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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/mm/slab.c
3 * Written by Mark Hemment, 1996/97.
4 * (markhe@nextd.demon.co.uk)
5 *
6 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
7 *
8 * Major cleanup, different bufctl logic, per-cpu arrays
9 * (c) 2000 Manfred Spraul
10 *
11 * Cleanup, make the head arrays unconditional, preparation for NUMA
12 * (c) 2002 Manfred Spraul
13 *
14 * An implementation of the Slab Allocator as described in outline in;
15 * UNIX Internals: The New Frontiers by Uresh Vahalia
16 * Pub: Prentice Hall ISBN 0-13-101908-2
17 * or with a little more detail in;
18 * The Slab Allocator: An Object-Caching Kernel Memory Allocator
19 * Jeff Bonwick (Sun Microsystems).
20 * Presented at: USENIX Summer 1994 Technical Conference
21 *
22 * The memory is organized in caches, one cache for each object type.
23 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
24 * Each cache consists out of many slabs (they are small (usually one
25 * page long) and always contiguous), and each slab contains multiple
26 * initialized objects.
27 *
28 * This means, that your constructor is used only for newly allocated
29 * slabs and you must pass objects with the same intializations to
30 * kmem_cache_free.
31 *
32 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
33 * normal). If you need a special memory type, then must create a new
34 * cache for that memory type.
35 *
36 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
37 * full slabs with 0 free objects
38 * partial slabs
39 * empty slabs with no allocated objects
40 *
41 * If partial slabs exist, then new allocations come from these slabs,
42 * otherwise from empty slabs or new slabs are allocated.
43 *
44 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
45 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
46 *
47 * Each cache has a short per-cpu head array, most allocs
48 * and frees go into that array, and if that array overflows, then 1/2
49 * of the entries in the array are given back into the global cache.
50 * The head array is strictly LIFO and should improve the cache hit rates.
51 * On SMP, it additionally reduces the spinlock operations.
52 *
53 * The c_cpuarray may not be read with enabled local interrupts -
54 * it's changed with a smp_call_function().
55 *
56 * SMP synchronization:
57 * constructors and destructors are called without any locking.
58 * Several members in kmem_cache_t and struct slab never change, they
59 * are accessed without any locking.
60 * The per-cpu arrays are never accessed from the wrong cpu, no locking,
61 * and local interrupts are disabled so slab code is preempt-safe.
62 * The non-constant members are protected with a per-cache irq spinlock.
63 *
64 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
65 * in 2000 - many ideas in the current implementation are derived from
66 * his patch.
67 *
68 * Further notes from the original documentation:
69 *
70 * 11 April '97. Started multi-threading - markhe
71 * The global cache-chain is protected by the semaphore 'cache_chain_sem'.
72 * The sem is only needed when accessing/extending the cache-chain, which
73 * can never happen inside an interrupt (kmem_cache_create(),
74 * kmem_cache_shrink() and kmem_cache_reap()).
75 *
76 * At present, each engine can be growing a cache. This should be blocked.
77 *
Christoph Lametere498be72005-09-09 13:03:32 -070078 * 15 March 2005. NUMA slab allocator.
79 * Shai Fultheim <shai@scalex86.org>.
80 * Shobhit Dayal <shobhit@calsoftinc.com>
81 * Alok N Kataria <alokk@calsoftinc.com>
82 * Christoph Lameter <christoph@lameter.com>
83 *
84 * Modified the slab allocator to be node aware on NUMA systems.
85 * Each node has its own list of partial, free and full slabs.
86 * All object allocations for a node occur from node specific slab lists.
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 */
88
89#include <linux/config.h>
90#include <linux/slab.h>
91#include <linux/mm.h>
92#include <linux/swap.h>
93#include <linux/cache.h>
94#include <linux/interrupt.h>
95#include <linux/init.h>
96#include <linux/compiler.h>
97#include <linux/seq_file.h>
98#include <linux/notifier.h>
99#include <linux/kallsyms.h>
100#include <linux/cpu.h>
101#include <linux/sysctl.h>
102#include <linux/module.h>
103#include <linux/rcupdate.h>
Paulo Marques543537b2005-06-23 00:09:02 -0700104#include <linux/string.h>
Christoph Lametere498be72005-09-09 13:03:32 -0700105#include <linux/nodemask.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107#include <asm/uaccess.h>
108#include <asm/cacheflush.h>
109#include <asm/tlbflush.h>
110#include <asm/page.h>
111
112/*
113 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
114 * SLAB_RED_ZONE & SLAB_POISON.
115 * 0 for faster, smaller code (especially in the critical paths).
116 *
117 * STATS - 1 to collect stats for /proc/slabinfo.
118 * 0 for faster, smaller code (especially in the critical paths).
119 *
120 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
121 */
122
123#ifdef CONFIG_DEBUG_SLAB
124#define DEBUG 1
125#define STATS 1
126#define FORCED_DEBUG 1
127#else
128#define DEBUG 0
129#define STATS 0
130#define FORCED_DEBUG 0
131#endif
132
133
134/* Shouldn't this be in a header file somewhere? */
135#define BYTES_PER_WORD sizeof(void *)
136
137#ifndef cache_line_size
138#define cache_line_size() L1_CACHE_BYTES
139#endif
140
141#ifndef ARCH_KMALLOC_MINALIGN
142/*
143 * Enforce a minimum alignment for the kmalloc caches.
144 * Usually, the kmalloc caches are cache_line_size() aligned, except when
145 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
146 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
147 * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
148 * Note that this flag disables some debug features.
149 */
150#define ARCH_KMALLOC_MINALIGN 0
151#endif
152
153#ifndef ARCH_SLAB_MINALIGN
154/*
155 * Enforce a minimum alignment for all caches.
156 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
157 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
158 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
159 * some debug features.
160 */
161#define ARCH_SLAB_MINALIGN 0
162#endif
163
164#ifndef ARCH_KMALLOC_FLAGS
165#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
166#endif
167
168/* Legal flag mask for kmem_cache_create(). */
169#if DEBUG
170# define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
171 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
172 SLAB_NO_REAP | SLAB_CACHE_DMA | \
173 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
174 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
175 SLAB_DESTROY_BY_RCU)
176#else
177# define CREATE_MASK (SLAB_HWCACHE_ALIGN | SLAB_NO_REAP | \
178 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
179 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
180 SLAB_DESTROY_BY_RCU)
181#endif
182
183/*
184 * kmem_bufctl_t:
185 *
186 * Bufctl's are used for linking objs within a slab
187 * linked offsets.
188 *
189 * This implementation relies on "struct page" for locating the cache &
190 * slab an object belongs to.
191 * This allows the bufctl structure to be small (one int), but limits
192 * the number of objects a slab (not a cache) can contain when off-slab
193 * bufctls are used. The limit is the size of the largest general cache
194 * that does not use off-slab slabs.
195 * For 32bit archs with 4 kB pages, is this 56.
196 * This is not serious, as it is only for large objects, when it is unwise
197 * to have too many per slab.
198 * Note: This limit can be raised by introducing a general cache whose size
199 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
200 */
201
Kyle Moffettfa5b08d2005-09-03 15:55:03 -0700202typedef unsigned int kmem_bufctl_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
204#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
205#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-2)
206
207/* Max number of objs-per-slab for caches which use off-slab slabs.
208 * Needed to avoid a possible looping condition in cache_grow().
209 */
210static unsigned long offslab_limit;
211
212/*
213 * struct slab
214 *
215 * Manages the objs in a slab. Placed either at the beginning of mem allocated
216 * for a slab, or allocated from an general cache.
217 * Slabs are chained into three list: fully used, partial, fully free slabs.
218 */
219struct slab {
220 struct list_head list;
221 unsigned long colouroff;
222 void *s_mem; /* including colour offset */
223 unsigned int inuse; /* num of objs active in slab */
224 kmem_bufctl_t free;
Christoph Lametere498be72005-09-09 13:03:32 -0700225 unsigned short nodeid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226};
227
228/*
229 * struct slab_rcu
230 *
231 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
232 * arrange for kmem_freepages to be called via RCU. This is useful if
233 * we need to approach a kernel structure obliquely, from its address
234 * obtained without the usual locking. We can lock the structure to
235 * stabilize it and check it's still at the given address, only if we
236 * can be sure that the memory has not been meanwhile reused for some
237 * other kind of object (which our subsystem's lock might corrupt).
238 *
239 * rcu_read_lock before reading the address, then rcu_read_unlock after
240 * taking the spinlock within the structure expected at that address.
241 *
242 * We assume struct slab_rcu can overlay struct slab when destroying.
243 */
244struct slab_rcu {
245 struct rcu_head head;
246 kmem_cache_t *cachep;
247 void *addr;
248};
249
250/*
251 * struct array_cache
252 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 * Purpose:
254 * - LIFO ordering, to hand out cache-warm objects from _alloc
255 * - reduce the number of linked list operations
256 * - reduce spinlock operations
257 *
258 * The limit is stored in the per-cpu structure to reduce the data cache
259 * footprint.
260 *
261 */
262struct array_cache {
263 unsigned int avail;
264 unsigned int limit;
265 unsigned int batchcount;
266 unsigned int touched;
Christoph Lametere498be72005-09-09 13:03:32 -0700267 spinlock_t lock;
268 void *entry[0]; /*
269 * Must have this definition in here for the proper
270 * alignment of array_cache. Also simplifies accessing
271 * the entries.
272 * [0] is for gcc 2.95. It should really be [].
273 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274};
275
276/* bootstrap: The caches do not work without cpuarrays anymore,
277 * but the cpuarrays are allocated from the generic caches...
278 */
279#define BOOT_CPUCACHE_ENTRIES 1
280struct arraycache_init {
281 struct array_cache cache;
282 void * entries[BOOT_CPUCACHE_ENTRIES];
283};
284
285/*
Christoph Lametere498be72005-09-09 13:03:32 -0700286 * The slab lists for all objects.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 */
288struct kmem_list3 {
289 struct list_head slabs_partial; /* partial list first, better asm code */
290 struct list_head slabs_full;
291 struct list_head slabs_free;
292 unsigned long free_objects;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 unsigned long next_reap;
Christoph Lametere498be72005-09-09 13:03:32 -0700294 int free_touched;
295 unsigned int free_limit;
296 spinlock_t list_lock;
297 struct array_cache *shared; /* shared per node */
298 struct array_cache **alien; /* on other nodes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299};
300
Christoph Lametere498be72005-09-09 13:03:32 -0700301/*
302 * Need this for bootstrapping a per node allocator.
303 */
304#define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
305struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
306#define CACHE_CACHE 0
307#define SIZE_AC 1
308#define SIZE_L3 (1 + MAX_NUMNODES)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309
Christoph Lametere498be72005-09-09 13:03:32 -0700310/*
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700311 * This function must be completely optimized away if
Christoph Lametere498be72005-09-09 13:03:32 -0700312 * a constant is passed to it. Mostly the same as
313 * what is in linux/slab.h except it returns an
314 * index.
315 */
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700316static __always_inline int index_of(const size_t size)
Christoph Lametere498be72005-09-09 13:03:32 -0700317{
318 if (__builtin_constant_p(size)) {
319 int i = 0;
320
321#define CACHE(x) \
322 if (size <=x) \
323 return i; \
324 else \
325 i++;
326#include "linux/kmalloc_sizes.h"
327#undef CACHE
328 {
329 extern void __bad_size(void);
330 __bad_size();
331 }
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700332 } else
333 BUG();
Christoph Lametere498be72005-09-09 13:03:32 -0700334 return 0;
335}
336
337#define INDEX_AC index_of(sizeof(struct arraycache_init))
338#define INDEX_L3 index_of(sizeof(struct kmem_list3))
339
340static inline void kmem_list3_init(struct kmem_list3 *parent)
341{
342 INIT_LIST_HEAD(&parent->slabs_full);
343 INIT_LIST_HEAD(&parent->slabs_partial);
344 INIT_LIST_HEAD(&parent->slabs_free);
345 parent->shared = NULL;
346 parent->alien = NULL;
347 spin_lock_init(&parent->list_lock);
348 parent->free_objects = 0;
349 parent->free_touched = 0;
350}
351
352#define MAKE_LIST(cachep, listp, slab, nodeid) \
353 do { \
354 INIT_LIST_HEAD(listp); \
355 list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
356 } while (0)
357
358#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
359 do { \
360 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
361 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
362 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
363 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
365/*
366 * kmem_cache_t
367 *
368 * manages a cache.
369 */
370
Pekka J Enberg2109a2d2005-11-07 00:58:01 -0800371struct kmem_cache {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372/* 1) per-cpu data, touched during every alloc/free */
373 struct array_cache *array[NR_CPUS];
374 unsigned int batchcount;
375 unsigned int limit;
Christoph Lametere498be72005-09-09 13:03:32 -0700376 unsigned int shared;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 unsigned int objsize;
Christoph Lametere498be72005-09-09 13:03:32 -0700378/* 2) touched by every alloc & free from the backend */
379 struct kmem_list3 *nodelists[MAX_NUMNODES];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 unsigned int flags; /* constant flags */
381 unsigned int num; /* # of objs per slab */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 spinlock_t spinlock;
383
384/* 3) cache_grow/shrink */
385 /* order of pgs per slab (2^n) */
386 unsigned int gfporder;
387
388 /* force GFP flags, e.g. GFP_DMA */
Al Viro6daa0e22005-10-21 03:18:50 -0400389 gfp_t gfpflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390
391 size_t colour; /* cache colouring range */
392 unsigned int colour_off; /* colour offset */
393 unsigned int colour_next; /* cache colouring */
394 kmem_cache_t *slabp_cache;
395 unsigned int slab_size;
396 unsigned int dflags; /* dynamic flags */
397
398 /* constructor func */
399 void (*ctor)(void *, kmem_cache_t *, unsigned long);
400
401 /* de-constructor func */
402 void (*dtor)(void *, kmem_cache_t *, unsigned long);
403
404/* 4) cache creation/removal */
405 const char *name;
406 struct list_head next;
407
408/* 5) statistics */
409#if STATS
410 unsigned long num_active;
411 unsigned long num_allocations;
412 unsigned long high_mark;
413 unsigned long grown;
414 unsigned long reaped;
415 unsigned long errors;
416 unsigned long max_freeable;
417 unsigned long node_allocs;
Christoph Lametere498be72005-09-09 13:03:32 -0700418 unsigned long node_frees;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 atomic_t allochit;
420 atomic_t allocmiss;
421 atomic_t freehit;
422 atomic_t freemiss;
423#endif
424#if DEBUG
425 int dbghead;
426 int reallen;
427#endif
428};
429
430#define CFLGS_OFF_SLAB (0x80000000UL)
431#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
432
433#define BATCHREFILL_LIMIT 16
434/* Optimization question: fewer reaps means less
435 * probability for unnessary cpucache drain/refill cycles.
436 *
437 * OTHO the cpuarrays can contain lots of objects,
438 * which could lock up otherwise freeable slabs.
439 */
440#define REAPTIMEOUT_CPUC (2*HZ)
441#define REAPTIMEOUT_LIST3 (4*HZ)
442
443#if STATS
444#define STATS_INC_ACTIVE(x) ((x)->num_active++)
445#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
446#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
447#define STATS_INC_GROWN(x) ((x)->grown++)
448#define STATS_INC_REAPED(x) ((x)->reaped++)
449#define STATS_SET_HIGH(x) do { if ((x)->num_active > (x)->high_mark) \
450 (x)->high_mark = (x)->num_active; \
451 } while (0)
452#define STATS_INC_ERR(x) ((x)->errors++)
453#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
Christoph Lametere498be72005-09-09 13:03:32 -0700454#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455#define STATS_SET_FREEABLE(x, i) \
456 do { if ((x)->max_freeable < i) \
457 (x)->max_freeable = i; \
458 } while (0)
459
460#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
461#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
462#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
463#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
464#else
465#define STATS_INC_ACTIVE(x) do { } while (0)
466#define STATS_DEC_ACTIVE(x) do { } while (0)
467#define STATS_INC_ALLOCED(x) do { } while (0)
468#define STATS_INC_GROWN(x) do { } while (0)
469#define STATS_INC_REAPED(x) do { } while (0)
470#define STATS_SET_HIGH(x) do { } while (0)
471#define STATS_INC_ERR(x) do { } while (0)
472#define STATS_INC_NODEALLOCS(x) do { } while (0)
Christoph Lametere498be72005-09-09 13:03:32 -0700473#define STATS_INC_NODEFREES(x) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474#define STATS_SET_FREEABLE(x, i) \
475 do { } while (0)
476
477#define STATS_INC_ALLOCHIT(x) do { } while (0)
478#define STATS_INC_ALLOCMISS(x) do { } while (0)
479#define STATS_INC_FREEHIT(x) do { } while (0)
480#define STATS_INC_FREEMISS(x) do { } while (0)
481#endif
482
483#if DEBUG
484/* Magic nums for obj red zoning.
485 * Placed in the first word before and the first word after an obj.
486 */
487#define RED_INACTIVE 0x5A2CF071UL /* when obj is inactive */
488#define RED_ACTIVE 0x170FC2A5UL /* when obj is active */
489
490/* ...and for poisoning */
491#define POISON_INUSE 0x5a /* for use-uninitialised poisoning */
492#define POISON_FREE 0x6b /* for use-after-free poisoning */
493#define POISON_END 0xa5 /* end-byte of poisoning */
494
495/* memory layout of objects:
496 * 0 : objp
497 * 0 .. cachep->dbghead - BYTES_PER_WORD - 1: padding. This ensures that
498 * the end of an object is aligned with the end of the real
499 * allocation. Catches writes behind the end of the allocation.
500 * cachep->dbghead - BYTES_PER_WORD .. cachep->dbghead - 1:
501 * redzone word.
502 * cachep->dbghead: The real object.
503 * cachep->objsize - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
504 * cachep->objsize - 1* BYTES_PER_WORD: last caller address [BYTES_PER_WORD long]
505 */
506static int obj_dbghead(kmem_cache_t *cachep)
507{
508 return cachep->dbghead;
509}
510
511static int obj_reallen(kmem_cache_t *cachep)
512{
513 return cachep->reallen;
514}
515
516static unsigned long *dbg_redzone1(kmem_cache_t *cachep, void *objp)
517{
518 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
519 return (unsigned long*) (objp+obj_dbghead(cachep)-BYTES_PER_WORD);
520}
521
522static unsigned long *dbg_redzone2(kmem_cache_t *cachep, void *objp)
523{
524 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
525 if (cachep->flags & SLAB_STORE_USER)
526 return (unsigned long*) (objp+cachep->objsize-2*BYTES_PER_WORD);
527 return (unsigned long*) (objp+cachep->objsize-BYTES_PER_WORD);
528}
529
530static void **dbg_userword(kmem_cache_t *cachep, void *objp)
531{
532 BUG_ON(!(cachep->flags & SLAB_STORE_USER));
533 return (void**)(objp+cachep->objsize-BYTES_PER_WORD);
534}
535
536#else
537
538#define obj_dbghead(x) 0
539#define obj_reallen(cachep) (cachep->objsize)
540#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;})
541#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;})
542#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
543
544#endif
545
546/*
547 * Maximum size of an obj (in 2^order pages)
548 * and absolute limit for the gfp order.
549 */
550#if defined(CONFIG_LARGE_ALLOCS)
551#define MAX_OBJ_ORDER 13 /* up to 32Mb */
552#define MAX_GFP_ORDER 13 /* up to 32Mb */
553#elif defined(CONFIG_MMU)
554#define MAX_OBJ_ORDER 5 /* 32 pages */
555#define MAX_GFP_ORDER 5 /* 32 pages */
556#else
557#define MAX_OBJ_ORDER 8 /* up to 1Mb */
558#define MAX_GFP_ORDER 8 /* up to 1Mb */
559#endif
560
561/*
562 * Do not go above this order unless 0 objects fit into the slab.
563 */
564#define BREAK_GFP_ORDER_HI 1
565#define BREAK_GFP_ORDER_LO 0
566static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
567
568/* Macros for storing/retrieving the cachep and or slab from the
569 * global 'mem_map'. These are used to find the slab an obj belongs to.
570 * With kfree(), these are used to find the cache which an obj belongs to.
571 */
572#define SET_PAGE_CACHE(pg,x) ((pg)->lru.next = (struct list_head *)(x))
573#define GET_PAGE_CACHE(pg) ((kmem_cache_t *)(pg)->lru.next)
574#define SET_PAGE_SLAB(pg,x) ((pg)->lru.prev = (struct list_head *)(x))
575#define GET_PAGE_SLAB(pg) ((struct slab *)(pg)->lru.prev)
576
577/* These are the default caches for kmalloc. Custom caches can have other sizes. */
578struct cache_sizes malloc_sizes[] = {
579#define CACHE(x) { .cs_size = (x) },
580#include <linux/kmalloc_sizes.h>
581 CACHE(ULONG_MAX)
582#undef CACHE
583};
584EXPORT_SYMBOL(malloc_sizes);
585
586/* Must match cache_sizes above. Out of line to keep cache footprint low. */
587struct cache_names {
588 char *name;
589 char *name_dma;
590};
591
592static struct cache_names __initdata cache_names[] = {
593#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
594#include <linux/kmalloc_sizes.h>
595 { NULL, }
596#undef CACHE
597};
598
599static struct arraycache_init initarray_cache __initdata =
600 { { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
601static struct arraycache_init initarray_generic =
602 { { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
603
604/* internal cache of cache description objs */
605static kmem_cache_t cache_cache = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 .batchcount = 1,
607 .limit = BOOT_CPUCACHE_ENTRIES,
Christoph Lametere498be72005-09-09 13:03:32 -0700608 .shared = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 .objsize = sizeof(kmem_cache_t),
610 .flags = SLAB_NO_REAP,
611 .spinlock = SPIN_LOCK_UNLOCKED,
612 .name = "kmem_cache",
613#if DEBUG
614 .reallen = sizeof(kmem_cache_t),
615#endif
616};
617
618/* Guard access to the cache-chain. */
619static struct semaphore cache_chain_sem;
620static struct list_head cache_chain;
621
622/*
623 * vm_enough_memory() looks at this to determine how many
624 * slab-allocated pages are possibly freeable under pressure
625 *
626 * SLAB_RECLAIM_ACCOUNT turns this on per-slab
627 */
628atomic_t slab_reclaim_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630/*
631 * chicken and egg problem: delay the per-cpu array allocation
632 * until the general caches are up.
633 */
634static enum {
635 NONE,
Christoph Lametere498be72005-09-09 13:03:32 -0700636 PARTIAL_AC,
637 PARTIAL_L3,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 FULL
639} g_cpucache_up;
640
641static DEFINE_PER_CPU(struct work_struct, reap_work);
642
Christoph Lameterff694162005-09-22 21:44:02 -0700643static void free_block(kmem_cache_t* cachep, void** objpp, int len, int node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644static void enable_cpucache (kmem_cache_t *cachep);
645static void cache_reap (void *unused);
Christoph Lametere498be72005-09-09 13:03:32 -0700646static int __node_shrink(kmem_cache_t *cachep, int node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
648static inline struct array_cache *ac_data(kmem_cache_t *cachep)
649{
650 return cachep->array[smp_processor_id()];
651}
652
Al Virodd0fc662005-10-07 07:46:04 +0100653static inline kmem_cache_t *__find_general_cachep(size_t size, gfp_t gfpflags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654{
655 struct cache_sizes *csizep = malloc_sizes;
656
657#if DEBUG
658 /* This happens if someone tries to call
659 * kmem_cache_create(), or __kmalloc(), before
660 * the generic caches are initialized.
661 */
Alok Katariac7e43c72005-09-14 12:17:53 -0700662 BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663#endif
664 while (size > csizep->cs_size)
665 csizep++;
666
667 /*
Martin Hicks0abf40c2005-09-03 15:54:54 -0700668 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 * has cs_{dma,}cachep==NULL. Thus no special case
670 * for large kmalloc calls required.
671 */
672 if (unlikely(gfpflags & GFP_DMA))
673 return csizep->cs_dmacachep;
674 return csizep->cs_cachep;
675}
676
Al Virodd0fc662005-10-07 07:46:04 +0100677kmem_cache_t *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700678{
679 return __find_general_cachep(size, gfpflags);
680}
681EXPORT_SYMBOL(kmem_find_general_cachep);
682
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683/* Cal the num objs, wastage, and bytes left over for a given slab size. */
684static void cache_estimate(unsigned long gfporder, size_t size, size_t align,
685 int flags, size_t *left_over, unsigned int *num)
686{
687 int i;
688 size_t wastage = PAGE_SIZE<<gfporder;
689 size_t extra = 0;
690 size_t base = 0;
691
692 if (!(flags & CFLGS_OFF_SLAB)) {
693 base = sizeof(struct slab);
694 extra = sizeof(kmem_bufctl_t);
695 }
696 i = 0;
697 while (i*size + ALIGN(base+i*extra, align) <= wastage)
698 i++;
699 if (i > 0)
700 i--;
701
702 if (i > SLAB_LIMIT)
703 i = SLAB_LIMIT;
704
705 *num = i;
706 wastage -= i*size;
707 wastage -= ALIGN(base+i*extra, align);
708 *left_over = wastage;
709}
710
711#define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
712
713static void __slab_error(const char *function, kmem_cache_t *cachep, char *msg)
714{
715 printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
716 function, cachep->name, msg);
717 dump_stack();
718}
719
720/*
721 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
722 * via the workqueue/eventd.
723 * Add the CPU number into the expiration time to minimize the possibility of
724 * the CPUs getting into lockstep and contending for the global cache chain
725 * lock.
726 */
727static void __devinit start_cpu_timer(int cpu)
728{
729 struct work_struct *reap_work = &per_cpu(reap_work, cpu);
730
731 /*
732 * When this gets called from do_initcalls via cpucache_init(),
733 * init_workqueues() has already run, so keventd will be setup
734 * at that time.
735 */
736 if (keventd_up() && reap_work->func == NULL) {
737 INIT_WORK(reap_work, cache_reap, NULL);
738 schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
739 }
740}
741
Christoph Lametere498be72005-09-09 13:03:32 -0700742static struct array_cache *alloc_arraycache(int node, int entries,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 int batchcount)
744{
745 int memsize = sizeof(void*)*entries+sizeof(struct array_cache);
746 struct array_cache *nc = NULL;
747
Christoph Lametere498be72005-09-09 13:03:32 -0700748 nc = kmalloc_node(memsize, GFP_KERNEL, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 if (nc) {
750 nc->avail = 0;
751 nc->limit = entries;
752 nc->batchcount = batchcount;
753 nc->touched = 0;
Christoph Lametere498be72005-09-09 13:03:32 -0700754 spin_lock_init(&nc->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 }
756 return nc;
757}
758
Christoph Lametere498be72005-09-09 13:03:32 -0700759#ifdef CONFIG_NUMA
760static inline struct array_cache **alloc_alien_cache(int node, int limit)
761{
762 struct array_cache **ac_ptr;
763 int memsize = sizeof(void*)*MAX_NUMNODES;
764 int i;
765
766 if (limit > 1)
767 limit = 12;
768 ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node);
769 if (ac_ptr) {
770 for_each_node(i) {
771 if (i == node || !node_online(i)) {
772 ac_ptr[i] = NULL;
773 continue;
774 }
775 ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d);
776 if (!ac_ptr[i]) {
777 for (i--; i <=0; i--)
778 kfree(ac_ptr[i]);
779 kfree(ac_ptr);
780 return NULL;
781 }
782 }
783 }
784 return ac_ptr;
785}
786
787static inline void free_alien_cache(struct array_cache **ac_ptr)
788{
789 int i;
790
791 if (!ac_ptr)
792 return;
793
794 for_each_node(i)
795 kfree(ac_ptr[i]);
796
797 kfree(ac_ptr);
798}
799
800static inline void __drain_alien_cache(kmem_cache_t *cachep, struct array_cache *ac, int node)
801{
802 struct kmem_list3 *rl3 = cachep->nodelists[node];
803
804 if (ac->avail) {
805 spin_lock(&rl3->list_lock);
Christoph Lameterff694162005-09-22 21:44:02 -0700806 free_block(cachep, ac->entry, ac->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -0700807 ac->avail = 0;
808 spin_unlock(&rl3->list_lock);
809 }
810}
811
812static void drain_alien_cache(kmem_cache_t *cachep, struct kmem_list3 *l3)
813{
814 int i=0;
815 struct array_cache *ac;
816 unsigned long flags;
817
818 for_each_online_node(i) {
819 ac = l3->alien[i];
820 if (ac) {
821 spin_lock_irqsave(&ac->lock, flags);
822 __drain_alien_cache(cachep, ac, i);
823 spin_unlock_irqrestore(&ac->lock, flags);
824 }
825 }
826}
827#else
828#define alloc_alien_cache(node, limit) do { } while (0)
829#define free_alien_cache(ac_ptr) do { } while (0)
830#define drain_alien_cache(cachep, l3) do { } while (0)
831#endif
832
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833static int __devinit cpuup_callback(struct notifier_block *nfb,
834 unsigned long action, void *hcpu)
835{
836 long cpu = (long)hcpu;
837 kmem_cache_t* cachep;
Christoph Lametere498be72005-09-09 13:03:32 -0700838 struct kmem_list3 *l3 = NULL;
839 int node = cpu_to_node(cpu);
840 int memsize = sizeof(struct kmem_list3);
841 struct array_cache *nc = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
843 switch (action) {
844 case CPU_UP_PREPARE:
845 down(&cache_chain_sem);
Christoph Lametere498be72005-09-09 13:03:32 -0700846 /* we need to do this right in the beginning since
847 * alloc_arraycache's are going to use this list.
848 * kmalloc_node allows us to add the slab to the right
849 * kmem_list3 and not this cpu's kmem_list3
850 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851
Christoph Lametere498be72005-09-09 13:03:32 -0700852 list_for_each_entry(cachep, &cache_chain, next) {
853 /* setup the size64 kmemlist for cpu before we can
854 * begin anything. Make sure some other cpu on this
855 * node has not already allocated this
856 */
857 if (!cachep->nodelists[node]) {
858 if (!(l3 = kmalloc_node(memsize,
859 GFP_KERNEL, node)))
860 goto bad;
861 kmem_list3_init(l3);
862 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
863 ((unsigned long)cachep)%REAPTIMEOUT_LIST3;
864
865 cachep->nodelists[node] = l3;
866 }
867
868 spin_lock_irq(&cachep->nodelists[node]->list_lock);
869 cachep->nodelists[node]->free_limit =
870 (1 + nr_cpus_node(node)) *
871 cachep->batchcount + cachep->num;
872 spin_unlock_irq(&cachep->nodelists[node]->list_lock);
873 }
874
875 /* Now we can go ahead with allocating the shared array's
876 & array cache's */
877 list_for_each_entry(cachep, &cache_chain, next) {
878 nc = alloc_arraycache(node, cachep->limit,
879 cachep->batchcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 if (!nc)
881 goto bad;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 cachep->array[cpu] = nc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
Christoph Lametere498be72005-09-09 13:03:32 -0700884 l3 = cachep->nodelists[node];
885 BUG_ON(!l3);
886 if (!l3->shared) {
887 if (!(nc = alloc_arraycache(node,
888 cachep->shared*cachep->batchcount,
889 0xbaadf00d)))
890 goto bad;
891
892 /* we are serialised from CPU_DEAD or
893 CPU_UP_CANCELLED by the cpucontrol lock */
894 l3->shared = nc;
895 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 }
897 up(&cache_chain_sem);
898 break;
899 case CPU_ONLINE:
900 start_cpu_timer(cpu);
901 break;
902#ifdef CONFIG_HOTPLUG_CPU
903 case CPU_DEAD:
904 /* fall thru */
905 case CPU_UP_CANCELED:
906 down(&cache_chain_sem);
907
908 list_for_each_entry(cachep, &cache_chain, next) {
909 struct array_cache *nc;
Christoph Lametere498be72005-09-09 13:03:32 -0700910 cpumask_t mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911
Christoph Lametere498be72005-09-09 13:03:32 -0700912 mask = node_to_cpumask(node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 spin_lock_irq(&cachep->spinlock);
914 /* cpu is dead; no one can alloc from it. */
915 nc = cachep->array[cpu];
916 cachep->array[cpu] = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -0700917 l3 = cachep->nodelists[node];
918
919 if (!l3)
920 goto unlock_cache;
921
922 spin_lock(&l3->list_lock);
923
924 /* Free limit for this kmem_list3 */
925 l3->free_limit -= cachep->batchcount;
926 if (nc)
Christoph Lameterff694162005-09-22 21:44:02 -0700927 free_block(cachep, nc->entry, nc->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -0700928
929 if (!cpus_empty(mask)) {
930 spin_unlock(&l3->list_lock);
931 goto unlock_cache;
932 }
933
934 if (l3->shared) {
935 free_block(cachep, l3->shared->entry,
Christoph Lameterff694162005-09-22 21:44:02 -0700936 l3->shared->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -0700937 kfree(l3->shared);
938 l3->shared = NULL;
939 }
940 if (l3->alien) {
941 drain_alien_cache(cachep, l3);
942 free_alien_cache(l3->alien);
943 l3->alien = NULL;
944 }
945
946 /* free slabs belonging to this node */
947 if (__node_shrink(cachep, node)) {
948 cachep->nodelists[node] = NULL;
949 spin_unlock(&l3->list_lock);
950 kfree(l3);
951 } else {
952 spin_unlock(&l3->list_lock);
953 }
954unlock_cache:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 spin_unlock_irq(&cachep->spinlock);
956 kfree(nc);
957 }
958 up(&cache_chain_sem);
959 break;
960#endif
961 }
962 return NOTIFY_OK;
963bad:
964 up(&cache_chain_sem);
965 return NOTIFY_BAD;
966}
967
968static struct notifier_block cpucache_notifier = { &cpuup_callback, NULL, 0 };
969
Christoph Lametere498be72005-09-09 13:03:32 -0700970/*
971 * swap the static kmem_list3 with kmalloced memory
972 */
973static void init_list(kmem_cache_t *cachep, struct kmem_list3 *list,
974 int nodeid)
975{
976 struct kmem_list3 *ptr;
977
978 BUG_ON(cachep->nodelists[nodeid] != list);
979 ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid);
980 BUG_ON(!ptr);
981
982 local_irq_disable();
983 memcpy(ptr, list, sizeof(struct kmem_list3));
984 MAKE_ALL_LISTS(cachep, ptr, nodeid);
985 cachep->nodelists[nodeid] = ptr;
986 local_irq_enable();
987}
988
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989/* Initialisation.
990 * Called after the gfp() functions have been enabled, and before smp_init().
991 */
992void __init kmem_cache_init(void)
993{
994 size_t left_over;
995 struct cache_sizes *sizes;
996 struct cache_names *names;
Christoph Lametere498be72005-09-09 13:03:32 -0700997 int i;
998
999 for (i = 0; i < NUM_INIT_LISTS; i++) {
1000 kmem_list3_init(&initkmem_list3[i]);
1001 if (i < MAX_NUMNODES)
1002 cache_cache.nodelists[i] = NULL;
1003 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004
1005 /*
1006 * Fragmentation resistance on low memory - only use bigger
1007 * page orders on machines with more than 32MB of memory.
1008 */
1009 if (num_physpages > (32 << 20) >> PAGE_SHIFT)
1010 slab_break_gfp_order = BREAK_GFP_ORDER_HI;
1011
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 /* Bootstrap is tricky, because several objects are allocated
1013 * from caches that do not exist yet:
1014 * 1) initialize the cache_cache cache: it contains the kmem_cache_t
1015 * structures of all caches, except cache_cache itself: cache_cache
1016 * is statically allocated.
Christoph Lametere498be72005-09-09 13:03:32 -07001017 * Initially an __init data area is used for the head array and the
1018 * kmem_list3 structures, it's replaced with a kmalloc allocated
1019 * array at the end of the bootstrap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 * 2) Create the first kmalloc cache.
Christoph Lametere498be72005-09-09 13:03:32 -07001021 * The kmem_cache_t for the new cache is allocated normally.
1022 * An __init data area is used for the head array.
1023 * 3) Create the remaining kmalloc caches, with minimally sized
1024 * head arrays.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025 * 4) Replace the __init data head arrays for cache_cache and the first
1026 * kmalloc cache with kmalloc allocated arrays.
Christoph Lametere498be72005-09-09 13:03:32 -07001027 * 5) Replace the __init data for kmem_list3 for cache_cache and
1028 * the other cache's with kmalloc allocated memory.
1029 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 */
1031
1032 /* 1) create the cache_cache */
1033 init_MUTEX(&cache_chain_sem);
1034 INIT_LIST_HEAD(&cache_chain);
1035 list_add(&cache_cache.next, &cache_chain);
1036 cache_cache.colour_off = cache_line_size();
1037 cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
Christoph Lametere498be72005-09-09 13:03:32 -07001038 cache_cache.nodelists[numa_node_id()] = &initkmem_list3[CACHE_CACHE];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039
1040 cache_cache.objsize = ALIGN(cache_cache.objsize, cache_line_size());
1041
1042 cache_estimate(0, cache_cache.objsize, cache_line_size(), 0,
1043 &left_over, &cache_cache.num);
1044 if (!cache_cache.num)
1045 BUG();
1046
1047 cache_cache.colour = left_over/cache_cache.colour_off;
1048 cache_cache.colour_next = 0;
1049 cache_cache.slab_size = ALIGN(cache_cache.num*sizeof(kmem_bufctl_t) +
1050 sizeof(struct slab), cache_line_size());
1051
1052 /* 2+3) create the kmalloc caches */
1053 sizes = malloc_sizes;
1054 names = cache_names;
1055
Christoph Lametere498be72005-09-09 13:03:32 -07001056 /* Initialize the caches that provide memory for the array cache
1057 * and the kmem_list3 structures first.
1058 * Without this, further allocations will bug
1059 */
1060
1061 sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
1062 sizes[INDEX_AC].cs_size, ARCH_KMALLOC_MINALIGN,
1063 (ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL);
1064
1065 if (INDEX_AC != INDEX_L3)
1066 sizes[INDEX_L3].cs_cachep =
1067 kmem_cache_create(names[INDEX_L3].name,
1068 sizes[INDEX_L3].cs_size, ARCH_KMALLOC_MINALIGN,
1069 (ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL);
1070
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 while (sizes->cs_size != ULONG_MAX) {
Christoph Lametere498be72005-09-09 13:03:32 -07001072 /*
1073 * For performance, all the general caches are L1 aligned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 * This should be particularly beneficial on SMP boxes, as it
1075 * eliminates "false sharing".
1076 * Note for systems short on memory removing the alignment will
Christoph Lametere498be72005-09-09 13:03:32 -07001077 * allow tighter packing of the smaller caches.
1078 */
1079 if(!sizes->cs_cachep)
1080 sizes->cs_cachep = kmem_cache_create(names->name,
1081 sizes->cs_size, ARCH_KMALLOC_MINALIGN,
1082 (ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083
1084 /* Inc off-slab bufctl limit until the ceiling is hit. */
1085 if (!(OFF_SLAB(sizes->cs_cachep))) {
1086 offslab_limit = sizes->cs_size-sizeof(struct slab);
1087 offslab_limit /= sizeof(kmem_bufctl_t);
1088 }
1089
1090 sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
1091 sizes->cs_size, ARCH_KMALLOC_MINALIGN,
1092 (ARCH_KMALLOC_FLAGS | SLAB_CACHE_DMA | SLAB_PANIC),
1093 NULL, NULL);
1094
1095 sizes++;
1096 names++;
1097 }
1098 /* 4) Replace the bootstrap head arrays */
1099 {
1100 void * ptr;
Christoph Lametere498be72005-09-09 13:03:32 -07001101
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
Christoph Lametere498be72005-09-09 13:03:32 -07001103
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104 local_irq_disable();
1105 BUG_ON(ac_data(&cache_cache) != &initarray_cache.cache);
Christoph Lametere498be72005-09-09 13:03:32 -07001106 memcpy(ptr, ac_data(&cache_cache),
1107 sizeof(struct arraycache_init));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108 cache_cache.array[smp_processor_id()] = ptr;
1109 local_irq_enable();
Christoph Lametere498be72005-09-09 13:03:32 -07001110
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
Christoph Lametere498be72005-09-09 13:03:32 -07001112
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 local_irq_disable();
Christoph Lametere498be72005-09-09 13:03:32 -07001114 BUG_ON(ac_data(malloc_sizes[INDEX_AC].cs_cachep)
1115 != &initarray_generic.cache);
1116 memcpy(ptr, ac_data(malloc_sizes[INDEX_AC].cs_cachep),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 sizeof(struct arraycache_init));
Christoph Lametere498be72005-09-09 13:03:32 -07001118 malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
1119 ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120 local_irq_enable();
1121 }
Christoph Lametere498be72005-09-09 13:03:32 -07001122 /* 5) Replace the bootstrap kmem_list3's */
1123 {
1124 int node;
1125 /* Replace the static kmem_list3 structures for the boot cpu */
1126 init_list(&cache_cache, &initkmem_list3[CACHE_CACHE],
1127 numa_node_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128
Christoph Lametere498be72005-09-09 13:03:32 -07001129 for_each_online_node(node) {
1130 init_list(malloc_sizes[INDEX_AC].cs_cachep,
1131 &initkmem_list3[SIZE_AC+node], node);
1132
1133 if (INDEX_AC != INDEX_L3) {
1134 init_list(malloc_sizes[INDEX_L3].cs_cachep,
1135 &initkmem_list3[SIZE_L3+node],
1136 node);
1137 }
1138 }
1139 }
1140
1141 /* 6) resize the head arrays to their final sizes */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 {
1143 kmem_cache_t *cachep;
1144 down(&cache_chain_sem);
1145 list_for_each_entry(cachep, &cache_chain, next)
1146 enable_cpucache(cachep);
1147 up(&cache_chain_sem);
1148 }
1149
1150 /* Done! */
1151 g_cpucache_up = FULL;
1152
1153 /* Register a cpu startup notifier callback
1154 * that initializes ac_data for all new cpus
1155 */
1156 register_cpu_notifier(&cpucache_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157
1158 /* The reap timers are started later, with a module init call:
1159 * That part of the kernel is not yet operational.
1160 */
1161}
1162
1163static int __init cpucache_init(void)
1164{
1165 int cpu;
1166
1167 /*
1168 * Register the timers that return unneeded
1169 * pages to gfp.
1170 */
Christoph Lametere498be72005-09-09 13:03:32 -07001171 for_each_online_cpu(cpu)
1172 start_cpu_timer(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173
1174 return 0;
1175}
1176
1177__initcall(cpucache_init);
1178
1179/*
1180 * Interface to system's page allocator. No need to hold the cache-lock.
1181 *
1182 * If we requested dmaable memory, we will get it. Even if we
1183 * did not request dmaable memory, we might get it, but that
1184 * would be relatively rare and ignorable.
1185 */
Al Virodd0fc662005-10-07 07:46:04 +01001186static void *kmem_getpages(kmem_cache_t *cachep, gfp_t flags, int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187{
1188 struct page *page;
1189 void *addr;
1190 int i;
1191
1192 flags |= cachep->gfpflags;
1193 if (likely(nodeid == -1)) {
1194 page = alloc_pages(flags, cachep->gfporder);
1195 } else {
1196 page = alloc_pages_node(nodeid, flags, cachep->gfporder);
1197 }
1198 if (!page)
1199 return NULL;
1200 addr = page_address(page);
1201
1202 i = (1 << cachep->gfporder);
1203 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1204 atomic_add(i, &slab_reclaim_pages);
1205 add_page_state(nr_slab, i);
1206 while (i--) {
1207 SetPageSlab(page);
1208 page++;
1209 }
1210 return addr;
1211}
1212
1213/*
1214 * Interface to system's page release.
1215 */
1216static void kmem_freepages(kmem_cache_t *cachep, void *addr)
1217{
1218 unsigned long i = (1<<cachep->gfporder);
1219 struct page *page = virt_to_page(addr);
1220 const unsigned long nr_freed = i;
1221
1222 while (i--) {
1223 if (!TestClearPageSlab(page))
1224 BUG();
1225 page++;
1226 }
1227 sub_page_state(nr_slab, nr_freed);
1228 if (current->reclaim_state)
1229 current->reclaim_state->reclaimed_slab += nr_freed;
1230 free_pages((unsigned long)addr, cachep->gfporder);
1231 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1232 atomic_sub(1<<cachep->gfporder, &slab_reclaim_pages);
1233}
1234
1235static void kmem_rcu_free(struct rcu_head *head)
1236{
1237 struct slab_rcu *slab_rcu = (struct slab_rcu *) head;
1238 kmem_cache_t *cachep = slab_rcu->cachep;
1239
1240 kmem_freepages(cachep, slab_rcu->addr);
1241 if (OFF_SLAB(cachep))
1242 kmem_cache_free(cachep->slabp_cache, slab_rcu);
1243}
1244
1245#if DEBUG
1246
1247#ifdef CONFIG_DEBUG_PAGEALLOC
1248static void store_stackinfo(kmem_cache_t *cachep, unsigned long *addr,
1249 unsigned long caller)
1250{
1251 int size = obj_reallen(cachep);
1252
1253 addr = (unsigned long *)&((char*)addr)[obj_dbghead(cachep)];
1254
1255 if (size < 5*sizeof(unsigned long))
1256 return;
1257
1258 *addr++=0x12345678;
1259 *addr++=caller;
1260 *addr++=smp_processor_id();
1261 size -= 3*sizeof(unsigned long);
1262 {
1263 unsigned long *sptr = &caller;
1264 unsigned long svalue;
1265
1266 while (!kstack_end(sptr)) {
1267 svalue = *sptr++;
1268 if (kernel_text_address(svalue)) {
1269 *addr++=svalue;
1270 size -= sizeof(unsigned long);
1271 if (size <= sizeof(unsigned long))
1272 break;
1273 }
1274 }
1275
1276 }
1277 *addr++=0x87654321;
1278}
1279#endif
1280
1281static void poison_obj(kmem_cache_t *cachep, void *addr, unsigned char val)
1282{
1283 int size = obj_reallen(cachep);
1284 addr = &((char*)addr)[obj_dbghead(cachep)];
1285
1286 memset(addr, val, size);
1287 *(unsigned char *)(addr+size-1) = POISON_END;
1288}
1289
1290static void dump_line(char *data, int offset, int limit)
1291{
1292 int i;
1293 printk(KERN_ERR "%03x:", offset);
1294 for (i=0;i<limit;i++) {
1295 printk(" %02x", (unsigned char)data[offset+i]);
1296 }
1297 printk("\n");
1298}
1299#endif
1300
1301#if DEBUG
1302
1303static void print_objinfo(kmem_cache_t *cachep, void *objp, int lines)
1304{
1305 int i, size;
1306 char *realobj;
1307
1308 if (cachep->flags & SLAB_RED_ZONE) {
1309 printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n",
1310 *dbg_redzone1(cachep, objp),
1311 *dbg_redzone2(cachep, objp));
1312 }
1313
1314 if (cachep->flags & SLAB_STORE_USER) {
1315 printk(KERN_ERR "Last user: [<%p>]",
1316 *dbg_userword(cachep, objp));
1317 print_symbol("(%s)",
1318 (unsigned long)*dbg_userword(cachep, objp));
1319 printk("\n");
1320 }
1321 realobj = (char*)objp+obj_dbghead(cachep);
1322 size = obj_reallen(cachep);
1323 for (i=0; i<size && lines;i+=16, lines--) {
1324 int limit;
1325 limit = 16;
1326 if (i+limit > size)
1327 limit = size-i;
1328 dump_line(realobj, i, limit);
1329 }
1330}
1331
1332static void check_poison_obj(kmem_cache_t *cachep, void *objp)
1333{
1334 char *realobj;
1335 int size, i;
1336 int lines = 0;
1337
1338 realobj = (char*)objp+obj_dbghead(cachep);
1339 size = obj_reallen(cachep);
1340
1341 for (i=0;i<size;i++) {
1342 char exp = POISON_FREE;
1343 if (i == size-1)
1344 exp = POISON_END;
1345 if (realobj[i] != exp) {
1346 int limit;
1347 /* Mismatch ! */
1348 /* Print header */
1349 if (lines == 0) {
1350 printk(KERN_ERR "Slab corruption: start=%p, len=%d\n",
1351 realobj, size);
1352 print_objinfo(cachep, objp, 0);
1353 }
1354 /* Hexdump the affected line */
1355 i = (i/16)*16;
1356 limit = 16;
1357 if (i+limit > size)
1358 limit = size-i;
1359 dump_line(realobj, i, limit);
1360 i += 16;
1361 lines++;
1362 /* Limit to 5 lines */
1363 if (lines > 5)
1364 break;
1365 }
1366 }
1367 if (lines != 0) {
1368 /* Print some data about the neighboring objects, if they
1369 * exist:
1370 */
1371 struct slab *slabp = GET_PAGE_SLAB(virt_to_page(objp));
1372 int objnr;
1373
1374 objnr = (objp-slabp->s_mem)/cachep->objsize;
1375 if (objnr) {
1376 objp = slabp->s_mem+(objnr-1)*cachep->objsize;
1377 realobj = (char*)objp+obj_dbghead(cachep);
1378 printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
1379 realobj, size);
1380 print_objinfo(cachep, objp, 2);
1381 }
1382 if (objnr+1 < cachep->num) {
1383 objp = slabp->s_mem+(objnr+1)*cachep->objsize;
1384 realobj = (char*)objp+obj_dbghead(cachep);
1385 printk(KERN_ERR "Next obj: start=%p, len=%d\n",
1386 realobj, size);
1387 print_objinfo(cachep, objp, 2);
1388 }
1389 }
1390}
1391#endif
1392
1393/* Destroy all the objs in a slab, and release the mem back to the system.
1394 * Before calling the slab must have been unlinked from the cache.
1395 * The cache-lock is not held/needed.
1396 */
1397static void slab_destroy (kmem_cache_t *cachep, struct slab *slabp)
1398{
1399 void *addr = slabp->s_mem - slabp->colouroff;
1400
1401#if DEBUG
1402 int i;
1403 for (i = 0; i < cachep->num; i++) {
1404 void *objp = slabp->s_mem + cachep->objsize * i;
1405
1406 if (cachep->flags & SLAB_POISON) {
1407#ifdef CONFIG_DEBUG_PAGEALLOC
1408 if ((cachep->objsize%PAGE_SIZE)==0 && OFF_SLAB(cachep))
1409 kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE,1);
1410 else
1411 check_poison_obj(cachep, objp);
1412#else
1413 check_poison_obj(cachep, objp);
1414#endif
1415 }
1416 if (cachep->flags & SLAB_RED_ZONE) {
1417 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
1418 slab_error(cachep, "start of a freed object "
1419 "was overwritten");
1420 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
1421 slab_error(cachep, "end of a freed object "
1422 "was overwritten");
1423 }
1424 if (cachep->dtor && !(cachep->flags & SLAB_POISON))
1425 (cachep->dtor)(objp+obj_dbghead(cachep), cachep, 0);
1426 }
1427#else
1428 if (cachep->dtor) {
1429 int i;
1430 for (i = 0; i < cachep->num; i++) {
1431 void* objp = slabp->s_mem+cachep->objsize*i;
1432 (cachep->dtor)(objp, cachep, 0);
1433 }
1434 }
1435#endif
1436
1437 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
1438 struct slab_rcu *slab_rcu;
1439
1440 slab_rcu = (struct slab_rcu *) slabp;
1441 slab_rcu->cachep = cachep;
1442 slab_rcu->addr = addr;
1443 call_rcu(&slab_rcu->head, kmem_rcu_free);
1444 } else {
1445 kmem_freepages(cachep, addr);
1446 if (OFF_SLAB(cachep))
1447 kmem_cache_free(cachep->slabp_cache, slabp);
1448 }
1449}
1450
Christoph Lametere498be72005-09-09 13:03:32 -07001451/* For setting up all the kmem_list3s for cache whose objsize is same
1452 as size of kmem_list3. */
1453static inline void set_up_list3s(kmem_cache_t *cachep, int index)
1454{
1455 int node;
1456
1457 for_each_online_node(node) {
1458 cachep->nodelists[node] = &initkmem_list3[index+node];
1459 cachep->nodelists[node]->next_reap = jiffies +
1460 REAPTIMEOUT_LIST3 +
1461 ((unsigned long)cachep)%REAPTIMEOUT_LIST3;
1462 }
1463}
1464
Linus Torvalds1da177e2005-04-16 15:20:36 -07001465/**
1466 * kmem_cache_create - Create a cache.
1467 * @name: A string which is used in /proc/slabinfo to identify this cache.
1468 * @size: The size of objects to be created in this cache.
1469 * @align: The required alignment for the objects.
1470 * @flags: SLAB flags
1471 * @ctor: A constructor for the objects.
1472 * @dtor: A destructor for the objects.
1473 *
1474 * Returns a ptr to the cache on success, NULL on failure.
1475 * Cannot be called within a int, but can be interrupted.
1476 * The @ctor is run when new pages are allocated by the cache
1477 * and the @dtor is run before the pages are handed back.
1478 *
1479 * @name must be valid until the cache is destroyed. This implies that
1480 * the module calling this has to destroy the cache before getting
1481 * unloaded.
1482 *
1483 * The flags are
1484 *
1485 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
1486 * to catch references to uninitialised memory.
1487 *
1488 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
1489 * for buffer overruns.
1490 *
1491 * %SLAB_NO_REAP - Don't automatically reap this cache when we're under
1492 * memory pressure.
1493 *
1494 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
1495 * cacheline. This can be beneficial if you're counting cycles as closely
1496 * as davem.
1497 */
1498kmem_cache_t *
1499kmem_cache_create (const char *name, size_t size, size_t align,
1500 unsigned long flags, void (*ctor)(void*, kmem_cache_t *, unsigned long),
1501 void (*dtor)(void*, kmem_cache_t *, unsigned long))
1502{
1503 size_t left_over, slab_size, ralign;
1504 kmem_cache_t *cachep = NULL;
Andrew Morton4f12bb42005-11-07 00:58:00 -08001505 struct list_head *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506
1507 /*
1508 * Sanity checks... these are all serious usage bugs.
1509 */
1510 if ((!name) ||
1511 in_interrupt() ||
1512 (size < BYTES_PER_WORD) ||
1513 (size > (1<<MAX_OBJ_ORDER)*PAGE_SIZE) ||
1514 (dtor && !ctor)) {
1515 printk(KERN_ERR "%s: Early error in slab %s\n",
1516 __FUNCTION__, name);
1517 BUG();
1518 }
1519
Andrew Morton4f12bb42005-11-07 00:58:00 -08001520 down(&cache_chain_sem);
1521
1522 list_for_each(p, &cache_chain) {
1523 kmem_cache_t *pc = list_entry(p, kmem_cache_t, next);
1524 mm_segment_t old_fs = get_fs();
1525 char tmp;
1526 int res;
1527
1528 /*
1529 * This happens when the module gets unloaded and doesn't
1530 * destroy its slab cache and no-one else reuses the vmalloc
1531 * area of the module. Print a warning.
1532 */
1533 set_fs(KERNEL_DS);
1534 res = __get_user(tmp, pc->name);
1535 set_fs(old_fs);
1536 if (res) {
1537 printk("SLAB: cache with size %d has lost its name\n",
1538 pc->objsize);
1539 continue;
1540 }
1541
1542 if (!strcmp(pc->name,name)) {
1543 printk("kmem_cache_create: duplicate cache %s\n", name);
1544 dump_stack();
1545 goto oops;
1546 }
1547 }
1548
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549#if DEBUG
1550 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
1551 if ((flags & SLAB_DEBUG_INITIAL) && !ctor) {
1552 /* No constructor, but inital state check requested */
1553 printk(KERN_ERR "%s: No con, but init state check "
1554 "requested - %s\n", __FUNCTION__, name);
1555 flags &= ~SLAB_DEBUG_INITIAL;
1556 }
1557
1558#if FORCED_DEBUG
1559 /*
1560 * Enable redzoning and last user accounting, except for caches with
1561 * large objects, if the increased size would increase the object size
1562 * above the next power of two: caches with object sizes just above a
1563 * power of two have a significant amount of internal fragmentation.
1564 */
1565 if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD)))
1566 flags |= SLAB_RED_ZONE|SLAB_STORE_USER;
1567 if (!(flags & SLAB_DESTROY_BY_RCU))
1568 flags |= SLAB_POISON;
1569#endif
1570 if (flags & SLAB_DESTROY_BY_RCU)
1571 BUG_ON(flags & SLAB_POISON);
1572#endif
1573 if (flags & SLAB_DESTROY_BY_RCU)
1574 BUG_ON(dtor);
1575
1576 /*
1577 * Always checks flags, a caller might be expecting debug
1578 * support which isn't available.
1579 */
1580 if (flags & ~CREATE_MASK)
1581 BUG();
1582
1583 /* Check that size is in terms of words. This is needed to avoid
1584 * unaligned accesses for some archs when redzoning is used, and makes
1585 * sure any on-slab bufctl's are also correctly aligned.
1586 */
1587 if (size & (BYTES_PER_WORD-1)) {
1588 size += (BYTES_PER_WORD-1);
1589 size &= ~(BYTES_PER_WORD-1);
1590 }
1591
1592 /* calculate out the final buffer alignment: */
1593 /* 1) arch recommendation: can be overridden for debug */
1594 if (flags & SLAB_HWCACHE_ALIGN) {
1595 /* Default alignment: as specified by the arch code.
1596 * Except if an object is really small, then squeeze multiple
1597 * objects into one cacheline.
1598 */
1599 ralign = cache_line_size();
1600 while (size <= ralign/2)
1601 ralign /= 2;
1602 } else {
1603 ralign = BYTES_PER_WORD;
1604 }
1605 /* 2) arch mandated alignment: disables debug if necessary */
1606 if (ralign < ARCH_SLAB_MINALIGN) {
1607 ralign = ARCH_SLAB_MINALIGN;
1608 if (ralign > BYTES_PER_WORD)
1609 flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER);
1610 }
1611 /* 3) caller mandated alignment: disables debug if necessary */
1612 if (ralign < align) {
1613 ralign = align;
1614 if (ralign > BYTES_PER_WORD)
1615 flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER);
1616 }
1617 /* 4) Store it. Note that the debug code below can reduce
1618 * the alignment to BYTES_PER_WORD.
1619 */
1620 align = ralign;
1621
1622 /* Get cache's description obj. */
1623 cachep = (kmem_cache_t *) kmem_cache_alloc(&cache_cache, SLAB_KERNEL);
1624 if (!cachep)
Andrew Morton4f12bb42005-11-07 00:58:00 -08001625 goto oops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001626 memset(cachep, 0, sizeof(kmem_cache_t));
1627
1628#if DEBUG
1629 cachep->reallen = size;
1630
1631 if (flags & SLAB_RED_ZONE) {
1632 /* redzoning only works with word aligned caches */
1633 align = BYTES_PER_WORD;
1634
1635 /* add space for red zone words */
1636 cachep->dbghead += BYTES_PER_WORD;
1637 size += 2*BYTES_PER_WORD;
1638 }
1639 if (flags & SLAB_STORE_USER) {
1640 /* user store requires word alignment and
1641 * one word storage behind the end of the real
1642 * object.
1643 */
1644 align = BYTES_PER_WORD;
1645 size += BYTES_PER_WORD;
1646 }
1647#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
Christoph Lametere498be72005-09-09 13:03:32 -07001648 if (size >= malloc_sizes[INDEX_L3+1].cs_size && cachep->reallen > cache_line_size() && size < PAGE_SIZE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649 cachep->dbghead += PAGE_SIZE - size;
1650 size = PAGE_SIZE;
1651 }
1652#endif
1653#endif
1654
1655 /* Determine if the slab management is 'on' or 'off' slab. */
1656 if (size >= (PAGE_SIZE>>3))
1657 /*
1658 * Size is large, assume best to place the slab management obj
1659 * off-slab (should allow better packing of objs).
1660 */
1661 flags |= CFLGS_OFF_SLAB;
1662
1663 size = ALIGN(size, align);
1664
1665 if ((flags & SLAB_RECLAIM_ACCOUNT) && size <= PAGE_SIZE) {
1666 /*
1667 * A VFS-reclaimable slab tends to have most allocations
1668 * as GFP_NOFS and we really don't want to have to be allocating
1669 * higher-order pages when we are unable to shrink dcache.
1670 */
1671 cachep->gfporder = 0;
1672 cache_estimate(cachep->gfporder, size, align, flags,
1673 &left_over, &cachep->num);
1674 } else {
1675 /*
1676 * Calculate size (in pages) of slabs, and the num of objs per
1677 * slab. This could be made much more intelligent. For now,
1678 * try to avoid using high page-orders for slabs. When the
1679 * gfp() funcs are more friendly towards high-order requests,
1680 * this should be changed.
1681 */
1682 do {
1683 unsigned int break_flag = 0;
1684cal_wastage:
1685 cache_estimate(cachep->gfporder, size, align, flags,
1686 &left_over, &cachep->num);
1687 if (break_flag)
1688 break;
1689 if (cachep->gfporder >= MAX_GFP_ORDER)
1690 break;
1691 if (!cachep->num)
1692 goto next;
1693 if (flags & CFLGS_OFF_SLAB &&
1694 cachep->num > offslab_limit) {
1695 /* This num of objs will cause problems. */
1696 cachep->gfporder--;
1697 break_flag++;
1698 goto cal_wastage;
1699 }
1700
1701 /*
1702 * Large num of objs is good, but v. large slabs are
1703 * currently bad for the gfp()s.
1704 */
1705 if (cachep->gfporder >= slab_break_gfp_order)
1706 break;
1707
1708 if ((left_over*8) <= (PAGE_SIZE<<cachep->gfporder))
1709 break; /* Acceptable internal fragmentation. */
1710next:
1711 cachep->gfporder++;
1712 } while (1);
1713 }
1714
1715 if (!cachep->num) {
1716 printk("kmem_cache_create: couldn't create cache %s.\n", name);
1717 kmem_cache_free(&cache_cache, cachep);
1718 cachep = NULL;
Andrew Morton4f12bb42005-11-07 00:58:00 -08001719 goto oops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720 }
1721 slab_size = ALIGN(cachep->num*sizeof(kmem_bufctl_t)
1722 + sizeof(struct slab), align);
1723
1724 /*
1725 * If the slab has been placed off-slab, and we have enough space then
1726 * move it on-slab. This is at the expense of any extra colouring.
1727 */
1728 if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
1729 flags &= ~CFLGS_OFF_SLAB;
1730 left_over -= slab_size;
1731 }
1732
1733 if (flags & CFLGS_OFF_SLAB) {
1734 /* really off slab. No need for manual alignment */
1735 slab_size = cachep->num*sizeof(kmem_bufctl_t)+sizeof(struct slab);
1736 }
1737
1738 cachep->colour_off = cache_line_size();
1739 /* Offset must be a multiple of the alignment. */
1740 if (cachep->colour_off < align)
1741 cachep->colour_off = align;
1742 cachep->colour = left_over/cachep->colour_off;
1743 cachep->slab_size = slab_size;
1744 cachep->flags = flags;
1745 cachep->gfpflags = 0;
1746 if (flags & SLAB_CACHE_DMA)
1747 cachep->gfpflags |= GFP_DMA;
1748 spin_lock_init(&cachep->spinlock);
1749 cachep->objsize = size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750
1751 if (flags & CFLGS_OFF_SLAB)
Victor Fuscob2d55072005-09-10 00:26:36 -07001752 cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 cachep->ctor = ctor;
1754 cachep->dtor = dtor;
1755 cachep->name = name;
1756
1757 /* Don't let CPUs to come and go */
1758 lock_cpu_hotplug();
1759
1760 if (g_cpucache_up == FULL) {
1761 enable_cpucache(cachep);
1762 } else {
1763 if (g_cpucache_up == NONE) {
1764 /* Note: the first kmem_cache_create must create
1765 * the cache that's used by kmalloc(24), otherwise
1766 * the creation of further caches will BUG().
1767 */
Christoph Lametere498be72005-09-09 13:03:32 -07001768 cachep->array[smp_processor_id()] =
1769 &initarray_generic.cache;
1770
1771 /* If the cache that's used by
1772 * kmalloc(sizeof(kmem_list3)) is the first cache,
1773 * then we need to set up all its list3s, otherwise
1774 * the creation of further caches will BUG().
1775 */
1776 set_up_list3s(cachep, SIZE_AC);
1777 if (INDEX_AC == INDEX_L3)
1778 g_cpucache_up = PARTIAL_L3;
1779 else
1780 g_cpucache_up = PARTIAL_AC;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001781 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07001782 cachep->array[smp_processor_id()] =
1783 kmalloc(sizeof(struct arraycache_init),
1784 GFP_KERNEL);
1785
1786 if (g_cpucache_up == PARTIAL_AC) {
1787 set_up_list3s(cachep, SIZE_L3);
1788 g_cpucache_up = PARTIAL_L3;
1789 } else {
1790 int node;
1791 for_each_online_node(node) {
1792
1793 cachep->nodelists[node] =
1794 kmalloc_node(sizeof(struct kmem_list3),
1795 GFP_KERNEL, node);
1796 BUG_ON(!cachep->nodelists[node]);
1797 kmem_list3_init(cachep->nodelists[node]);
1798 }
1799 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 }
Christoph Lametere498be72005-09-09 13:03:32 -07001801 cachep->nodelists[numa_node_id()]->next_reap =
1802 jiffies + REAPTIMEOUT_LIST3 +
1803 ((unsigned long)cachep)%REAPTIMEOUT_LIST3;
1804
Linus Torvalds1da177e2005-04-16 15:20:36 -07001805 BUG_ON(!ac_data(cachep));
1806 ac_data(cachep)->avail = 0;
1807 ac_data(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
1808 ac_data(cachep)->batchcount = 1;
1809 ac_data(cachep)->touched = 0;
1810 cachep->batchcount = 1;
1811 cachep->limit = BOOT_CPUCACHE_ENTRIES;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 }
1813
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814 /* cache setup completed, link it into the list */
1815 list_add(&cachep->next, &cache_chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001816 unlock_cpu_hotplug();
Andrew Morton4f12bb42005-11-07 00:58:00 -08001817oops:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818 if (!cachep && (flags & SLAB_PANIC))
1819 panic("kmem_cache_create(): failed to create slab `%s'\n",
1820 name);
Andrew Morton4f12bb42005-11-07 00:58:00 -08001821 up(&cache_chain_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001822 return cachep;
1823}
1824EXPORT_SYMBOL(kmem_cache_create);
1825
1826#if DEBUG
1827static void check_irq_off(void)
1828{
1829 BUG_ON(!irqs_disabled());
1830}
1831
1832static void check_irq_on(void)
1833{
1834 BUG_ON(irqs_disabled());
1835}
1836
1837static void check_spinlock_acquired(kmem_cache_t *cachep)
1838{
1839#ifdef CONFIG_SMP
1840 check_irq_off();
Christoph Lametere498be72005-09-09 13:03:32 -07001841 assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001842#endif
1843}
Christoph Lametere498be72005-09-09 13:03:32 -07001844
1845static inline void check_spinlock_acquired_node(kmem_cache_t *cachep, int node)
1846{
1847#ifdef CONFIG_SMP
1848 check_irq_off();
1849 assert_spin_locked(&cachep->nodelists[node]->list_lock);
1850#endif
1851}
1852
Linus Torvalds1da177e2005-04-16 15:20:36 -07001853#else
1854#define check_irq_off() do { } while(0)
1855#define check_irq_on() do { } while(0)
1856#define check_spinlock_acquired(x) do { } while(0)
Christoph Lametere498be72005-09-09 13:03:32 -07001857#define check_spinlock_acquired_node(x, y) do { } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001858#endif
1859
1860/*
1861 * Waits for all CPUs to execute func().
1862 */
1863static void smp_call_function_all_cpus(void (*func) (void *arg), void *arg)
1864{
1865 check_irq_on();
1866 preempt_disable();
1867
1868 local_irq_disable();
1869 func(arg);
1870 local_irq_enable();
1871
1872 if (smp_call_function(func, arg, 1, 1))
1873 BUG();
1874
1875 preempt_enable();
1876}
1877
1878static void drain_array_locked(kmem_cache_t* cachep,
Christoph Lametere498be72005-09-09 13:03:32 -07001879 struct array_cache *ac, int force, int node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001880
1881static void do_drain(void *arg)
1882{
1883 kmem_cache_t *cachep = (kmem_cache_t*)arg;
1884 struct array_cache *ac;
Christoph Lameterff694162005-09-22 21:44:02 -07001885 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001886
1887 check_irq_off();
1888 ac = ac_data(cachep);
Christoph Lameterff694162005-09-22 21:44:02 -07001889 spin_lock(&cachep->nodelists[node]->list_lock);
1890 free_block(cachep, ac->entry, ac->avail, node);
1891 spin_unlock(&cachep->nodelists[node]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892 ac->avail = 0;
1893}
1894
1895static void drain_cpu_caches(kmem_cache_t *cachep)
1896{
Christoph Lametere498be72005-09-09 13:03:32 -07001897 struct kmem_list3 *l3;
1898 int node;
1899
Linus Torvalds1da177e2005-04-16 15:20:36 -07001900 smp_call_function_all_cpus(do_drain, cachep);
1901 check_irq_on();
1902 spin_lock_irq(&cachep->spinlock);
Christoph Lametere498be72005-09-09 13:03:32 -07001903 for_each_online_node(node) {
1904 l3 = cachep->nodelists[node];
1905 if (l3) {
1906 spin_lock(&l3->list_lock);
1907 drain_array_locked(cachep, l3->shared, 1, node);
1908 spin_unlock(&l3->list_lock);
1909 if (l3->alien)
1910 drain_alien_cache(cachep, l3);
1911 }
1912 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913 spin_unlock_irq(&cachep->spinlock);
1914}
1915
Christoph Lametere498be72005-09-09 13:03:32 -07001916static int __node_shrink(kmem_cache_t *cachep, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001917{
1918 struct slab *slabp;
Christoph Lametere498be72005-09-09 13:03:32 -07001919 struct kmem_list3 *l3 = cachep->nodelists[node];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001920 int ret;
1921
Christoph Lametere498be72005-09-09 13:03:32 -07001922 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001923 struct list_head *p;
1924
Christoph Lametere498be72005-09-09 13:03:32 -07001925 p = l3->slabs_free.prev;
1926 if (p == &l3->slabs_free)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001927 break;
1928
Christoph Lametere498be72005-09-09 13:03:32 -07001929 slabp = list_entry(l3->slabs_free.prev, struct slab, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001930#if DEBUG
1931 if (slabp->inuse)
1932 BUG();
1933#endif
1934 list_del(&slabp->list);
1935
Christoph Lametere498be72005-09-09 13:03:32 -07001936 l3->free_objects -= cachep->num;
1937 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001938 slab_destroy(cachep, slabp);
Christoph Lametere498be72005-09-09 13:03:32 -07001939 spin_lock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001940 }
Christoph Lametere498be72005-09-09 13:03:32 -07001941 ret = !list_empty(&l3->slabs_full) ||
1942 !list_empty(&l3->slabs_partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001943 return ret;
1944}
1945
Christoph Lametere498be72005-09-09 13:03:32 -07001946static int __cache_shrink(kmem_cache_t *cachep)
1947{
1948 int ret = 0, i = 0;
1949 struct kmem_list3 *l3;
1950
1951 drain_cpu_caches(cachep);
1952
1953 check_irq_on();
1954 for_each_online_node(i) {
1955 l3 = cachep->nodelists[i];
1956 if (l3) {
1957 spin_lock_irq(&l3->list_lock);
1958 ret += __node_shrink(cachep, i);
1959 spin_unlock_irq(&l3->list_lock);
1960 }
1961 }
1962 return (ret ? 1 : 0);
1963}
1964
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965/**
1966 * kmem_cache_shrink - Shrink a cache.
1967 * @cachep: The cache to shrink.
1968 *
1969 * Releases as many slabs as possible for a cache.
1970 * To help debugging, a zero exit status indicates all slabs were released.
1971 */
1972int kmem_cache_shrink(kmem_cache_t *cachep)
1973{
1974 if (!cachep || in_interrupt())
1975 BUG();
1976
1977 return __cache_shrink(cachep);
1978}
1979EXPORT_SYMBOL(kmem_cache_shrink);
1980
1981/**
1982 * kmem_cache_destroy - delete a cache
1983 * @cachep: the cache to destroy
1984 *
1985 * Remove a kmem_cache_t object from the slab cache.
1986 * Returns 0 on success.
1987 *
1988 * It is expected this function will be called by a module when it is
1989 * unloaded. This will remove the cache completely, and avoid a duplicate
1990 * cache being allocated each time a module is loaded and unloaded, if the
1991 * module doesn't have persistent in-kernel storage across loads and unloads.
1992 *
1993 * The cache must be empty before calling this function.
1994 *
1995 * The caller must guarantee that noone will allocate memory from the cache
1996 * during the kmem_cache_destroy().
1997 */
1998int kmem_cache_destroy(kmem_cache_t * cachep)
1999{
2000 int i;
Christoph Lametere498be72005-09-09 13:03:32 -07002001 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002002
2003 if (!cachep || in_interrupt())
2004 BUG();
2005
2006 /* Don't let CPUs to come and go */
2007 lock_cpu_hotplug();
2008
2009 /* Find the cache in the chain of caches. */
2010 down(&cache_chain_sem);
2011 /*
2012 * the chain is never empty, cache_cache is never destroyed
2013 */
2014 list_del(&cachep->next);
2015 up(&cache_chain_sem);
2016
2017 if (__cache_shrink(cachep)) {
2018 slab_error(cachep, "Can't free all objects");
2019 down(&cache_chain_sem);
2020 list_add(&cachep->next,&cache_chain);
2021 up(&cache_chain_sem);
2022 unlock_cpu_hotplug();
2023 return 1;
2024 }
2025
2026 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07002027 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002028
Christoph Lametere498be72005-09-09 13:03:32 -07002029 for_each_online_cpu(i)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002030 kfree(cachep->array[i]);
2031
2032 /* NUMA: free the list3 structures */
Christoph Lametere498be72005-09-09 13:03:32 -07002033 for_each_online_node(i) {
2034 if ((l3 = cachep->nodelists[i])) {
2035 kfree(l3->shared);
2036 free_alien_cache(l3->alien);
2037 kfree(l3);
2038 }
2039 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002040 kmem_cache_free(&cache_cache, cachep);
2041
2042 unlock_cpu_hotplug();
2043
2044 return 0;
2045}
2046EXPORT_SYMBOL(kmem_cache_destroy);
2047
2048/* Get the memory for a slab management obj. */
Christoph Lametere498be72005-09-09 13:03:32 -07002049static struct slab* alloc_slabmgmt(kmem_cache_t *cachep, void *objp,
Al Virodd0fc662005-10-07 07:46:04 +01002050 int colour_off, gfp_t local_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002051{
2052 struct slab *slabp;
2053
2054 if (OFF_SLAB(cachep)) {
2055 /* Slab management obj is off-slab. */
2056 slabp = kmem_cache_alloc(cachep->slabp_cache, local_flags);
2057 if (!slabp)
2058 return NULL;
2059 } else {
2060 slabp = objp+colour_off;
2061 colour_off += cachep->slab_size;
2062 }
2063 slabp->inuse = 0;
2064 slabp->colouroff = colour_off;
2065 slabp->s_mem = objp+colour_off;
2066
2067 return slabp;
2068}
2069
2070static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
2071{
2072 return (kmem_bufctl_t *)(slabp+1);
2073}
2074
2075static void cache_init_objs(kmem_cache_t *cachep,
2076 struct slab *slabp, unsigned long ctor_flags)
2077{
2078 int i;
2079
2080 for (i = 0; i < cachep->num; i++) {
Christoph Lametere498be72005-09-09 13:03:32 -07002081 void *objp = slabp->s_mem+cachep->objsize*i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002082#if DEBUG
2083 /* need to poison the objs? */
2084 if (cachep->flags & SLAB_POISON)
2085 poison_obj(cachep, objp, POISON_FREE);
2086 if (cachep->flags & SLAB_STORE_USER)
2087 *dbg_userword(cachep, objp) = NULL;
2088
2089 if (cachep->flags & SLAB_RED_ZONE) {
2090 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2091 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2092 }
2093 /*
2094 * Constructors are not allowed to allocate memory from
2095 * the same cache which they are a constructor for.
2096 * Otherwise, deadlock. They must also be threaded.
2097 */
2098 if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2099 cachep->ctor(objp+obj_dbghead(cachep), cachep, ctor_flags);
2100
2101 if (cachep->flags & SLAB_RED_ZONE) {
2102 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
2103 slab_error(cachep, "constructor overwrote the"
2104 " end of an object");
2105 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
2106 slab_error(cachep, "constructor overwrote the"
2107 " start of an object");
2108 }
2109 if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
2110 kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0);
2111#else
2112 if (cachep->ctor)
2113 cachep->ctor(objp, cachep, ctor_flags);
2114#endif
2115 slab_bufctl(slabp)[i] = i+1;
2116 }
2117 slab_bufctl(slabp)[i-1] = BUFCTL_END;
2118 slabp->free = 0;
2119}
2120
Al Viro6daa0e22005-10-21 03:18:50 -04002121static void kmem_flagcheck(kmem_cache_t *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002122{
2123 if (flags & SLAB_DMA) {
2124 if (!(cachep->gfpflags & GFP_DMA))
2125 BUG();
2126 } else {
2127 if (cachep->gfpflags & GFP_DMA)
2128 BUG();
2129 }
2130}
2131
2132static void set_slab_attr(kmem_cache_t *cachep, struct slab *slabp, void *objp)
2133{
2134 int i;
2135 struct page *page;
2136
2137 /* Nasty!!!!!! I hope this is OK. */
2138 i = 1 << cachep->gfporder;
2139 page = virt_to_page(objp);
2140 do {
2141 SET_PAGE_CACHE(page, cachep);
2142 SET_PAGE_SLAB(page, slabp);
2143 page++;
2144 } while (--i);
2145}
2146
2147/*
2148 * Grow (by 1) the number of slabs within a cache. This is called by
2149 * kmem_cache_alloc() when there are no active objs left in a cache.
2150 */
Al Virodd0fc662005-10-07 07:46:04 +01002151static int cache_grow(kmem_cache_t *cachep, gfp_t flags, int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002152{
2153 struct slab *slabp;
2154 void *objp;
2155 size_t offset;
Al Viro6daa0e22005-10-21 03:18:50 -04002156 gfp_t local_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002157 unsigned long ctor_flags;
Christoph Lametere498be72005-09-09 13:03:32 -07002158 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002159
2160 /* Be lazy and only check for valid flags here,
2161 * keeping it out of the critical path in kmem_cache_alloc().
2162 */
2163 if (flags & ~(SLAB_DMA|SLAB_LEVEL_MASK|SLAB_NO_GROW))
2164 BUG();
2165 if (flags & SLAB_NO_GROW)
2166 return 0;
2167
2168 ctor_flags = SLAB_CTOR_CONSTRUCTOR;
2169 local_flags = (flags & SLAB_LEVEL_MASK);
2170 if (!(local_flags & __GFP_WAIT))
2171 /*
2172 * Not allowed to sleep. Need to tell a constructor about
2173 * this - it might need to know...
2174 */
2175 ctor_flags |= SLAB_CTOR_ATOMIC;
2176
2177 /* About to mess with non-constant members - lock. */
2178 check_irq_off();
2179 spin_lock(&cachep->spinlock);
2180
2181 /* Get colour for the slab, and cal the next value. */
2182 offset = cachep->colour_next;
2183 cachep->colour_next++;
2184 if (cachep->colour_next >= cachep->colour)
2185 cachep->colour_next = 0;
2186 offset *= cachep->colour_off;
2187
2188 spin_unlock(&cachep->spinlock);
2189
Christoph Lametere498be72005-09-09 13:03:32 -07002190 check_irq_off();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002191 if (local_flags & __GFP_WAIT)
2192 local_irq_enable();
2193
2194 /*
2195 * The test for missing atomic flag is performed here, rather than
2196 * the more obvious place, simply to reduce the critical path length
2197 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2198 * will eventually be caught here (where it matters).
2199 */
2200 kmem_flagcheck(cachep, flags);
2201
Christoph Lametere498be72005-09-09 13:03:32 -07002202 /* Get mem for the objs.
2203 * Attempt to allocate a physical page from 'nodeid',
2204 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002205 if (!(objp = kmem_getpages(cachep, flags, nodeid)))
2206 goto failed;
2207
2208 /* Get slab management. */
2209 if (!(slabp = alloc_slabmgmt(cachep, objp, offset, local_flags)))
2210 goto opps1;
2211
Christoph Lametere498be72005-09-09 13:03:32 -07002212 slabp->nodeid = nodeid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002213 set_slab_attr(cachep, slabp, objp);
2214
2215 cache_init_objs(cachep, slabp, ctor_flags);
2216
2217 if (local_flags & __GFP_WAIT)
2218 local_irq_disable();
2219 check_irq_off();
Christoph Lametere498be72005-09-09 13:03:32 -07002220 l3 = cachep->nodelists[nodeid];
2221 spin_lock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002222
2223 /* Make slab active. */
Christoph Lametere498be72005-09-09 13:03:32 -07002224 list_add_tail(&slabp->list, &(l3->slabs_free));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002225 STATS_INC_GROWN(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07002226 l3->free_objects += cachep->num;
2227 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002228 return 1;
2229opps1:
2230 kmem_freepages(cachep, objp);
2231failed:
2232 if (local_flags & __GFP_WAIT)
2233 local_irq_disable();
2234 return 0;
2235}
2236
2237#if DEBUG
2238
2239/*
2240 * Perform extra freeing checks:
2241 * - detect bad pointers.
2242 * - POISON/RED_ZONE checking
2243 * - destructor calls, for caches with POISON+dtor
2244 */
2245static void kfree_debugcheck(const void *objp)
2246{
2247 struct page *page;
2248
2249 if (!virt_addr_valid(objp)) {
2250 printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
2251 (unsigned long)objp);
2252 BUG();
2253 }
2254 page = virt_to_page(objp);
2255 if (!PageSlab(page)) {
2256 printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n", (unsigned long)objp);
2257 BUG();
2258 }
2259}
2260
2261static void *cache_free_debugcheck(kmem_cache_t *cachep, void *objp,
2262 void *caller)
2263{
2264 struct page *page;
2265 unsigned int objnr;
2266 struct slab *slabp;
2267
2268 objp -= obj_dbghead(cachep);
2269 kfree_debugcheck(objp);
2270 page = virt_to_page(objp);
2271
2272 if (GET_PAGE_CACHE(page) != cachep) {
2273 printk(KERN_ERR "mismatch in kmem_cache_free: expected cache %p, got %p\n",
2274 GET_PAGE_CACHE(page),cachep);
2275 printk(KERN_ERR "%p is %s.\n", cachep, cachep->name);
2276 printk(KERN_ERR "%p is %s.\n", GET_PAGE_CACHE(page), GET_PAGE_CACHE(page)->name);
2277 WARN_ON(1);
2278 }
2279 slabp = GET_PAGE_SLAB(page);
2280
2281 if (cachep->flags & SLAB_RED_ZONE) {
2282 if (*dbg_redzone1(cachep, objp) != RED_ACTIVE || *dbg_redzone2(cachep, objp) != RED_ACTIVE) {
2283 slab_error(cachep, "double free, or memory outside"
2284 " object was overwritten");
2285 printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n",
2286 objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp));
2287 }
2288 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2289 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2290 }
2291 if (cachep->flags & SLAB_STORE_USER)
2292 *dbg_userword(cachep, objp) = caller;
2293
2294 objnr = (objp-slabp->s_mem)/cachep->objsize;
2295
2296 BUG_ON(objnr >= cachep->num);
2297 BUG_ON(objp != slabp->s_mem + objnr*cachep->objsize);
2298
2299 if (cachep->flags & SLAB_DEBUG_INITIAL) {
2300 /* Need to call the slab's constructor so the
2301 * caller can perform a verify of its state (debugging).
2302 * Called without the cache-lock held.
2303 */
2304 cachep->ctor(objp+obj_dbghead(cachep),
2305 cachep, SLAB_CTOR_CONSTRUCTOR|SLAB_CTOR_VERIFY);
2306 }
2307 if (cachep->flags & SLAB_POISON && cachep->dtor) {
2308 /* we want to cache poison the object,
2309 * call the destruction callback
2310 */
2311 cachep->dtor(objp+obj_dbghead(cachep), cachep, 0);
2312 }
2313 if (cachep->flags & SLAB_POISON) {
2314#ifdef CONFIG_DEBUG_PAGEALLOC
2315 if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) {
2316 store_stackinfo(cachep, objp, (unsigned long)caller);
2317 kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0);
2318 } else {
2319 poison_obj(cachep, objp, POISON_FREE);
2320 }
2321#else
2322 poison_obj(cachep, objp, POISON_FREE);
2323#endif
2324 }
2325 return objp;
2326}
2327
2328static void check_slabp(kmem_cache_t *cachep, struct slab *slabp)
2329{
2330 kmem_bufctl_t i;
2331 int entries = 0;
2332
Linus Torvalds1da177e2005-04-16 15:20:36 -07002333 /* Check slab's freelist to see if this obj is there. */
2334 for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
2335 entries++;
2336 if (entries > cachep->num || i >= cachep->num)
2337 goto bad;
2338 }
2339 if (entries != cachep->num - slabp->inuse) {
2340bad:
2341 printk(KERN_ERR "slab: Internal list corruption detected in cache '%s'(%d), slabp %p(%d). Hexdump:\n",
2342 cachep->name, cachep->num, slabp, slabp->inuse);
2343 for (i=0;i<sizeof(slabp)+cachep->num*sizeof(kmem_bufctl_t);i++) {
2344 if ((i%16)==0)
2345 printk("\n%03x:", i);
2346 printk(" %02x", ((unsigned char*)slabp)[i]);
2347 }
2348 printk("\n");
2349 BUG();
2350 }
2351}
2352#else
2353#define kfree_debugcheck(x) do { } while(0)
2354#define cache_free_debugcheck(x,objp,z) (objp)
2355#define check_slabp(x,y) do { } while(0)
2356#endif
2357
Al Virodd0fc662005-10-07 07:46:04 +01002358static void *cache_alloc_refill(kmem_cache_t *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002359{
2360 int batchcount;
2361 struct kmem_list3 *l3;
2362 struct array_cache *ac;
2363
2364 check_irq_off();
2365 ac = ac_data(cachep);
2366retry:
2367 batchcount = ac->batchcount;
2368 if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
2369 /* if there was little recent activity on this
2370 * cache, then perform only a partial refill.
2371 * Otherwise we could generate refill bouncing.
2372 */
2373 batchcount = BATCHREFILL_LIMIT;
2374 }
Christoph Lametere498be72005-09-09 13:03:32 -07002375 l3 = cachep->nodelists[numa_node_id()];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002376
Christoph Lametere498be72005-09-09 13:03:32 -07002377 BUG_ON(ac->avail > 0 || !l3);
2378 spin_lock(&l3->list_lock);
2379
Linus Torvalds1da177e2005-04-16 15:20:36 -07002380 if (l3->shared) {
2381 struct array_cache *shared_array = l3->shared;
2382 if (shared_array->avail) {
2383 if (batchcount > shared_array->avail)
2384 batchcount = shared_array->avail;
2385 shared_array->avail -= batchcount;
2386 ac->avail = batchcount;
Christoph Lametere498be72005-09-09 13:03:32 -07002387 memcpy(ac->entry,
2388 &(shared_array->entry[shared_array->avail]),
2389 sizeof(void*)*batchcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002390 shared_array->touched = 1;
2391 goto alloc_done;
2392 }
2393 }
2394 while (batchcount > 0) {
2395 struct list_head *entry;
2396 struct slab *slabp;
2397 /* Get slab alloc is to come from. */
2398 entry = l3->slabs_partial.next;
2399 if (entry == &l3->slabs_partial) {
2400 l3->free_touched = 1;
2401 entry = l3->slabs_free.next;
2402 if (entry == &l3->slabs_free)
2403 goto must_grow;
2404 }
2405
2406 slabp = list_entry(entry, struct slab, list);
2407 check_slabp(cachep, slabp);
2408 check_spinlock_acquired(cachep);
2409 while (slabp->inuse < cachep->num && batchcount--) {
2410 kmem_bufctl_t next;
2411 STATS_INC_ALLOCED(cachep);
2412 STATS_INC_ACTIVE(cachep);
2413 STATS_SET_HIGH(cachep);
2414
2415 /* get obj pointer */
Christoph Lametere498be72005-09-09 13:03:32 -07002416 ac->entry[ac->avail++] = slabp->s_mem +
2417 slabp->free*cachep->objsize;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002418
2419 slabp->inuse++;
2420 next = slab_bufctl(slabp)[slabp->free];
2421#if DEBUG
2422 slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
Christoph Lameter09ad4bb2005-10-29 18:15:52 -07002423 WARN_ON(numa_node_id() != slabp->nodeid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002424#endif
2425 slabp->free = next;
2426 }
2427 check_slabp(cachep, slabp);
2428
2429 /* move slabp to correct slabp list: */
2430 list_del(&slabp->list);
2431 if (slabp->free == BUFCTL_END)
2432 list_add(&slabp->list, &l3->slabs_full);
2433 else
2434 list_add(&slabp->list, &l3->slabs_partial);
2435 }
2436
2437must_grow:
2438 l3->free_objects -= ac->avail;
2439alloc_done:
Christoph Lametere498be72005-09-09 13:03:32 -07002440 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002441
2442 if (unlikely(!ac->avail)) {
2443 int x;
Christoph Lametere498be72005-09-09 13:03:32 -07002444 x = cache_grow(cachep, flags, numa_node_id());
2445
Linus Torvalds1da177e2005-04-16 15:20:36 -07002446 // cache_grow can reenable interrupts, then ac could change.
2447 ac = ac_data(cachep);
2448 if (!x && ac->avail == 0) // no objects in sight? abort
2449 return NULL;
2450
2451 if (!ac->avail) // objects refilled by interrupt?
2452 goto retry;
2453 }
2454 ac->touched = 1;
Christoph Lametere498be72005-09-09 13:03:32 -07002455 return ac->entry[--ac->avail];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002456}
2457
2458static inline void
Al Virodd0fc662005-10-07 07:46:04 +01002459cache_alloc_debugcheck_before(kmem_cache_t *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002460{
2461 might_sleep_if(flags & __GFP_WAIT);
2462#if DEBUG
2463 kmem_flagcheck(cachep, flags);
2464#endif
2465}
2466
2467#if DEBUG
2468static void *
2469cache_alloc_debugcheck_after(kmem_cache_t *cachep,
Al Virodd0fc662005-10-07 07:46:04 +01002470 gfp_t flags, void *objp, void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002471{
2472 if (!objp)
2473 return objp;
2474 if (cachep->flags & SLAB_POISON) {
2475#ifdef CONFIG_DEBUG_PAGEALLOC
2476 if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
2477 kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 1);
2478 else
2479 check_poison_obj(cachep, objp);
2480#else
2481 check_poison_obj(cachep, objp);
2482#endif
2483 poison_obj(cachep, objp, POISON_INUSE);
2484 }
2485 if (cachep->flags & SLAB_STORE_USER)
2486 *dbg_userword(cachep, objp) = caller;
2487
2488 if (cachep->flags & SLAB_RED_ZONE) {
2489 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
2490 slab_error(cachep, "double free, or memory outside"
2491 " object was overwritten");
2492 printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n",
2493 objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp));
2494 }
2495 *dbg_redzone1(cachep, objp) = RED_ACTIVE;
2496 *dbg_redzone2(cachep, objp) = RED_ACTIVE;
2497 }
2498 objp += obj_dbghead(cachep);
2499 if (cachep->ctor && cachep->flags & SLAB_POISON) {
2500 unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
2501
2502 if (!(flags & __GFP_WAIT))
2503 ctor_flags |= SLAB_CTOR_ATOMIC;
2504
2505 cachep->ctor(objp, cachep, ctor_flags);
2506 }
2507 return objp;
2508}
2509#else
2510#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
2511#endif
2512
Al Virodd0fc662005-10-07 07:46:04 +01002513static inline void *____cache_alloc(kmem_cache_t *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002514{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002515 void* objp;
2516 struct array_cache *ac;
2517
Alok N Kataria5c382302005-09-27 21:45:46 -07002518 check_irq_off();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002519 ac = ac_data(cachep);
2520 if (likely(ac->avail)) {
2521 STATS_INC_ALLOCHIT(cachep);
2522 ac->touched = 1;
Christoph Lametere498be72005-09-09 13:03:32 -07002523 objp = ac->entry[--ac->avail];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002524 } else {
2525 STATS_INC_ALLOCMISS(cachep);
2526 objp = cache_alloc_refill(cachep, flags);
2527 }
Alok N Kataria5c382302005-09-27 21:45:46 -07002528 return objp;
2529}
2530
Al Virodd0fc662005-10-07 07:46:04 +01002531static inline void *__cache_alloc(kmem_cache_t *cachep, gfp_t flags)
Alok N Kataria5c382302005-09-27 21:45:46 -07002532{
2533 unsigned long save_flags;
2534 void* objp;
2535
2536 cache_alloc_debugcheck_before(cachep, flags);
2537
2538 local_irq_save(save_flags);
2539 objp = ____cache_alloc(cachep, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002540 local_irq_restore(save_flags);
Eric Dumazet34342e82005-09-03 15:55:06 -07002541 objp = cache_alloc_debugcheck_after(cachep, flags, objp,
2542 __builtin_return_address(0));
2543 prefetchw(objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002544 return objp;
2545}
2546
Christoph Lametere498be72005-09-09 13:03:32 -07002547#ifdef CONFIG_NUMA
2548/*
2549 * A interface to enable slab creation on nodeid
Linus Torvalds1da177e2005-04-16 15:20:36 -07002550 */
Al Viro6daa0e22005-10-21 03:18:50 -04002551static void *__cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int nodeid)
Christoph Lametere498be72005-09-09 13:03:32 -07002552{
2553 struct list_head *entry;
2554 struct slab *slabp;
2555 struct kmem_list3 *l3;
2556 void *obj;
2557 kmem_bufctl_t next;
2558 int x;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002559
Christoph Lametere498be72005-09-09 13:03:32 -07002560 l3 = cachep->nodelists[nodeid];
2561 BUG_ON(!l3);
2562
2563retry:
2564 spin_lock(&l3->list_lock);
2565 entry = l3->slabs_partial.next;
2566 if (entry == &l3->slabs_partial) {
2567 l3->free_touched = 1;
2568 entry = l3->slabs_free.next;
2569 if (entry == &l3->slabs_free)
2570 goto must_grow;
2571 }
2572
2573 slabp = list_entry(entry, struct slab, list);
2574 check_spinlock_acquired_node(cachep, nodeid);
2575 check_slabp(cachep, slabp);
2576
2577 STATS_INC_NODEALLOCS(cachep);
2578 STATS_INC_ACTIVE(cachep);
2579 STATS_SET_HIGH(cachep);
2580
2581 BUG_ON(slabp->inuse == cachep->num);
2582
2583 /* get obj pointer */
2584 obj = slabp->s_mem + slabp->free*cachep->objsize;
2585 slabp->inuse++;
2586 next = slab_bufctl(slabp)[slabp->free];
2587#if DEBUG
2588 slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
2589#endif
2590 slabp->free = next;
2591 check_slabp(cachep, slabp);
2592 l3->free_objects--;
2593 /* move slabp to correct slabp list: */
2594 list_del(&slabp->list);
2595
2596 if (slabp->free == BUFCTL_END) {
2597 list_add(&slabp->list, &l3->slabs_full);
2598 } else {
2599 list_add(&slabp->list, &l3->slabs_partial);
2600 }
2601
2602 spin_unlock(&l3->list_lock);
2603 goto done;
2604
2605must_grow:
2606 spin_unlock(&l3->list_lock);
2607 x = cache_grow(cachep, flags, nodeid);
2608
2609 if (!x)
2610 return NULL;
2611
2612 goto retry;
2613done:
2614 return obj;
2615}
2616#endif
2617
2618/*
2619 * Caller needs to acquire correct kmem_list's list_lock
2620 */
Christoph Lameterff694162005-09-22 21:44:02 -07002621static void free_block(kmem_cache_t *cachep, void **objpp, int nr_objects, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002622{
2623 int i;
Christoph Lametere498be72005-09-09 13:03:32 -07002624 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002625
2626 for (i = 0; i < nr_objects; i++) {
2627 void *objp = objpp[i];
2628 struct slab *slabp;
2629 unsigned int objnr;
2630
2631 slabp = GET_PAGE_SLAB(virt_to_page(objp));
Christoph Lameterff694162005-09-22 21:44:02 -07002632 l3 = cachep->nodelists[node];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002633 list_del(&slabp->list);
2634 objnr = (objp - slabp->s_mem) / cachep->objsize;
Christoph Lameterff694162005-09-22 21:44:02 -07002635 check_spinlock_acquired_node(cachep, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002636 check_slabp(cachep, slabp);
Christoph Lametere498be72005-09-09 13:03:32 -07002637
Linus Torvalds1da177e2005-04-16 15:20:36 -07002638#if DEBUG
Christoph Lameter09ad4bb2005-10-29 18:15:52 -07002639 /* Verify that the slab belongs to the intended node */
2640 WARN_ON(slabp->nodeid != node);
2641
Linus Torvalds1da177e2005-04-16 15:20:36 -07002642 if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
Christoph Lametere498be72005-09-09 13:03:32 -07002643 printk(KERN_ERR "slab: double free detected in cache "
2644 "'%s', objp %p\n", cachep->name, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002645 BUG();
2646 }
2647#endif
2648 slab_bufctl(slabp)[objnr] = slabp->free;
2649 slabp->free = objnr;
2650 STATS_DEC_ACTIVE(cachep);
2651 slabp->inuse--;
Christoph Lametere498be72005-09-09 13:03:32 -07002652 l3->free_objects++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002653 check_slabp(cachep, slabp);
2654
2655 /* fixup slab chains */
2656 if (slabp->inuse == 0) {
Christoph Lametere498be72005-09-09 13:03:32 -07002657 if (l3->free_objects > l3->free_limit) {
2658 l3->free_objects -= cachep->num;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002659 slab_destroy(cachep, slabp);
2660 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07002661 list_add(&slabp->list, &l3->slabs_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002662 }
2663 } else {
2664 /* Unconditionally move a slab to the end of the
2665 * partial list on free - maximum time for the
2666 * other objects to be freed, too.
2667 */
Christoph Lametere498be72005-09-09 13:03:32 -07002668 list_add_tail(&slabp->list, &l3->slabs_partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002669 }
2670 }
2671}
2672
2673static void cache_flusharray(kmem_cache_t *cachep, struct array_cache *ac)
2674{
2675 int batchcount;
Christoph Lametere498be72005-09-09 13:03:32 -07002676 struct kmem_list3 *l3;
Christoph Lameterff694162005-09-22 21:44:02 -07002677 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002678
2679 batchcount = ac->batchcount;
2680#if DEBUG
2681 BUG_ON(!batchcount || batchcount > ac->avail);
2682#endif
2683 check_irq_off();
Christoph Lameterff694162005-09-22 21:44:02 -07002684 l3 = cachep->nodelists[node];
Christoph Lametere498be72005-09-09 13:03:32 -07002685 spin_lock(&l3->list_lock);
2686 if (l3->shared) {
2687 struct array_cache *shared_array = l3->shared;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002688 int max = shared_array->limit-shared_array->avail;
2689 if (max) {
2690 if (batchcount > max)
2691 batchcount = max;
Christoph Lametere498be72005-09-09 13:03:32 -07002692 memcpy(&(shared_array->entry[shared_array->avail]),
2693 ac->entry,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002694 sizeof(void*)*batchcount);
2695 shared_array->avail += batchcount;
2696 goto free_done;
2697 }
2698 }
2699
Christoph Lameterff694162005-09-22 21:44:02 -07002700 free_block(cachep, ac->entry, batchcount, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002701free_done:
2702#if STATS
2703 {
2704 int i = 0;
2705 struct list_head *p;
2706
Christoph Lametere498be72005-09-09 13:03:32 -07002707 p = l3->slabs_free.next;
2708 while (p != &(l3->slabs_free)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002709 struct slab *slabp;
2710
2711 slabp = list_entry(p, struct slab, list);
2712 BUG_ON(slabp->inuse);
2713
2714 i++;
2715 p = p->next;
2716 }
2717 STATS_SET_FREEABLE(cachep, i);
2718 }
2719#endif
Christoph Lametere498be72005-09-09 13:03:32 -07002720 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002721 ac->avail -= batchcount;
Christoph Lametere498be72005-09-09 13:03:32 -07002722 memmove(ac->entry, &(ac->entry[batchcount]),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002723 sizeof(void*)*ac->avail);
2724}
2725
Christoph Lametere498be72005-09-09 13:03:32 -07002726
Linus Torvalds1da177e2005-04-16 15:20:36 -07002727/*
2728 * __cache_free
2729 * Release an obj back to its cache. If the obj has a constructed
2730 * state, it must be in this state _before_ it is released.
2731 *
2732 * Called with disabled ints.
2733 */
2734static inline void __cache_free(kmem_cache_t *cachep, void *objp)
2735{
2736 struct array_cache *ac = ac_data(cachep);
2737
2738 check_irq_off();
2739 objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
2740
Christoph Lametere498be72005-09-09 13:03:32 -07002741 /* Make sure we are not freeing a object from another
2742 * node to the array cache on this cpu.
2743 */
2744#ifdef CONFIG_NUMA
2745 {
2746 struct slab *slabp;
2747 slabp = GET_PAGE_SLAB(virt_to_page(objp));
2748 if (unlikely(slabp->nodeid != numa_node_id())) {
2749 struct array_cache *alien = NULL;
2750 int nodeid = slabp->nodeid;
2751 struct kmem_list3 *l3 = cachep->nodelists[numa_node_id()];
2752
2753 STATS_INC_NODEFREES(cachep);
2754 if (l3->alien && l3->alien[nodeid]) {
2755 alien = l3->alien[nodeid];
2756 spin_lock(&alien->lock);
2757 if (unlikely(alien->avail == alien->limit))
2758 __drain_alien_cache(cachep,
2759 alien, nodeid);
2760 alien->entry[alien->avail++] = objp;
2761 spin_unlock(&alien->lock);
2762 } else {
2763 spin_lock(&(cachep->nodelists[nodeid])->
2764 list_lock);
Christoph Lameterff694162005-09-22 21:44:02 -07002765 free_block(cachep, &objp, 1, nodeid);
Christoph Lametere498be72005-09-09 13:03:32 -07002766 spin_unlock(&(cachep->nodelists[nodeid])->
2767 list_lock);
2768 }
2769 return;
2770 }
2771 }
2772#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002773 if (likely(ac->avail < ac->limit)) {
2774 STATS_INC_FREEHIT(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07002775 ac->entry[ac->avail++] = objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002776 return;
2777 } else {
2778 STATS_INC_FREEMISS(cachep);
2779 cache_flusharray(cachep, ac);
Christoph Lametere498be72005-09-09 13:03:32 -07002780 ac->entry[ac->avail++] = objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002781 }
2782}
2783
2784/**
2785 * kmem_cache_alloc - Allocate an object
2786 * @cachep: The cache to allocate from.
2787 * @flags: See kmalloc().
2788 *
2789 * Allocate an object from this cache. The flags are only relevant
2790 * if the cache has no available objects.
2791 */
Al Virodd0fc662005-10-07 07:46:04 +01002792void *kmem_cache_alloc(kmem_cache_t *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002793{
2794 return __cache_alloc(cachep, flags);
2795}
2796EXPORT_SYMBOL(kmem_cache_alloc);
2797
2798/**
2799 * kmem_ptr_validate - check if an untrusted pointer might
2800 * be a slab entry.
2801 * @cachep: the cache we're checking against
2802 * @ptr: pointer to validate
2803 *
2804 * This verifies that the untrusted pointer looks sane:
2805 * it is _not_ a guarantee that the pointer is actually
2806 * part of the slab cache in question, but it at least
2807 * validates that the pointer can be dereferenced and
2808 * looks half-way sane.
2809 *
2810 * Currently only used for dentry validation.
2811 */
2812int fastcall kmem_ptr_validate(kmem_cache_t *cachep, void *ptr)
2813{
2814 unsigned long addr = (unsigned long) ptr;
2815 unsigned long min_addr = PAGE_OFFSET;
2816 unsigned long align_mask = BYTES_PER_WORD-1;
2817 unsigned long size = cachep->objsize;
2818 struct page *page;
2819
2820 if (unlikely(addr < min_addr))
2821 goto out;
2822 if (unlikely(addr > (unsigned long)high_memory - size))
2823 goto out;
2824 if (unlikely(addr & align_mask))
2825 goto out;
2826 if (unlikely(!kern_addr_valid(addr)))
2827 goto out;
2828 if (unlikely(!kern_addr_valid(addr + size - 1)))
2829 goto out;
2830 page = virt_to_page(ptr);
2831 if (unlikely(!PageSlab(page)))
2832 goto out;
2833 if (unlikely(GET_PAGE_CACHE(page) != cachep))
2834 goto out;
2835 return 1;
2836out:
2837 return 0;
2838}
2839
2840#ifdef CONFIG_NUMA
2841/**
2842 * kmem_cache_alloc_node - Allocate an object on the specified node
2843 * @cachep: The cache to allocate from.
2844 * @flags: See kmalloc().
2845 * @nodeid: node number of the target node.
2846 *
2847 * Identical to kmem_cache_alloc, except that this function is slow
2848 * and can sleep. And it will allocate memory on the given node, which
2849 * can improve the performance for cpu bound structures.
Christoph Lametere498be72005-09-09 13:03:32 -07002850 * New and improved: it will now make sure that the object gets
2851 * put on the correct node list so that there is no false sharing.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002852 */
Al Virodd0fc662005-10-07 07:46:04 +01002853void *kmem_cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002854{
Christoph Lametere498be72005-09-09 13:03:32 -07002855 unsigned long save_flags;
2856 void *ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002857
Christoph Lameterff694162005-09-22 21:44:02 -07002858 if (nodeid == -1)
Christoph Lametere498be72005-09-09 13:03:32 -07002859 return __cache_alloc(cachep, flags);
Christoph Lameter83b78bd2005-07-06 10:47:07 -07002860
Christoph Lametere498be72005-09-09 13:03:32 -07002861 if (unlikely(!cachep->nodelists[nodeid])) {
2862 /* Fall back to __cache_alloc if we run into trouble */
2863 printk(KERN_WARNING "slab: not allocating in inactive node %d for cache %s\n", nodeid, cachep->name);
2864 return __cache_alloc(cachep,flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002865 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002866
Christoph Lametere498be72005-09-09 13:03:32 -07002867 cache_alloc_debugcheck_before(cachep, flags);
2868 local_irq_save(save_flags);
Alok N Kataria5c382302005-09-27 21:45:46 -07002869 if (nodeid == numa_node_id())
2870 ptr = ____cache_alloc(cachep, flags);
2871 else
2872 ptr = __cache_alloc_node(cachep, flags, nodeid);
Christoph Lametere498be72005-09-09 13:03:32 -07002873 local_irq_restore(save_flags);
2874 ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002875
Christoph Lametere498be72005-09-09 13:03:32 -07002876 return ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002877}
2878EXPORT_SYMBOL(kmem_cache_alloc_node);
2879
Al Virodd0fc662005-10-07 07:46:04 +01002880void *kmalloc_node(size_t size, gfp_t flags, int node)
Manfred Spraul97e2bde2005-05-01 08:58:38 -07002881{
2882 kmem_cache_t *cachep;
2883
2884 cachep = kmem_find_general_cachep(size, flags);
2885 if (unlikely(cachep == NULL))
2886 return NULL;
2887 return kmem_cache_alloc_node(cachep, flags, node);
2888}
2889EXPORT_SYMBOL(kmalloc_node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002890#endif
2891
2892/**
2893 * kmalloc - allocate memory
2894 * @size: how many bytes of memory are required.
2895 * @flags: the type of memory to allocate.
2896 *
2897 * kmalloc is the normal method of allocating memory
2898 * in the kernel.
2899 *
2900 * The @flags argument may be one of:
2901 *
2902 * %GFP_USER - Allocate memory on behalf of user. May sleep.
2903 *
2904 * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
2905 *
2906 * %GFP_ATOMIC - Allocation will not sleep. Use inside interrupt handlers.
2907 *
2908 * Additionally, the %GFP_DMA flag may be set to indicate the memory
2909 * must be suitable for DMA. This can mean different things on different
2910 * platforms. For example, on i386, it means that the memory must come
2911 * from the first 16MB.
2912 */
Al Virodd0fc662005-10-07 07:46:04 +01002913void *__kmalloc(size_t size, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002914{
2915 kmem_cache_t *cachep;
2916
Manfred Spraul97e2bde2005-05-01 08:58:38 -07002917 /* If you want to save a few bytes .text space: replace
2918 * __ with kmem_.
2919 * Then kmalloc uses the uninlined functions instead of the inline
2920 * functions.
2921 */
2922 cachep = __find_general_cachep(size, flags);
Andrew Mortondbdb9042005-09-23 13:24:10 -07002923 if (unlikely(cachep == NULL))
2924 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002925 return __cache_alloc(cachep, flags);
2926}
2927EXPORT_SYMBOL(__kmalloc);
2928
2929#ifdef CONFIG_SMP
2930/**
2931 * __alloc_percpu - allocate one copy of the object for every present
2932 * cpu in the system, zeroing them.
2933 * Objects should be dereferenced using the per_cpu_ptr macro only.
2934 *
2935 * @size: how many bytes of memory are required.
2936 * @align: the alignment, which can't be greater than SMP_CACHE_BYTES.
2937 */
2938void *__alloc_percpu(size_t size, size_t align)
2939{
2940 int i;
2941 struct percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL);
2942
2943 if (!pdata)
2944 return NULL;
2945
Christoph Lametere498be72005-09-09 13:03:32 -07002946 /*
2947 * Cannot use for_each_online_cpu since a cpu may come online
2948 * and we have no way of figuring out how to fix the array
2949 * that we have allocated then....
2950 */
2951 for_each_cpu(i) {
2952 int node = cpu_to_node(i);
2953
2954 if (node_online(node))
2955 pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node);
2956 else
2957 pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002958
2959 if (!pdata->ptrs[i])
2960 goto unwind_oom;
2961 memset(pdata->ptrs[i], 0, size);
2962 }
2963
2964 /* Catch derefs w/o wrappers */
2965 return (void *) (~(unsigned long) pdata);
2966
2967unwind_oom:
2968 while (--i >= 0) {
2969 if (!cpu_possible(i))
2970 continue;
2971 kfree(pdata->ptrs[i]);
2972 }
2973 kfree(pdata);
2974 return NULL;
2975}
2976EXPORT_SYMBOL(__alloc_percpu);
2977#endif
2978
2979/**
2980 * kmem_cache_free - Deallocate an object
2981 * @cachep: The cache the allocation was from.
2982 * @objp: The previously allocated object.
2983 *
2984 * Free an object which was previously allocated from this
2985 * cache.
2986 */
2987void kmem_cache_free(kmem_cache_t *cachep, void *objp)
2988{
2989 unsigned long flags;
2990
2991 local_irq_save(flags);
2992 __cache_free(cachep, objp);
2993 local_irq_restore(flags);
2994}
2995EXPORT_SYMBOL(kmem_cache_free);
2996
2997/**
Pekka J Enbergdd392712005-09-06 15:18:31 -07002998 * kzalloc - allocate memory. The memory is set to zero.
2999 * @size: how many bytes of memory are required.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003000 * @flags: the type of memory to allocate.
3001 */
Al Virodd0fc662005-10-07 07:46:04 +01003002void *kzalloc(size_t size, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003003{
Pekka J Enbergdd392712005-09-06 15:18:31 -07003004 void *ret = kmalloc(size, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003005 if (ret)
Pekka J Enbergdd392712005-09-06 15:18:31 -07003006 memset(ret, 0, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003007 return ret;
3008}
Pekka J Enbergdd392712005-09-06 15:18:31 -07003009EXPORT_SYMBOL(kzalloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003010
3011/**
3012 * kfree - free previously allocated memory
3013 * @objp: pointer returned by kmalloc.
3014 *
Pekka Enberg80e93ef2005-09-09 13:10:16 -07003015 * If @objp is NULL, no operation is performed.
3016 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003017 * Don't free memory not originally allocated by kmalloc()
3018 * or you will run into trouble.
3019 */
3020void kfree(const void *objp)
3021{
3022 kmem_cache_t *c;
3023 unsigned long flags;
3024
3025 if (unlikely(!objp))
3026 return;
3027 local_irq_save(flags);
3028 kfree_debugcheck(objp);
3029 c = GET_PAGE_CACHE(virt_to_page(objp));
3030 __cache_free(c, (void*)objp);
3031 local_irq_restore(flags);
3032}
3033EXPORT_SYMBOL(kfree);
3034
3035#ifdef CONFIG_SMP
3036/**
3037 * free_percpu - free previously allocated percpu memory
3038 * @objp: pointer returned by alloc_percpu.
3039 *
3040 * Don't free memory not originally allocated by alloc_percpu()
3041 * The complemented objp is to check for that.
3042 */
3043void
3044free_percpu(const void *objp)
3045{
3046 int i;
3047 struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp);
3048
Christoph Lametere498be72005-09-09 13:03:32 -07003049 /*
3050 * We allocate for all cpus so we cannot use for online cpu here.
3051 */
3052 for_each_cpu(i)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003053 kfree(p->ptrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003054 kfree(p);
3055}
3056EXPORT_SYMBOL(free_percpu);
3057#endif
3058
3059unsigned int kmem_cache_size(kmem_cache_t *cachep)
3060{
3061 return obj_reallen(cachep);
3062}
3063EXPORT_SYMBOL(kmem_cache_size);
3064
Arnaldo Carvalho de Melo19449722005-06-18 22:46:19 -07003065const char *kmem_cache_name(kmem_cache_t *cachep)
3066{
3067 return cachep->name;
3068}
3069EXPORT_SYMBOL_GPL(kmem_cache_name);
3070
Christoph Lametere498be72005-09-09 13:03:32 -07003071/*
3072 * This initializes kmem_list3 for all nodes.
3073 */
3074static int alloc_kmemlist(kmem_cache_t *cachep)
3075{
3076 int node;
3077 struct kmem_list3 *l3;
3078 int err = 0;
3079
3080 for_each_online_node(node) {
3081 struct array_cache *nc = NULL, *new;
3082 struct array_cache **new_alien = NULL;
3083#ifdef CONFIG_NUMA
3084 if (!(new_alien = alloc_alien_cache(node, cachep->limit)))
3085 goto fail;
3086#endif
3087 if (!(new = alloc_arraycache(node, (cachep->shared*
3088 cachep->batchcount), 0xbaadf00d)))
3089 goto fail;
3090 if ((l3 = cachep->nodelists[node])) {
3091
3092 spin_lock_irq(&l3->list_lock);
3093
3094 if ((nc = cachep->nodelists[node]->shared))
3095 free_block(cachep, nc->entry,
Christoph Lameterff694162005-09-22 21:44:02 -07003096 nc->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07003097
3098 l3->shared = new;
3099 if (!cachep->nodelists[node]->alien) {
3100 l3->alien = new_alien;
3101 new_alien = NULL;
3102 }
3103 l3->free_limit = (1 + nr_cpus_node(node))*
3104 cachep->batchcount + cachep->num;
3105 spin_unlock_irq(&l3->list_lock);
3106 kfree(nc);
3107 free_alien_cache(new_alien);
3108 continue;
3109 }
3110 if (!(l3 = kmalloc_node(sizeof(struct kmem_list3),
3111 GFP_KERNEL, node)))
3112 goto fail;
3113
3114 kmem_list3_init(l3);
3115 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
3116 ((unsigned long)cachep)%REAPTIMEOUT_LIST3;
3117 l3->shared = new;
3118 l3->alien = new_alien;
3119 l3->free_limit = (1 + nr_cpus_node(node))*
3120 cachep->batchcount + cachep->num;
3121 cachep->nodelists[node] = l3;
3122 }
3123 return err;
3124fail:
3125 err = -ENOMEM;
3126 return err;
3127}
3128
Linus Torvalds1da177e2005-04-16 15:20:36 -07003129struct ccupdate_struct {
3130 kmem_cache_t *cachep;
3131 struct array_cache *new[NR_CPUS];
3132};
3133
3134static void do_ccupdate_local(void *info)
3135{
3136 struct ccupdate_struct *new = (struct ccupdate_struct *)info;
3137 struct array_cache *old;
3138
3139 check_irq_off();
3140 old = ac_data(new->cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003141
Linus Torvalds1da177e2005-04-16 15:20:36 -07003142 new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
3143 new->new[smp_processor_id()] = old;
3144}
3145
3146
3147static int do_tune_cpucache(kmem_cache_t *cachep, int limit, int batchcount,
3148 int shared)
3149{
3150 struct ccupdate_struct new;
Christoph Lametere498be72005-09-09 13:03:32 -07003151 int i, err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003152
3153 memset(&new.new,0,sizeof(new.new));
Christoph Lametere498be72005-09-09 13:03:32 -07003154 for_each_online_cpu(i) {
3155 new.new[i] = alloc_arraycache(cpu_to_node(i), limit, batchcount);
3156 if (!new.new[i]) {
3157 for (i--; i >= 0; i--) kfree(new.new[i]);
3158 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003159 }
3160 }
3161 new.cachep = cachep;
3162
3163 smp_call_function_all_cpus(do_ccupdate_local, (void *)&new);
Christoph Lametere498be72005-09-09 13:03:32 -07003164
Linus Torvalds1da177e2005-04-16 15:20:36 -07003165 check_irq_on();
3166 spin_lock_irq(&cachep->spinlock);
3167 cachep->batchcount = batchcount;
3168 cachep->limit = limit;
Christoph Lametere498be72005-09-09 13:03:32 -07003169 cachep->shared = shared;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003170 spin_unlock_irq(&cachep->spinlock);
3171
Christoph Lametere498be72005-09-09 13:03:32 -07003172 for_each_online_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003173 struct array_cache *ccold = new.new[i];
3174 if (!ccold)
3175 continue;
Christoph Lametere498be72005-09-09 13:03:32 -07003176 spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
Christoph Lameterff694162005-09-22 21:44:02 -07003177 free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
Christoph Lametere498be72005-09-09 13:03:32 -07003178 spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003179 kfree(ccold);
3180 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003181
Christoph Lametere498be72005-09-09 13:03:32 -07003182 err = alloc_kmemlist(cachep);
3183 if (err) {
3184 printk(KERN_ERR "alloc_kmemlist failed for %s, error %d.\n",
3185 cachep->name, -err);
3186 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003187 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003188 return 0;
3189}
3190
3191
3192static void enable_cpucache(kmem_cache_t *cachep)
3193{
3194 int err;
3195 int limit, shared;
3196
3197 /* The head array serves three purposes:
3198 * - create a LIFO ordering, i.e. return objects that are cache-warm
3199 * - reduce the number of spinlock operations.
3200 * - reduce the number of linked list operations on the slab and
3201 * bufctl chains: array operations are cheaper.
3202 * The numbers are guessed, we should auto-tune as described by
3203 * Bonwick.
3204 */
3205 if (cachep->objsize > 131072)
3206 limit = 1;
3207 else if (cachep->objsize > PAGE_SIZE)
3208 limit = 8;
3209 else if (cachep->objsize > 1024)
3210 limit = 24;
3211 else if (cachep->objsize > 256)
3212 limit = 54;
3213 else
3214 limit = 120;
3215
3216 /* Cpu bound tasks (e.g. network routing) can exhibit cpu bound
3217 * allocation behaviour: Most allocs on one cpu, most free operations
3218 * on another cpu. For these cases, an efficient object passing between
3219 * cpus is necessary. This is provided by a shared array. The array
3220 * replaces Bonwick's magazine layer.
3221 * On uniprocessor, it's functionally equivalent (but less efficient)
3222 * to a larger limit. Thus disabled by default.
3223 */
3224 shared = 0;
3225#ifdef CONFIG_SMP
3226 if (cachep->objsize <= PAGE_SIZE)
3227 shared = 8;
3228#endif
3229
3230#if DEBUG
3231 /* With debugging enabled, large batchcount lead to excessively
3232 * long periods with disabled local interrupts. Limit the
3233 * batchcount
3234 */
3235 if (limit > 32)
3236 limit = 32;
3237#endif
3238 err = do_tune_cpucache(cachep, limit, (limit+1)/2, shared);
3239 if (err)
3240 printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
3241 cachep->name, -err);
3242}
3243
3244static void drain_array_locked(kmem_cache_t *cachep,
Christoph Lametere498be72005-09-09 13:03:32 -07003245 struct array_cache *ac, int force, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003246{
3247 int tofree;
3248
Christoph Lametere498be72005-09-09 13:03:32 -07003249 check_spinlock_acquired_node(cachep, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003250 if (ac->touched && !force) {
3251 ac->touched = 0;
3252 } else if (ac->avail) {
3253 tofree = force ? ac->avail : (ac->limit+4)/5;
3254 if (tofree > ac->avail) {
3255 tofree = (ac->avail+1)/2;
3256 }
Christoph Lameterff694162005-09-22 21:44:02 -07003257 free_block(cachep, ac->entry, tofree, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003258 ac->avail -= tofree;
Christoph Lametere498be72005-09-09 13:03:32 -07003259 memmove(ac->entry, &(ac->entry[tofree]),
Linus Torvalds1da177e2005-04-16 15:20:36 -07003260 sizeof(void*)*ac->avail);
3261 }
3262}
3263
3264/**
3265 * cache_reap - Reclaim memory from caches.
Randy Dunlap1e5d5332005-11-07 01:01:06 -08003266 * @unused: unused parameter
Linus Torvalds1da177e2005-04-16 15:20:36 -07003267 *
3268 * Called from workqueue/eventd every few seconds.
3269 * Purpose:
3270 * - clear the per-cpu caches for this CPU.
3271 * - return freeable pages to the main free memory pool.
3272 *
3273 * If we cannot acquire the cache chain semaphore then just give up - we'll
3274 * try again on the next iteration.
3275 */
3276static void cache_reap(void *unused)
3277{
3278 struct list_head *walk;
Christoph Lametere498be72005-09-09 13:03:32 -07003279 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003280
3281 if (down_trylock(&cache_chain_sem)) {
3282 /* Give up. Setup the next iteration. */
Manfred Spraulcd61ef62005-11-07 00:58:02 -08003283 schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003284 return;
3285 }
3286
3287 list_for_each(walk, &cache_chain) {
3288 kmem_cache_t *searchp;
3289 struct list_head* p;
3290 int tofree;
3291 struct slab *slabp;
3292
3293 searchp = list_entry(walk, kmem_cache_t, next);
3294
3295 if (searchp->flags & SLAB_NO_REAP)
3296 goto next;
3297
3298 check_irq_on();
3299
Christoph Lametere498be72005-09-09 13:03:32 -07003300 l3 = searchp->nodelists[numa_node_id()];
3301 if (l3->alien)
3302 drain_alien_cache(searchp, l3);
3303 spin_lock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003304
Christoph Lametere498be72005-09-09 13:03:32 -07003305 drain_array_locked(searchp, ac_data(searchp), 0,
3306 numa_node_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003307
Christoph Lametere498be72005-09-09 13:03:32 -07003308 if (time_after(l3->next_reap, jiffies))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003309 goto next_unlock;
3310
Christoph Lametere498be72005-09-09 13:03:32 -07003311 l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003312
Christoph Lametere498be72005-09-09 13:03:32 -07003313 if (l3->shared)
3314 drain_array_locked(searchp, l3->shared, 0,
3315 numa_node_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003316
Christoph Lametere498be72005-09-09 13:03:32 -07003317 if (l3->free_touched) {
3318 l3->free_touched = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003319 goto next_unlock;
3320 }
3321
Christoph Lametere498be72005-09-09 13:03:32 -07003322 tofree = (l3->free_limit+5*searchp->num-1)/(5*searchp->num);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003323 do {
Christoph Lametere498be72005-09-09 13:03:32 -07003324 p = l3->slabs_free.next;
3325 if (p == &(l3->slabs_free))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003326 break;
3327
3328 slabp = list_entry(p, struct slab, list);
3329 BUG_ON(slabp->inuse);
3330 list_del(&slabp->list);
3331 STATS_INC_REAPED(searchp);
3332
3333 /* Safe to drop the lock. The slab is no longer
3334 * linked to the cache.
3335 * searchp cannot disappear, we hold
3336 * cache_chain_lock
3337 */
Christoph Lametere498be72005-09-09 13:03:32 -07003338 l3->free_objects -= searchp->num;
3339 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003340 slab_destroy(searchp, slabp);
Christoph Lametere498be72005-09-09 13:03:32 -07003341 spin_lock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003342 } while(--tofree > 0);
3343next_unlock:
Christoph Lametere498be72005-09-09 13:03:32 -07003344 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003345next:
3346 cond_resched();
3347 }
3348 check_irq_on();
3349 up(&cache_chain_sem);
Christoph Lameter4ae7c032005-06-21 17:14:57 -07003350 drain_remote_pages();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003351 /* Setup the next iteration */
Manfred Spraulcd61ef62005-11-07 00:58:02 -08003352 schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003353}
3354
3355#ifdef CONFIG_PROC_FS
3356
3357static void *s_start(struct seq_file *m, loff_t *pos)
3358{
3359 loff_t n = *pos;
3360 struct list_head *p;
3361
3362 down(&cache_chain_sem);
3363 if (!n) {
3364 /*
3365 * Output format version, so at least we can change it
3366 * without _too_ many complaints.
3367 */
3368#if STATS
3369 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
3370#else
3371 seq_puts(m, "slabinfo - version: 2.1\n");
3372#endif
3373 seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
3374 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
3375 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
3376#if STATS
3377 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped>"
Christoph Lametere498be72005-09-09 13:03:32 -07003378 " <error> <maxfreeable> <nodeallocs> <remotefrees>");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003379 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
3380#endif
3381 seq_putc(m, '\n');
3382 }
3383 p = cache_chain.next;
3384 while (n--) {
3385 p = p->next;
3386 if (p == &cache_chain)
3387 return NULL;
3388 }
3389 return list_entry(p, kmem_cache_t, next);
3390}
3391
3392static void *s_next(struct seq_file *m, void *p, loff_t *pos)
3393{
3394 kmem_cache_t *cachep = p;
3395 ++*pos;
3396 return cachep->next.next == &cache_chain ? NULL
3397 : list_entry(cachep->next.next, kmem_cache_t, next);
3398}
3399
3400static void s_stop(struct seq_file *m, void *p)
3401{
3402 up(&cache_chain_sem);
3403}
3404
3405static int s_show(struct seq_file *m, void *p)
3406{
3407 kmem_cache_t *cachep = p;
3408 struct list_head *q;
3409 struct slab *slabp;
3410 unsigned long active_objs;
3411 unsigned long num_objs;
3412 unsigned long active_slabs = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07003413 unsigned long num_slabs, free_objects = 0, shared_avail = 0;
3414 const char *name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003415 char *error = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07003416 int node;
3417 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003418
3419 check_irq_on();
3420 spin_lock_irq(&cachep->spinlock);
3421 active_objs = 0;
3422 num_slabs = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07003423 for_each_online_node(node) {
3424 l3 = cachep->nodelists[node];
3425 if (!l3)
3426 continue;
3427
3428 spin_lock(&l3->list_lock);
3429
3430 list_for_each(q,&l3->slabs_full) {
3431 slabp = list_entry(q, struct slab, list);
3432 if (slabp->inuse != cachep->num && !error)
3433 error = "slabs_full accounting error";
3434 active_objs += cachep->num;
3435 active_slabs++;
3436 }
3437 list_for_each(q,&l3->slabs_partial) {
3438 slabp = list_entry(q, struct slab, list);
3439 if (slabp->inuse == cachep->num && !error)
3440 error = "slabs_partial inuse accounting error";
3441 if (!slabp->inuse && !error)
3442 error = "slabs_partial/inuse accounting error";
3443 active_objs += slabp->inuse;
3444 active_slabs++;
3445 }
3446 list_for_each(q,&l3->slabs_free) {
3447 slabp = list_entry(q, struct slab, list);
3448 if (slabp->inuse && !error)
3449 error = "slabs_free/inuse accounting error";
3450 num_slabs++;
3451 }
3452 free_objects += l3->free_objects;
3453 shared_avail += l3->shared->avail;
3454
3455 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003456 }
3457 num_slabs+=active_slabs;
3458 num_objs = num_slabs*cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07003459 if (num_objs - active_objs != free_objects && !error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003460 error = "free_objects accounting error";
3461
3462 name = cachep->name;
3463 if (error)
3464 printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
3465
3466 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
3467 name, active_objs, num_objs, cachep->objsize,
3468 cachep->num, (1<<cachep->gfporder));
3469 seq_printf(m, " : tunables %4u %4u %4u",
3470 cachep->limit, cachep->batchcount,
Christoph Lametere498be72005-09-09 13:03:32 -07003471 cachep->shared);
3472 seq_printf(m, " : slabdata %6lu %6lu %6lu",
3473 active_slabs, num_slabs, shared_avail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003474#if STATS
3475 { /* list3 stats */
3476 unsigned long high = cachep->high_mark;
3477 unsigned long allocs = cachep->num_allocations;
3478 unsigned long grown = cachep->grown;
3479 unsigned long reaped = cachep->reaped;
3480 unsigned long errors = cachep->errors;
3481 unsigned long max_freeable = cachep->max_freeable;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003482 unsigned long node_allocs = cachep->node_allocs;
Christoph Lametere498be72005-09-09 13:03:32 -07003483 unsigned long node_frees = cachep->node_frees;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003484
Christoph Lametere498be72005-09-09 13:03:32 -07003485 seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
3486 %4lu %4lu %4lu %4lu",
3487 allocs, high, grown, reaped, errors,
3488 max_freeable, node_allocs, node_frees);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003489 }
3490 /* cpu stats */
3491 {
3492 unsigned long allochit = atomic_read(&cachep->allochit);
3493 unsigned long allocmiss = atomic_read(&cachep->allocmiss);
3494 unsigned long freehit = atomic_read(&cachep->freehit);
3495 unsigned long freemiss = atomic_read(&cachep->freemiss);
3496
3497 seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
3498 allochit, allocmiss, freehit, freemiss);
3499 }
3500#endif
3501 seq_putc(m, '\n');
3502 spin_unlock_irq(&cachep->spinlock);
3503 return 0;
3504}
3505
3506/*
3507 * slabinfo_op - iterator that generates /proc/slabinfo
3508 *
3509 * Output layout:
3510 * cache-name
3511 * num-active-objs
3512 * total-objs
3513 * object size
3514 * num-active-slabs
3515 * total-slabs
3516 * num-pages-per-slab
3517 * + further values on SMP and with statistics enabled
3518 */
3519
3520struct seq_operations slabinfo_op = {
3521 .start = s_start,
3522 .next = s_next,
3523 .stop = s_stop,
3524 .show = s_show,
3525};
3526
3527#define MAX_SLABINFO_WRITE 128
3528/**
3529 * slabinfo_write - Tuning for the slab allocator
3530 * @file: unused
3531 * @buffer: user buffer
3532 * @count: data length
3533 * @ppos: unused
3534 */
3535ssize_t slabinfo_write(struct file *file, const char __user *buffer,
3536 size_t count, loff_t *ppos)
3537{
3538 char kbuf[MAX_SLABINFO_WRITE+1], *tmp;
3539 int limit, batchcount, shared, res;
3540 struct list_head *p;
3541
3542 if (count > MAX_SLABINFO_WRITE)
3543 return -EINVAL;
3544 if (copy_from_user(&kbuf, buffer, count))
3545 return -EFAULT;
3546 kbuf[MAX_SLABINFO_WRITE] = '\0';
3547
3548 tmp = strchr(kbuf, ' ');
3549 if (!tmp)
3550 return -EINVAL;
3551 *tmp = '\0';
3552 tmp++;
3553 if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
3554 return -EINVAL;
3555
3556 /* Find the cache in the chain of caches. */
3557 down(&cache_chain_sem);
3558 res = -EINVAL;
3559 list_for_each(p,&cache_chain) {
3560 kmem_cache_t *cachep = list_entry(p, kmem_cache_t, next);
3561
3562 if (!strcmp(cachep->name, kbuf)) {
3563 if (limit < 1 ||
3564 batchcount < 1 ||
3565 batchcount > limit ||
3566 shared < 0) {
Christoph Lametere498be72005-09-09 13:03:32 -07003567 res = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003568 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07003569 res = do_tune_cpucache(cachep, limit,
3570 batchcount, shared);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003571 }
3572 break;
3573 }
3574 }
3575 up(&cache_chain_sem);
3576 if (res >= 0)
3577 res = count;
3578 return res;
3579}
3580#endif
3581
Manfred Spraul00e145b2005-09-03 15:55:07 -07003582/**
3583 * ksize - get the actual amount of memory allocated for a given object
3584 * @objp: Pointer to the object
3585 *
3586 * kmalloc may internally round up allocations and return more memory
3587 * than requested. ksize() can be used to determine the actual amount of
3588 * memory allocated. The caller may use this additional memory, even though
3589 * a smaller amount of memory was initially specified with the kmalloc call.
3590 * The caller must guarantee that objp points to a valid object previously
3591 * allocated with either kmalloc() or kmem_cache_alloc(). The object
3592 * must not be freed during the duration of the call.
3593 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003594unsigned int ksize(const void *objp)
3595{
Manfred Spraul00e145b2005-09-03 15:55:07 -07003596 if (unlikely(objp == NULL))
3597 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003598
Manfred Spraul00e145b2005-09-03 15:55:07 -07003599 return obj_reallen(GET_PAGE_CACHE(virt_to_page(objp)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003600}
Paulo Marques543537b2005-06-23 00:09:02 -07003601
3602
3603/*
3604 * kstrdup - allocate space for and copy an existing string
3605 *
3606 * @s: the string to duplicate
3607 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
3608 */
Al Virodd0fc662005-10-07 07:46:04 +01003609char *kstrdup(const char *s, gfp_t gfp)
Paulo Marques543537b2005-06-23 00:09:02 -07003610{
3611 size_t len;
3612 char *buf;
3613
3614 if (!s)
3615 return NULL;
3616
3617 len = strlen(s) + 1;
3618 buf = kmalloc(len, gfp);
3619 if (buf)
3620 memcpy(buf, s, len);
3621 return buf;
3622}
3623EXPORT_SYMBOL(kstrdup);