creation on nodeid
L
Linus Torvalds 已提交
2561
 */
A
Al Viro 已提交
2562
static void *__cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int nodeid)
2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618
{
	struct list_head *entry;
 	struct slab *slabp;
 	struct kmem_list3 *l3;
 	void *obj;
 	kmem_bufctl_t next;
 	int x;

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

retry:
 	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);

 	/* get obj pointer */
 	obj =  slabp->s_mem + slabp->free*cachep->objsize;
 	slabp->inuse++;
 	next = slab_bufctl(slabp)[slabp->free];
#if DEBUG
 	slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
#endif
 	slabp->free = next;
 	check_slabp(cachep, slabp);
 	l3->free_objects--;
 	/* 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);
 	}

 	spin_unlock(&l3->list_lock);
 	goto done;

must_grow:
 	spin_unlock(&l3->list_lock);
 	x = cache_grow(cachep, flags, nodeid);
L
Linus Torvalds 已提交
2619

2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631
 	if (!x)
 		return NULL;

 	goto retry;
done:
 	return obj;
}
#endif

/*
 * Caller needs to acquire correct kmem_list's list_lock
 */
2632
static void free_block(kmem_cache_t *cachep, void **objpp, int nr_objects, int node)
L
Linus Torvalds 已提交
2633 2634
{
	int i;
2635
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
2636 2637 2638 2639 2640 2641

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

2642
		slabp = page_get_slab(virt_to_page(objp));
2643
		l3 = cachep->nodelists[node];
L
Linus Torvalds 已提交
2644 2645
		list_del(&slabp->list);
		objnr = (objp - slabp->s_mem) / cachep->objsize;
2646
		check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
2647
		check_slabp(cachep, slabp);
2648

L
Linus Torvalds 已提交
2649
#if DEBUG
2650 2651 2652
		/* Verify that the slab belongs to the intended node */
		WARN_ON(slabp->nodeid != node);

L
Linus Torvalds 已提交
2653
		if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
2654 2655
			printk(KERN_ERR "slab: double free detected in cache "
					"'%s', objp %p\n", cachep->name, objp);
L
Linus Torvalds 已提交
2656 2657 2658 2659 2660 2661 2662
			BUG();
		}
#endif
		slab_bufctl(slabp)[objnr] = slabp->free;
		slabp->free = objnr;
		STATS_DEC_ACTIVE(cachep);
		slabp->inuse--;
2663
		l3->free_objects++;
L
Linus Torvalds 已提交
2664 2665 2666 2667
		check_slabp(cachep, slabp);

		/* fixup slab chains */
		if (slabp->inuse == 0) {
2668 2669
			if (l3->free_objects > l3->free_limit) {
				l3->free_objects -= cachep->num;
L
Linus Torvalds 已提交
2670 2671
				slab_destroy(cachep, slabp);
			} else {
2672
				list_add(&slabp->list, &l3->slabs_free);
L
Linus Torvalds 已提交
2673 2674 2675 2676 2677 2678
			}
		} else {
			/* Unconditionally move a slab to the end of the
			 * partial list on free - maximum time for the
			 * other objects to be freed, too.
			 */
2679
			list_add_tail(&slabp->list, &l3->slabs_partial);
L
Linus Torvalds 已提交
2680 2681 2682 2683 2684 2685 2686
		}
	}
}

static void cache_flusharray(kmem_cache_t *cachep, struct array_cache *ac)
{
	int batchcount;
2687
	struct kmem_list3 *l3;
2688
	int node = numa_node_id();
L
Linus Torvalds 已提交
2689 2690 2691 2692 2693 2694

	batchcount = ac->batchcount;
#if DEBUG
	BUG_ON(!batchcount || batchcount > ac->avail);
#endif
	check_irq_off();
2695
	l3 = cachep->nodelists[node];
2696 2697 2698
	spin_lock(&l3->list_lock);
	if (l3->shared) {
		struct array_cache *shared_array = l3->shared;
L
Linus Torvalds 已提交
2699 2700 2701 2702
		int max = shared_array->limit-shared_array->avail;
		if (max) {
			if (batchcount > max)
				batchcount = max;
2703 2704
			memcpy(&(shared_array->entry[shared_array->avail]),
					ac->entry,
L
Linus Torvalds 已提交
2705 2706 2707 2708 2709 2710
					sizeof(void*)*batchcount);
			shared_array->avail += batchcount;
			goto free_done;
		}
	}

2711
	free_block(cachep, ac->entry, batchcount, node);
L
Linus Torvalds 已提交
2712 2713 2714 2715 2716 2717
free_done:
#if STATS
	{
		int i = 0;
		struct list_head *p;

2718 2719
		p = l3->slabs_free.next;
		while (p != &(l3->slabs_free)) {
L
Linus Torvalds 已提交
2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730
			struct slab *slabp;

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

			i++;
			p = p->next;
		}
		STATS_SET_FREEABLE(cachep, i);
	}
#endif
2731
	spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
2732
	ac->avail -= batchcount;
2733
	memmove(ac->entry, &(ac->entry[batchcount]),
L
Linus Torvalds 已提交
2734 2735 2736
			sizeof(void*)*ac->avail);
}

2737

L
Linus Torvalds 已提交
2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751
/*
 * __cache_free
 * 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.
 */
static inline void __cache_free(kmem_cache_t *cachep, void *objp)
{
	struct array_cache *ac = ac_data(cachep);

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

2752 2753 2754 2755 2756 2757
	/* Make sure we are not freeing a object from another
	 * node to the array cache on this cpu.
	 */
#ifdef CONFIG_NUMA
	{
		struct slab *slabp;
2758
		slabp = page_get_slab(virt_to_page(objp));
2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775
		if (unlikely(slabp->nodeid != numa_node_id())) {
			struct array_cache *alien = NULL;
			int nodeid = slabp->nodeid;
			struct kmem_list3 *l3 = cachep->nodelists[numa_node_id()];

			STATS_INC_NODEFREES(cachep);
			if (l3->alien && l3->alien[nodeid]) {
				alien = l3->alien[nodeid];
				spin_lock(&alien->lock);
				if (unlikely(alien->avail == alien->limit))
					__drain_alien_cache(cachep,
							alien, nodeid);
				alien->entry[alien->avail++] = objp;
				spin_unlock(&alien->lock);
			} else {
				spin_lock(&(cachep->nodelists[nodeid])->
						list_lock);
2776
				free_block(cachep, &objp, 1, nodeid);
2777 2778 2779 2780 2781 2782 2783
				spin_unlock(&(cachep->nodelists[nodeid])->
						list_lock);
			}
			return;
		}
	}
#endif
L
Linus Torvalds 已提交
2784 2785
	if (likely(ac->avail < ac->limit)) {
		STATS_INC_FREEHIT(cachep);
2786
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
2787 2788 2789 2790
		return;
	} else {
		STATS_INC_FREEMISS(cachep);
		cache_flusharray(cachep, ac);
2791
		ac->entry[ac->avail++] = objp;
L
Linus Torvalds 已提交
2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802
	}
}

/**
 * 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.
 */
A
Al Viro 已提交
2803
void *kmem_cache_alloc(kmem_cache_t *cachep, gfp_t flags)
L
Linus Torvalds 已提交
2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843
{
	return __cache_alloc(cachep, flags);
}
EXPORT_SYMBOL(kmem_cache_alloc);

/**
 * kmem_ptr_validate - check if an untrusted pointer might
 *	be a slab entry.
 * @cachep: the cache we're checking against
 * @ptr: pointer to validate
 *
 * This verifies that the untrusted pointer looks sane:
 * it is _not_ a guarantee that the pointer is actually
 * part of the slab cache in question, but it at least
 * validates that the pointer can be dereferenced and
 * looks half-way sane.
 *
 * Currently only used for dentry validation.
 */
int fastcall kmem_ptr_validate(kmem_cache_t *cachep, void *ptr)
{
	unsigned long addr = (unsigned long) ptr;
	unsigned long min_addr = PAGE_OFFSET;
	unsigned long align_mask = BYTES_PER_WORD-1;
	unsigned long size = cachep->objsize;
	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;
2844
	if (unlikely(page_get_cache(page) != cachep))
L
Linus Torvalds 已提交
2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860
		goto out;
	return 1;
out:
	return 0;
}

#ifdef CONFIG_NUMA
/**
 * kmem_cache_alloc_node - Allocate an object on the specified node
 * @cachep: The cache to allocate from.
 * @flags: See kmalloc().
 * @nodeid: node number of the target node.
 *
 * Identical to kmem_cache_alloc, except that this function is slow
 * and can sleep. And it will allocate memory on the given node, which
 * can improve the performance for cpu bound structures.
2861 2862
 * New and improved: it will now make sure that the object gets
 * put on the correct node list so that there is no false sharing.
L
Linus Torvalds 已提交
2863
 */
A
Al Viro 已提交
2864
void *kmem_cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int nodeid)
L
Linus Torvalds 已提交
2865
{
2866 2867
	unsigned long save_flags;
	void *ptr;
L
Linus Torvalds 已提交
2868

2869
	if (nodeid == -1)
2870
		return __cache_alloc(cachep, flags);
L
Linus Torvalds 已提交
2871

2872 2873 2874 2875
	if (unlikely(!cachep->nodelists[nodeid])) {
		/* Fall back to __cache_alloc if we run into trouble */
		printk(KERN_WARNING "slab: not allocating in inactive node %d for cache %s\n", nodeid, cachep->name);
		return __cache_alloc(cachep,flags);
L
Linus Torvalds 已提交
2876 2877
	}

2878 2879
	cache_alloc_debugcheck_before(cachep, flags);
	local_irq_save(save_flags);
2880 2881 2882 2883
	if (nodeid == numa_node_id())
		ptr = ____cache_alloc(cachep, flags);
	else
		ptr = __cache_alloc_node(cachep, flags, nodeid);
2884 2885
	local_irq_restore(save_flags);
	ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, __builtin_return_address(0));
L
Linus Torvalds 已提交
2886

2887
	return ptr;
L
Linus Torvalds 已提交
2888 2889 2890
}
EXPORT_SYMBOL(kmem_cache_alloc_node);

A
Al Viro 已提交
2891
void *kmalloc_node(size_t size, gfp_t flags, int node)
2892 2893 2894 2895 2896 2897 2898 2899 2900
{
	kmem_cache_t *cachep;

	cachep = kmem_find_general_cachep(size, flags);
	if (unlikely(cachep == NULL))
		return NULL;
	return kmem_cache_alloc_node(cachep, flags, node);
}
EXPORT_SYMBOL(kmalloc_node);
L
Linus Torvalds 已提交
2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923
#endif

/**
 * kmalloc - allocate memory
 * @size: how many bytes of memory are required.
 * @flags: the type of memory to allocate.
 *
 * kmalloc is the normal method of allocating memory
 * in the kernel.
 *
 * The @flags argument may be one of:
 *
 * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 *
 * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 *
 * %GFP_ATOMIC - Allocation will not sleep.  Use inside interrupt handlers.
 *
 * Additionally, the %GFP_DMA flag may be set to indicate the memory
 * must be suitable for DMA.  This can mean different things on different
 * platforms.  For example, on i386, it means that the memory must come
 * from the first 16MB.
 */
A
Al Viro 已提交
2924
void *__kmalloc(size_t size, gfp_t flags)
L
Linus Torvalds 已提交
2925 2926 2927
{
	kmem_cache_t *cachep;

2928 2929 2930 2931 2932 2933
	/* 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);
2934 2935
	if (unlikely(cachep == NULL))
		return NULL;
L
Linus Torvalds 已提交
2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956
	return __cache_alloc(cachep, flags);
}
EXPORT_SYMBOL(__kmalloc);

#ifdef CONFIG_SMP
/**
 * __alloc_percpu - allocate one copy of the object for every present
 * cpu in the system, zeroing them.
 * Objects should be dereferenced using the per_cpu_ptr macro only.
 *
 * @size: how many bytes of memory are required.
 * @align: the alignment, which can't be greater than SMP_CACHE_BYTES.
 */
void *__alloc_percpu(size_t size, size_t align)
{
	int i;
	struct percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL);

	if (!pdata)
		return NULL;

2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968
	/*
	 * Cannot use for_each_online_cpu since a cpu may come online
	 * and we have no way of figuring out how to fix the array
	 * that we have allocated then....
	 */
	for_each_cpu(i) {
		int node = cpu_to_node(i);

		if (node_online(node))
			pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node);
		else
			pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
L
Linus Torvalds 已提交
2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008

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

	/* Catch derefs w/o wrappers */
	return (void *) (~(unsigned long) pdata);

unwind_oom:
	while (--i >= 0) {
		if (!cpu_possible(i))
			continue;
		kfree(pdata->ptrs[i]);
	}
	kfree(pdata);
	return NULL;
}
EXPORT_SYMBOL(__alloc_percpu);
#endif

/**
 * kmem_cache_free - Deallocate an object
 * @cachep: The cache the allocation was from.
 * @objp: The previously allocated object.
 *
 * Free an object which was previously allocated from this
 * cache.
 */
void kmem_cache_free(kmem_cache_t *cachep, void *objp)
{
	unsigned long flags;

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

/**
3009 3010
 * kzalloc - allocate memory. The memory is set to zero.
 * @size: how many bytes of memory are required.
L
Linus Torvalds 已提交
3011 3012
 * @flags: the type of memory to allocate.
 */
A
Al Viro 已提交
3013
void *kzalloc(size_t size, gfp_t flags)
L
Linus Torvalds 已提交
3014
{
3015
	void *ret = kmalloc(size, flags);
L
Linus Torvalds 已提交
3016
	if (ret)
3017
		memset(ret, 0, size);
L
Linus Torvalds 已提交
3018 3019
	return ret;
}
3020
EXPORT_SYMBOL(kzalloc);
L
Linus Torvalds 已提交
3021 3022 3023 3024 3025

/**
 * kfree - free previously allocated memory
 * @objp: pointer returned by kmalloc.
 *
3026 3027
 * If @objp is NULL, no operation is performed.
 *
L
Linus Torvalds 已提交
3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039
 * Don't free memory not originally allocated by kmalloc()
 * or you will run into trouble.
 */
void kfree(const void *objp)
{
	kmem_cache_t *c;
	unsigned long flags;

	if (unlikely(!objp))
		return;
	local_irq_save(flags);
	kfree_debugcheck(objp);
3040
	c = page_get_cache(virt_to_page(objp));
L
Linus Torvalds 已提交
3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059
	__cache_free(c, (void*)objp);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);

#ifdef CONFIG_SMP
/**
 * free_percpu - free previously allocated percpu memory
 * @objp: pointer returned by alloc_percpu.
 *
 * Don't free memory not originally allocated by alloc_percpu()
 * The complemented objp is to check for that.
 */
void
free_percpu(const void *objp)
{
	int i;
	struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp);

3060 3061 3062 3063
	/*
	 * We allocate for all cpus so we cannot use for online cpu here.
	 */
	for_each_cpu(i)
L
Linus Torvalds 已提交
3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075
		kfree(p->ptrs[i]);
	kfree(p);
}
EXPORT_SYMBOL(free_percpu);
#endif

unsigned int kmem_cache_size(kmem_cache_t *cachep)
{
	return obj_reallen(cachep);
}
EXPORT_SYMBOL(kmem_cache_size);

3076 3077 3078 3079 3080 3081
const char *kmem_cache_name(kmem_cache_t *cachep)
{
	return cachep->name;
}
EXPORT_SYMBOL_GPL(kmem_cache_name);

3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106
/*
 * This initializes kmem_list3 for all nodes.
 */
static int alloc_kmemlist(kmem_cache_t *cachep)
{
	int node;
	struct kmem_list3 *l3;
	int err = 0;

	for_each_online_node(node) {
		struct array_cache *nc = NULL, *new;
		struct array_cache **new_alien = NULL;
#ifdef CONFIG_NUMA
		if (!(new_alien = alloc_alien_cache(node, cachep->limit)))
			goto fail;
#endif
		if (!(new = alloc_arraycache(node, (cachep->shared*
				cachep->batchcount), 0xbaadf00d)))
			goto fail;
		if ((l3 = cachep->nodelists[node])) {

			spin_lock_irq(&l3->list_lock);

			if ((nc = cachep->nodelists[node]->shared))
				free_block(cachep, nc->entry,
3107
							nc->avail, node);
3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139

			l3->shared = new;
			if (!cachep->nodelists[node]->alien) {
				l3->alien = new_alien;
				new_alien = NULL;
			}
			l3->free_limit = (1 + nr_cpus_node(node))*
				cachep->batchcount + cachep->num;
			spin_unlock_irq(&l3->list_lock);
			kfree(nc);
			free_alien_cache(new_alien);
			continue;
		}
		if (!(l3 = kmalloc_node(sizeof(struct kmem_list3),
						GFP_KERNEL, node)))
			goto fail;

		kmem_list3_init(l3);
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
			((unsigned long)cachep)%REAPTIMEOUT_LIST3;
		l3->shared = new;
		l3->alien = new_alien;
		l3->free_limit = (1 + nr_cpus_node(node))*
			cachep->batchcount + cachep->num;
		cachep->nodelists[node] = l3;
	}
	return err;
fail:
	err = -ENOMEM;
	return err;
}

L
Linus Torvalds 已提交
3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151
struct ccupdate_struct {
	kmem_cache_t *cachep;
	struct array_cache *new[NR_CPUS];
};

static void do_ccupdate_local(void *info)
{
	struct ccupdate_struct *new = (struct ccupdate_struct *)info;
	struct array_cache *old;

	check_irq_off();
	old = ac_data(new->cachep);
3152

L
Linus Torvalds 已提交
3153 3154 3155 3156 3157 3158 3159 3160 3161
	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
	new->new[smp_processor_id()] = old;
}


static int do_tune_cpucache(kmem_cache_t *cachep, int limit, int batchcount,
				int shared)
{
	struct ccupdate_struct new;
3162
	int i, err;
L
Linus Torvalds 已提交
3163 3164

	memset(&new.new,0,sizeof(new.new));
3165 3166 3167 3168 3169
	for_each_online_cpu(i) {
		new.new[i] = alloc_arraycache(cpu_to_node(i), limit, batchcount);
		if (!new.new[i]) {
			for (i--; i >= 0; i--) kfree(new.new[i]);
			return -ENOMEM;
L
Linus Torvalds 已提交
3170 3171 3172 3173 3174
		}
	}
	new.cachep = cachep;

	smp_call_function_all_cpus(do_ccupdate_local, (void *)&new);
3175

L
Linus Torvalds 已提交
3176 3177 3178 3179
	check_irq_on();
	spin_lock_irq(&cachep->spinlock);
	cachep->batchcount = batchcount;
	cachep->limit = limit;
3180
	cachep->shared = shared;
L
Linus Torvalds 已提交
3181 3182
	spin_unlock_irq(&cachep->spinlock);

3183
	for_each_online_cpu(i) {
L
Linus Torvalds 已提交
3184 3185 3186
		struct array_cache *ccold = new.new[i];
		if (!ccold)
			continue;
3187
		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3188
		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3189
		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
L
Linus Torvalds 已提交
3190 3191 3192
		kfree(ccold);
	}

3193 3194 3195 3196 3197
	err = alloc_kmemlist(cachep);
	if (err) {
		printk(KERN_ERR "alloc_kmemlist failed for %s, error %d.\n",
				cachep->name, -err);
		BUG();
L
Linus Torvalds 已提交
3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255
	}
	return 0;
}


static void enable_cpucache(kmem_cache_t *cachep)
{
	int err;
	int limit, shared;

	/* The head array serves three purposes:
	 * - create a LIFO ordering, i.e. return objects that are cache-warm
	 * - reduce the number of spinlock operations.
	 * - reduce the number of linked list operations on the slab and 
	 *   bufctl chains: array operations are cheaper.
	 * The numbers are guessed, we should auto-tune as described by
	 * Bonwick.
	 */
	if (cachep->objsize > 131072)
		limit = 1;
	else if (cachep->objsize > PAGE_SIZE)
		limit = 8;
	else if (cachep->objsize > 1024)
		limit = 24;
	else if (cachep->objsize > 256)
		limit = 54;
	else
		limit = 120;

	/* Cpu bound tasks (e.g. network routing) can exhibit cpu bound
	 * allocation behaviour: Most allocs on one cpu, most free operations
	 * on another cpu. For these cases, an efficient object passing between
	 * cpus is necessary. This is provided by a shared array. The array
	 * replaces Bonwick's magazine layer.
	 * On uniprocessor, it's functionally equivalent (but less efficient)
	 * to a larger limit. Thus disabled by default.
	 */
	shared = 0;
#ifdef CONFIG_SMP
	if (cachep->objsize <= PAGE_SIZE)
		shared = 8;
#endif

#if DEBUG
	/* With debugging enabled, large batchcount lead to excessively
	 * long periods with disabled local interrupts. Limit the 
	 * batchcount
	 */
	if (limit > 32)
		limit = 32;
#endif
	err = do_tune_cpucache(cachep, limit, (limit+1)/2, shared);
	if (err)
		printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
					cachep->name, -err);
}

static void drain_array_locked(kmem_cache_t *cachep,
3256
				struct array_cache *ac, int force, int node)
L
Linus Torvalds 已提交
3257 3258 3259
{
	int tofree;

3260
	check_spinlock_acquired_node(cachep, node);
L
Linus Torvalds 已提交
3261 3262 3263 3264 3265 3266 3267
	if (ac->touched && !force) {
		ac->touched = 0;
	} else if (ac->avail) {
		tofree = force ? ac->avail : (ac->limit+4)/5;
		if (tofree > ac->avail) {
			tofree = (ac->avail+1)/2;
		}
3268
		free_block(cachep, ac->entry, tofree, node);
L
Linus Torvalds 已提交
3269
		ac->avail -= tofree;
3270
		memmove(ac->entry, &(ac->entry[tofree]),
L
Linus Torvalds 已提交
3271 3272 3273 3274 3275 3276
					sizeof(void*)*ac->avail);
	}
}

/**
 * cache_reap - Reclaim memory from caches.
3277
 * @unused: unused parameter
L
Linus Torvalds 已提交
3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289
 *
 * 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.
 *
 * If we cannot acquire the cache chain semaphore then just give up - we'll
 * try again on the next iteration.
 */
static void cache_reap(void *unused)
{
	struct list_head *walk;
3290
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3291 3292 3293

	if (down_trylock(&cache_chain_sem)) {
		/* Give up. Setup the next iteration. */
3294
		schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
L
Linus Torvalds 已提交
3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310
		return;
	}

	list_for_each(walk, &cache_chain) {
		kmem_cache_t *searchp;
		struct list_head* p;
		int tofree;
		struct slab *slabp;

		searchp = list_entry(walk, kmem_cache_t, next);

		if (searchp->flags & SLAB_NO_REAP)
			goto next;

		check_irq_on();

3311 3312 3313 3314
		l3 = searchp->nodelists[numa_node_id()];
		if (l3->alien)
			drain_alien_cache(searchp, l3);
		spin_lock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3315

3316 3317
		drain_array_locked(searchp, ac_data(searchp), 0,
				numa_node_id());
L
Linus Torvalds 已提交
3318

3319
		if (time_after(l3->next_reap, jiffies))
L
Linus Torvalds 已提交
3320 3321
			goto next_unlock;

3322
		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
L
Linus Torvalds 已提交
3323

3324 3325 3326
		if (l3->shared)
			drain_array_locked(searchp, l3->shared, 0,
				numa_node_id());
L
Linus Torvalds 已提交
3327

3328 3329
		if (l3->free_touched) {
			l3->free_touched = 0;
L
Linus Torvalds 已提交
3330 3331 3332
			goto next_unlock;
		}

3333
		tofree = (l3->free_limit+5*searchp->num-1)/(5*searchp->num);
L
Linus Torvalds 已提交
3334
		do {
3335 3336
			p = l3->slabs_free.next;
			if (p == &(l3->slabs_free))
L
Linus Torvalds 已提交
3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348
				break;

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

			/* Safe to drop the lock. The slab is no longer
			 * linked to the cache.
			 * searchp cannot disappear, we hold
			 * cache_chain_lock
			 */
3349 3350
			l3->free_objects -= searchp->num;
			spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3351
			slab_destroy(searchp, slabp);
3352
			spin_lock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3353 3354
		} while(--tofree > 0);
next_unlock:
3355
		spin_unlock_irq(&l3->list_lock);
L
Linus Torvalds 已提交
3356 3357 3358 3359 3360
next:
		cond_resched();
	}
	check_irq_on();
	up(&cache_chain_sem);
3361
	drain_remote_pages();
L
Linus Torvalds 已提交
3362
	/* Setup the next iteration */
3363
	schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
L
Linus Torvalds 已提交
3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388
}

#ifdef CONFIG_PROC_FS

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

	down(&cache_chain_sem);
	if (!n) {
		/*
		 * Output format version, so at least we can change it
		 * without _too_ many complaints.
		 */
#if STATS
		seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
#else
		seq_puts(m, "slabinfo - version: 2.1\n");
#endif
		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>");
#if STATS
		seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped>"
3389
				" <error> <maxfreeable> <nodeallocs> <remotefrees>");
L
Linus Torvalds 已提交
3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423
		seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
#endif
		seq_putc(m, '\n');
	}
	p = cache_chain.next;
	while (n--) {
		p = p->next;
		if (p == &cache_chain)
			return NULL;
	}
	return list_entry(p, kmem_cache_t, next);
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
	kmem_cache_t *cachep = p;
	++*pos;
	return cachep->next.next == &cache_chain ? NULL
		: list_entry(cachep->next.next, kmem_cache_t, next);
}

static void s_stop(struct seq_file *m, void *p)
{
	up(&cache_chain_sem);
}

static int s_show(struct seq_file *m, void *p)
{
	kmem_cache_t *cachep = p;
	struct list_head *q;
	struct slab	*slabp;
	unsigned long	active_objs;
	unsigned long	num_objs;
	unsigned long	active_slabs = 0;
3424 3425
	unsigned long	num_slabs, free_objects = 0, shared_avail = 0;
	const char *name;
L
Linus Torvalds 已提交
3426
	char *error = NULL;
3427 3428
	int node;
	struct kmem_list3 *l3;
L
Linus Torvalds 已提交
3429 3430 3431 3432 3433

	check_irq_on();
	spin_lock_irq(&cachep->spinlock);
	active_objs = 0;
	num_slabs = 0;
3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466
	for_each_online_node(node) {
		l3 = cachep->nodelists[node];
		if (!l3)
			continue;

		spin_lock(&l3->list_lock);

		list_for_each(q,&l3->slabs_full) {
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse != cachep->num && !error)
				error = "slabs_full accounting error";
			active_objs += cachep->num;
			active_slabs++;
		}
		list_for_each(q,&l3->slabs_partial) {
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse == cachep->num && !error)
				error = "slabs_partial inuse accounting error";
			if (!slabp->inuse && !error)
				error = "slabs_partial/inuse accounting error";
			active_objs += slabp->inuse;
			active_slabs++;
		}
		list_for_each(q,&l3->slabs_free) {
			slabp = list_entry(q, struct slab, list);
			if (slabp->inuse && !error)
				error = "slabs_free/inuse accounting error";
			num_slabs++;
		}
		free_objects += l3->free_objects;
		shared_avail += l3->shared->avail;

		spin_unlock(&l3->list_lock);
L
Linus Torvalds 已提交
3467 3468 3469
	}
	num_slabs+=active_slabs;
	num_objs = num_slabs*cachep->num;
3470
	if (num_objs - active_objs != free_objects && !error)
L
Linus Torvalds 已提交
3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481
		error = "free_objects accounting error";

	name = cachep->name; 
	if (error)
		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);

	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
		name, active_objs, num_objs, cachep->objsize,
		cachep->num, (1<<cachep->gfporder));
	seq_printf(m, " : tunables %4u %4u %4u",
			cachep->limit, cachep->batchcount,
3482 3483 3484
			cachep->shared);
	seq_printf(m, " : slabdata %6lu %6lu %6lu",
			active_slabs, num_slabs, shared_avail);
L
Linus Torvalds 已提交
3485 3486 3487 3488 3489 3490 3491 3492 3493
#if STATS
	{	/* list3 stats */
		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;
3494
		unsigned long node_frees = cachep->node_frees;
L
Linus Torvalds 已提交
3495

3496 3497 3498 3499
		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
				%4lu %4lu %4lu %4lu",
				allocs, high, grown, reaped, errors,
				max_freeable, node_allocs, node_frees);
L
Linus Torvalds 已提交
3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577
	}
	/* 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",
			allochit, allocmiss, freehit, freemiss);
	}
#endif
	seq_putc(m, '\n');
	spin_unlock_irq(&cachep->spinlock);
	return 0;
}

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

struct seq_operations slabinfo_op = {
	.start	= s_start,
	.next	= s_next,
	.stop	= s_stop,
	.show	= s_show,
};

#define MAX_SLABINFO_WRITE 128
/**
 * slabinfo_write - Tuning for the slab allocator
 * @file: unused
 * @buffer: user buffer
 * @count: data length
 * @ppos: unused
 */
ssize_t slabinfo_write(struct file *file, const char __user *buffer,
				size_t count, loff_t *ppos)
{
	char kbuf[MAX_SLABINFO_WRITE+1], *tmp;
	int limit, batchcount, shared, res;
	struct list_head *p;
	
	if (count > MAX_SLABINFO_WRITE)
		return -EINVAL;
	if (copy_from_user(&kbuf, buffer, count))
		return -EFAULT;
	kbuf[MAX_SLABINFO_WRITE] = '\0'; 

	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. */
	down(&cache_chain_sem);
	res = -EINVAL;
	list_for_each(p,&cache_chain) {
		kmem_cache_t *cachep = list_entry(p, kmem_cache_t, next);

		if (!strcmp(cachep->name, kbuf)) {
			if (limit < 1 ||
			    batchcount < 1 ||
			    batchcount > limit ||
			    shared < 0) {
3578
				res = 0;
L
Linus Torvalds 已提交
3579
			} else {
3580 3581
				res = do_tune_cpucache(cachep, limit,
							batchcount, shared);
L
Linus Torvalds 已提交
3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592
			}
			break;
		}
	}
	up(&cache_chain_sem);
	if (res >= 0)
		res = count;
	return res;
}
#endif

3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604
/**
 * ksize - get the actual amount of memory allocated for a given object
 * @objp: Pointer to the object
 *
 * kmalloc may internally round up allocations and return more memory
 * than requested. ksize() can be used to determine the actual amount of
 * memory allocated. The caller may use this additional memory, even though
 * a smaller amount of memory was initially specified with the kmalloc call.
 * The caller must guarantee that objp points to a valid object previously
 * allocated with either kmalloc() or kmem_cache_alloc(). The object
 * must not be freed during the duration of the call.
 */
L
Linus Torvalds 已提交
3605 3606
unsigned int ksize(const void *objp)
{
3607 3608
	if (unlikely(objp == NULL))
		return 0;
L
Linus Torvalds 已提交
3609

3610
	return obj_reallen(page_get_cache(virt_to_page(objp)));
L
Linus Torvalds 已提交
3611
}
3612 3613 3614 3615 3616 3617 3618 3619


/*
 * kstrdup - allocate space for and copy an existing string
 *
 * @s: the string to duplicate
 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
 */
A
Al Viro 已提交
3620
char *kstrdup(const char *s, gfp_t gfp)
3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634
{
	size_t len;
	char *buf;

	if (!s)
		return NULL;

	len = strlen(s) + 1;
	buf = kmalloc(len, gfp);
	if (buf)
		memcpy(buf, s, len);
	return buf;
}
EXPORT_SYMBOL(kstrdup);