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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 *
Andrew Mortona737b3e2006-03-22 00:08:11 -080053 * The c_cpuarray may not be read with enabled local interrupts -
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 * it's changed with a smp_call_function().
55 *
56 * SMP synchronization:
57 * constructors and destructors are called without any locking.
Pekka Enberg343e0d72006-02-01 03:05:50 -080058 * Several members in struct kmem_cache and struct slab never change, they
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 * 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
Ingo Molnarfc0abb12006-01-18 17:42:33 -080071 * The global cache-chain is protected by the mutex 'cache_chain_mutex'.
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#include <linux/slab.h>
90#include <linux/mm.h>
Randy Dunlapc9cf5522006-06-27 02:53:52 -070091#include <linux/poison.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070092#include <linux/swap.h>
93#include <linux/cache.h>
94#include <linux/interrupt.h>
95#include <linux/init.h>
96#include <linux/compiler.h>
Paul Jackson101a5002006-03-24 03:16:07 -080097#include <linux/cpuset.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070098#include <linux/seq_file.h>
99#include <linux/notifier.h>
100#include <linux/kallsyms.h>
101#include <linux/cpu.h>
102#include <linux/sysctl.h>
103#include <linux/module.h>
104#include <linux/rcupdate.h>
Paulo Marques543537b2005-06-23 00:09:02 -0700105#include <linux/string.h>
Andrew Morton138ae662006-12-06 20:36:41 -0800106#include <linux/uaccess.h>
Christoph Lametere498be72005-09-09 13:03:32 -0700107#include <linux/nodemask.h>
Christoph Lameterdc85da12006-01-18 17:42:36 -0800108#include <linux/mempolicy.h>
Ingo Molnarfc0abb12006-01-18 17:42:33 -0800109#include <linux/mutex.h>
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800110#include <linux/fault-inject.h>
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700111#include <linux/rtmutex.h>
Eric Dumazet6a2d7a92006-12-13 00:34:27 -0800112#include <linux/reciprocal_div.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114#include <asm/cacheflush.h>
115#include <asm/tlbflush.h>
116#include <asm/page.h>
117
118/*
Christoph Lameter50953fe2007-05-06 14:50:16 -0700119 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 * 0 for faster, smaller code (especially in the critical paths).
121 *
122 * STATS - 1 to collect stats for /proc/slabinfo.
123 * 0 for faster, smaller code (especially in the critical paths).
124 *
125 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
126 */
127
128#ifdef CONFIG_DEBUG_SLAB
129#define DEBUG 1
130#define STATS 1
131#define FORCED_DEBUG 1
132#else
133#define DEBUG 0
134#define STATS 0
135#define FORCED_DEBUG 0
136#endif
137
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138/* Shouldn't this be in a header file somewhere? */
139#define BYTES_PER_WORD sizeof(void *)
David Woodhouse87a927c2007-07-04 21:26:44 -0400140#define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
142#ifndef cache_line_size
143#define cache_line_size() L1_CACHE_BYTES
144#endif
145
146#ifndef ARCH_KMALLOC_MINALIGN
147/*
148 * Enforce a minimum alignment for the kmalloc caches.
149 * Usually, the kmalloc caches are cache_line_size() aligned, except when
150 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
151 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
David Woodhouseb46b8f12007-05-08 00:22:59 -0700152 * alignment larger than the alignment of a 64-bit integer.
153 * ARCH_KMALLOC_MINALIGN allows that.
154 * Note that increasing this value may disable some debug features.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 */
David Woodhouseb46b8f12007-05-08 00:22:59 -0700156#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157#endif
158
159#ifndef ARCH_SLAB_MINALIGN
160/*
161 * Enforce a minimum alignment for all caches.
162 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
163 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
164 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
165 * some debug features.
166 */
167#define ARCH_SLAB_MINALIGN 0
168#endif
169
170#ifndef ARCH_KMALLOC_FLAGS
171#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
172#endif
173
174/* Legal flag mask for kmem_cache_create(). */
175#if DEBUG
Christoph Lameter50953fe2007-05-06 14:50:16 -0700176# define CREATE_MASK (SLAB_RED_ZONE | \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
Christoph Lameterac2b8982006-03-22 00:08:15 -0800178 SLAB_CACHE_DMA | \
Christoph Lameter5af60832007-05-06 14:49:56 -0700179 SLAB_STORE_USER | \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
Paul Jackson101a5002006-03-24 03:16:07 -0800181 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182#else
Christoph Lameterac2b8982006-03-22 00:08:15 -0800183# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
Christoph Lameter5af60832007-05-06 14:49:56 -0700184 SLAB_CACHE_DMA | \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
Paul Jackson101a5002006-03-24 03:16:07 -0800186 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187#endif
188
189/*
190 * kmem_bufctl_t:
191 *
192 * Bufctl's are used for linking objs within a slab
193 * linked offsets.
194 *
195 * This implementation relies on "struct page" for locating the cache &
196 * slab an object belongs to.
197 * This allows the bufctl structure to be small (one int), but limits
198 * the number of objects a slab (not a cache) can contain when off-slab
199 * bufctls are used. The limit is the size of the largest general cache
200 * that does not use off-slab slabs.
201 * For 32bit archs with 4 kB pages, is this 56.
202 * This is not serious, as it is only for large objects, when it is unwise
203 * to have too many per slab.
204 * Note: This limit can be raised by introducing a general cache whose size
205 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
206 */
207
Kyle Moffettfa5b08d2005-09-03 15:55:03 -0700208typedef unsigned int kmem_bufctl_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
210#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
Al Viro871751e2006-03-25 03:06:39 -0800211#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
212#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214/*
215 * struct slab
216 *
217 * Manages the objs in a slab. Placed either at the beginning of mem allocated
218 * for a slab, or allocated from an general cache.
219 * Slabs are chained into three list: fully used, partial, fully free slabs.
220 */
221struct slab {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800222 struct list_head list;
223 unsigned long colouroff;
224 void *s_mem; /* including colour offset */
225 unsigned int inuse; /* num of objs active in slab */
226 kmem_bufctl_t free;
227 unsigned short nodeid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228};
229
230/*
231 * struct slab_rcu
232 *
233 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
234 * arrange for kmem_freepages to be called via RCU. This is useful if
235 * we need to approach a kernel structure obliquely, from its address
236 * obtained without the usual locking. We can lock the structure to
237 * stabilize it and check it's still at the given address, only if we
238 * can be sure that the memory has not been meanwhile reused for some
239 * other kind of object (which our subsystem's lock might corrupt).
240 *
241 * rcu_read_lock before reading the address, then rcu_read_unlock after
242 * taking the spinlock within the structure expected at that address.
243 *
244 * We assume struct slab_rcu can overlay struct slab when destroying.
245 */
246struct slab_rcu {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800247 struct rcu_head head;
Pekka Enberg343e0d72006-02-01 03:05:50 -0800248 struct kmem_cache *cachep;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800249 void *addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250};
251
252/*
253 * struct array_cache
254 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 * Purpose:
256 * - LIFO ordering, to hand out cache-warm objects from _alloc
257 * - reduce the number of linked list operations
258 * - reduce spinlock operations
259 *
260 * The limit is stored in the per-cpu structure to reduce the data cache
261 * footprint.
262 *
263 */
264struct array_cache {
265 unsigned int avail;
266 unsigned int limit;
267 unsigned int batchcount;
268 unsigned int touched;
Christoph Lametere498be72005-09-09 13:03:32 -0700269 spinlock_t lock;
Andrew Mortona737b3e2006-03-22 00:08:11 -0800270 void *entry[0]; /*
271 * Must have this definition in here for the proper
272 * alignment of array_cache. Also simplifies accessing
273 * the entries.
274 * [0] is for gcc 2.95. It should really be [].
275 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276};
277
Andrew Mortona737b3e2006-03-22 00:08:11 -0800278/*
279 * bootstrap: The caches do not work without cpuarrays anymore, but the
280 * cpuarrays are allocated from the generic caches...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 */
282#define BOOT_CPUCACHE_ENTRIES 1
283struct arraycache_init {
284 struct array_cache cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800285 void *entries[BOOT_CPUCACHE_ENTRIES];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286};
287
288/*
Christoph Lametere498be72005-09-09 13:03:32 -0700289 * The slab lists for all objects.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 */
291struct kmem_list3 {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800292 struct list_head slabs_partial; /* partial list first, better asm code */
293 struct list_head slabs_full;
294 struct list_head slabs_free;
295 unsigned long free_objects;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800296 unsigned int free_limit;
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -0800297 unsigned int colour_next; /* Per-node cache coloring */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800298 spinlock_t list_lock;
299 struct array_cache *shared; /* shared per node */
300 struct array_cache **alien; /* on other nodes */
Christoph Lameter35386e32006-03-22 00:09:05 -0800301 unsigned long next_reap; /* updated without locking */
302 int free_touched; /* updated without locking */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303};
304
Christoph Lametere498be72005-09-09 13:03:32 -0700305/*
306 * Need this for bootstrapping a per node allocator.
307 */
308#define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
309struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
310#define CACHE_CACHE 0
311#define SIZE_AC 1
312#define SIZE_L3 (1 + MAX_NUMNODES)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313
Christoph Lametered11d9e2006-06-30 01:55:45 -0700314static int drain_freelist(struct kmem_cache *cache,
315 struct kmem_list3 *l3, int tofree);
316static void free_block(struct kmem_cache *cachep, void **objpp, int len,
317 int node);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -0700318static int enable_cpucache(struct kmem_cache *cachep);
David Howells65f27f32006-11-22 14:55:48 +0000319static void cache_reap(struct work_struct *unused);
Christoph Lametered11d9e2006-06-30 01:55:45 -0700320
Christoph Lametere498be72005-09-09 13:03:32 -0700321/*
Andrew Mortona737b3e2006-03-22 00:08:11 -0800322 * This function must be completely optimized away if a constant is passed to
323 * it. Mostly the same as what is in linux/slab.h except it returns an index.
Christoph Lametere498be72005-09-09 13:03:32 -0700324 */
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700325static __always_inline int index_of(const size_t size)
Christoph Lametere498be72005-09-09 13:03:32 -0700326{
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800327 extern void __bad_size(void);
328
Christoph Lametere498be72005-09-09 13:03:32 -0700329 if (__builtin_constant_p(size)) {
330 int i = 0;
331
332#define CACHE(x) \
333 if (size <=x) \
334 return i; \
335 else \
336 i++;
337#include "linux/kmalloc_sizes.h"
338#undef CACHE
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800339 __bad_size();
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700340 } else
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800341 __bad_size();
Christoph Lametere498be72005-09-09 13:03:32 -0700342 return 0;
343}
344
Ingo Molnare0a42722006-06-23 02:03:46 -0700345static int slab_early_init = 1;
346
Christoph Lametere498be72005-09-09 13:03:32 -0700347#define INDEX_AC index_of(sizeof(struct arraycache_init))
348#define INDEX_L3 index_of(sizeof(struct kmem_list3))
349
Pekka Enberg5295a742006-02-01 03:05:48 -0800350static void kmem_list3_init(struct kmem_list3 *parent)
Christoph Lametere498be72005-09-09 13:03:32 -0700351{
352 INIT_LIST_HEAD(&parent->slabs_full);
353 INIT_LIST_HEAD(&parent->slabs_partial);
354 INIT_LIST_HEAD(&parent->slabs_free);
355 parent->shared = NULL;
356 parent->alien = NULL;
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -0800357 parent->colour_next = 0;
Christoph Lametere498be72005-09-09 13:03:32 -0700358 spin_lock_init(&parent->list_lock);
359 parent->free_objects = 0;
360 parent->free_touched = 0;
361}
362
Andrew Mortona737b3e2006-03-22 00:08:11 -0800363#define MAKE_LIST(cachep, listp, slab, nodeid) \
364 do { \
365 INIT_LIST_HEAD(listp); \
366 list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
Christoph Lametere498be72005-09-09 13:03:32 -0700367 } while (0)
368
Andrew Mortona737b3e2006-03-22 00:08:11 -0800369#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
370 do { \
Christoph Lametere498be72005-09-09 13:03:32 -0700371 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
372 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
373 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
374 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
376/*
Pekka Enberg343e0d72006-02-01 03:05:50 -0800377 * struct kmem_cache
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 *
379 * manages a cache.
380 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800381
Pekka J Enberg2109a2d2005-11-07 00:58:01 -0800382struct kmem_cache {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383/* 1) per-cpu data, touched during every alloc/free */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800384 struct array_cache *array[NR_CPUS];
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800385/* 2) Cache tunables. Protected by cache_chain_mutex */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800386 unsigned int batchcount;
387 unsigned int limit;
388 unsigned int shared;
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800389
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800390 unsigned int buffer_size;
Eric Dumazet6a2d7a92006-12-13 00:34:27 -0800391 u32 reciprocal_buffer_size;
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800392/* 3) touched by every alloc & free from the backend */
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800393
Andrew Mortona737b3e2006-03-22 00:08:11 -0800394 unsigned int flags; /* constant flags */
395 unsigned int num; /* # of objs per slab */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800397/* 4) cache_grow/shrink */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 /* order of pgs per slab (2^n) */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800399 unsigned int gfporder;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
401 /* force GFP flags, e.g. GFP_DMA */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800402 gfp_t gfpflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
Andrew Mortona737b3e2006-03-22 00:08:11 -0800404 size_t colour; /* cache colouring range */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800405 unsigned int colour_off; /* colour offset */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800406 struct kmem_cache *slabp_cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800407 unsigned int slab_size;
Andrew Mortona737b3e2006-03-22 00:08:11 -0800408 unsigned int dflags; /* dynamic flags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
410 /* constructor func */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800411 void (*ctor) (void *, struct kmem_cache *, unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800413/* 5) cache creation/removal */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800414 const char *name;
415 struct list_head next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800417/* 6) statistics */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418#if STATS
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800419 unsigned long num_active;
420 unsigned long num_allocations;
421 unsigned long high_mark;
422 unsigned long grown;
423 unsigned long reaped;
424 unsigned long errors;
425 unsigned long max_freeable;
426 unsigned long node_allocs;
427 unsigned long node_frees;
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -0700428 unsigned long node_overflow;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800429 atomic_t allochit;
430 atomic_t allocmiss;
431 atomic_t freehit;
432 atomic_t freemiss;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433#endif
434#if DEBUG
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800435 /*
436 * If debugging is enabled, then the allocator can add additional
437 * fields and/or padding to every object. buffer_size contains the total
438 * object size including these internal fields, the following two
439 * variables contain the offset to the user object and its size.
440 */
441 int obj_offset;
442 int obj_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443#endif
Eric Dumazet8da34302007-05-06 14:49:29 -0700444 /*
445 * We put nodelists[] at the end of kmem_cache, because we want to size
446 * this array to nr_node_ids slots instead of MAX_NUMNODES
447 * (see kmem_cache_init())
448 * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache
449 * is statically defined, so we reserve the max number of nodes.
450 */
451 struct kmem_list3 *nodelists[MAX_NUMNODES];
452 /*
453 * Do not add fields after nodelists[]
454 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455};
456
457#define CFLGS_OFF_SLAB (0x80000000UL)
458#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
459
460#define BATCHREFILL_LIMIT 16
Andrew Mortona737b3e2006-03-22 00:08:11 -0800461/*
462 * Optimization question: fewer reaps means less probability for unnessary
463 * cpucache drain/refill cycles.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 *
Adrian Bunkdc6f3f22005-11-08 16:44:08 +0100465 * OTOH the cpuarrays can contain lots of objects,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 * which could lock up otherwise freeable slabs.
467 */
468#define REAPTIMEOUT_CPUC (2*HZ)
469#define REAPTIMEOUT_LIST3 (4*HZ)
470
471#if STATS
472#define STATS_INC_ACTIVE(x) ((x)->num_active++)
473#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
474#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
475#define STATS_INC_GROWN(x) ((x)->grown++)
Christoph Lametered11d9e2006-06-30 01:55:45 -0700476#define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
Andrew Mortona737b3e2006-03-22 00:08:11 -0800477#define STATS_SET_HIGH(x) \
478 do { \
479 if ((x)->num_active > (x)->high_mark) \
480 (x)->high_mark = (x)->num_active; \
481 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482#define STATS_INC_ERR(x) ((x)->errors++)
483#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
Christoph Lametere498be72005-09-09 13:03:32 -0700484#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -0700485#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
Andrew Mortona737b3e2006-03-22 00:08:11 -0800486#define STATS_SET_FREEABLE(x, i) \
487 do { \
488 if ((x)->max_freeable < i) \
489 (x)->max_freeable = i; \
490 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
492#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
493#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
494#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
495#else
496#define STATS_INC_ACTIVE(x) do { } while (0)
497#define STATS_DEC_ACTIVE(x) do { } while (0)
498#define STATS_INC_ALLOCED(x) do { } while (0)
499#define STATS_INC_GROWN(x) do { } while (0)
Christoph Lametered11d9e2006-06-30 01:55:45 -0700500#define STATS_ADD_REAPED(x,y) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501#define STATS_SET_HIGH(x) do { } while (0)
502#define STATS_INC_ERR(x) do { } while (0)
503#define STATS_INC_NODEALLOCS(x) do { } while (0)
Christoph Lametere498be72005-09-09 13:03:32 -0700504#define STATS_INC_NODEFREES(x) do { } while (0)
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -0700505#define STATS_INC_ACOVERFLOW(x) do { } while (0)
Andrew Mortona737b3e2006-03-22 00:08:11 -0800506#define STATS_SET_FREEABLE(x, i) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507#define STATS_INC_ALLOCHIT(x) do { } while (0)
508#define STATS_INC_ALLOCMISS(x) do { } while (0)
509#define STATS_INC_FREEHIT(x) do { } while (0)
510#define STATS_INC_FREEMISS(x) do { } while (0)
511#endif
512
513#if DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
Andrew Mortona737b3e2006-03-22 00:08:11 -0800515/*
516 * memory layout of objects:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 * 0 : objp
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800518 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 * the end of an object is aligned with the end of the real
520 * allocation. Catches writes behind the end of the allocation.
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800521 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 * redzone word.
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800523 * cachep->obj_offset: The real object.
524 * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
Andrew Mortona737b3e2006-03-22 00:08:11 -0800525 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
526 * [BYTES_PER_WORD long]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800528static int obj_offset(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529{
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800530 return cachep->obj_offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531}
532
Pekka Enberg343e0d72006-02-01 03:05:50 -0800533static int obj_size(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534{
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800535 return cachep->obj_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536}
537
David Woodhouseb46b8f12007-05-08 00:22:59 -0700538static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539{
540 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
David Woodhouseb46b8f12007-05-08 00:22:59 -0700541 return (unsigned long long*) (objp + obj_offset(cachep) -
542 sizeof(unsigned long long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543}
544
David Woodhouseb46b8f12007-05-08 00:22:59 -0700545static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546{
547 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
548 if (cachep->flags & SLAB_STORE_USER)
David Woodhouseb46b8f12007-05-08 00:22:59 -0700549 return (unsigned long long *)(objp + cachep->buffer_size -
550 sizeof(unsigned long long) -
David Woodhouse87a927c2007-07-04 21:26:44 -0400551 REDZONE_ALIGN);
David Woodhouseb46b8f12007-05-08 00:22:59 -0700552 return (unsigned long long *) (objp + cachep->buffer_size -
553 sizeof(unsigned long long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554}
555
Pekka Enberg343e0d72006-02-01 03:05:50 -0800556static void **dbg_userword(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557{
558 BUG_ON(!(cachep->flags & SLAB_STORE_USER));
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800559 return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560}
561
562#else
563
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800564#define obj_offset(x) 0
565#define obj_size(cachep) (cachep->buffer_size)
David Woodhouseb46b8f12007-05-08 00:22:59 -0700566#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
567#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
569
570#endif
571
572/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 * Do not go above this order unless 0 objects fit into the slab.
574 */
575#define BREAK_GFP_ORDER_HI 1
576#define BREAK_GFP_ORDER_LO 0
577static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
578
Andrew Mortona737b3e2006-03-22 00:08:11 -0800579/*
580 * Functions for storing/retrieving the cachep and or slab from the page
581 * allocator. These are used to find the slab an obj belongs to. With kfree(),
582 * these are used to find the cache which an obj belongs to.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 */
Pekka Enberg065d41c2005-11-13 16:06:46 -0800584static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
585{
586 page->lru.next = (struct list_head *)cache;
587}
588
589static inline struct kmem_cache *page_get_cache(struct page *page)
590{
Christoph Lameterd85f3382007-05-06 14:49:39 -0700591 page = compound_head(page);
Pekka Enbergddc2e812006-06-23 02:03:40 -0700592 BUG_ON(!PageSlab(page));
Pekka Enberg065d41c2005-11-13 16:06:46 -0800593 return (struct kmem_cache *)page->lru.next;
594}
595
596static inline void page_set_slab(struct page *page, struct slab *slab)
597{
598 page->lru.prev = (struct list_head *)slab;
599}
600
601static inline struct slab *page_get_slab(struct page *page)
602{
Pekka Enbergddc2e812006-06-23 02:03:40 -0700603 BUG_ON(!PageSlab(page));
Pekka Enberg065d41c2005-11-13 16:06:46 -0800604 return (struct slab *)page->lru.prev;
605}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -0800607static inline struct kmem_cache *virt_to_cache(const void *obj)
608{
Christoph Lameterb49af682007-05-06 14:49:41 -0700609 struct page *page = virt_to_head_page(obj);
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -0800610 return page_get_cache(page);
611}
612
613static inline struct slab *virt_to_slab(const void *obj)
614{
Christoph Lameterb49af682007-05-06 14:49:41 -0700615 struct page *page = virt_to_head_page(obj);
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -0800616 return page_get_slab(page);
617}
618
Pekka Enberg8fea4e92006-03-22 00:08:10 -0800619static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
620 unsigned int idx)
621{
622 return slab->s_mem + cache->buffer_size * idx;
623}
624
Eric Dumazet6a2d7a92006-12-13 00:34:27 -0800625/*
626 * We want to avoid an expensive divide : (offset / cache->buffer_size)
627 * Using the fact that buffer_size is a constant for a particular cache,
628 * we can replace (offset / cache->buffer_size) by
629 * reciprocal_divide(offset, cache->reciprocal_buffer_size)
630 */
631static inline unsigned int obj_to_index(const struct kmem_cache *cache,
632 const struct slab *slab, void *obj)
Pekka Enberg8fea4e92006-03-22 00:08:10 -0800633{
Eric Dumazet6a2d7a92006-12-13 00:34:27 -0800634 u32 offset = (obj - slab->s_mem);
635 return reciprocal_divide(offset, cache->reciprocal_buffer_size);
Pekka Enberg8fea4e92006-03-22 00:08:10 -0800636}
637
Andrew Mortona737b3e2006-03-22 00:08:11 -0800638/*
639 * These are the default caches for kmalloc. Custom caches can have other sizes.
640 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641struct cache_sizes malloc_sizes[] = {
642#define CACHE(x) { .cs_size = (x) },
643#include <linux/kmalloc_sizes.h>
644 CACHE(ULONG_MAX)
645#undef CACHE
646};
647EXPORT_SYMBOL(malloc_sizes);
648
649/* Must match cache_sizes above. Out of line to keep cache footprint low. */
650struct cache_names {
651 char *name;
652 char *name_dma;
653};
654
655static struct cache_names __initdata cache_names[] = {
656#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
657#include <linux/kmalloc_sizes.h>
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800658 {NULL,}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659#undef CACHE
660};
661
662static struct arraycache_init initarray_cache __initdata =
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800663 { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664static struct arraycache_init initarray_generic =
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800665 { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666
667/* internal cache of cache description objs */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800668static struct kmem_cache cache_cache = {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800669 .batchcount = 1,
670 .limit = BOOT_CPUCACHE_ENTRIES,
671 .shared = 1,
Pekka Enberg343e0d72006-02-01 03:05:50 -0800672 .buffer_size = sizeof(struct kmem_cache),
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800673 .name = "kmem_cache",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674};
675
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700676#define BAD_ALIEN_MAGIC 0x01020304ul
677
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200678#ifdef CONFIG_LOCKDEP
679
680/*
681 * Slab sometimes uses the kmalloc slabs to store the slab headers
682 * for other slabs "off slab".
683 * The locking for this is tricky in that it nests within the locks
684 * of all other slabs in a few places; to deal with this special
685 * locking we put on-slab caches into a separate lock-class.
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700686 *
687 * We set lock class for alien array caches which are up during init.
688 * The lock annotation will be lost if all cpus of a node goes down and
689 * then comes back up during hotplug
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200690 */
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700691static struct lock_class_key on_slab_l3_key;
692static struct lock_class_key on_slab_alc_key;
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200693
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700694static inline void init_lock_keys(void)
695
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200696{
697 int q;
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700698 struct cache_sizes *s = malloc_sizes;
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200699
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700700 while (s->cs_size != ULONG_MAX) {
701 for_each_node(q) {
702 struct array_cache **alc;
703 int r;
704 struct kmem_list3 *l3 = s->cs_cachep->nodelists[q];
705 if (!l3 || OFF_SLAB(s->cs_cachep))
706 continue;
707 lockdep_set_class(&l3->list_lock, &on_slab_l3_key);
708 alc = l3->alien;
709 /*
710 * FIXME: This check for BAD_ALIEN_MAGIC
711 * should go away when common slab code is taught to
712 * work even without alien caches.
713 * Currently, non NUMA code returns BAD_ALIEN_MAGIC
714 * for alloc_alien_cache,
715 */
716 if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC)
717 continue;
718 for_each_node(r) {
719 if (alc[r])
720 lockdep_set_class(&alc[r]->lock,
721 &on_slab_alc_key);
722 }
723 }
724 s++;
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200725 }
726}
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200727#else
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700728static inline void init_lock_keys(void)
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200729{
730}
731#endif
732
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -0800733/*
734 * 1. Guard access to the cache-chain.
735 * 2. Protect sanity of cpu_online_map against cpu hotplug events
736 */
Ingo Molnarfc0abb12006-01-18 17:42:33 -0800737static DEFINE_MUTEX(cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738static struct list_head cache_chain;
739
740/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 * chicken and egg problem: delay the per-cpu array allocation
742 * until the general caches are up.
743 */
744static enum {
745 NONE,
Christoph Lametere498be72005-09-09 13:03:32 -0700746 PARTIAL_AC,
747 PARTIAL_L3,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 FULL
749} g_cpucache_up;
750
Mike Kravetz39d24e62006-05-15 09:44:13 -0700751/*
752 * used by boot code to determine if it can use slab based allocator
753 */
754int slab_is_available(void)
755{
756 return g_cpucache_up == FULL;
757}
758
David Howells52bad642006-11-22 14:54:01 +0000759static DEFINE_PER_CPU(struct delayed_work, reap_work);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
Pekka Enberg343e0d72006-02-01 03:05:50 -0800761static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762{
763 return cachep->array[smp_processor_id()];
764}
765
Andrew Mortona737b3e2006-03-22 00:08:11 -0800766static inline struct kmem_cache *__find_general_cachep(size_t size,
767 gfp_t gfpflags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768{
769 struct cache_sizes *csizep = malloc_sizes;
770
771#if DEBUG
772 /* This happens if someone tries to call
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800773 * kmem_cache_create(), or __kmalloc(), before
774 * the generic caches are initialized.
775 */
Alok Katariac7e43c72005-09-14 12:17:53 -0700776 BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777#endif
Christoph Lameter6cb8f912007-07-17 04:03:22 -0700778 if (!size)
779 return ZERO_SIZE_PTR;
780
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 while (size > csizep->cs_size)
782 csizep++;
783
784 /*
Martin Hicks0abf40c2005-09-03 15:54:54 -0700785 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 * has cs_{dma,}cachep==NULL. Thus no special case
787 * for large kmalloc calls required.
788 */
Christoph Lameter4b51d662007-02-10 01:43:10 -0800789#ifdef CONFIG_ZONE_DMA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 if (unlikely(gfpflags & GFP_DMA))
791 return csizep->cs_dmacachep;
Christoph Lameter4b51d662007-02-10 01:43:10 -0800792#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 return csizep->cs_cachep;
794}
795
Adrian Bunkb2213852006-09-25 23:31:02 -0700796static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700797{
798 return __find_general_cachep(size, gfpflags);
799}
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700800
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800801static size_t slab_mgmt_size(size_t nr_objs, size_t align)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802{
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800803 return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
804}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805
Andrew Mortona737b3e2006-03-22 00:08:11 -0800806/*
807 * Calculate the number of objects and left-over bytes for a given buffer size.
808 */
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800809static void cache_estimate(unsigned long gfporder, size_t buffer_size,
810 size_t align, int flags, size_t *left_over,
811 unsigned int *num)
812{
813 int nr_objs;
814 size_t mgmt_size;
815 size_t slab_size = PAGE_SIZE << gfporder;
816
817 /*
818 * The slab management structure can be either off the slab or
819 * on it. For the latter case, the memory allocated for a
820 * slab is used for:
821 *
822 * - The struct slab
823 * - One kmem_bufctl_t for each object
824 * - Padding to respect alignment of @align
825 * - @buffer_size bytes for each object
826 *
827 * If the slab management structure is off the slab, then the
828 * alignment will already be calculated into the size. Because
829 * the slabs are all pages aligned, the objects will be at the
830 * correct alignment when allocated.
831 */
832 if (flags & CFLGS_OFF_SLAB) {
833 mgmt_size = 0;
834 nr_objs = slab_size / buffer_size;
835
836 if (nr_objs > SLAB_LIMIT)
837 nr_objs = SLAB_LIMIT;
838 } else {
839 /*
840 * Ignore padding for the initial guess. The padding
841 * is at most @align-1 bytes, and @buffer_size is at
842 * least @align. In the worst case, this result will
843 * be one greater than the number of objects that fit
844 * into the memory allocation when taking the padding
845 * into account.
846 */
847 nr_objs = (slab_size - sizeof(struct slab)) /
848 (buffer_size + sizeof(kmem_bufctl_t));
849
850 /*
851 * This calculated number will be either the right
852 * amount, or one greater than what we want.
853 */
854 if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size
855 > slab_size)
856 nr_objs--;
857
858 if (nr_objs > SLAB_LIMIT)
859 nr_objs = SLAB_LIMIT;
860
861 mgmt_size = slab_mgmt_size(nr_objs, align);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 }
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800863 *num = nr_objs;
864 *left_over = slab_size - nr_objs*buffer_size - mgmt_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865}
866
867#define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
868
Andrew Mortona737b3e2006-03-22 00:08:11 -0800869static void __slab_error(const char *function, struct kmem_cache *cachep,
870 char *msg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871{
872 printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800873 function, cachep->name, msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 dump_stack();
875}
876
Paul Menage3395ee02006-12-06 20:32:16 -0800877/*
878 * By default on NUMA we use alien caches to stage the freeing of
879 * objects allocated from other nodes. This causes massive memory
880 * inefficiencies when using fake NUMA setup to split memory into a
881 * large number of small nodes, so it can be disabled on the command
882 * line
883 */
884
885static int use_alien_caches __read_mostly = 1;
Siddha, Suresh B1807a1a2007-08-22 14:01:49 -0700886static int numa_platform __read_mostly = 1;
Paul Menage3395ee02006-12-06 20:32:16 -0800887static int __init noaliencache_setup(char *s)
888{
889 use_alien_caches = 0;
890 return 1;
891}
892__setup("noaliencache", noaliencache_setup);
893
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800894#ifdef CONFIG_NUMA
895/*
896 * Special reaping functions for NUMA systems called from cache_reap().
897 * These take care of doing round robin flushing of alien caches (containing
898 * objects freed on different nodes from which they were allocated) and the
899 * flushing of remote pcps by calling drain_node_pages.
900 */
901static DEFINE_PER_CPU(unsigned long, reap_node);
902
903static void init_reap_node(int cpu)
904{
905 int node;
906
907 node = next_node(cpu_to_node(cpu), node_online_map);
908 if (node == MAX_NUMNODES)
Paul Jackson442295c2006-03-22 00:09:11 -0800909 node = first_node(node_online_map);
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800910
Daniel Yeisley7f6b8872006-11-02 22:07:14 -0800911 per_cpu(reap_node, cpu) = node;
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800912}
913
914static void next_reap_node(void)
915{
916 int node = __get_cpu_var(reap_node);
917
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800918 node = next_node(node, node_online_map);
919 if (unlikely(node >= MAX_NUMNODES))
920 node = first_node(node_online_map);
921 __get_cpu_var(reap_node) = node;
922}
923
924#else
925#define init_reap_node(cpu) do { } while (0)
926#define next_reap_node(void) do { } while (0)
927#endif
928
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929/*
930 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
931 * via the workqueue/eventd.
932 * Add the CPU number into the expiration time to minimize the possibility of
933 * the CPUs getting into lockstep and contending for the global cache chain
934 * lock.
935 */
Adrian Bunk897e6792007-07-15 23:38:20 -0700936static void __cpuinit start_cpu_timer(int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937{
David Howells52bad642006-11-22 14:54:01 +0000938 struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939
940 /*
941 * When this gets called from do_initcalls via cpucache_init(),
942 * init_workqueues() has already run, so keventd will be setup
943 * at that time.
944 */
David Howells52bad642006-11-22 14:54:01 +0000945 if (keventd_up() && reap_work->work.func == NULL) {
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800946 init_reap_node(cpu);
David Howells65f27f32006-11-22 14:55:48 +0000947 INIT_DELAYED_WORK(reap_work, cache_reap);
Arjan van de Ven2b284212006-12-10 02:21:28 -0800948 schedule_delayed_work_on(cpu, reap_work,
949 __round_jiffies_relative(HZ, cpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 }
951}
952
Christoph Lametere498be72005-09-09 13:03:32 -0700953static struct array_cache *alloc_arraycache(int node, int entries,
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800954 int batchcount)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955{
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800956 int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 struct array_cache *nc = NULL;
958
Christoph Lametere498be72005-09-09 13:03:32 -0700959 nc = kmalloc_node(memsize, GFP_KERNEL, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 if (nc) {
961 nc->avail = 0;
962 nc->limit = entries;
963 nc->batchcount = batchcount;
964 nc->touched = 0;
Christoph Lametere498be72005-09-09 13:03:32 -0700965 spin_lock_init(&nc->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 }
967 return nc;
968}
969
Christoph Lameter3ded1752006-03-25 03:06:44 -0800970/*
971 * Transfer objects in one arraycache to another.
972 * Locking must be handled by the caller.
973 *
974 * Return the number of entries transferred.
975 */
976static int transfer_objects(struct array_cache *to,
977 struct array_cache *from, unsigned int max)
978{
979 /* Figure out how many entries to transfer */
980 int nr = min(min(from->avail, max), to->limit - to->avail);
981
982 if (!nr)
983 return 0;
984
985 memcpy(to->entry + to->avail, from->entry + from->avail -nr,
986 sizeof(void *) *nr);
987
988 from->avail -= nr;
989 to->avail += nr;
990 to->touched = 1;
991 return nr;
992}
993
Christoph Lameter765c4502006-09-27 01:50:08 -0700994#ifndef CONFIG_NUMA
995
996#define drain_alien_cache(cachep, alien) do { } while (0)
997#define reap_alien(cachep, l3) do { } while (0)
998
999static inline struct array_cache **alloc_alien_cache(int node, int limit)
1000{
1001 return (struct array_cache **)BAD_ALIEN_MAGIC;
1002}
1003
1004static inline void free_alien_cache(struct array_cache **ac_ptr)
1005{
1006}
1007
1008static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1009{
1010 return 0;
1011}
1012
1013static inline void *alternate_node_alloc(struct kmem_cache *cachep,
1014 gfp_t flags)
1015{
1016 return NULL;
1017}
1018
Christoph Hellwig8b98c162006-12-06 20:32:30 -08001019static inline void *____cache_alloc_node(struct kmem_cache *cachep,
Christoph Lameter765c4502006-09-27 01:50:08 -07001020 gfp_t flags, int nodeid)
1021{
1022 return NULL;
1023}
1024
1025#else /* CONFIG_NUMA */
1026
Christoph Hellwig8b98c162006-12-06 20:32:30 -08001027static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
Paul Jacksonc61afb12006-03-24 03:16:08 -08001028static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
Christoph Lameterdc85da12006-01-18 17:42:36 -08001029
Pekka Enberg5295a742006-02-01 03:05:48 -08001030static struct array_cache **alloc_alien_cache(int node, int limit)
Christoph Lametere498be72005-09-09 13:03:32 -07001031{
1032 struct array_cache **ac_ptr;
Christoph Lameter8ef82862007-02-20 13:57:52 -08001033 int memsize = sizeof(void *) * nr_node_ids;
Christoph Lametere498be72005-09-09 13:03:32 -07001034 int i;
1035
1036 if (limit > 1)
1037 limit = 12;
1038 ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node);
1039 if (ac_ptr) {
1040 for_each_node(i) {
1041 if (i == node || !node_online(i)) {
1042 ac_ptr[i] = NULL;
1043 continue;
1044 }
1045 ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d);
1046 if (!ac_ptr[i]) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001047 for (i--; i <= 0; i--)
Christoph Lametere498be72005-09-09 13:03:32 -07001048 kfree(ac_ptr[i]);
1049 kfree(ac_ptr);
1050 return NULL;
1051 }
1052 }
1053 }
1054 return ac_ptr;
1055}
1056
Pekka Enberg5295a742006-02-01 03:05:48 -08001057static void free_alien_cache(struct array_cache **ac_ptr)
Christoph Lametere498be72005-09-09 13:03:32 -07001058{
1059 int i;
1060
1061 if (!ac_ptr)
1062 return;
Christoph Lametere498be72005-09-09 13:03:32 -07001063 for_each_node(i)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001064 kfree(ac_ptr[i]);
Christoph Lametere498be72005-09-09 13:03:32 -07001065 kfree(ac_ptr);
1066}
1067
Pekka Enberg343e0d72006-02-01 03:05:50 -08001068static void __drain_alien_cache(struct kmem_cache *cachep,
Pekka Enberg5295a742006-02-01 03:05:48 -08001069 struct array_cache *ac, int node)
Christoph Lametere498be72005-09-09 13:03:32 -07001070{
1071 struct kmem_list3 *rl3 = cachep->nodelists[node];
1072
1073 if (ac->avail) {
1074 spin_lock(&rl3->list_lock);
Christoph Lametere00946f2006-03-25 03:06:45 -08001075 /*
1076 * Stuff objects into the remote nodes shared array first.
1077 * That way we could avoid the overhead of putting the objects
1078 * into the free lists and getting them back later.
1079 */
shin, jacob693f7d32006-04-28 10:54:37 -05001080 if (rl3->shared)
1081 transfer_objects(rl3->shared, ac, ac->limit);
Christoph Lametere00946f2006-03-25 03:06:45 -08001082
Christoph Lameterff694162005-09-22 21:44:02 -07001083 free_block(cachep, ac->entry, ac->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001084 ac->avail = 0;
1085 spin_unlock(&rl3->list_lock);
1086 }
1087}
1088
Christoph Lameter8fce4d82006-03-09 17:33:54 -08001089/*
1090 * Called from cache_reap() to regularly drain alien caches round robin.
1091 */
1092static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
1093{
1094 int node = __get_cpu_var(reap_node);
1095
1096 if (l3->alien) {
1097 struct array_cache *ac = l3->alien[node];
Christoph Lametere00946f2006-03-25 03:06:45 -08001098
1099 if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
Christoph Lameter8fce4d82006-03-09 17:33:54 -08001100 __drain_alien_cache(cachep, ac, node);
1101 spin_unlock_irq(&ac->lock);
1102 }
1103 }
1104}
1105
Andrew Mortona737b3e2006-03-22 00:08:11 -08001106static void drain_alien_cache(struct kmem_cache *cachep,
1107 struct array_cache **alien)
Christoph Lametere498be72005-09-09 13:03:32 -07001108{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001109 int i = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07001110 struct array_cache *ac;
1111 unsigned long flags;
1112
1113 for_each_online_node(i) {
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001114 ac = alien[i];
Christoph Lametere498be72005-09-09 13:03:32 -07001115 if (ac) {
1116 spin_lock_irqsave(&ac->lock, flags);
1117 __drain_alien_cache(cachep, ac, i);
1118 spin_unlock_irqrestore(&ac->lock, flags);
1119 }
1120 }
1121}
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001122
Ingo Molnar873623d2006-07-13 14:44:38 +02001123static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001124{
1125 struct slab *slabp = virt_to_slab(objp);
1126 int nodeid = slabp->nodeid;
1127 struct kmem_list3 *l3;
1128 struct array_cache *alien = NULL;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001129 int node;
1130
1131 node = numa_node_id();
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001132
1133 /*
1134 * Make sure we are not freeing a object from another node to the array
1135 * cache on this cpu.
1136 */
Siddha, Suresh B62918a02007-05-02 19:27:18 +02001137 if (likely(slabp->nodeid == node))
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001138 return 0;
1139
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001140 l3 = cachep->nodelists[node];
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001141 STATS_INC_NODEFREES(cachep);
1142 if (l3->alien && l3->alien[nodeid]) {
1143 alien = l3->alien[nodeid];
Ingo Molnar873623d2006-07-13 14:44:38 +02001144 spin_lock(&alien->lock);
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001145 if (unlikely(alien->avail == alien->limit)) {
1146 STATS_INC_ACOVERFLOW(cachep);
1147 __drain_alien_cache(cachep, alien, nodeid);
1148 }
1149 alien->entry[alien->avail++] = objp;
1150 spin_unlock(&alien->lock);
1151 } else {
1152 spin_lock(&(cachep->nodelists[nodeid])->list_lock);
1153 free_block(cachep, &objp, 1, nodeid);
1154 spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
1155 }
1156 return 1;
1157}
Christoph Lametere498be72005-09-09 13:03:32 -07001158#endif
1159
Chandra Seetharaman8c78f302006-07-30 03:03:35 -07001160static int __cpuinit cpuup_callback(struct notifier_block *nfb,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001161 unsigned long action, void *hcpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162{
1163 long cpu = (long)hcpu;
Pekka Enberg343e0d72006-02-01 03:05:50 -08001164 struct kmem_cache *cachep;
Christoph Lametere498be72005-09-09 13:03:32 -07001165 struct kmem_list3 *l3 = NULL;
1166 int node = cpu_to_node(cpu);
David Howellsea02e3d2007-07-19 01:49:09 -07001167 const int memsize = sizeof(struct kmem_list3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168
1169 switch (action) {
Heiko Carstens38c3bd92007-05-09 02:34:05 -07001170 case CPU_LOCK_ACQUIRE:
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001171 mutex_lock(&cache_chain_mutex);
Heiko Carstens38c3bd92007-05-09 02:34:05 -07001172 break;
1173 case CPU_UP_PREPARE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001174 case CPU_UP_PREPARE_FROZEN:
Andrew Mortona737b3e2006-03-22 00:08:11 -08001175 /*
1176 * We need to do this right in the beginning since
Christoph Lametere498be72005-09-09 13:03:32 -07001177 * alloc_arraycache's are going to use this list.
1178 * kmalloc_node allows us to add the slab to the right
1179 * kmem_list3 and not this cpu's kmem_list3
1180 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181
Christoph Lametere498be72005-09-09 13:03:32 -07001182 list_for_each_entry(cachep, &cache_chain, next) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08001183 /*
1184 * Set up the size64 kmemlist for cpu before we can
Christoph Lametere498be72005-09-09 13:03:32 -07001185 * begin anything. Make sure some other cpu on this
1186 * node has not already allocated this
1187 */
1188 if (!cachep->nodelists[node]) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08001189 l3 = kmalloc_node(memsize, GFP_KERNEL, node);
1190 if (!l3)
Christoph Lametere498be72005-09-09 13:03:32 -07001191 goto bad;
1192 kmem_list3_init(l3);
1193 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001194 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametere498be72005-09-09 13:03:32 -07001195
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001196 /*
1197 * The l3s don't come and go as CPUs come and
1198 * go. cache_chain_mutex is sufficient
1199 * protection here.
1200 */
Christoph Lametere498be72005-09-09 13:03:32 -07001201 cachep->nodelists[node] = l3;
1202 }
1203
1204 spin_lock_irq(&cachep->nodelists[node]->list_lock);
1205 cachep->nodelists[node]->free_limit =
Andrew Mortona737b3e2006-03-22 00:08:11 -08001206 (1 + nr_cpus_node(node)) *
1207 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07001208 spin_unlock_irq(&cachep->nodelists[node]->list_lock);
1209 }
1210
Andrew Mortona737b3e2006-03-22 00:08:11 -08001211 /*
1212 * Now we can go ahead with allocating the shared arrays and
1213 * array caches
1214 */
Christoph Lametere498be72005-09-09 13:03:32 -07001215 list_for_each_entry(cachep, &cache_chain, next) {
Tobias Klausercd105df2006-01-08 01:00:59 -08001216 struct array_cache *nc;
Eric Dumazet63109842007-05-06 14:49:28 -07001217 struct array_cache *shared = NULL;
Paul Menage3395ee02006-12-06 20:32:16 -08001218 struct array_cache **alien = NULL;
Tobias Klausercd105df2006-01-08 01:00:59 -08001219
Christoph Lametere498be72005-09-09 13:03:32 -07001220 nc = alloc_arraycache(node, cachep->limit,
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001221 cachep->batchcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222 if (!nc)
1223 goto bad;
Eric Dumazet63109842007-05-06 14:49:28 -07001224 if (cachep->shared) {
1225 shared = alloc_arraycache(node,
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001226 cachep->shared * cachep->batchcount,
1227 0xbaadf00d);
Eric Dumazet63109842007-05-06 14:49:28 -07001228 if (!shared)
1229 goto bad;
1230 }
Paul Menage3395ee02006-12-06 20:32:16 -08001231 if (use_alien_caches) {
1232 alien = alloc_alien_cache(node, cachep->limit);
1233 if (!alien)
1234 goto bad;
1235 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 cachep->array[cpu] = nc;
Christoph Lametere498be72005-09-09 13:03:32 -07001237 l3 = cachep->nodelists[node];
1238 BUG_ON(!l3);
Christoph Lametere498be72005-09-09 13:03:32 -07001239
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001240 spin_lock_irq(&l3->list_lock);
1241 if (!l3->shared) {
1242 /*
1243 * We are serialised from CPU_DEAD or
1244 * CPU_UP_CANCELLED by the cpucontrol lock
1245 */
1246 l3->shared = shared;
1247 shared = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07001248 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001249#ifdef CONFIG_NUMA
1250 if (!l3->alien) {
1251 l3->alien = alien;
1252 alien = NULL;
1253 }
1254#endif
1255 spin_unlock_irq(&l3->list_lock);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001256 kfree(shared);
1257 free_alien_cache(alien);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 break;
1260 case CPU_ONLINE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001261 case CPU_ONLINE_FROZEN:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 start_cpu_timer(cpu);
1263 break;
1264#ifdef CONFIG_HOTPLUG_CPU
Christoph Lameter5830c592007-05-09 02:34:22 -07001265 case CPU_DOWN_PREPARE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001266 case CPU_DOWN_PREPARE_FROZEN:
Christoph Lameter5830c592007-05-09 02:34:22 -07001267 /*
1268 * Shutdown cache reaper. Note that the cache_chain_mutex is
1269 * held so that if cache_reap() is invoked it cannot do
1270 * anything expensive but will only modify reap_work
1271 * and reschedule the timer.
1272 */
1273 cancel_rearming_delayed_work(&per_cpu(reap_work, cpu));
1274 /* Now the cache_reaper is guaranteed to be not running. */
1275 per_cpu(reap_work, cpu).work.func = NULL;
1276 break;
1277 case CPU_DOWN_FAILED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001278 case CPU_DOWN_FAILED_FROZEN:
Christoph Lameter5830c592007-05-09 02:34:22 -07001279 start_cpu_timer(cpu);
1280 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001282 case CPU_DEAD_FROZEN:
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001283 /*
1284 * Even if all the cpus of a node are down, we don't free the
1285 * kmem_list3 of any cache. This to avoid a race between
1286 * cpu_down, and a kmalloc allocation from another cpu for
1287 * memory from the node of the cpu going down. The list3
1288 * structure is usually allocated from kmem_cache_create() and
1289 * gets destroyed at kmem_cache_destroy().
1290 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 /* fall thru */
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08001292#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001293 case CPU_UP_CANCELED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001294 case CPU_UP_CANCELED_FROZEN:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 list_for_each_entry(cachep, &cache_chain, next) {
1296 struct array_cache *nc;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001297 struct array_cache *shared;
1298 struct array_cache **alien;
Christoph Lametere498be72005-09-09 13:03:32 -07001299 cpumask_t mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300
Christoph Lametere498be72005-09-09 13:03:32 -07001301 mask = node_to_cpumask(node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 /* cpu is dead; no one can alloc from it. */
1303 nc = cachep->array[cpu];
1304 cachep->array[cpu] = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07001305 l3 = cachep->nodelists[node];
1306
1307 if (!l3)
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001308 goto free_array_cache;
Christoph Lametere498be72005-09-09 13:03:32 -07001309
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08001310 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07001311
1312 /* Free limit for this kmem_list3 */
1313 l3->free_limit -= cachep->batchcount;
1314 if (nc)
Christoph Lameterff694162005-09-22 21:44:02 -07001315 free_block(cachep, nc->entry, nc->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001316
1317 if (!cpus_empty(mask)) {
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08001318 spin_unlock_irq(&l3->list_lock);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001319 goto free_array_cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001320 }
Christoph Lametere498be72005-09-09 13:03:32 -07001321
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001322 shared = l3->shared;
1323 if (shared) {
Eric Dumazet63109842007-05-06 14:49:28 -07001324 free_block(cachep, shared->entry,
1325 shared->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001326 l3->shared = NULL;
1327 }
Christoph Lametere498be72005-09-09 13:03:32 -07001328
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001329 alien = l3->alien;
1330 l3->alien = NULL;
1331
1332 spin_unlock_irq(&l3->list_lock);
1333
1334 kfree(shared);
1335 if (alien) {
1336 drain_alien_cache(cachep, alien);
1337 free_alien_cache(alien);
Christoph Lametere498be72005-09-09 13:03:32 -07001338 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001339free_array_cache:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340 kfree(nc);
1341 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001342 /*
1343 * In the previous loop, all the objects were freed to
1344 * the respective cache's slabs, now we can go ahead and
1345 * shrink each nodelist to its limit.
1346 */
1347 list_for_each_entry(cachep, &cache_chain, next) {
1348 l3 = cachep->nodelists[node];
1349 if (!l3)
1350 continue;
Christoph Lametered11d9e2006-06-30 01:55:45 -07001351 drain_freelist(cachep, l3, l3->free_objects);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001352 }
Heiko Carstens38c3bd92007-05-09 02:34:05 -07001353 break;
1354 case CPU_LOCK_RELEASE:
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001355 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001356 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357 }
1358 return NOTIFY_OK;
Andrew Mortona737b3e2006-03-22 00:08:11 -08001359bad:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360 return NOTIFY_BAD;
1361}
1362
Chandra Seetharaman74b85f32006-06-27 02:54:09 -07001363static struct notifier_block __cpuinitdata cpucache_notifier = {
1364 &cpuup_callback, NULL, 0
1365};
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366
Christoph Lametere498be72005-09-09 13:03:32 -07001367/*
1368 * swap the static kmem_list3 with kmalloced memory
1369 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001370static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
1371 int nodeid)
Christoph Lametere498be72005-09-09 13:03:32 -07001372{
1373 struct kmem_list3 *ptr;
1374
Christoph Lametere498be72005-09-09 13:03:32 -07001375 ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid);
1376 BUG_ON(!ptr);
1377
1378 local_irq_disable();
1379 memcpy(ptr, list, sizeof(struct kmem_list3));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001380 /*
1381 * Do not assume that spinlocks can be initialized via memcpy:
1382 */
1383 spin_lock_init(&ptr->list_lock);
1384
Christoph Lametere498be72005-09-09 13:03:32 -07001385 MAKE_ALL_LISTS(cachep, ptr, nodeid);
1386 cachep->nodelists[nodeid] = ptr;
1387 local_irq_enable();
1388}
1389
Andrew Mortona737b3e2006-03-22 00:08:11 -08001390/*
1391 * Initialisation. Called after the page allocator have been initialised and
1392 * before smp_init().
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393 */
1394void __init kmem_cache_init(void)
1395{
1396 size_t left_over;
1397 struct cache_sizes *sizes;
1398 struct cache_names *names;
Christoph Lametere498be72005-09-09 13:03:32 -07001399 int i;
Jack Steiner07ed76b2006-03-07 21:55:46 -08001400 int order;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001401 int node;
Christoph Lametere498be72005-09-09 13:03:32 -07001402
Siddha, Suresh B1807a1a2007-08-22 14:01:49 -07001403 if (num_possible_nodes() == 1) {
Siddha, Suresh B62918a02007-05-02 19:27:18 +02001404 use_alien_caches = 0;
Siddha, Suresh B1807a1a2007-08-22 14:01:49 -07001405 numa_platform = 0;
1406 }
Siddha, Suresh B62918a02007-05-02 19:27:18 +02001407
Christoph Lametere498be72005-09-09 13:03:32 -07001408 for (i = 0; i < NUM_INIT_LISTS; i++) {
1409 kmem_list3_init(&initkmem_list3[i]);
1410 if (i < MAX_NUMNODES)
1411 cache_cache.nodelists[i] = NULL;
1412 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413
1414 /*
1415 * Fragmentation resistance on low memory - only use bigger
1416 * page orders on machines with more than 32MB of memory.
1417 */
1418 if (num_physpages > (32 << 20) >> PAGE_SHIFT)
1419 slab_break_gfp_order = BREAK_GFP_ORDER_HI;
1420
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 /* Bootstrap is tricky, because several objects are allocated
1422 * from caches that do not exist yet:
Andrew Mortona737b3e2006-03-22 00:08:11 -08001423 * 1) initialize the cache_cache cache: it contains the struct
1424 * kmem_cache structures of all caches, except cache_cache itself:
1425 * cache_cache is statically allocated.
Christoph Lametere498be72005-09-09 13:03:32 -07001426 * Initially an __init data area is used for the head array and the
1427 * kmem_list3 structures, it's replaced with a kmalloc allocated
1428 * array at the end of the bootstrap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429 * 2) Create the first kmalloc cache.
Pekka Enberg343e0d72006-02-01 03:05:50 -08001430 * The struct kmem_cache for the new cache is allocated normally.
Christoph Lametere498be72005-09-09 13:03:32 -07001431 * An __init data area is used for the head array.
1432 * 3) Create the remaining kmalloc caches, with minimally sized
1433 * head arrays.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 * 4) Replace the __init data head arrays for cache_cache and the first
1435 * kmalloc cache with kmalloc allocated arrays.
Christoph Lametere498be72005-09-09 13:03:32 -07001436 * 5) Replace the __init data for kmem_list3 for cache_cache and
1437 * the other cache's with kmalloc allocated memory.
1438 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439 */
1440
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001441 node = numa_node_id();
1442
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 /* 1) create the cache_cache */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444 INIT_LIST_HEAD(&cache_chain);
1445 list_add(&cache_cache.next, &cache_chain);
1446 cache_cache.colour_off = cache_line_size();
1447 cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001448 cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449
Eric Dumazet8da34302007-05-06 14:49:29 -07001450 /*
1451 * struct kmem_cache size depends on nr_node_ids, which
1452 * can be less than MAX_NUMNODES.
1453 */
1454 cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) +
1455 nr_node_ids * sizeof(struct kmem_list3 *);
1456#if DEBUG
1457 cache_cache.obj_size = cache_cache.buffer_size;
1458#endif
Andrew Mortona737b3e2006-03-22 00:08:11 -08001459 cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
1460 cache_line_size());
Eric Dumazet6a2d7a92006-12-13 00:34:27 -08001461 cache_cache.reciprocal_buffer_size =
1462 reciprocal_value(cache_cache.buffer_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463
Jack Steiner07ed76b2006-03-07 21:55:46 -08001464 for (order = 0; order < MAX_ORDER; order++) {
1465 cache_estimate(order, cache_cache.buffer_size,
1466 cache_line_size(), 0, &left_over, &cache_cache.num);
1467 if (cache_cache.num)
1468 break;
1469 }
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02001470 BUG_ON(!cache_cache.num);
Jack Steiner07ed76b2006-03-07 21:55:46 -08001471 cache_cache.gfporder = order;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001472 cache_cache.colour = left_over / cache_cache.colour_off;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001473 cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
1474 sizeof(struct slab), cache_line_size());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001475
1476 /* 2+3) create the kmalloc caches */
1477 sizes = malloc_sizes;
1478 names = cache_names;
1479
Andrew Mortona737b3e2006-03-22 00:08:11 -08001480 /*
1481 * Initialize the caches that provide memory for the array cache and the
1482 * kmem_list3 structures first. Without this, further allocations will
1483 * bug.
Christoph Lametere498be72005-09-09 13:03:32 -07001484 */
1485
1486 sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001487 sizes[INDEX_AC].cs_size,
1488 ARCH_KMALLOC_MINALIGN,
1489 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
Paul Mundt20c2df82007-07-20 10:11:58 +09001490 NULL);
Christoph Lametere498be72005-09-09 13:03:32 -07001491
Andrew Mortona737b3e2006-03-22 00:08:11 -08001492 if (INDEX_AC != INDEX_L3) {
Christoph Lametere498be72005-09-09 13:03:32 -07001493 sizes[INDEX_L3].cs_cachep =
Andrew Mortona737b3e2006-03-22 00:08:11 -08001494 kmem_cache_create(names[INDEX_L3].name,
1495 sizes[INDEX_L3].cs_size,
1496 ARCH_KMALLOC_MINALIGN,
1497 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
Paul Mundt20c2df82007-07-20 10:11:58 +09001498 NULL);
Andrew Mortona737b3e2006-03-22 00:08:11 -08001499 }
Christoph Lametere498be72005-09-09 13:03:32 -07001500
Ingo Molnare0a42722006-06-23 02:03:46 -07001501 slab_early_init = 0;
1502
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503 while (sizes->cs_size != ULONG_MAX) {
Christoph Lametere498be72005-09-09 13:03:32 -07001504 /*
1505 * For performance, all the general caches are L1 aligned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506 * This should be particularly beneficial on SMP boxes, as it
1507 * eliminates "false sharing".
1508 * Note for systems short on memory removing the alignment will
Christoph Lametere498be72005-09-09 13:03:32 -07001509 * allow tighter packing of the smaller caches.
1510 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001511 if (!sizes->cs_cachep) {
Christoph Lametere498be72005-09-09 13:03:32 -07001512 sizes->cs_cachep = kmem_cache_create(names->name,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001513 sizes->cs_size,
1514 ARCH_KMALLOC_MINALIGN,
1515 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
Paul Mundt20c2df82007-07-20 10:11:58 +09001516 NULL);
Andrew Mortona737b3e2006-03-22 00:08:11 -08001517 }
Christoph Lameter4b51d662007-02-10 01:43:10 -08001518#ifdef CONFIG_ZONE_DMA
1519 sizes->cs_dmacachep = kmem_cache_create(
1520 names->name_dma,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001521 sizes->cs_size,
1522 ARCH_KMALLOC_MINALIGN,
1523 ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
1524 SLAB_PANIC,
Paul Mundt20c2df82007-07-20 10:11:58 +09001525 NULL);
Christoph Lameter4b51d662007-02-10 01:43:10 -08001526#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001527 sizes++;
1528 names++;
1529 }
1530 /* 4) Replace the bootstrap head arrays */
1531 {
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001532 struct array_cache *ptr;
Christoph Lametere498be72005-09-09 13:03:32 -07001533
Linus Torvalds1da177e2005-04-16 15:20:36 -07001534 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
Christoph Lametere498be72005-09-09 13:03:32 -07001535
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536 local_irq_disable();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001537 BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
1538 memcpy(ptr, cpu_cache_get(&cache_cache),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001539 sizeof(struct arraycache_init));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001540 /*
1541 * Do not assume that spinlocks can be initialized via memcpy:
1542 */
1543 spin_lock_init(&ptr->lock);
1544
Linus Torvalds1da177e2005-04-16 15:20:36 -07001545 cache_cache.array[smp_processor_id()] = ptr;
1546 local_irq_enable();
Christoph Lametere498be72005-09-09 13:03:32 -07001547
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
Christoph Lametere498be72005-09-09 13:03:32 -07001549
Linus Torvalds1da177e2005-04-16 15:20:36 -07001550 local_irq_disable();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001551 BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001552 != &initarray_generic.cache);
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001553 memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001554 sizeof(struct arraycache_init));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001555 /*
1556 * Do not assume that spinlocks can be initialized via memcpy:
1557 */
1558 spin_lock_init(&ptr->lock);
1559
Christoph Lametere498be72005-09-09 13:03:32 -07001560 malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001561 ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562 local_irq_enable();
1563 }
Christoph Lametere498be72005-09-09 13:03:32 -07001564 /* 5) Replace the bootstrap kmem_list3's */
1565 {
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001566 int nid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001568 /* Replace the static kmem_list3 structures for the boot cpu */
1569 init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node);
1570
1571 for_each_online_node(nid) {
Christoph Lametere498be72005-09-09 13:03:32 -07001572 init_list(malloc_sizes[INDEX_AC].cs_cachep,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001573 &initkmem_list3[SIZE_AC + nid], nid);
Christoph Lametere498be72005-09-09 13:03:32 -07001574
1575 if (INDEX_AC != INDEX_L3) {
1576 init_list(malloc_sizes[INDEX_L3].cs_cachep,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001577 &initkmem_list3[SIZE_L3 + nid], nid);
Christoph Lametere498be72005-09-09 13:03:32 -07001578 }
1579 }
1580 }
1581
1582 /* 6) resize the head arrays to their final sizes */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 {
Pekka Enberg343e0d72006-02-01 03:05:50 -08001584 struct kmem_cache *cachep;
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001585 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586 list_for_each_entry(cachep, &cache_chain, next)
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07001587 if (enable_cpucache(cachep))
1588 BUG();
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001589 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001590 }
1591
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -07001592 /* Annotate slab for lockdep -- annotate the malloc caches */
1593 init_lock_keys();
1594
1595
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596 /* Done! */
1597 g_cpucache_up = FULL;
1598
Andrew Mortona737b3e2006-03-22 00:08:11 -08001599 /*
1600 * Register a cpu startup notifier callback that initializes
1601 * cpu_cache_get for all new cpus
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602 */
1603 register_cpu_notifier(&cpucache_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604
Andrew Mortona737b3e2006-03-22 00:08:11 -08001605 /*
1606 * The reap timers are started later, with a module init call: That part
1607 * of the kernel is not yet operational.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001608 */
1609}
1610
1611static int __init cpucache_init(void)
1612{
1613 int cpu;
1614
Andrew Mortona737b3e2006-03-22 00:08:11 -08001615 /*
1616 * Register the timers that return unneeded pages to the page allocator
Linus Torvalds1da177e2005-04-16 15:20:36 -07001617 */
Christoph Lametere498be72005-09-09 13:03:32 -07001618 for_each_online_cpu(cpu)
Andrew Mortona737b3e2006-03-22 00:08:11 -08001619 start_cpu_timer(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620 return 0;
1621}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622__initcall(cpucache_init);
1623
1624/*
1625 * Interface to system's page allocator. No need to hold the cache-lock.
1626 *
1627 * If we requested dmaable memory, we will get it. Even if we
1628 * did not request dmaable memory, we might get it, but that
1629 * would be relatively rare and ignorable.
1630 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001631static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632{
1633 struct page *page;
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001634 int nr_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001635 int i;
1636
Luke Yangd6fef9d2006-04-10 22:52:56 -07001637#ifndef CONFIG_MMU
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001638 /*
1639 * Nommu uses slab's for process anonymous memory allocations, and thus
1640 * requires __GFP_COMP to properly refcount higher order allocations
Luke Yangd6fef9d2006-04-10 22:52:56 -07001641 */
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001642 flags |= __GFP_COMP;
Luke Yangd6fef9d2006-04-10 22:52:56 -07001643#endif
Christoph Lameter765c4502006-09-27 01:50:08 -07001644
Christoph Lameter3c517a62006-12-06 20:33:29 -08001645 flags |= cachep->gfpflags;
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001646
1647 page = alloc_pages_node(nodeid, flags, cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001648 if (!page)
1649 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001650
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001651 nr_pages = (1 << cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
Christoph Lameter972d1a72006-09-25 23:31:51 -07001653 add_zone_page_state(page_zone(page),
1654 NR_SLAB_RECLAIMABLE, nr_pages);
1655 else
1656 add_zone_page_state(page_zone(page),
1657 NR_SLAB_UNRECLAIMABLE, nr_pages);
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001658 for (i = 0; i < nr_pages; i++)
1659 __SetPageSlab(page + i);
1660 return page_address(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661}
1662
1663/*
1664 * Interface to system's page release.
1665 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001666static void kmem_freepages(struct kmem_cache *cachep, void *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001668 unsigned long i = (1 << cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669 struct page *page = virt_to_page(addr);
1670 const unsigned long nr_freed = i;
1671
Christoph Lameter972d1a72006-09-25 23:31:51 -07001672 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1673 sub_zone_page_state(page_zone(page),
1674 NR_SLAB_RECLAIMABLE, nr_freed);
1675 else
1676 sub_zone_page_state(page_zone(page),
1677 NR_SLAB_UNRECLAIMABLE, nr_freed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001678 while (i--) {
Nick Pigginf205b2f2006-03-22 00:08:02 -08001679 BUG_ON(!PageSlab(page));
1680 __ClearPageSlab(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681 page++;
1682 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683 if (current->reclaim_state)
1684 current->reclaim_state->reclaimed_slab += nr_freed;
1685 free_pages((unsigned long)addr, cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686}
1687
1688static void kmem_rcu_free(struct rcu_head *head)
1689{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001690 struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
Pekka Enberg343e0d72006-02-01 03:05:50 -08001691 struct kmem_cache *cachep = slab_rcu->cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001692
1693 kmem_freepages(cachep, slab_rcu->addr);
1694 if (OFF_SLAB(cachep))
1695 kmem_cache_free(cachep->slabp_cache, slab_rcu);
1696}
1697
1698#if DEBUG
1699
1700#ifdef CONFIG_DEBUG_PAGEALLOC
Pekka Enberg343e0d72006-02-01 03:05:50 -08001701static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001702 unsigned long caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001704 int size = obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001705
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001706 addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001708 if (size < 5 * sizeof(unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709 return;
1710
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001711 *addr++ = 0x12345678;
1712 *addr++ = caller;
1713 *addr++ = smp_processor_id();
1714 size -= 3 * sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001715 {
1716 unsigned long *sptr = &caller;
1717 unsigned long svalue;
1718
1719 while (!kstack_end(sptr)) {
1720 svalue = *sptr++;
1721 if (kernel_text_address(svalue)) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001722 *addr++ = svalue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001723 size -= sizeof(unsigned long);
1724 if (size <= sizeof(unsigned long))
1725 break;
1726 }
1727 }
1728
1729 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001730 *addr++ = 0x87654321;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731}
1732#endif
1733
Pekka Enberg343e0d72006-02-01 03:05:50 -08001734static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001736 int size = obj_size(cachep);
1737 addr = &((char *)addr)[obj_offset(cachep)];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738
1739 memset(addr, val, size);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001740 *(unsigned char *)(addr + size - 1) = POISON_END;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741}
1742
1743static void dump_line(char *data, int offset, int limit)
1744{
1745 int i;
Dave Jonesaa83aa42006-09-29 01:59:51 -07001746 unsigned char error = 0;
1747 int bad_count = 0;
1748
Linus Torvalds1da177e2005-04-16 15:20:36 -07001749 printk(KERN_ERR "%03x:", offset);
Dave Jonesaa83aa42006-09-29 01:59:51 -07001750 for (i = 0; i < limit; i++) {
1751 if (data[offset + i] != POISON_FREE) {
1752 error = data[offset + i];
1753 bad_count++;
1754 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001755 printk(" %02x", (unsigned char)data[offset + i]);
Dave Jonesaa83aa42006-09-29 01:59:51 -07001756 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001757 printk("\n");
Dave Jonesaa83aa42006-09-29 01:59:51 -07001758
1759 if (bad_count == 1) {
1760 error ^= POISON_FREE;
1761 if (!(error & (error - 1))) {
1762 printk(KERN_ERR "Single bit error detected. Probably "
1763 "bad RAM.\n");
1764#ifdef CONFIG_X86
1765 printk(KERN_ERR "Run memtest86+ or a similar memory "
1766 "test tool.\n");
1767#else
1768 printk(KERN_ERR "Run a memory test tool.\n");
1769#endif
1770 }
1771 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772}
1773#endif
1774
1775#if DEBUG
1776
Pekka Enberg343e0d72006-02-01 03:05:50 -08001777static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778{
1779 int i, size;
1780 char *realobj;
1781
1782 if (cachep->flags & SLAB_RED_ZONE) {
David Woodhouseb46b8f12007-05-08 00:22:59 -07001783 printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001784 *dbg_redzone1(cachep, objp),
1785 *dbg_redzone2(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786 }
1787
1788 if (cachep->flags & SLAB_STORE_USER) {
1789 printk(KERN_ERR "Last user: [<%p>]",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001790 *dbg_userword(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001791 print_symbol("(%s)",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001792 (unsigned long)*dbg_userword(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793 printk("\n");
1794 }
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001795 realobj = (char *)objp + obj_offset(cachep);
1796 size = obj_size(cachep);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001797 for (i = 0; i < size && lines; i += 16, lines--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001798 int limit;
1799 limit = 16;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001800 if (i + limit > size)
1801 limit = size - i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802 dump_line(realobj, i, limit);
1803 }
1804}
1805
Pekka Enberg343e0d72006-02-01 03:05:50 -08001806static void check_poison_obj(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807{
1808 char *realobj;
1809 int size, i;
1810 int lines = 0;
1811
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001812 realobj = (char *)objp + obj_offset(cachep);
1813 size = obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001815 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001816 char exp = POISON_FREE;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001817 if (i == size - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818 exp = POISON_END;
1819 if (realobj[i] != exp) {
1820 int limit;
1821 /* Mismatch ! */
1822 /* Print header */
1823 if (lines == 0) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001824 printk(KERN_ERR
David Howellse94a40c2007-04-02 23:46:28 +01001825 "Slab corruption: %s start=%p, len=%d\n",
1826 cachep->name, realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001827 print_objinfo(cachep, objp, 0);
1828 }
1829 /* Hexdump the affected line */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001830 i = (i / 16) * 16;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001831 limit = 16;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001832 if (i + limit > size)
1833 limit = size - i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001834 dump_line(realobj, i, limit);
1835 i += 16;
1836 lines++;
1837 /* Limit to 5 lines */
1838 if (lines > 5)
1839 break;
1840 }
1841 }
1842 if (lines != 0) {
1843 /* Print some data about the neighboring objects, if they
1844 * exist:
1845 */
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -08001846 struct slab *slabp = virt_to_slab(objp);
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001847 unsigned int objnr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001848
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001849 objnr = obj_to_index(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001850 if (objnr) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001851 objp = index_to_obj(cachep, slabp, objnr - 1);
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001852 realobj = (char *)objp + obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001853 printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001854 realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855 print_objinfo(cachep, objp, 2);
1856 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001857 if (objnr + 1 < cachep->num) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001858 objp = index_to_obj(cachep, slabp, objnr + 1);
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001859 realobj = (char *)objp + obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001860 printk(KERN_ERR "Next obj: start=%p, len=%d\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001861 realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001862 print_objinfo(cachep, objp, 2);
1863 }
1864 }
1865}
1866#endif
1867
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868#if DEBUG
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001869/**
Randy Dunlap911851e2006-03-22 00:08:14 -08001870 * slab_destroy_objs - destroy a slab and its objects
1871 * @cachep: cache pointer being destroyed
1872 * @slabp: slab pointer being destroyed
1873 *
1874 * Call the registered destructor for each object in a slab that is being
1875 * destroyed.
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001876 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001877static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001878{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879 int i;
1880 for (i = 0; i < cachep->num; i++) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001881 void *objp = index_to_obj(cachep, slabp, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001882
1883 if (cachep->flags & SLAB_POISON) {
1884#ifdef CONFIG_DEBUG_PAGEALLOC
Andrew Mortona737b3e2006-03-22 00:08:11 -08001885 if (cachep->buffer_size % PAGE_SIZE == 0 &&
1886 OFF_SLAB(cachep))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001887 kernel_map_pages(virt_to_page(objp),
Andrew Mortona737b3e2006-03-22 00:08:11 -08001888 cachep->buffer_size / PAGE_SIZE, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001889 else
1890 check_poison_obj(cachep, objp);
1891#else
1892 check_poison_obj(cachep, objp);
1893#endif
1894 }
1895 if (cachep->flags & SLAB_RED_ZONE) {
1896 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
1897 slab_error(cachep, "start of a freed object "
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001898 "was overwritten");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
1900 slab_error(cachep, "end of a freed object "
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001901 "was overwritten");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001902 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001903 }
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001904}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001905#else
Pekka Enberg343e0d72006-02-01 03:05:50 -08001906static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001907{
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001908}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001909#endif
1910
Randy Dunlap911851e2006-03-22 00:08:14 -08001911/**
1912 * slab_destroy - destroy and release all objects in a slab
1913 * @cachep: cache pointer being destroyed
1914 * @slabp: slab pointer being destroyed
1915 *
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001916 * Destroy all the objs in a slab, and release the mem back to the system.
Andrew Mortona737b3e2006-03-22 00:08:11 -08001917 * Before calling the slab must have been unlinked from the cache. The
1918 * cache-lock is not held/needed.
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001919 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001920static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001921{
1922 void *addr = slabp->s_mem - slabp->colouroff;
1923
1924 slab_destroy_objs(cachep, slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
1926 struct slab_rcu *slab_rcu;
1927
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001928 slab_rcu = (struct slab_rcu *)slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001929 slab_rcu->cachep = cachep;
1930 slab_rcu->addr = addr;
1931 call_rcu(&slab_rcu->head, kmem_rcu_free);
1932 } else {
1933 kmem_freepages(cachep, addr);
Ingo Molnar873623d2006-07-13 14:44:38 +02001934 if (OFF_SLAB(cachep))
1935 kmem_cache_free(cachep->slabp_cache, slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001936 }
1937}
1938
Andrew Mortona737b3e2006-03-22 00:08:11 -08001939/*
1940 * For setting up all the kmem_list3s for cache whose buffer_size is same as
1941 * size of kmem_list3.
1942 */
Andrew Mortona3a02be2007-05-06 14:49:31 -07001943static void __init set_up_list3s(struct kmem_cache *cachep, int index)
Christoph Lametere498be72005-09-09 13:03:32 -07001944{
1945 int node;
1946
1947 for_each_online_node(node) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001948 cachep->nodelists[node] = &initkmem_list3[index + node];
Christoph Lametere498be72005-09-09 13:03:32 -07001949 cachep->nodelists[node]->next_reap = jiffies +
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001950 REAPTIMEOUT_LIST3 +
1951 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametere498be72005-09-09 13:03:32 -07001952 }
1953}
1954
Christoph Lameter117f6eb2006-09-25 23:31:37 -07001955static void __kmem_cache_destroy(struct kmem_cache *cachep)
1956{
1957 int i;
1958 struct kmem_list3 *l3;
1959
1960 for_each_online_cpu(i)
1961 kfree(cachep->array[i]);
1962
1963 /* NUMA: free the list3 structures */
1964 for_each_online_node(i) {
1965 l3 = cachep->nodelists[i];
1966 if (l3) {
1967 kfree(l3->shared);
1968 free_alien_cache(l3->alien);
1969 kfree(l3);
1970 }
1971 }
1972 kmem_cache_free(&cache_cache, cachep);
1973}
1974
1975
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976/**
Randy.Dunlapa70773d2006-02-01 03:05:52 -08001977 * calculate_slab_order - calculate size (page order) of slabs
1978 * @cachep: pointer to the cache that is being created
1979 * @size: size of objects to be created in this cache.
1980 * @align: required alignment for the objects.
1981 * @flags: slab allocation flags
1982 *
1983 * Also calculates the number of objects per slab.
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001984 *
1985 * This could be made much more intelligent. For now, try to avoid using
1986 * high order pages for slabs. When the gfp() functions are more friendly
1987 * towards high-order requests, this should be changed.
1988 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001989static size_t calculate_slab_order(struct kmem_cache *cachep,
Randy Dunlapee13d782006-02-01 03:05:53 -08001990 size_t size, size_t align, unsigned long flags)
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001991{
Ingo Molnarb1ab41c2006-06-02 15:44:58 +02001992 unsigned long offslab_limit;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001993 size_t left_over = 0;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001994 int gfporder;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001995
Christoph Lameter0aa817f2007-05-16 22:11:01 -07001996 for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001997 unsigned int num;
1998 size_t remainder;
1999
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002000 cache_estimate(gfporder, size, align, flags, &remainder, &num);
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002001 if (!num)
2002 continue;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002003
Ingo Molnarb1ab41c2006-06-02 15:44:58 +02002004 if (flags & CFLGS_OFF_SLAB) {
2005 /*
2006 * Max number of objs-per-slab for caches which
2007 * use off-slab slabs. Needed to avoid a possible
2008 * looping condition in cache_grow().
2009 */
2010 offslab_limit = size - sizeof(struct slab);
2011 offslab_limit /= sizeof(kmem_bufctl_t);
2012
2013 if (num > offslab_limit)
2014 break;
2015 }
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002016
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002017 /* Found something acceptable - save it away */
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002018 cachep->num = num;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002019 cachep->gfporder = gfporder;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002020 left_over = remainder;
2021
2022 /*
Linus Torvaldsf78bb8a2006-03-08 10:33:05 -08002023 * A VFS-reclaimable slab tends to have most allocations
2024 * as GFP_NOFS and we really don't want to have to be allocating
2025 * higher-order pages when we are unable to shrink dcache.
2026 */
2027 if (flags & SLAB_RECLAIM_ACCOUNT)
2028 break;
2029
2030 /*
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002031 * Large number of objects is good, but very large slabs are
2032 * currently bad for the gfp()s.
2033 */
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002034 if (gfporder >= slab_break_gfp_order)
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002035 break;
2036
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002037 /*
2038 * Acceptable internal fragmentation?
2039 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002040 if (left_over * 8 <= (PAGE_SIZE << gfporder))
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002041 break;
2042 }
2043 return left_over;
2044}
2045
Sam Ravnborg38bdc322007-05-17 23:48:19 +02002046static int __init_refok setup_cpu_cache(struct kmem_cache *cachep)
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002047{
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002048 if (g_cpucache_up == FULL)
2049 return enable_cpucache(cachep);
2050
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002051 if (g_cpucache_up == NONE) {
2052 /*
2053 * Note: the first kmem_cache_create must create the cache
2054 * that's used by kmalloc(24), otherwise the creation of
2055 * further caches will BUG().
2056 */
2057 cachep->array[smp_processor_id()] = &initarray_generic.cache;
2058
2059 /*
2060 * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
2061 * the first cache, then we need to set up all its list3s,
2062 * otherwise the creation of further caches will BUG().
2063 */
2064 set_up_list3s(cachep, SIZE_AC);
2065 if (INDEX_AC == INDEX_L3)
2066 g_cpucache_up = PARTIAL_L3;
2067 else
2068 g_cpucache_up = PARTIAL_AC;
2069 } else {
2070 cachep->array[smp_processor_id()] =
2071 kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
2072
2073 if (g_cpucache_up == PARTIAL_AC) {
2074 set_up_list3s(cachep, SIZE_L3);
2075 g_cpucache_up = PARTIAL_L3;
2076 } else {
2077 int node;
2078 for_each_online_node(node) {
2079 cachep->nodelists[node] =
2080 kmalloc_node(sizeof(struct kmem_list3),
2081 GFP_KERNEL, node);
2082 BUG_ON(!cachep->nodelists[node]);
2083 kmem_list3_init(cachep->nodelists[node]);
2084 }
2085 }
2086 }
2087 cachep->nodelists[numa_node_id()]->next_reap =
2088 jiffies + REAPTIMEOUT_LIST3 +
2089 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
2090
2091 cpu_cache_get(cachep)->avail = 0;
2092 cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
2093 cpu_cache_get(cachep)->batchcount = 1;
2094 cpu_cache_get(cachep)->touched = 0;
2095 cachep->batchcount = 1;
2096 cachep->limit = BOOT_CPUCACHE_ENTRIES;
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002097 return 0;
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002098}
2099
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002100/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07002101 * kmem_cache_create - Create a cache.
2102 * @name: A string which is used in /proc/slabinfo to identify this cache.
2103 * @size: The size of objects to be created in this cache.
2104 * @align: The required alignment for the objects.
2105 * @flags: SLAB flags
2106 * @ctor: A constructor for the objects.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002107 *
2108 * Returns a ptr to the cache on success, NULL on failure.
2109 * Cannot be called within a int, but can be interrupted.
Paul Mundt20c2df82007-07-20 10:11:58 +09002110 * The @ctor is run when new pages are allocated by the cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002111 *
2112 * @name must be valid until the cache is destroyed. This implies that
Andrew Mortona737b3e2006-03-22 00:08:11 -08002113 * the module calling this has to destroy the cache before getting unloaded.
2114 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002115 * The flags are
2116 *
2117 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2118 * to catch references to uninitialised memory.
2119 *
2120 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2121 * for buffer overruns.
2122 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002123 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2124 * cacheline. This can be beneficial if you're counting cycles as closely
2125 * as davem.
2126 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002127struct kmem_cache *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002128kmem_cache_create (const char *name, size_t size, size_t align,
Andrew Mortona737b3e2006-03-22 00:08:11 -08002129 unsigned long flags,
Paul Mundt20c2df82007-07-20 10:11:58 +09002130 void (*ctor)(void*, struct kmem_cache *, unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002131{
2132 size_t left_over, slab_size, ralign;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07002133 struct kmem_cache *cachep = NULL, *pc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002134
2135 /*
2136 * Sanity checks... these are all serious usage bugs.
2137 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002138 if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
Paul Mundt20c2df82007-07-20 10:11:58 +09002139 size > KMALLOC_MAX_SIZE) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002140 printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
2141 name);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002142 BUG();
2143 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002144
Ravikiran G Thirumalaif0188f42006-02-10 01:51:13 -08002145 /*
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002146 * We use cache_chain_mutex to ensure a consistent view of
2147 * cpu_online_map as well. Please see cpuup_callback
Ravikiran G Thirumalaif0188f42006-02-10 01:51:13 -08002148 */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002149 mutex_lock(&cache_chain_mutex);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002150
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07002151 list_for_each_entry(pc, &cache_chain, next) {
Andrew Morton4f12bb42005-11-07 00:58:00 -08002152 char tmp;
2153 int res;
2154
2155 /*
2156 * This happens when the module gets unloaded and doesn't
2157 * destroy its slab cache and no-one else reuses the vmalloc
2158 * area of the module. Print a warning.
2159 */
Andrew Morton138ae662006-12-06 20:36:41 -08002160 res = probe_kernel_address(pc->name, tmp);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002161 if (res) {
matzeb4169522007-05-06 14:49:52 -07002162 printk(KERN_ERR
2163 "SLAB: cache with size %d has lost its name\n",
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002164 pc->buffer_size);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002165 continue;
2166 }
2167
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002168 if (!strcmp(pc->name, name)) {
matzeb4169522007-05-06 14:49:52 -07002169 printk(KERN_ERR
2170 "kmem_cache_create: duplicate cache %s\n", name);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002171 dump_stack();
2172 goto oops;
2173 }
2174 }
2175
Linus Torvalds1da177e2005-04-16 15:20:36 -07002176#if DEBUG
2177 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002178#if FORCED_DEBUG
2179 /*
2180 * Enable redzoning and last user accounting, except for caches with
2181 * large objects, if the increased size would increase the object size
2182 * above the next power of two: caches with object sizes just above a
2183 * power of two have a significant amount of internal fragmentation.
2184 */
David Woodhouse87a927c2007-07-04 21:26:44 -04002185 if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
2186 2 * sizeof(unsigned long long)))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002187 flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002188 if (!(flags & SLAB_DESTROY_BY_RCU))
2189 flags |= SLAB_POISON;
2190#endif
2191 if (flags & SLAB_DESTROY_BY_RCU)
2192 BUG_ON(flags & SLAB_POISON);
2193#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002194 /*
Andrew Mortona737b3e2006-03-22 00:08:11 -08002195 * Always checks flags, a caller might be expecting debug support which
2196 * isn't available.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002197 */
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002198 BUG_ON(flags & ~CREATE_MASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002199
Andrew Mortona737b3e2006-03-22 00:08:11 -08002200 /*
2201 * Check that size is in terms of words. This is needed to avoid
Linus Torvalds1da177e2005-04-16 15:20:36 -07002202 * unaligned accesses for some archs when redzoning is used, and makes
2203 * sure any on-slab bufctl's are also correctly aligned.
2204 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002205 if (size & (BYTES_PER_WORD - 1)) {
2206 size += (BYTES_PER_WORD - 1);
2207 size &= ~(BYTES_PER_WORD - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002208 }
2209
Andrew Mortona737b3e2006-03-22 00:08:11 -08002210 /* calculate the final buffer alignment: */
2211
Linus Torvalds1da177e2005-04-16 15:20:36 -07002212 /* 1) arch recommendation: can be overridden for debug */
2213 if (flags & SLAB_HWCACHE_ALIGN) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002214 /*
2215 * Default alignment: as specified by the arch code. Except if
2216 * an object is really small, then squeeze multiple objects into
2217 * one cacheline.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002218 */
2219 ralign = cache_line_size();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002220 while (size <= ralign / 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002221 ralign /= 2;
2222 } else {
2223 ralign = BYTES_PER_WORD;
2224 }
Pekka Enbergca5f9702006-09-25 23:31:25 -07002225
2226 /*
David Woodhouse87a927c2007-07-04 21:26:44 -04002227 * Redzoning and user store require word alignment or possibly larger.
2228 * Note this will be overridden by architecture or caller mandated
2229 * alignment if either is greater than BYTES_PER_WORD.
Pekka Enbergca5f9702006-09-25 23:31:25 -07002230 */
David Woodhouse87a927c2007-07-04 21:26:44 -04002231 if (flags & SLAB_STORE_USER)
2232 ralign = BYTES_PER_WORD;
2233
2234 if (flags & SLAB_RED_ZONE) {
2235 ralign = REDZONE_ALIGN;
2236 /* If redzoning, ensure that the second redzone is suitably
2237 * aligned, by adjusting the object size accordingly. */
2238 size += REDZONE_ALIGN - 1;
2239 size &= ~(REDZONE_ALIGN - 1);
2240 }
Pekka Enbergca5f9702006-09-25 23:31:25 -07002241
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002242 /* 2) arch mandated alignment */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002243 if (ralign < ARCH_SLAB_MINALIGN) {
2244 ralign = ARCH_SLAB_MINALIGN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 }
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002246 /* 3) caller mandated alignment */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002247 if (ralign < align) {
2248 ralign = align;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002249 }
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002250 /* disable debug if necessary */
David Woodhouseb46b8f12007-05-08 00:22:59 -07002251 if (ralign > __alignof__(unsigned long long))
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002252 flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002253 /*
Pekka Enbergca5f9702006-09-25 23:31:25 -07002254 * 4) Store it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255 */
2256 align = ralign;
2257
2258 /* Get cache's description obj. */
Christoph Lametere94b1762006-12-06 20:33:17 -08002259 cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002260 if (!cachep)
Andrew Morton4f12bb42005-11-07 00:58:00 -08002261 goto oops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002262
2263#if DEBUG
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002264 cachep->obj_size = size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002265
Pekka Enbergca5f9702006-09-25 23:31:25 -07002266 /*
2267 * Both debugging options require word-alignment which is calculated
2268 * into align above.
2269 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002270 if (flags & SLAB_RED_ZONE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002271 /* add space for red zone words */
David Woodhouseb46b8f12007-05-08 00:22:59 -07002272 cachep->obj_offset += sizeof(unsigned long long);
2273 size += 2 * sizeof(unsigned long long);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002274 }
2275 if (flags & SLAB_STORE_USER) {
Pekka Enbergca5f9702006-09-25 23:31:25 -07002276 /* user store requires one word storage behind the end of
David Woodhouse87a927c2007-07-04 21:26:44 -04002277 * the real object. But if the second red zone needs to be
2278 * aligned to 64 bits, we must allow that much space.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002279 */
David Woodhouse87a927c2007-07-04 21:26:44 -04002280 if (flags & SLAB_RED_ZONE)
2281 size += REDZONE_ALIGN;
2282 else
2283 size += BYTES_PER_WORD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002284 }
2285#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002286 if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002287 && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
2288 cachep->obj_offset += PAGE_SIZE - size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002289 size = PAGE_SIZE;
2290 }
2291#endif
2292#endif
2293
Ingo Molnare0a42722006-06-23 02:03:46 -07002294 /*
2295 * Determine if the slab management is 'on' or 'off' slab.
2296 * (bootstrapping cannot cope with offslab caches so don't do
2297 * it too early on.)
2298 */
2299 if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002300 /*
2301 * Size is large, assume best to place the slab management obj
2302 * off-slab (should allow better packing of objs).
2303 */
2304 flags |= CFLGS_OFF_SLAB;
2305
2306 size = ALIGN(size, align);
2307
Linus Torvaldsf78bb8a2006-03-08 10:33:05 -08002308 left_over = calculate_slab_order(cachep, size, align, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002309
2310 if (!cachep->num) {
matzeb4169522007-05-06 14:49:52 -07002311 printk(KERN_ERR
2312 "kmem_cache_create: couldn't create cache %s.\n", name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002313 kmem_cache_free(&cache_cache, cachep);
2314 cachep = NULL;
Andrew Morton4f12bb42005-11-07 00:58:00 -08002315 goto oops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002316 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002317 slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
2318 + sizeof(struct slab), align);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002319
2320 /*
2321 * If the slab has been placed off-slab, and we have enough space then
2322 * move it on-slab. This is at the expense of any extra colouring.
2323 */
2324 if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
2325 flags &= ~CFLGS_OFF_SLAB;
2326 left_over -= slab_size;
2327 }
2328
2329 if (flags & CFLGS_OFF_SLAB) {
2330 /* really off slab. No need for manual alignment */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002331 slab_size =
2332 cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002333 }
2334
2335 cachep->colour_off = cache_line_size();
2336 /* Offset must be a multiple of the alignment. */
2337 if (cachep->colour_off < align)
2338 cachep->colour_off = align;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002339 cachep->colour = left_over / cachep->colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002340 cachep->slab_size = slab_size;
2341 cachep->flags = flags;
2342 cachep->gfpflags = 0;
Christoph Lameter4b51d662007-02-10 01:43:10 -08002343 if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002344 cachep->gfpflags |= GFP_DMA;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002345 cachep->buffer_size = size;
Eric Dumazet6a2d7a92006-12-13 00:34:27 -08002346 cachep->reciprocal_buffer_size = reciprocal_value(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002347
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002348 if (flags & CFLGS_OFF_SLAB) {
Victor Fuscob2d55072005-09-10 00:26:36 -07002349 cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002350 /*
2351 * This is a possibility for one of the malloc_sizes caches.
2352 * But since we go off slab only for object size greater than
2353 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
2354 * this should not happen at all.
2355 * But leave a BUG_ON for some lucky dude.
2356 */
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002357 BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002358 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002359 cachep->ctor = ctor;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002360 cachep->name = name;
2361
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002362 if (setup_cpu_cache(cachep)) {
2363 __kmem_cache_destroy(cachep);
2364 cachep = NULL;
2365 goto oops;
2366 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002367
Linus Torvalds1da177e2005-04-16 15:20:36 -07002368 /* cache setup completed, link it into the list */
2369 list_add(&cachep->next, &cache_chain);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002370oops:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002371 if (!cachep && (flags & SLAB_PANIC))
2372 panic("kmem_cache_create(): failed to create slab `%s'\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002373 name);
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002374 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002375 return cachep;
2376}
2377EXPORT_SYMBOL(kmem_cache_create);
2378
2379#if DEBUG
2380static void check_irq_off(void)
2381{
2382 BUG_ON(!irqs_disabled());
2383}
2384
2385static void check_irq_on(void)
2386{
2387 BUG_ON(irqs_disabled());
2388}
2389
Pekka Enberg343e0d72006-02-01 03:05:50 -08002390static void check_spinlock_acquired(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002391{
2392#ifdef CONFIG_SMP
2393 check_irq_off();
Christoph Lametere498be72005-09-09 13:03:32 -07002394 assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002395#endif
2396}
Christoph Lametere498be72005-09-09 13:03:32 -07002397
Pekka Enberg343e0d72006-02-01 03:05:50 -08002398static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
Christoph Lametere498be72005-09-09 13:03:32 -07002399{
2400#ifdef CONFIG_SMP
2401 check_irq_off();
2402 assert_spin_locked(&cachep->nodelists[node]->list_lock);
2403#endif
2404}
2405
Linus Torvalds1da177e2005-04-16 15:20:36 -07002406#else
2407#define check_irq_off() do { } while(0)
2408#define check_irq_on() do { } while(0)
2409#define check_spinlock_acquired(x) do { } while(0)
Christoph Lametere498be72005-09-09 13:03:32 -07002410#define check_spinlock_acquired_node(x, y) do { } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002411#endif
2412
Christoph Lameteraab22072006-03-22 00:09:06 -08002413static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
2414 struct array_cache *ac,
2415 int force, int node);
2416
Linus Torvalds1da177e2005-04-16 15:20:36 -07002417static void do_drain(void *arg)
2418{
Andrew Mortona737b3e2006-03-22 00:08:11 -08002419 struct kmem_cache *cachep = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002420 struct array_cache *ac;
Christoph Lameterff694162005-09-22 21:44:02 -07002421 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002422
2423 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08002424 ac = cpu_cache_get(cachep);
Christoph Lameterff694162005-09-22 21:44:02 -07002425 spin_lock(&cachep->nodelists[node]->list_lock);
2426 free_block(cachep, ac->entry, ac->avail, node);
2427 spin_unlock(&cachep->nodelists[node]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002428 ac->avail = 0;
2429}
2430
Pekka Enberg343e0d72006-02-01 03:05:50 -08002431static void drain_cpu_caches(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002432{
Christoph Lametere498be72005-09-09 13:03:32 -07002433 struct kmem_list3 *l3;
2434 int node;
2435
Andrew Mortona07fa392006-03-22 00:08:17 -08002436 on_each_cpu(do_drain, cachep, 1, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002437 check_irq_on();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002438 for_each_online_node(node) {
Christoph Lametere498be72005-09-09 13:03:32 -07002439 l3 = cachep->nodelists[node];
Roland Dreiera4523a82006-05-15 11:41:00 -07002440 if (l3 && l3->alien)
2441 drain_alien_cache(cachep, l3->alien);
2442 }
2443
2444 for_each_online_node(node) {
2445 l3 = cachep->nodelists[node];
2446 if (l3)
Christoph Lameteraab22072006-03-22 00:09:06 -08002447 drain_array(cachep, l3, l3->shared, 1, node);
Christoph Lametere498be72005-09-09 13:03:32 -07002448 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002449}
2450
Christoph Lametered11d9e2006-06-30 01:55:45 -07002451/*
2452 * Remove slabs from the list of free slabs.
2453 * Specify the number of slabs to drain in tofree.
2454 *
2455 * Returns the actual number of slabs released.
2456 */
2457static int drain_freelist(struct kmem_cache *cache,
2458 struct kmem_list3 *l3, int tofree)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002459{
Christoph Lametered11d9e2006-06-30 01:55:45 -07002460 struct list_head *p;
2461 int nr_freed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002462 struct slab *slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002463
Christoph Lametered11d9e2006-06-30 01:55:45 -07002464 nr_freed = 0;
2465 while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002466
Christoph Lametered11d9e2006-06-30 01:55:45 -07002467 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07002468 p = l3->slabs_free.prev;
Christoph Lametered11d9e2006-06-30 01:55:45 -07002469 if (p == &l3->slabs_free) {
2470 spin_unlock_irq(&l3->list_lock);
2471 goto out;
2472 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002473
Christoph Lametered11d9e2006-06-30 01:55:45 -07002474 slabp = list_entry(p, struct slab, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002475#if DEBUG
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002476 BUG_ON(slabp->inuse);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002477#endif
2478 list_del(&slabp->list);
Christoph Lametered11d9e2006-06-30 01:55:45 -07002479 /*
2480 * Safe to drop the lock. The slab is no longer linked
2481 * to the cache.
2482 */
2483 l3->free_objects -= cache->num;
Christoph Lametere498be72005-09-09 13:03:32 -07002484 spin_unlock_irq(&l3->list_lock);
Christoph Lametered11d9e2006-06-30 01:55:45 -07002485 slab_destroy(cache, slabp);
2486 nr_freed++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002487 }
Christoph Lametered11d9e2006-06-30 01:55:45 -07002488out:
2489 return nr_freed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002490}
2491
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002492/* Called with cache_chain_mutex held to protect against cpu hotplug */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002493static int __cache_shrink(struct kmem_cache *cachep)
Christoph Lametere498be72005-09-09 13:03:32 -07002494{
2495 int ret = 0, i = 0;
2496 struct kmem_list3 *l3;
2497
2498 drain_cpu_caches(cachep);
2499
2500 check_irq_on();
2501 for_each_online_node(i) {
2502 l3 = cachep->nodelists[i];
Christoph Lametered11d9e2006-06-30 01:55:45 -07002503 if (!l3)
2504 continue;
2505
2506 drain_freelist(cachep, l3, l3->free_objects);
2507
2508 ret += !list_empty(&l3->slabs_full) ||
2509 !list_empty(&l3->slabs_partial);
Christoph Lametere498be72005-09-09 13:03:32 -07002510 }
2511 return (ret ? 1 : 0);
2512}
2513
Linus Torvalds1da177e2005-04-16 15:20:36 -07002514/**
2515 * kmem_cache_shrink - Shrink a cache.
2516 * @cachep: The cache to shrink.
2517 *
2518 * Releases as many slabs as possible for a cache.
2519 * To help debugging, a zero exit status indicates all slabs were released.
2520 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002521int kmem_cache_shrink(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002522{
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002523 int ret;
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002524 BUG_ON(!cachep || in_interrupt());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002525
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002526 mutex_lock(&cache_chain_mutex);
2527 ret = __cache_shrink(cachep);
2528 mutex_unlock(&cache_chain_mutex);
2529 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002530}
2531EXPORT_SYMBOL(kmem_cache_shrink);
2532
2533/**
2534 * kmem_cache_destroy - delete a cache
2535 * @cachep: the cache to destroy
2536 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08002537 * Remove a &struct kmem_cache object from the slab cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538 *
2539 * It is expected this function will be called by a module when it is
2540 * unloaded. This will remove the cache completely, and avoid a duplicate
2541 * cache being allocated each time a module is loaded and unloaded, if the
2542 * module doesn't have persistent in-kernel storage across loads and unloads.
2543 *
2544 * The cache must be empty before calling this function.
2545 *
2546 * The caller must guarantee that noone will allocate memory from the cache
2547 * during the kmem_cache_destroy().
2548 */
Alexey Dobriyan133d2052006-09-27 01:49:41 -07002549void kmem_cache_destroy(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002550{
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002551 BUG_ON(!cachep || in_interrupt());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002552
Linus Torvalds1da177e2005-04-16 15:20:36 -07002553 /* Find the cache in the chain of caches. */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002554 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002555 /*
2556 * the chain is never empty, cache_cache is never destroyed
2557 */
2558 list_del(&cachep->next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002559 if (__cache_shrink(cachep)) {
2560 slab_error(cachep, "Can't free all objects");
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002561 list_add(&cachep->next, &cache_chain);
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002562 mutex_unlock(&cache_chain_mutex);
Alexey Dobriyan133d2052006-09-27 01:49:41 -07002563 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002564 }
2565
2566 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07002567 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002568
Christoph Lameter117f6eb2006-09-25 23:31:37 -07002569 __kmem_cache_destroy(cachep);
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002570 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002571}
2572EXPORT_SYMBOL(kmem_cache_destroy);
2573
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002574/*
2575 * Get the memory for a slab management obj.
2576 * For a slab cache when the slab descriptor is off-slab, slab descriptors
2577 * always come from malloc_sizes caches. The slab descriptor cannot
2578 * come from the same cache which is getting created because,
2579 * when we are searching for an appropriate cache for these
2580 * descriptors in kmem_cache_create, we search through the malloc_sizes array.
2581 * If we are creating a malloc_sizes cache here it would not be visible to
2582 * kmem_find_general_cachep till the initialization is complete.
2583 * Hence we cannot have slabp_cache same as the original cache.
2584 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002585static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002586 int colour_off, gfp_t local_flags,
2587 int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002588{
2589 struct slab *slabp;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002590
Linus Torvalds1da177e2005-04-16 15:20:36 -07002591 if (OFF_SLAB(cachep)) {
2592 /* Slab management obj is off-slab. */
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002593 slabp = kmem_cache_alloc_node(cachep->slabp_cache,
Christoph Lameter3c517a62006-12-06 20:33:29 -08002594 local_flags & ~GFP_THISNODE, nodeid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002595 if (!slabp)
2596 return NULL;
2597 } else {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002598 slabp = objp + colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002599 colour_off += cachep->slab_size;
2600 }
2601 slabp->inuse = 0;
2602 slabp->colouroff = colour_off;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002603 slabp->s_mem = objp + colour_off;
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002604 slabp->nodeid = nodeid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002605 return slabp;
2606}
2607
2608static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
2609{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002610 return (kmem_bufctl_t *) (slabp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002611}
2612
Pekka Enberg343e0d72006-02-01 03:05:50 -08002613static void cache_init_objs(struct kmem_cache *cachep,
Christoph Lametera35afb82007-05-16 22:10:57 -07002614 struct slab *slabp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002615{
2616 int i;
2617
2618 for (i = 0; i < cachep->num; i++) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002619 void *objp = index_to_obj(cachep, slabp, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002620#if DEBUG
2621 /* need to poison the objs? */
2622 if (cachep->flags & SLAB_POISON)
2623 poison_obj(cachep, objp, POISON_FREE);
2624 if (cachep->flags & SLAB_STORE_USER)
2625 *dbg_userword(cachep, objp) = NULL;
2626
2627 if (cachep->flags & SLAB_RED_ZONE) {
2628 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2629 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2630 }
2631 /*
Andrew Mortona737b3e2006-03-22 00:08:11 -08002632 * Constructors are not allowed to allocate memory from the same
2633 * cache which they are a constructor for. Otherwise, deadlock.
2634 * They must also be threaded.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002635 */
2636 if (cachep->ctor && !(cachep->flags & SLAB_POISON))
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002637 cachep->ctor(objp + obj_offset(cachep), cachep,
Christoph Lametera35afb82007-05-16 22:10:57 -07002638 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002639
2640 if (cachep->flags & SLAB_RED_ZONE) {
2641 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
2642 slab_error(cachep, "constructor overwrote the"
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002643 " end of an object");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002644 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
2645 slab_error(cachep, "constructor overwrote the"
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002646 " start of an object");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002647 }
Andrew Mortona737b3e2006-03-22 00:08:11 -08002648 if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
2649 OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002650 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002651 cachep->buffer_size / PAGE_SIZE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002652#else
2653 if (cachep->ctor)
Christoph Lametera35afb82007-05-16 22:10:57 -07002654 cachep->ctor(objp, cachep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002655#endif
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002656 slab_bufctl(slabp)[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002657 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002658 slab_bufctl(slabp)[i - 1] = BUFCTL_END;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002659 slabp->free = 0;
2660}
2661
Pekka Enberg343e0d72006-02-01 03:05:50 -08002662static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002663{
Christoph Lameter4b51d662007-02-10 01:43:10 -08002664 if (CONFIG_ZONE_DMA_FLAG) {
2665 if (flags & GFP_DMA)
2666 BUG_ON(!(cachep->gfpflags & GFP_DMA));
2667 else
2668 BUG_ON(cachep->gfpflags & GFP_DMA);
2669 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002670}
2671
Andrew Mortona737b3e2006-03-22 00:08:11 -08002672static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
2673 int nodeid)
Matthew Dobson78d382d2006-02-01 03:05:47 -08002674{
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002675 void *objp = index_to_obj(cachep, slabp, slabp->free);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002676 kmem_bufctl_t next;
2677
2678 slabp->inuse++;
2679 next = slab_bufctl(slabp)[slabp->free];
2680#if DEBUG
2681 slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
2682 WARN_ON(slabp->nodeid != nodeid);
2683#endif
2684 slabp->free = next;
2685
2686 return objp;
2687}
2688
Andrew Mortona737b3e2006-03-22 00:08:11 -08002689static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
2690 void *objp, int nodeid)
Matthew Dobson78d382d2006-02-01 03:05:47 -08002691{
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002692 unsigned int objnr = obj_to_index(cachep, slabp, objp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002693
2694#if DEBUG
2695 /* Verify that the slab belongs to the intended node */
2696 WARN_ON(slabp->nodeid != nodeid);
2697
Al Viro871751e2006-03-25 03:06:39 -08002698 if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
Matthew Dobson78d382d2006-02-01 03:05:47 -08002699 printk(KERN_ERR "slab: double free detected in cache "
Andrew Mortona737b3e2006-03-22 00:08:11 -08002700 "'%s', objp %p\n", cachep->name, objp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002701 BUG();
2702 }
2703#endif
2704 slab_bufctl(slabp)[objnr] = slabp->free;
2705 slabp->free = objnr;
2706 slabp->inuse--;
2707}
2708
Pekka Enberg47768742006-06-23 02:03:07 -07002709/*
2710 * Map pages beginning at addr to the given cache and slab. This is required
2711 * for the slab allocator to be able to lookup the cache and slab of a
2712 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
2713 */
2714static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
2715 void *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002716{
Pekka Enberg47768742006-06-23 02:03:07 -07002717 int nr_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002718 struct page *page;
2719
Pekka Enberg47768742006-06-23 02:03:07 -07002720 page = virt_to_page(addr);
Nick Piggin84097512006-03-22 00:08:34 -08002721
Pekka Enberg47768742006-06-23 02:03:07 -07002722 nr_pages = 1;
Nick Piggin84097512006-03-22 00:08:34 -08002723 if (likely(!PageCompound(page)))
Pekka Enberg47768742006-06-23 02:03:07 -07002724 nr_pages <<= cache->gfporder;
2725
Linus Torvalds1da177e2005-04-16 15:20:36 -07002726 do {
Pekka Enberg47768742006-06-23 02:03:07 -07002727 page_set_cache(page, cache);
2728 page_set_slab(page, slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002729 page++;
Pekka Enberg47768742006-06-23 02:03:07 -07002730 } while (--nr_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002731}
2732
2733/*
2734 * Grow (by 1) the number of slabs within a cache. This is called by
2735 * kmem_cache_alloc() when there are no active objs left in a cache.
2736 */
Christoph Lameter3c517a62006-12-06 20:33:29 -08002737static int cache_grow(struct kmem_cache *cachep,
2738 gfp_t flags, int nodeid, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002739{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002740 struct slab *slabp;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002741 size_t offset;
2742 gfp_t local_flags;
Christoph Lametere498be72005-09-09 13:03:32 -07002743 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002744
Andrew Mortona737b3e2006-03-22 00:08:11 -08002745 /*
2746 * Be lazy and only check for valid flags here, keeping it out of the
2747 * critical path in kmem_cache_alloc().
Linus Torvalds1da177e2005-04-16 15:20:36 -07002748 */
Christoph Lameterd07dbea2007-07-17 04:03:23 -07002749 BUG_ON(flags & ~(GFP_DMA | __GFP_ZERO | GFP_LEVEL_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002750
Christoph Lametera06d72c2006-12-06 20:33:12 -08002751 local_flags = (flags & GFP_LEVEL_MASK);
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002752 /* Take the l3 list lock to change the colour_next on this node */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002753 check_irq_off();
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002754 l3 = cachep->nodelists[nodeid];
2755 spin_lock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002756
2757 /* Get colour for the slab, and cal the next value. */
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002758 offset = l3->colour_next;
2759 l3->colour_next++;
2760 if (l3->colour_next >= cachep->colour)
2761 l3->colour_next = 0;
2762 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002763
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002764 offset *= cachep->colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002765
2766 if (local_flags & __GFP_WAIT)
2767 local_irq_enable();
2768
2769 /*
2770 * The test for missing atomic flag is performed here, rather than
2771 * the more obvious place, simply to reduce the critical path length
2772 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2773 * will eventually be caught here (where it matters).
2774 */
2775 kmem_flagcheck(cachep, flags);
2776
Andrew Mortona737b3e2006-03-22 00:08:11 -08002777 /*
2778 * Get mem for the objs. Attempt to allocate a physical page from
2779 * 'nodeid'.
Christoph Lametere498be72005-09-09 13:03:32 -07002780 */
Christoph Lameter3c517a62006-12-06 20:33:29 -08002781 if (!objp)
Andrew Mortonb8c1c5d2007-07-24 12:02:40 -07002782 objp = kmem_getpages(cachep, local_flags, nodeid);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002783 if (!objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002784 goto failed;
2785
2786 /* Get slab management. */
Christoph Lameter3c517a62006-12-06 20:33:29 -08002787 slabp = alloc_slabmgmt(cachep, objp, offset,
2788 local_flags & ~GFP_THISNODE, nodeid);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002789 if (!slabp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002790 goto opps1;
2791
Christoph Lametere498be72005-09-09 13:03:32 -07002792 slabp->nodeid = nodeid;
Pekka Enberg47768742006-06-23 02:03:07 -07002793 slab_map_pages(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002794
Christoph Lametera35afb82007-05-16 22:10:57 -07002795 cache_init_objs(cachep, slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002796
2797 if (local_flags & __GFP_WAIT)
2798 local_irq_disable();
2799 check_irq_off();
Christoph Lametere498be72005-09-09 13:03:32 -07002800 spin_lock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002801
2802 /* Make slab active. */
Christoph Lametere498be72005-09-09 13:03:32 -07002803 list_add_tail(&slabp->list, &(l3->slabs_free));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002804 STATS_INC_GROWN(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07002805 l3->free_objects += cachep->num;
2806 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002807 return 1;
Andrew Mortona737b3e2006-03-22 00:08:11 -08002808opps1:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002809 kmem_freepages(cachep, objp);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002810failed:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002811 if (local_flags & __GFP_WAIT)
2812 local_irq_disable();
2813 return 0;
2814}
2815
2816#if DEBUG
2817
2818/*
2819 * Perform extra freeing checks:
2820 * - detect bad pointers.
2821 * - POISON/RED_ZONE checking
Linus Torvalds1da177e2005-04-16 15:20:36 -07002822 */
2823static void kfree_debugcheck(const void *objp)
2824{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002825 if (!virt_addr_valid(objp)) {
2826 printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002827 (unsigned long)objp);
2828 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002829 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002830}
2831
Pekka Enberg58ce1fd2006-06-23 02:03:24 -07002832static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
2833{
David Woodhouseb46b8f12007-05-08 00:22:59 -07002834 unsigned long long redzone1, redzone2;
Pekka Enberg58ce1fd2006-06-23 02:03:24 -07002835
2836 redzone1 = *dbg_redzone1(cache, obj);
2837 redzone2 = *dbg_redzone2(cache, obj);
2838
2839 /*
2840 * Redzone is ok.
2841 */
2842 if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
2843 return;
2844
2845 if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
2846 slab_error(cache, "double free detected");
2847 else
2848 slab_error(cache, "memory outside object was overwritten");
2849
David Woodhouseb46b8f12007-05-08 00:22:59 -07002850 printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
Pekka Enberg58ce1fd2006-06-23 02:03:24 -07002851 obj, redzone1, redzone2);
2852}
2853
Pekka Enberg343e0d72006-02-01 03:05:50 -08002854static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002855 void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002856{
2857 struct page *page;
2858 unsigned int objnr;
2859 struct slab *slabp;
2860
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002861 objp -= obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002862 kfree_debugcheck(objp);
Christoph Lameterb49af682007-05-06 14:49:41 -07002863 page = virt_to_head_page(objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002864
Pekka Enberg065d41c2005-11-13 16:06:46 -08002865 slabp = page_get_slab(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002866
2867 if (cachep->flags & SLAB_RED_ZONE) {
Pekka Enberg58ce1fd2006-06-23 02:03:24 -07002868 verify_redzone_free(cachep, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002869 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2870 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2871 }
2872 if (cachep->flags & SLAB_STORE_USER)
2873 *dbg_userword(cachep, objp) = caller;
2874
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002875 objnr = obj_to_index(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002876
2877 BUG_ON(objnr >= cachep->num);
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002878 BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002879
Al Viro871751e2006-03-25 03:06:39 -08002880#ifdef CONFIG_DEBUG_SLAB_LEAK
2881 slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
2882#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002883 if (cachep->flags & SLAB_POISON) {
2884#ifdef CONFIG_DEBUG_PAGEALLOC
Andrew Mortona737b3e2006-03-22 00:08:11 -08002885 if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002886 store_stackinfo(cachep, objp, (unsigned long)caller);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002887 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002888 cachep->buffer_size / PAGE_SIZE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002889 } else {
2890 poison_obj(cachep, objp, POISON_FREE);
2891 }
2892#else
2893 poison_obj(cachep, objp, POISON_FREE);
2894#endif
2895 }
2896 return objp;
2897}
2898
Pekka Enberg343e0d72006-02-01 03:05:50 -08002899static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002900{
2901 kmem_bufctl_t i;
2902 int entries = 0;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002903
Linus Torvalds1da177e2005-04-16 15:20:36 -07002904 /* Check slab's freelist to see if this obj is there. */
2905 for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
2906 entries++;
2907 if (entries > cachep->num || i >= cachep->num)
2908 goto bad;
2909 }
2910 if (entries != cachep->num - slabp->inuse) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002911bad:
2912 printk(KERN_ERR "slab: Internal list corruption detected in "
2913 "cache '%s'(%d), slabp %p(%d). Hexdump:\n",
2914 cachep->name, cachep->num, slabp, slabp->inuse);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002915 for (i = 0;
Linus Torvalds264132b2006-03-06 12:10:07 -08002916 i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002917 i++) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002918 if (i % 16 == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002919 printk("\n%03x:", i);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002920 printk(" %02x", ((unsigned char *)slabp)[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002921 }
2922 printk("\n");
2923 BUG();
2924 }
2925}
2926#else
2927#define kfree_debugcheck(x) do { } while(0)
2928#define cache_free_debugcheck(x,objp,z) (objp)
2929#define check_slabp(x,y) do { } while(0)
2930#endif
2931
Pekka Enberg343e0d72006-02-01 03:05:50 -08002932static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002933{
2934 int batchcount;
2935 struct kmem_list3 *l3;
2936 struct array_cache *ac;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002937 int node;
2938
2939 node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002940
2941 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08002942 ac = cpu_cache_get(cachep);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002943retry:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002944 batchcount = ac->batchcount;
2945 if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002946 /*
2947 * If there was little recent activity on this cache, then
2948 * perform only a partial refill. Otherwise we could generate
2949 * refill bouncing.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002950 */
2951 batchcount = BATCHREFILL_LIMIT;
2952 }
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002953 l3 = cachep->nodelists[node];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002954
Christoph Lametere498be72005-09-09 13:03:32 -07002955 BUG_ON(ac->avail > 0 || !l3);
2956 spin_lock(&l3->list_lock);
2957
Christoph Lameter3ded1752006-03-25 03:06:44 -08002958 /* See if we can refill from the shared array */
2959 if (l3->shared && transfer_objects(ac, l3->shared, batchcount))
2960 goto alloc_done;
2961
Linus Torvalds1da177e2005-04-16 15:20:36 -07002962 while (batchcount > 0) {
2963 struct list_head *entry;
2964 struct slab *slabp;
2965 /* Get slab alloc is to come from. */
2966 entry = l3->slabs_partial.next;
2967 if (entry == &l3->slabs_partial) {
2968 l3->free_touched = 1;
2969 entry = l3->slabs_free.next;
2970 if (entry == &l3->slabs_free)
2971 goto must_grow;
2972 }
2973
2974 slabp = list_entry(entry, struct slab, list);
2975 check_slabp(cachep, slabp);
2976 check_spinlock_acquired(cachep);
Pekka Enberg714b81712007-05-06 14:49:03 -07002977
2978 /*
2979 * The slab was either on partial or free list so
2980 * there must be at least one object available for
2981 * allocation.
2982 */
2983 BUG_ON(slabp->inuse < 0 || slabp->inuse >= cachep->num);
2984
Linus Torvalds1da177e2005-04-16 15:20:36 -07002985 while (slabp->inuse < cachep->num && batchcount--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002986 STATS_INC_ALLOCED(cachep);
2987 STATS_INC_ACTIVE(cachep);
2988 STATS_SET_HIGH(cachep);
2989
Matthew Dobson78d382d2006-02-01 03:05:47 -08002990 ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002991 node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002992 }
2993 check_slabp(cachep, slabp);
2994
2995 /* move slabp to correct slabp list: */
2996 list_del(&slabp->list);
2997 if (slabp->free == BUFCTL_END)
2998 list_add(&slabp->list, &l3->slabs_full);
2999 else
3000 list_add(&slabp->list, &l3->slabs_partial);
3001 }
3002
Andrew Mortona737b3e2006-03-22 00:08:11 -08003003must_grow:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003004 l3->free_objects -= ac->avail;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003005alloc_done:
Christoph Lametere498be72005-09-09 13:03:32 -07003006 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003007
3008 if (unlikely(!ac->avail)) {
3009 int x;
Christoph Lameter3c517a62006-12-06 20:33:29 -08003010 x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
Christoph Lametere498be72005-09-09 13:03:32 -07003011
Andrew Mortona737b3e2006-03-22 00:08:11 -08003012 /* cache_grow can reenable interrupts, then ac could change. */
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003013 ac = cpu_cache_get(cachep);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003014 if (!x && ac->avail == 0) /* no objects in sight? abort */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003015 return NULL;
3016
Andrew Mortona737b3e2006-03-22 00:08:11 -08003017 if (!ac->avail) /* objects refilled by interrupt? */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003018 goto retry;
3019 }
3020 ac->touched = 1;
Christoph Lametere498be72005-09-09 13:03:32 -07003021 return ac->entry[--ac->avail];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003022}
3023
Andrew Mortona737b3e2006-03-22 00:08:11 -08003024static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
3025 gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003026{
3027 might_sleep_if(flags & __GFP_WAIT);
3028#if DEBUG
3029 kmem_flagcheck(cachep, flags);
3030#endif
3031}
3032
3033#if DEBUG
Andrew Mortona737b3e2006-03-22 00:08:11 -08003034static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
3035 gfp_t flags, void *objp, void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003036{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003037 if (!objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003038 return objp;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003039 if (cachep->flags & SLAB_POISON) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003040#ifdef CONFIG_DEBUG_PAGEALLOC
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003041 if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003042 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003043 cachep->buffer_size / PAGE_SIZE, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003044 else
3045 check_poison_obj(cachep, objp);
3046#else
3047 check_poison_obj(cachep, objp);
3048#endif
3049 poison_obj(cachep, objp, POISON_INUSE);
3050 }
3051 if (cachep->flags & SLAB_STORE_USER)
3052 *dbg_userword(cachep, objp) = caller;
3053
3054 if (cachep->flags & SLAB_RED_ZONE) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08003055 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
3056 *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
3057 slab_error(cachep, "double free, or memory outside"
3058 " object was overwritten");
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003059 printk(KERN_ERR
David Woodhouseb46b8f12007-05-08 00:22:59 -07003060 "%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
Andrew Mortona737b3e2006-03-22 00:08:11 -08003061 objp, *dbg_redzone1(cachep, objp),
3062 *dbg_redzone2(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003063 }
3064 *dbg_redzone1(cachep, objp) = RED_ACTIVE;
3065 *dbg_redzone2(cachep, objp) = RED_ACTIVE;
3066 }
Al Viro871751e2006-03-25 03:06:39 -08003067#ifdef CONFIG_DEBUG_SLAB_LEAK
3068 {
3069 struct slab *slabp;
3070 unsigned objnr;
3071
Christoph Lameterb49af682007-05-06 14:49:41 -07003072 slabp = page_get_slab(virt_to_head_page(objp));
Al Viro871751e2006-03-25 03:06:39 -08003073 objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
3074 slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
3075 }
3076#endif
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003077 objp += obj_offset(cachep);
Christoph Lameter4f104932007-05-06 14:50:17 -07003078 if (cachep->ctor && cachep->flags & SLAB_POISON)
Christoph Lametera35afb82007-05-16 22:10:57 -07003079 cachep->ctor(objp, cachep, 0);
Kevin Hilmana44b56d2006-12-06 20:32:11 -08003080#if ARCH_SLAB_MINALIGN
3081 if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
3082 printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
3083 objp, ARCH_SLAB_MINALIGN);
3084 }
3085#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07003086 return objp;
3087}
3088#else
3089#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
3090#endif
3091
Akinobu Mita8a8b6502006-12-08 02:39:44 -08003092#ifdef CONFIG_FAILSLAB
3093
3094static struct failslab_attr {
3095
3096 struct fault_attr attr;
3097
3098 u32 ignore_gfp_wait;
3099#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3100 struct dentry *ignore_gfp_wait_file;
3101#endif
3102
3103} failslab = {
3104 .attr = FAULT_ATTR_INITIALIZER,
Don Mullis6b1b60f2006-12-08 02:39:53 -08003105 .ignore_gfp_wait = 1,
Akinobu Mita8a8b6502006-12-08 02:39:44 -08003106};
3107
3108static int __init setup_failslab(char *str)
3109{
3110 return setup_fault_attr(&failslab.attr, str);
3111}
3112__setup("failslab=", setup_failslab);
3113
3114static int should_failslab(struct kmem_cache *cachep, gfp_t flags)
3115{
3116 if (cachep == &cache_cache)
3117 return 0;
3118 if (flags & __GFP_NOFAIL)
3119 return 0;
3120 if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT))
3121 return 0;
3122
3123 return should_fail(&failslab.attr, obj_size(cachep));
3124}
3125
3126#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3127
3128static int __init failslab_debugfs(void)
3129{
3130 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
3131 struct dentry *dir;
3132 int err;
3133
Akinobu Mita824ebef2007-05-06 14:49:58 -07003134 err = init_fault_attr_dentries(&failslab.attr, "failslab");
Akinobu Mita8a8b6502006-12-08 02:39:44 -08003135 if (err)
3136 return err;
3137 dir = failslab.attr.dentries.dir;
3138
3139 failslab.ignore_gfp_wait_file =
3140 debugfs_create_bool("ignore-gfp-wait", mode, dir,
3141 &failslab.ignore_gfp_wait);
3142
3143 if (!failslab.ignore_gfp_wait_file) {
3144 err = -ENOMEM;
3145 debugfs_remove(failslab.ignore_gfp_wait_file);
3146 cleanup_fault_attr_dentries(&failslab.attr);
3147 }
3148
3149 return err;
3150}
3151
3152late_initcall(failslab_debugfs);
3153
3154#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3155
3156#else /* CONFIG_FAILSLAB */
3157
3158static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags)
3159{
3160 return 0;
3161}
3162
3163#endif /* CONFIG_FAILSLAB */
3164
Pekka Enberg343e0d72006-02-01 03:05:50 -08003165static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003166{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003167 void *objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003168 struct array_cache *ac;
3169
Alok N Kataria5c382302005-09-27 21:45:46 -07003170 check_irq_off();
Akinobu Mita8a8b6502006-12-08 02:39:44 -08003171
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003172 ac = cpu_cache_get(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003173 if (likely(ac->avail)) {
3174 STATS_INC_ALLOCHIT(cachep);
3175 ac->touched = 1;
Christoph Lametere498be72005-09-09 13:03:32 -07003176 objp = ac->entry[--ac->avail];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003177 } else {
3178 STATS_INC_ALLOCMISS(cachep);
3179 objp = cache_alloc_refill(cachep, flags);
3180 }
Alok N Kataria5c382302005-09-27 21:45:46 -07003181 return objp;
3182}
3183
Christoph Lametere498be72005-09-09 13:03:32 -07003184#ifdef CONFIG_NUMA
3185/*
Paul Jacksonb2455392006-03-24 03:16:12 -08003186 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
Paul Jacksonc61afb12006-03-24 03:16:08 -08003187 *
3188 * If we are in_interrupt, then process context, including cpusets and
3189 * mempolicy, may not apply and should not be used for allocation policy.
3190 */
3191static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
3192{
3193 int nid_alloc, nid_here;
3194
Christoph Lameter765c4502006-09-27 01:50:08 -07003195 if (in_interrupt() || (flags & __GFP_THISNODE))
Paul Jacksonc61afb12006-03-24 03:16:08 -08003196 return NULL;
3197 nid_alloc = nid_here = numa_node_id();
3198 if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
3199 nid_alloc = cpuset_mem_spread_node();
3200 else if (current->mempolicy)
3201 nid_alloc = slab_node(current->mempolicy);
3202 if (nid_alloc != nid_here)
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003203 return ____cache_alloc_node(cachep, flags, nid_alloc);
Paul Jacksonc61afb12006-03-24 03:16:08 -08003204 return NULL;
3205}
3206
3207/*
Christoph Lameter765c4502006-09-27 01:50:08 -07003208 * Fallback function if there was no memory available and no objects on a
Christoph Lameter3c517a62006-12-06 20:33:29 -08003209 * certain node and fall back is permitted. First we scan all the
3210 * available nodelists for available objects. If that fails then we
3211 * perform an allocation without specifying a node. This allows the page
3212 * allocator to do its reclaim / fallback magic. We then insert the
3213 * slab into the proper nodelist and then allocate from it.
Christoph Lameter765c4502006-09-27 01:50:08 -07003214 */
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003215static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
Christoph Lameter765c4502006-09-27 01:50:08 -07003216{
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003217 struct zonelist *zonelist;
3218 gfp_t local_flags;
Christoph Lameter765c4502006-09-27 01:50:08 -07003219 struct zone **z;
3220 void *obj = NULL;
Christoph Lameter3c517a62006-12-06 20:33:29 -08003221 int nid;
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003222
3223 if (flags & __GFP_THISNODE)
3224 return NULL;
3225
3226 zonelist = &NODE_DATA(slab_node(current->mempolicy))
3227 ->node_zonelists[gfp_zone(flags)];
3228 local_flags = (flags & GFP_LEVEL_MASK);
Christoph Lameter765c4502006-09-27 01:50:08 -07003229
Christoph Lameter3c517a62006-12-06 20:33:29 -08003230retry:
3231 /*
3232 * Look through allowed nodes for objects available
3233 * from existing per node queues.
3234 */
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003235 for (z = zonelist->zones; *z && !obj; z++) {
Christoph Lameter3c517a62006-12-06 20:33:29 -08003236 nid = zone_to_nid(*z);
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003237
Paul Jackson02a0e532006-12-13 00:34:25 -08003238 if (cpuset_zone_allowed_hardwall(*z, flags) &&
Christoph Lameter3c517a62006-12-06 20:33:29 -08003239 cache->nodelists[nid] &&
3240 cache->nodelists[nid]->free_objects)
3241 obj = ____cache_alloc_node(cache,
3242 flags | GFP_THISNODE, nid);
3243 }
3244
Christoph Lametercfce6602007-05-06 14:50:17 -07003245 if (!obj) {
Christoph Lameter3c517a62006-12-06 20:33:29 -08003246 /*
3247 * This allocation will be performed within the constraints
3248 * of the current cpuset / memory policy requirements.
3249 * We may trigger various forms of reclaim on the allowed
3250 * set and go into memory reserves if necessary.
3251 */
Christoph Lameterdd47ea72006-12-13 00:34:11 -08003252 if (local_flags & __GFP_WAIT)
3253 local_irq_enable();
3254 kmem_flagcheck(cache, flags);
Christoph Lameter3c517a62006-12-06 20:33:29 -08003255 obj = kmem_getpages(cache, flags, -1);
Christoph Lameterdd47ea72006-12-13 00:34:11 -08003256 if (local_flags & __GFP_WAIT)
3257 local_irq_disable();
Christoph Lameter3c517a62006-12-06 20:33:29 -08003258 if (obj) {
3259 /*
3260 * Insert into the appropriate per node queues
3261 */
3262 nid = page_to_nid(virt_to_page(obj));
3263 if (cache_grow(cache, flags, nid, obj)) {
3264 obj = ____cache_alloc_node(cache,
3265 flags | GFP_THISNODE, nid);
3266 if (!obj)
3267 /*
3268 * Another processor may allocate the
3269 * objects in the slab since we are
3270 * not holding any locks.
3271 */
3272 goto retry;
3273 } else {
Hugh Dickinsb6a60452007-01-05 16:36:36 -08003274 /* cache_grow already freed obj */
Christoph Lameter3c517a62006-12-06 20:33:29 -08003275 obj = NULL;
3276 }
3277 }
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003278 }
Christoph Lameter765c4502006-09-27 01:50:08 -07003279 return obj;
3280}
3281
3282/*
Christoph Lametere498be72005-09-09 13:03:32 -07003283 * A interface to enable slab creation on nodeid
Linus Torvalds1da177e2005-04-16 15:20:36 -07003284 */
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003285static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003286 int nodeid)
Christoph Lametere498be72005-09-09 13:03:32 -07003287{
3288 struct list_head *entry;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003289 struct slab *slabp;
3290 struct kmem_list3 *l3;
3291 void *obj;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003292 int x;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003293
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003294 l3 = cachep->nodelists[nodeid];
3295 BUG_ON(!l3);
Christoph Lametere498be72005-09-09 13:03:32 -07003296
Andrew Mortona737b3e2006-03-22 00:08:11 -08003297retry:
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08003298 check_irq_off();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003299 spin_lock(&l3->list_lock);
3300 entry = l3->slabs_partial.next;
3301 if (entry == &l3->slabs_partial) {
3302 l3->free_touched = 1;
3303 entry = l3->slabs_free.next;
3304 if (entry == &l3->slabs_free)
3305 goto must_grow;
3306 }
Christoph Lametere498be72005-09-09 13:03:32 -07003307
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003308 slabp = list_entry(entry, struct slab, list);
3309 check_spinlock_acquired_node(cachep, nodeid);
3310 check_slabp(cachep, slabp);
Christoph Lametere498be72005-09-09 13:03:32 -07003311
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003312 STATS_INC_NODEALLOCS(cachep);
3313 STATS_INC_ACTIVE(cachep);
3314 STATS_SET_HIGH(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003315
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003316 BUG_ON(slabp->inuse == cachep->num);
Christoph Lametere498be72005-09-09 13:03:32 -07003317
Matthew Dobson78d382d2006-02-01 03:05:47 -08003318 obj = slab_get_obj(cachep, slabp, nodeid);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003319 check_slabp(cachep, slabp);
3320 l3->free_objects--;
3321 /* move slabp to correct slabp list: */
3322 list_del(&slabp->list);
Christoph Lametere498be72005-09-09 13:03:32 -07003323
Andrew Mortona737b3e2006-03-22 00:08:11 -08003324 if (slabp->free == BUFCTL_END)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003325 list_add(&slabp->list, &l3->slabs_full);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003326 else
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003327 list_add(&slabp->list, &l3->slabs_partial);
Christoph Lametere498be72005-09-09 13:03:32 -07003328
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003329 spin_unlock(&l3->list_lock);
3330 goto done;
Christoph Lametere498be72005-09-09 13:03:32 -07003331
Andrew Mortona737b3e2006-03-22 00:08:11 -08003332must_grow:
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003333 spin_unlock(&l3->list_lock);
Christoph Lameter3c517a62006-12-06 20:33:29 -08003334 x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
Christoph Lameter765c4502006-09-27 01:50:08 -07003335 if (x)
3336 goto retry;
Christoph Lametere498be72005-09-09 13:03:32 -07003337
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003338 return fallback_alloc(cachep, flags);
Christoph Lameter765c4502006-09-27 01:50:08 -07003339
Andrew Mortona737b3e2006-03-22 00:08:11 -08003340done:
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003341 return obj;
Christoph Lametere498be72005-09-09 13:03:32 -07003342}
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003343
3344/**
3345 * kmem_cache_alloc_node - Allocate an object on the specified node
3346 * @cachep: The cache to allocate from.
3347 * @flags: See kmalloc().
3348 * @nodeid: node number of the target node.
3349 * @caller: return address of caller, used for debug information
3350 *
3351 * Identical to kmem_cache_alloc but it will allocate memory on the given
3352 * node, which can improve the performance for cpu bound structures.
3353 *
3354 * Fallback to other node is possible if __GFP_THISNODE is not set.
3355 */
3356static __always_inline void *
3357__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
3358 void *caller)
3359{
3360 unsigned long save_flags;
3361 void *ptr;
3362
Akinobu Mita824ebef2007-05-06 14:49:58 -07003363 if (should_failslab(cachep, flags))
3364 return NULL;
3365
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003366 cache_alloc_debugcheck_before(cachep, flags);
3367 local_irq_save(save_flags);
3368
3369 if (unlikely(nodeid == -1))
3370 nodeid = numa_node_id();
3371
3372 if (unlikely(!cachep->nodelists[nodeid])) {
3373 /* Node not bootstrapped yet */
3374 ptr = fallback_alloc(cachep, flags);
3375 goto out;
3376 }
3377
3378 if (nodeid == numa_node_id()) {
3379 /*
3380 * Use the locally cached objects if possible.
3381 * However ____cache_alloc does not allow fallback
3382 * to other nodes. It may fail while we still have
3383 * objects on other nodes available.
3384 */
3385 ptr = ____cache_alloc(cachep, flags);
3386 if (ptr)
3387 goto out;
3388 }
3389 /* ___cache_alloc_node can fall back to other nodes */
3390 ptr = ____cache_alloc_node(cachep, flags, nodeid);
3391 out:
3392 local_irq_restore(save_flags);
3393 ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
3394
Christoph Lameterd07dbea2007-07-17 04:03:23 -07003395 if (unlikely((flags & __GFP_ZERO) && ptr))
3396 memset(ptr, 0, obj_size(cachep));
3397
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003398 return ptr;
3399}
3400
3401static __always_inline void *
3402__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
3403{
3404 void *objp;
3405
3406 if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
3407 objp = alternate_node_alloc(cache, flags);
3408 if (objp)
3409 goto out;
3410 }
3411 objp = ____cache_alloc(cache, flags);
3412
3413 /*
3414 * We may just have run out of memory on the local node.
3415 * ____cache_alloc_node() knows how to locate memory on other nodes
3416 */
3417 if (!objp)
3418 objp = ____cache_alloc_node(cache, flags, numa_node_id());
3419
3420 out:
3421 return objp;
3422}
3423#else
3424
3425static __always_inline void *
3426__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3427{
3428 return ____cache_alloc(cachep, flags);
3429}
3430
3431#endif /* CONFIG_NUMA */
3432
3433static __always_inline void *
3434__cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
3435{
3436 unsigned long save_flags;
3437 void *objp;
3438
Akinobu Mita824ebef2007-05-06 14:49:58 -07003439 if (should_failslab(cachep, flags))
3440 return NULL;
3441
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003442 cache_alloc_debugcheck_before(cachep, flags);
3443 local_irq_save(save_flags);
3444 objp = __do_cache_alloc(cachep, flags);
3445 local_irq_restore(save_flags);
3446 objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
3447 prefetchw(objp);
3448
Christoph Lameterd07dbea2007-07-17 04:03:23 -07003449 if (unlikely((flags & __GFP_ZERO) && objp))
3450 memset(objp, 0, obj_size(cachep));
3451
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003452 return objp;
3453}
Christoph Lametere498be72005-09-09 13:03:32 -07003454
3455/*
3456 * Caller needs to acquire correct kmem_list's list_lock
3457 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003458static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003459 int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003460{
3461 int i;
Christoph Lametere498be72005-09-09 13:03:32 -07003462 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003463
3464 for (i = 0; i < nr_objects; i++) {
3465 void *objp = objpp[i];
3466 struct slab *slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003467
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -08003468 slabp = virt_to_slab(objp);
Christoph Lameterff694162005-09-22 21:44:02 -07003469 l3 = cachep->nodelists[node];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003470 list_del(&slabp->list);
Christoph Lameterff694162005-09-22 21:44:02 -07003471 check_spinlock_acquired_node(cachep, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003472 check_slabp(cachep, slabp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08003473 slab_put_obj(cachep, slabp, objp, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003474 STATS_DEC_ACTIVE(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003475 l3->free_objects++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003476 check_slabp(cachep, slabp);
3477
3478 /* fixup slab chains */
3479 if (slabp->inuse == 0) {
Christoph Lametere498be72005-09-09 13:03:32 -07003480 if (l3->free_objects > l3->free_limit) {
3481 l3->free_objects -= cachep->num;
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07003482 /* No need to drop any previously held
3483 * lock here, even if we have a off-slab slab
3484 * descriptor it is guaranteed to come from
3485 * a different cache, refer to comments before
3486 * alloc_slabmgmt.
3487 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003488 slab_destroy(cachep, slabp);
3489 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07003490 list_add(&slabp->list, &l3->slabs_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003491 }
3492 } else {
3493 /* Unconditionally move a slab to the end of the
3494 * partial list on free - maximum time for the
3495 * other objects to be freed, too.
3496 */
Christoph Lametere498be72005-09-09 13:03:32 -07003497 list_add_tail(&slabp->list, &l3->slabs_partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003498 }
3499 }
3500}
3501
Pekka Enberg343e0d72006-02-01 03:05:50 -08003502static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003503{
3504 int batchcount;
Christoph Lametere498be72005-09-09 13:03:32 -07003505 struct kmem_list3 *l3;
Christoph Lameterff694162005-09-22 21:44:02 -07003506 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003507
3508 batchcount = ac->batchcount;
3509#if DEBUG
3510 BUG_ON(!batchcount || batchcount > ac->avail);
3511#endif
3512 check_irq_off();
Christoph Lameterff694162005-09-22 21:44:02 -07003513 l3 = cachep->nodelists[node];
Ingo Molnar873623d2006-07-13 14:44:38 +02003514 spin_lock(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07003515 if (l3->shared) {
3516 struct array_cache *shared_array = l3->shared;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003517 int max = shared_array->limit - shared_array->avail;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003518 if (max) {
3519 if (batchcount > max)
3520 batchcount = max;
Christoph Lametere498be72005-09-09 13:03:32 -07003521 memcpy(&(shared_array->entry[shared_array->avail]),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003522 ac->entry, sizeof(void *) * batchcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003523 shared_array->avail += batchcount;
3524 goto free_done;
3525 }
3526 }
3527
Christoph Lameterff694162005-09-22 21:44:02 -07003528 free_block(cachep, ac->entry, batchcount, node);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003529free_done:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003530#if STATS
3531 {
3532 int i = 0;
3533 struct list_head *p;
3534
Christoph Lametere498be72005-09-09 13:03:32 -07003535 p = l3->slabs_free.next;
3536 while (p != &(l3->slabs_free)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003537 struct slab *slabp;
3538
3539 slabp = list_entry(p, struct slab, list);
3540 BUG_ON(slabp->inuse);
3541
3542 i++;
3543 p = p->next;
3544 }
3545 STATS_SET_FREEABLE(cachep, i);
3546 }
3547#endif
Christoph Lametere498be72005-09-09 13:03:32 -07003548 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003549 ac->avail -= batchcount;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003550 memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003551}
3552
3553/*
Andrew Mortona737b3e2006-03-22 00:08:11 -08003554 * Release an obj back to its cache. If the obj has a constructed state, it must
3555 * be in this state _before_ it is released. Called with disabled ints.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003556 */
Ingo Molnar873623d2006-07-13 14:44:38 +02003557static inline void __cache_free(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003558{
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003559 struct array_cache *ac = cpu_cache_get(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003560
3561 check_irq_off();
3562 objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
3563
Siddha, Suresh B1807a1a2007-08-22 14:01:49 -07003564 /*
3565 * Skip calling cache_free_alien() when the platform is not numa.
3566 * This will avoid cache misses that happen while accessing slabp (which
3567 * is per page memory reference) to get nodeid. Instead use a global
3568 * variable to skip the call, which is mostly likely to be present in
3569 * the cache.
3570 */
3571 if (numa_platform && cache_free_alien(cachep, objp))
Pekka Enberg729bd0b2006-06-23 02:03:05 -07003572 return;
Christoph Lametere498be72005-09-09 13:03:32 -07003573
Linus Torvalds1da177e2005-04-16 15:20:36 -07003574 if (likely(ac->avail < ac->limit)) {
3575 STATS_INC_FREEHIT(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003576 ac->entry[ac->avail++] = objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003577 return;
3578 } else {
3579 STATS_INC_FREEMISS(cachep);
3580 cache_flusharray(cachep, ac);
Christoph Lametere498be72005-09-09 13:03:32 -07003581 ac->entry[ac->avail++] = objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003582 }
3583}
3584
3585/**
3586 * kmem_cache_alloc - Allocate an object
3587 * @cachep: The cache to allocate from.
3588 * @flags: See kmalloc().
3589 *
3590 * Allocate an object from this cache. The flags are only relevant
3591 * if the cache has no available objects.
3592 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003593void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003594{
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003595 return __cache_alloc(cachep, flags, __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003596}
3597EXPORT_SYMBOL(kmem_cache_alloc);
3598
3599/**
3600 * kmem_ptr_validate - check if an untrusted pointer might
3601 * be a slab entry.
3602 * @cachep: the cache we're checking against
3603 * @ptr: pointer to validate
3604 *
3605 * This verifies that the untrusted pointer looks sane:
3606 * it is _not_ a guarantee that the pointer is actually
3607 * part of the slab cache in question, but it at least
3608 * validates that the pointer can be dereferenced and
3609 * looks half-way sane.
3610 *
3611 * Currently only used for dentry validation.
3612 */
Christoph Lameterb7f869a22006-12-22 01:06:44 -08003613int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003614{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003615 unsigned long addr = (unsigned long)ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003616 unsigned long min_addr = PAGE_OFFSET;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003617 unsigned long align_mask = BYTES_PER_WORD - 1;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003618 unsigned long size = cachep->buffer_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003619 struct page *page;
3620
3621 if (unlikely(addr < min_addr))
3622 goto out;
3623 if (unlikely(addr > (unsigned long)high_memory - size))
3624 goto out;
3625 if (unlikely(addr & align_mask))
3626 goto out;
3627 if (unlikely(!kern_addr_valid(addr)))
3628 goto out;
3629 if (unlikely(!kern_addr_valid(addr + size - 1)))
3630 goto out;
3631 page = virt_to_page(ptr);
3632 if (unlikely(!PageSlab(page)))
3633 goto out;
Pekka Enberg065d41c2005-11-13 16:06:46 -08003634 if (unlikely(page_get_cache(page) != cachep))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003635 goto out;
3636 return 1;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003637out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003638 return 0;
3639}
3640
3641#ifdef CONFIG_NUMA
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003642void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
3643{
3644 return __cache_alloc_node(cachep, flags, nodeid,
3645 __builtin_return_address(0));
3646}
Linus Torvalds1da177e2005-04-16 15:20:36 -07003647EXPORT_SYMBOL(kmem_cache_alloc_node);
3648
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003649static __always_inline void *
3650__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003651{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003652 struct kmem_cache *cachep;
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003653
3654 cachep = kmem_find_general_cachep(size, flags);
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003655 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3656 return cachep;
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003657 return kmem_cache_alloc_node(cachep, flags, node);
3658}
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003659
3660#ifdef CONFIG_DEBUG_SLAB
3661void *__kmalloc_node(size_t size, gfp_t flags, int node)
3662{
3663 return __do_kmalloc_node(size, flags, node,
3664 __builtin_return_address(0));
3665}
Christoph Hellwigdbe5e692006-09-25 23:31:36 -07003666EXPORT_SYMBOL(__kmalloc_node);
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003667
3668void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
3669 int node, void *caller)
3670{
3671 return __do_kmalloc_node(size, flags, node, caller);
3672}
3673EXPORT_SYMBOL(__kmalloc_node_track_caller);
3674#else
3675void *__kmalloc_node(size_t size, gfp_t flags, int node)
3676{
3677 return __do_kmalloc_node(size, flags, node, NULL);
3678}
3679EXPORT_SYMBOL(__kmalloc_node);
3680#endif /* CONFIG_DEBUG_SLAB */
3681#endif /* CONFIG_NUMA */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003682
3683/**
Paul Drynoff800590f2006-06-23 02:03:48 -07003684 * __do_kmalloc - allocate memory
Linus Torvalds1da177e2005-04-16 15:20:36 -07003685 * @size: how many bytes of memory are required.
Paul Drynoff800590f2006-06-23 02:03:48 -07003686 * @flags: the type of memory to allocate (see kmalloc).
Randy Dunlap911851e2006-03-22 00:08:14 -08003687 * @caller: function caller for debug tracking of the caller
Linus Torvalds1da177e2005-04-16 15:20:36 -07003688 */
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003689static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
3690 void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003691{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003692 struct kmem_cache *cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003693
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003694 /* If you want to save a few bytes .text space: replace
3695 * __ with kmem_.
3696 * Then kmalloc uses the uninlined functions instead of the inline
3697 * functions.
3698 */
3699 cachep = __find_general_cachep(size, flags);
Linus Torvaldsa5c96d82007-07-19 13:17:15 -07003700 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3701 return cachep;
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003702 return __cache_alloc(cachep, flags, caller);
3703}
3704
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003705
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -07003706#ifdef CONFIG_DEBUG_SLAB
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003707void *__kmalloc(size_t size, gfp_t flags)
3708{
Al Viro871751e2006-03-25 03:06:39 -08003709 return __do_kmalloc(size, flags, __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003710}
3711EXPORT_SYMBOL(__kmalloc);
3712
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003713void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
3714{
3715 return __do_kmalloc(size, flags, caller);
3716}
3717EXPORT_SYMBOL(__kmalloc_track_caller);
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -07003718
3719#else
3720void *__kmalloc(size_t size, gfp_t flags)
3721{
3722 return __do_kmalloc(size, flags, NULL);
3723}
3724EXPORT_SYMBOL(__kmalloc);
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003725#endif
3726
Linus Torvalds1da177e2005-04-16 15:20:36 -07003727/**
3728 * kmem_cache_free - Deallocate an object
3729 * @cachep: The cache the allocation was from.
3730 * @objp: The previously allocated object.
3731 *
3732 * Free an object which was previously allocated from this
3733 * cache.
3734 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003735void kmem_cache_free(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003736{
3737 unsigned long flags;
3738
Pekka Enbergddc2e812006-06-23 02:03:40 -07003739 BUG_ON(virt_to_cache(objp) != cachep);
3740
Linus Torvalds1da177e2005-04-16 15:20:36 -07003741 local_irq_save(flags);
Ingo Molnar898552c2007-02-10 01:44:57 -08003742 debug_check_no_locks_freed(objp, obj_size(cachep));
Ingo Molnar873623d2006-07-13 14:44:38 +02003743 __cache_free(cachep, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003744 local_irq_restore(flags);
3745}
3746EXPORT_SYMBOL(kmem_cache_free);
3747
3748/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07003749 * kfree - free previously allocated memory
3750 * @objp: pointer returned by kmalloc.
3751 *
Pekka Enberg80e93ef2005-09-09 13:10:16 -07003752 * If @objp is NULL, no operation is performed.
3753 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003754 * Don't free memory not originally allocated by kmalloc()
3755 * or you will run into trouble.
3756 */
3757void kfree(const void *objp)
3758{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003759 struct kmem_cache *c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003760 unsigned long flags;
3761
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003762 if (unlikely(ZERO_OR_NULL_PTR(objp)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003763 return;
3764 local_irq_save(flags);
3765 kfree_debugcheck(objp);
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -08003766 c = virt_to_cache(objp);
Ingo Molnarf9b84042006-06-27 02:54:49 -07003767 debug_check_no_locks_freed(objp, obj_size(c));
Ingo Molnar873623d2006-07-13 14:44:38 +02003768 __cache_free(c, (void *)objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003769 local_irq_restore(flags);
3770}
3771EXPORT_SYMBOL(kfree);
3772
Pekka Enberg343e0d72006-02-01 03:05:50 -08003773unsigned int kmem_cache_size(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003774{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003775 return obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003776}
3777EXPORT_SYMBOL(kmem_cache_size);
3778
Pekka Enberg343e0d72006-02-01 03:05:50 -08003779const char *kmem_cache_name(struct kmem_cache *cachep)
Arnaldo Carvalho de Melo19449722005-06-18 22:46:19 -07003780{
3781 return cachep->name;
3782}
3783EXPORT_SYMBOL_GPL(kmem_cache_name);
3784
Christoph Lametere498be72005-09-09 13:03:32 -07003785/*
Christoph Lameter0718dc22006-03-25 03:06:47 -08003786 * This initializes kmem_list3 or resizes varioius caches for all nodes.
Christoph Lametere498be72005-09-09 13:03:32 -07003787 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003788static int alloc_kmemlist(struct kmem_cache *cachep)
Christoph Lametere498be72005-09-09 13:03:32 -07003789{
3790 int node;
3791 struct kmem_list3 *l3;
Christoph Lametercafeb022006-03-25 03:06:46 -08003792 struct array_cache *new_shared;
Paul Menage3395ee02006-12-06 20:32:16 -08003793 struct array_cache **new_alien = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07003794
3795 for_each_online_node(node) {
Christoph Lametercafeb022006-03-25 03:06:46 -08003796
Paul Menage3395ee02006-12-06 20:32:16 -08003797 if (use_alien_caches) {
3798 new_alien = alloc_alien_cache(node, cachep->limit);
3799 if (!new_alien)
3800 goto fail;
3801 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003802
Eric Dumazet63109842007-05-06 14:49:28 -07003803 new_shared = NULL;
3804 if (cachep->shared) {
3805 new_shared = alloc_arraycache(node,
Christoph Lameter0718dc22006-03-25 03:06:47 -08003806 cachep->shared*cachep->batchcount,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003807 0xbaadf00d);
Eric Dumazet63109842007-05-06 14:49:28 -07003808 if (!new_shared) {
3809 free_alien_cache(new_alien);
3810 goto fail;
3811 }
Christoph Lameter0718dc22006-03-25 03:06:47 -08003812 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003813
Andrew Mortona737b3e2006-03-22 00:08:11 -08003814 l3 = cachep->nodelists[node];
3815 if (l3) {
Christoph Lametercafeb022006-03-25 03:06:46 -08003816 struct array_cache *shared = l3->shared;
3817
Christoph Lametere498be72005-09-09 13:03:32 -07003818 spin_lock_irq(&l3->list_lock);
3819
Christoph Lametercafeb022006-03-25 03:06:46 -08003820 if (shared)
Christoph Lameter0718dc22006-03-25 03:06:47 -08003821 free_block(cachep, shared->entry,
3822 shared->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07003823
Christoph Lametercafeb022006-03-25 03:06:46 -08003824 l3->shared = new_shared;
3825 if (!l3->alien) {
Christoph Lametere498be72005-09-09 13:03:32 -07003826 l3->alien = new_alien;
3827 new_alien = NULL;
3828 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003829 l3->free_limit = (1 + nr_cpus_node(node)) *
Andrew Mortona737b3e2006-03-22 00:08:11 -08003830 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07003831 spin_unlock_irq(&l3->list_lock);
Christoph Lametercafeb022006-03-25 03:06:46 -08003832 kfree(shared);
Christoph Lametere498be72005-09-09 13:03:32 -07003833 free_alien_cache(new_alien);
3834 continue;
3835 }
Andrew Mortona737b3e2006-03-22 00:08:11 -08003836 l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
Christoph Lameter0718dc22006-03-25 03:06:47 -08003837 if (!l3) {
3838 free_alien_cache(new_alien);
3839 kfree(new_shared);
Christoph Lametere498be72005-09-09 13:03:32 -07003840 goto fail;
Christoph Lameter0718dc22006-03-25 03:06:47 -08003841 }
Christoph Lametere498be72005-09-09 13:03:32 -07003842
3843 kmem_list3_init(l3);
3844 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
Andrew Mortona737b3e2006-03-22 00:08:11 -08003845 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametercafeb022006-03-25 03:06:46 -08003846 l3->shared = new_shared;
Christoph Lametere498be72005-09-09 13:03:32 -07003847 l3->alien = new_alien;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003848 l3->free_limit = (1 + nr_cpus_node(node)) *
Andrew Mortona737b3e2006-03-22 00:08:11 -08003849 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07003850 cachep->nodelists[node] = l3;
3851 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003852 return 0;
Christoph Lameter0718dc22006-03-25 03:06:47 -08003853
Andrew Mortona737b3e2006-03-22 00:08:11 -08003854fail:
Christoph Lameter0718dc22006-03-25 03:06:47 -08003855 if (!cachep->next.next) {
3856 /* Cache is not active yet. Roll back what we did */
3857 node--;
3858 while (node >= 0) {
3859 if (cachep->nodelists[node]) {
3860 l3 = cachep->nodelists[node];
3861
3862 kfree(l3->shared);
3863 free_alien_cache(l3->alien);
3864 kfree(l3);
3865 cachep->nodelists[node] = NULL;
3866 }
3867 node--;
3868 }
3869 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003870 return -ENOMEM;
Christoph Lametere498be72005-09-09 13:03:32 -07003871}
3872
Linus Torvalds1da177e2005-04-16 15:20:36 -07003873struct ccupdate_struct {
Pekka Enberg343e0d72006-02-01 03:05:50 -08003874 struct kmem_cache *cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003875 struct array_cache *new[NR_CPUS];
3876};
3877
3878static void do_ccupdate_local(void *info)
3879{
Andrew Mortona737b3e2006-03-22 00:08:11 -08003880 struct ccupdate_struct *new = info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003881 struct array_cache *old;
3882
3883 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003884 old = cpu_cache_get(new->cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003885
Linus Torvalds1da177e2005-04-16 15:20:36 -07003886 new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
3887 new->new[smp_processor_id()] = old;
3888}
3889
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -08003890/* Always called with the cache_chain_mutex held */
Andrew Mortona737b3e2006-03-22 00:08:11 -08003891static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
3892 int batchcount, int shared)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003893{
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003894 struct ccupdate_struct *new;
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003895 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003896
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003897 new = kzalloc(sizeof(*new), GFP_KERNEL);
3898 if (!new)
3899 return -ENOMEM;
3900
Christoph Lametere498be72005-09-09 13:03:32 -07003901 for_each_online_cpu(i) {
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003902 new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003903 batchcount);
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003904 if (!new->new[i]) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003905 for (i--; i >= 0; i--)
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003906 kfree(new->new[i]);
3907 kfree(new);
Christoph Lametere498be72005-09-09 13:03:32 -07003908 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003909 }
3910 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003911 new->cachep = cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003912
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003913 on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
Christoph Lametere498be72005-09-09 13:03:32 -07003914
Linus Torvalds1da177e2005-04-16 15:20:36 -07003915 check_irq_on();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003916 cachep->batchcount = batchcount;
3917 cachep->limit = limit;
Christoph Lametere498be72005-09-09 13:03:32 -07003918 cachep->shared = shared;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003919
Christoph Lametere498be72005-09-09 13:03:32 -07003920 for_each_online_cpu(i) {
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003921 struct array_cache *ccold = new->new[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003922 if (!ccold)
3923 continue;
Christoph Lametere498be72005-09-09 13:03:32 -07003924 spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
Christoph Lameterff694162005-09-22 21:44:02 -07003925 free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
Christoph Lametere498be72005-09-09 13:03:32 -07003926 spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003927 kfree(ccold);
3928 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003929 kfree(new);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003930 return alloc_kmemlist(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003931}
3932
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -08003933/* Called with cache_chain_mutex held always */
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003934static int enable_cpucache(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003935{
3936 int err;
3937 int limit, shared;
3938
Andrew Mortona737b3e2006-03-22 00:08:11 -08003939 /*
3940 * The head array serves three purposes:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003941 * - create a LIFO ordering, i.e. return objects that are cache-warm
3942 * - reduce the number of spinlock operations.
Andrew Mortona737b3e2006-03-22 00:08:11 -08003943 * - reduce the number of linked list operations on the slab and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003944 * bufctl chains: array operations are cheaper.
3945 * The numbers are guessed, we should auto-tune as described by
3946 * Bonwick.
3947 */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003948 if (cachep->buffer_size > 131072)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003949 limit = 1;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003950 else if (cachep->buffer_size > PAGE_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003951 limit = 8;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003952 else if (cachep->buffer_size > 1024)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003953 limit = 24;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003954 else if (cachep->buffer_size > 256)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003955 limit = 54;
3956 else
3957 limit = 120;
3958
Andrew Mortona737b3e2006-03-22 00:08:11 -08003959 /*
3960 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
Linus Torvalds1da177e2005-04-16 15:20:36 -07003961 * allocation behaviour: Most allocs on one cpu, most free operations
3962 * on another cpu. For these cases, an efficient object passing between
3963 * cpus is necessary. This is provided by a shared array. The array
3964 * replaces Bonwick's magazine layer.
3965 * On uniprocessor, it's functionally equivalent (but less efficient)
3966 * to a larger limit. Thus disabled by default.
3967 */
3968 shared = 0;
Eric Dumazet364fbb22007-05-06 14:49:27 -07003969 if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003970 shared = 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003971
3972#if DEBUG
Andrew Mortona737b3e2006-03-22 00:08:11 -08003973 /*
3974 * With debugging enabled, large batchcount lead to excessively long
3975 * periods with disabled local interrupts. Limit the batchcount
Linus Torvalds1da177e2005-04-16 15:20:36 -07003976 */
3977 if (limit > 32)
3978 limit = 32;
3979#endif
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003980 err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003981 if (err)
3982 printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003983 cachep->name, -err);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003984 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003985}
3986
Christoph Lameter1b552532006-03-22 00:09:07 -08003987/*
3988 * Drain an array if it contains any elements taking the l3 lock only if
Christoph Lameterb18e7e62006-03-22 00:09:07 -08003989 * necessary. Note that the l3 listlock also protects the array_cache
3990 * if drain_array() is used on the shared array.
Christoph Lameter1b552532006-03-22 00:09:07 -08003991 */
3992void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
3993 struct array_cache *ac, int force, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003994{
3995 int tofree;
3996
Christoph Lameter1b552532006-03-22 00:09:07 -08003997 if (!ac || !ac->avail)
3998 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003999 if (ac->touched && !force) {
4000 ac->touched = 0;
Christoph Lameterb18e7e62006-03-22 00:09:07 -08004001 } else {
Christoph Lameter1b552532006-03-22 00:09:07 -08004002 spin_lock_irq(&l3->list_lock);
Christoph Lameterb18e7e62006-03-22 00:09:07 -08004003 if (ac->avail) {
4004 tofree = force ? ac->avail : (ac->limit + 4) / 5;
4005 if (tofree > ac->avail)
4006 tofree = (ac->avail + 1) / 2;
4007 free_block(cachep, ac->entry, tofree, node);
4008 ac->avail -= tofree;
4009 memmove(ac->entry, &(ac->entry[tofree]),
4010 sizeof(void *) * ac->avail);
4011 }
Christoph Lameter1b552532006-03-22 00:09:07 -08004012 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004013 }
4014}
4015
4016/**
4017 * cache_reap - Reclaim memory from caches.
Randy Dunlap05fb6bf2007-02-28 20:12:13 -08004018 * @w: work descriptor
Linus Torvalds1da177e2005-04-16 15:20:36 -07004019 *
4020 * Called from workqueue/eventd every few seconds.
4021 * Purpose:
4022 * - clear the per-cpu caches for this CPU.
4023 * - return freeable pages to the main free memory pool.
4024 *
Andrew Mortona737b3e2006-03-22 00:08:11 -08004025 * If we cannot acquire the cache chain mutex then just give up - we'll try
4026 * again on the next iteration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004027 */
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004028static void cache_reap(struct work_struct *w)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004029{
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004030 struct kmem_cache *searchp;
Christoph Lametere498be72005-09-09 13:03:32 -07004031 struct kmem_list3 *l3;
Christoph Lameteraab22072006-03-22 00:09:06 -08004032 int node = numa_node_id();
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004033 struct delayed_work *work =
4034 container_of(w, struct delayed_work, work);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004035
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004036 if (!mutex_trylock(&cache_chain_mutex))
Linus Torvalds1da177e2005-04-16 15:20:36 -07004037 /* Give up. Setup the next iteration. */
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004038 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004039
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004040 list_for_each_entry(searchp, &cache_chain, next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004041 check_irq_on();
4042
Christoph Lameter35386e32006-03-22 00:09:05 -08004043 /*
4044 * We only take the l3 lock if absolutely necessary and we
4045 * have established with reasonable certainty that
4046 * we can do some work if the lock was obtained.
4047 */
Christoph Lameteraab22072006-03-22 00:09:06 -08004048 l3 = searchp->nodelists[node];
Christoph Lameter35386e32006-03-22 00:09:05 -08004049
Christoph Lameter8fce4d82006-03-09 17:33:54 -08004050 reap_alien(searchp, l3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004051
Christoph Lameteraab22072006-03-22 00:09:06 -08004052 drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004053
Christoph Lameter35386e32006-03-22 00:09:05 -08004054 /*
4055 * These are racy checks but it does not matter
4056 * if we skip one check or scan twice.
4057 */
Christoph Lametere498be72005-09-09 13:03:32 -07004058 if (time_after(l3->next_reap, jiffies))
Christoph Lameter35386e32006-03-22 00:09:05 -08004059 goto next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004060
Christoph Lametere498be72005-09-09 13:03:32 -07004061 l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004062
Christoph Lameteraab22072006-03-22 00:09:06 -08004063 drain_array(searchp, l3, l3->shared, 0, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004064
Christoph Lametered11d9e2006-06-30 01:55:45 -07004065 if (l3->free_touched)
Christoph Lametere498be72005-09-09 13:03:32 -07004066 l3->free_touched = 0;
Christoph Lametered11d9e2006-06-30 01:55:45 -07004067 else {
4068 int freed;
4069
4070 freed = drain_freelist(searchp, l3, (l3->free_limit +
4071 5 * searchp->num - 1) / (5 * searchp->num));
4072 STATS_ADD_REAPED(searchp, freed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004073 }
Christoph Lameter35386e32006-03-22 00:09:05 -08004074next:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004075 cond_resched();
4076 }
4077 check_irq_on();
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004078 mutex_unlock(&cache_chain_mutex);
Christoph Lameter8fce4d82006-03-09 17:33:54 -08004079 next_reap_node();
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004080out:
Andrew Mortona737b3e2006-03-22 00:08:11 -08004081 /* Set up the next iteration */
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004082 schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004083}
4084
4085#ifdef CONFIG_PROC_FS
4086
Pekka Enberg85289f92006-01-08 01:00:36 -08004087static void print_slabinfo_header(struct seq_file *m)
4088{
4089 /*
4090 * Output format version, so at least we can change it
4091 * without _too_ many complaints.
4092 */
4093#if STATS
4094 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
4095#else
4096 seq_puts(m, "slabinfo - version: 2.1\n");
4097#endif
4098 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4099 "<objperslab> <pagesperslab>");
4100 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4101 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4102#if STATS
4103 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004104 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
Pekka Enberg85289f92006-01-08 01:00:36 -08004105 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
4106#endif
4107 seq_putc(m, '\n');
4108}
4109
Linus Torvalds1da177e2005-04-16 15:20:36 -07004110static void *s_start(struct seq_file *m, loff_t *pos)
4111{
4112 loff_t n = *pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004113
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004114 mutex_lock(&cache_chain_mutex);
Pekka Enberg85289f92006-01-08 01:00:36 -08004115 if (!n)
4116 print_slabinfo_header(m);
Pavel Emelianovb92151b2007-07-15 23:38:04 -07004117
4118 return seq_list_start(&cache_chain, *pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004119}
4120
4121static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4122{
Pavel Emelianovb92151b2007-07-15 23:38:04 -07004123 return seq_list_next(p, &cache_chain, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004124}
4125
4126static void s_stop(struct seq_file *m, void *p)
4127{
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004128 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004129}
4130
4131static int s_show(struct seq_file *m, void *p)
4132{
Pavel Emelianovb92151b2007-07-15 23:38:04 -07004133 struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004134 struct slab *slabp;
4135 unsigned long active_objs;
4136 unsigned long num_objs;
4137 unsigned long active_slabs = 0;
4138 unsigned long num_slabs, free_objects = 0, shared_avail = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07004139 const char *name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004140 char *error = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07004141 int node;
4142 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004143
Linus Torvalds1da177e2005-04-16 15:20:36 -07004144 active_objs = 0;
4145 num_slabs = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07004146 for_each_online_node(node) {
4147 l3 = cachep->nodelists[node];
4148 if (!l3)
4149 continue;
4150
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08004151 check_irq_on();
4152 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07004153
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004154 list_for_each_entry(slabp, &l3->slabs_full, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004155 if (slabp->inuse != cachep->num && !error)
4156 error = "slabs_full accounting error";
4157 active_objs += cachep->num;
4158 active_slabs++;
4159 }
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004160 list_for_each_entry(slabp, &l3->slabs_partial, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004161 if (slabp->inuse == cachep->num && !error)
4162 error = "slabs_partial inuse accounting error";
4163 if (!slabp->inuse && !error)
4164 error = "slabs_partial/inuse accounting error";
4165 active_objs += slabp->inuse;
4166 active_slabs++;
4167 }
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004168 list_for_each_entry(slabp, &l3->slabs_free, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004169 if (slabp->inuse && !error)
4170 error = "slabs_free/inuse accounting error";
4171 num_slabs++;
4172 }
4173 free_objects += l3->free_objects;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08004174 if (l3->shared)
4175 shared_avail += l3->shared->avail;
Christoph Lametere498be72005-09-09 13:03:32 -07004176
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08004177 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004178 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004179 num_slabs += active_slabs;
4180 num_objs = num_slabs * cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07004181 if (num_objs - active_objs != free_objects && !error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004182 error = "free_objects accounting error";
4183
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004184 name = cachep->name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004185 if (error)
4186 printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
4187
4188 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
Manfred Spraul3dafccf2006-02-01 03:05:42 -08004189 name, active_objs, num_objs, cachep->buffer_size,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004190 cachep->num, (1 << cachep->gfporder));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004191 seq_printf(m, " : tunables %4u %4u %4u",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004192 cachep->limit, cachep->batchcount, cachep->shared);
Christoph Lametere498be72005-09-09 13:03:32 -07004193 seq_printf(m, " : slabdata %6lu %6lu %6lu",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004194 active_slabs, num_slabs, shared_avail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004195#if STATS
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004196 { /* list3 stats */
Linus Torvalds1da177e2005-04-16 15:20:36 -07004197 unsigned long high = cachep->high_mark;
4198 unsigned long allocs = cachep->num_allocations;
4199 unsigned long grown = cachep->grown;
4200 unsigned long reaped = cachep->reaped;
4201 unsigned long errors = cachep->errors;
4202 unsigned long max_freeable = cachep->max_freeable;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004203 unsigned long node_allocs = cachep->node_allocs;
Christoph Lametere498be72005-09-09 13:03:32 -07004204 unsigned long node_frees = cachep->node_frees;
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004205 unsigned long overflows = cachep->node_overflow;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004206
Christoph Lametere498be72005-09-09 13:03:32 -07004207 seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004208 %4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
Andrew Mortona737b3e2006-03-22 00:08:11 -08004209 reaped, errors, max_freeable, node_allocs,
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004210 node_frees, overflows);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004211 }
4212 /* cpu stats */
4213 {
4214 unsigned long allochit = atomic_read(&cachep->allochit);
4215 unsigned long allocmiss = atomic_read(&cachep->allocmiss);
4216 unsigned long freehit = atomic_read(&cachep->freehit);
4217 unsigned long freemiss = atomic_read(&cachep->freemiss);
4218
4219 seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004220 allochit, allocmiss, freehit, freemiss);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004221 }
4222#endif
4223 seq_putc(m, '\n');
Linus Torvalds1da177e2005-04-16 15:20:36 -07004224 return 0;
4225}
4226
4227/*
4228 * slabinfo_op - iterator that generates /proc/slabinfo
4229 *
4230 * Output layout:
4231 * cache-name
4232 * num-active-objs
4233 * total-objs
4234 * object size
4235 * num-active-slabs
4236 * total-slabs
4237 * num-pages-per-slab
4238 * + further values on SMP and with statistics enabled
4239 */
4240
Helge Deller15ad7cd2006-12-06 20:40:36 -08004241const struct seq_operations slabinfo_op = {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004242 .start = s_start,
4243 .next = s_next,
4244 .stop = s_stop,
4245 .show = s_show,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004246};
4247
4248#define MAX_SLABINFO_WRITE 128
4249/**
4250 * slabinfo_write - Tuning for the slab allocator
4251 * @file: unused
4252 * @buffer: user buffer
4253 * @count: data length
4254 * @ppos: unused
4255 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004256ssize_t slabinfo_write(struct file *file, const char __user * buffer,
4257 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004258{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004259 char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004260 int limit, batchcount, shared, res;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004261 struct kmem_cache *cachep;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004262
Linus Torvalds1da177e2005-04-16 15:20:36 -07004263 if (count > MAX_SLABINFO_WRITE)
4264 return -EINVAL;
4265 if (copy_from_user(&kbuf, buffer, count))
4266 return -EFAULT;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004267 kbuf[MAX_SLABINFO_WRITE] = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -07004268
4269 tmp = strchr(kbuf, ' ');
4270 if (!tmp)
4271 return -EINVAL;
4272 *tmp = '\0';
4273 tmp++;
4274 if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
4275 return -EINVAL;
4276
4277 /* Find the cache in the chain of caches. */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004278 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004279 res = -EINVAL;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004280 list_for_each_entry(cachep, &cache_chain, next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004281 if (!strcmp(cachep->name, kbuf)) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08004282 if (limit < 1 || batchcount < 1 ||
4283 batchcount > limit || shared < 0) {
Christoph Lametere498be72005-09-09 13:03:32 -07004284 res = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004285 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07004286 res = do_tune_cpucache(cachep, limit,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004287 batchcount, shared);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004288 }
4289 break;
4290 }
4291 }
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004292 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004293 if (res >= 0)
4294 res = count;
4295 return res;
4296}
Al Viro871751e2006-03-25 03:06:39 -08004297
4298#ifdef CONFIG_DEBUG_SLAB_LEAK
4299
4300static void *leaks_start(struct seq_file *m, loff_t *pos)
4301{
Al Viro871751e2006-03-25 03:06:39 -08004302 mutex_lock(&cache_chain_mutex);
Pavel Emelianovb92151b2007-07-15 23:38:04 -07004303 return seq_list_start(&cache_chain, *pos);
Al Viro871751e2006-03-25 03:06:39 -08004304}
4305
4306static inline int add_caller(unsigned long *n, unsigned long v)
4307{
4308 unsigned long *p;
4309 int l;
4310 if (!v)
4311 return 1;
4312 l = n[1];
4313 p = n + 2;
4314 while (l) {
4315 int i = l/2;
4316 unsigned long *q = p + 2 * i;
4317 if (*q == v) {
4318 q[1]++;
4319 return 1;
4320 }
4321 if (*q > v) {
4322 l = i;
4323 } else {
4324 p = q + 2;
4325 l -= i + 1;
4326 }
4327 }
4328 if (++n[1] == n[0])
4329 return 0;
4330 memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n));
4331 p[0] = v;
4332 p[1] = 1;
4333 return 1;
4334}
4335
4336static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
4337{
4338 void *p;
4339 int i;
4340 if (n[0] == n[1])
4341 return;
4342 for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) {
4343 if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
4344 continue;
4345 if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
4346 return;
4347 }
4348}
4349
4350static void show_symbol(struct seq_file *m, unsigned long address)
4351{
4352#ifdef CONFIG_KALLSYMS
Al Viro871751e2006-03-25 03:06:39 -08004353 unsigned long offset, size;
Tejun Heo9281ace2007-07-17 04:03:51 -07004354 char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN];
Al Viro871751e2006-03-25 03:06:39 -08004355
Alexey Dobriyana5c43da2007-05-08 00:28:47 -07004356 if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) {
Al Viro871751e2006-03-25 03:06:39 -08004357 seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
Alexey Dobriyana5c43da2007-05-08 00:28:47 -07004358 if (modname[0])
Al Viro871751e2006-03-25 03:06:39 -08004359 seq_printf(m, " [%s]", modname);
4360 return;
4361 }
4362#endif
4363 seq_printf(m, "%p", (void *)address);
4364}
4365
4366static int leaks_show(struct seq_file *m, void *p)
4367{
Pavel Emelianovb92151b2007-07-15 23:38:04 -07004368 struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
Al Viro871751e2006-03-25 03:06:39 -08004369 struct slab *slabp;
4370 struct kmem_list3 *l3;
4371 const char *name;
4372 unsigned long *n = m->private;
4373 int node;
4374 int i;
4375
4376 if (!(cachep->flags & SLAB_STORE_USER))
4377 return 0;
4378 if (!(cachep->flags & SLAB_RED_ZONE))
4379 return 0;
4380
4381 /* OK, we can do it */
4382
4383 n[1] = 0;
4384
4385 for_each_online_node(node) {
4386 l3 = cachep->nodelists[node];
4387 if (!l3)
4388 continue;
4389
4390 check_irq_on();
4391 spin_lock_irq(&l3->list_lock);
4392
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004393 list_for_each_entry(slabp, &l3->slabs_full, list)
Al Viro871751e2006-03-25 03:06:39 -08004394 handle_slab(n, cachep, slabp);
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004395 list_for_each_entry(slabp, &l3->slabs_partial, list)
Al Viro871751e2006-03-25 03:06:39 -08004396 handle_slab(n, cachep, slabp);
Al Viro871751e2006-03-25 03:06:39 -08004397 spin_unlock_irq(&l3->list_lock);
4398 }
4399 name = cachep->name;
4400 if (n[0] == n[1]) {
4401 /* Increase the buffer size */
4402 mutex_unlock(&cache_chain_mutex);
4403 m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
4404 if (!m->private) {
4405 /* Too bad, we are really out */
4406 m->private = n;
4407 mutex_lock(&cache_chain_mutex);
4408 return -ENOMEM;
4409 }
4410 *(unsigned long *)m->private = n[0] * 2;
4411 kfree(n);
4412 mutex_lock(&cache_chain_mutex);
4413 /* Now make sure this entry will be retried */
4414 m->count = m->size;
4415 return 0;
4416 }
4417 for (i = 0; i < n[1]; i++) {
4418 seq_printf(m, "%s: %lu ", name, n[2*i+3]);
4419 show_symbol(m, n[2*i+2]);
4420 seq_putc(m, '\n');
4421 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07004422
Al Viro871751e2006-03-25 03:06:39 -08004423 return 0;
4424}
4425
Helge Deller15ad7cd2006-12-06 20:40:36 -08004426const struct seq_operations slabstats_op = {
Al Viro871751e2006-03-25 03:06:39 -08004427 .start = leaks_start,
4428 .next = s_next,
4429 .stop = s_stop,
4430 .show = leaks_show,
4431};
4432#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07004433#endif
4434
Manfred Spraul00e145b2005-09-03 15:55:07 -07004435/**
4436 * ksize - get the actual amount of memory allocated for a given object
4437 * @objp: Pointer to the object
4438 *
4439 * kmalloc may internally round up allocations and return more memory
4440 * than requested. ksize() can be used to determine the actual amount of
4441 * memory allocated. The caller may use this additional memory, even though
4442 * a smaller amount of memory was initially specified with the kmalloc call.
4443 * The caller must guarantee that objp points to a valid object previously
4444 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4445 * must not be freed during the duration of the call.
4446 */
Pekka Enbergfd76bab2007-05-06 14:48:40 -07004447size_t ksize(const void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004448{
Christoph Lameter6cb8f912007-07-17 04:03:22 -07004449 if (unlikely(ZERO_OR_NULL_PTR(objp)))
Manfred Spraul00e145b2005-09-03 15:55:07 -07004450 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004451
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -08004452 return obj_size(virt_to_cache(objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004453}