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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>
Christoph Lametere498be72005-09-09 13:03:32 -0700106#include <linux/nodemask.h>
Christoph Lameterdc85da12006-01-18 17:42:36 -0800107#include <linux/mempolicy.h>
Ingo Molnarfc0abb12006-01-18 17:42:33 -0800108#include <linux/mutex.h>
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700109#include <linux/rtmutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
111#include <asm/uaccess.h>
112#include <asm/cacheflush.h>
113#include <asm/tlbflush.h>
114#include <asm/page.h>
115
116/*
117 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
118 * SLAB_RED_ZONE & SLAB_POISON.
119 * 0 for faster, smaller code (especially in the critical paths).
120 *
121 * STATS - 1 to collect stats for /proc/slabinfo.
122 * 0 for faster, smaller code (especially in the critical paths).
123 *
124 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
125 */
126
127#ifdef CONFIG_DEBUG_SLAB
128#define DEBUG 1
129#define STATS 1
130#define FORCED_DEBUG 1
131#else
132#define DEBUG 0
133#define STATS 0
134#define FORCED_DEBUG 0
135#endif
136
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137/* Shouldn't this be in a header file somewhere? */
138#define BYTES_PER_WORD sizeof(void *)
139
140#ifndef cache_line_size
141#define cache_line_size() L1_CACHE_BYTES
142#endif
143
144#ifndef ARCH_KMALLOC_MINALIGN
145/*
146 * Enforce a minimum alignment for the kmalloc caches.
147 * Usually, the kmalloc caches are cache_line_size() aligned, except when
148 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
149 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
150 * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
151 * Note that this flag disables some debug features.
152 */
153#define ARCH_KMALLOC_MINALIGN 0
154#endif
155
156#ifndef ARCH_SLAB_MINALIGN
157/*
158 * Enforce a minimum alignment for all caches.
159 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
160 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
161 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
162 * some debug features.
163 */
164#define ARCH_SLAB_MINALIGN 0
165#endif
166
167#ifndef ARCH_KMALLOC_FLAGS
168#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
169#endif
170
171/* Legal flag mask for kmem_cache_create(). */
172#if DEBUG
173# define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
174 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
Christoph Lameterac2b8982006-03-22 00:08:15 -0800175 SLAB_CACHE_DMA | \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
177 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
Paul Jackson101a5002006-03-24 03:16:07 -0800178 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179#else
Christoph Lameterac2b8982006-03-22 00:08:15 -0800180# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
182 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
Paul Jackson101a5002006-03-24 03:16:07 -0800183 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184#endif
185
186/*
187 * kmem_bufctl_t:
188 *
189 * Bufctl's are used for linking objs within a slab
190 * linked offsets.
191 *
192 * This implementation relies on "struct page" for locating the cache &
193 * slab an object belongs to.
194 * This allows the bufctl structure to be small (one int), but limits
195 * the number of objects a slab (not a cache) can contain when off-slab
196 * bufctls are used. The limit is the size of the largest general cache
197 * that does not use off-slab slabs.
198 * For 32bit archs with 4 kB pages, is this 56.
199 * This is not serious, as it is only for large objects, when it is unwise
200 * to have too many per slab.
201 * Note: This limit can be raised by introducing a general cache whose size
202 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
203 */
204
Kyle Moffettfa5b08d2005-09-03 15:55:03 -0700205typedef unsigned int kmem_bufctl_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
207#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
Al Viro871751e2006-03-25 03:06:39 -0800208#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
209#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211/*
212 * struct slab
213 *
214 * Manages the objs in a slab. Placed either at the beginning of mem allocated
215 * for a slab, or allocated from an general cache.
216 * Slabs are chained into three list: fully used, partial, fully free slabs.
217 */
218struct slab {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800219 struct list_head list;
220 unsigned long colouroff;
221 void *s_mem; /* including colour offset */
222 unsigned int inuse; /* num of objs active in slab */
223 kmem_bufctl_t free;
224 unsigned short nodeid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225};
226
227/*
228 * struct slab_rcu
229 *
230 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
231 * arrange for kmem_freepages to be called via RCU. This is useful if
232 * we need to approach a kernel structure obliquely, from its address
233 * obtained without the usual locking. We can lock the structure to
234 * stabilize it and check it's still at the given address, only if we
235 * can be sure that the memory has not been meanwhile reused for some
236 * other kind of object (which our subsystem's lock might corrupt).
237 *
238 * rcu_read_lock before reading the address, then rcu_read_unlock after
239 * taking the spinlock within the structure expected at that address.
240 *
241 * We assume struct slab_rcu can overlay struct slab when destroying.
242 */
243struct slab_rcu {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800244 struct rcu_head head;
Pekka Enberg343e0d72006-02-01 03:05:50 -0800245 struct kmem_cache *cachep;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800246 void *addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247};
248
249/*
250 * struct array_cache
251 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 * Purpose:
253 * - LIFO ordering, to hand out cache-warm objects from _alloc
254 * - reduce the number of linked list operations
255 * - reduce spinlock operations
256 *
257 * The limit is stored in the per-cpu structure to reduce the data cache
258 * footprint.
259 *
260 */
261struct array_cache {
262 unsigned int avail;
263 unsigned int limit;
264 unsigned int batchcount;
265 unsigned int touched;
Christoph Lametere498be72005-09-09 13:03:32 -0700266 spinlock_t lock;
Andrew Mortona737b3e2006-03-22 00:08:11 -0800267 void *entry[0]; /*
268 * Must have this definition in here for the proper
269 * alignment of array_cache. Also simplifies accessing
270 * the entries.
271 * [0] is for gcc 2.95. It should really be [].
272 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273};
274
Andrew Mortona737b3e2006-03-22 00:08:11 -0800275/*
276 * bootstrap: The caches do not work without cpuarrays anymore, but the
277 * cpuarrays are allocated from the generic caches...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 */
279#define BOOT_CPUCACHE_ENTRIES 1
280struct arraycache_init {
281 struct array_cache cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800282 void *entries[BOOT_CPUCACHE_ENTRIES];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283};
284
285/*
Christoph Lametere498be72005-09-09 13:03:32 -0700286 * The slab lists for all objects.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 */
288struct kmem_list3 {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800289 struct list_head slabs_partial; /* partial list first, better asm code */
290 struct list_head slabs_full;
291 struct list_head slabs_free;
292 unsigned long free_objects;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800293 unsigned int free_limit;
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -0800294 unsigned int colour_next; /* Per-node cache coloring */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800295 spinlock_t list_lock;
296 struct array_cache *shared; /* shared per node */
297 struct array_cache **alien; /* on other nodes */
Christoph Lameter35386e32006-03-22 00:09:05 -0800298 unsigned long next_reap; /* updated without locking */
299 int free_touched; /* updated without locking */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300};
301
Christoph Lametere498be72005-09-09 13:03:32 -0700302/*
303 * Need this for bootstrapping a per node allocator.
304 */
305#define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
306struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
307#define CACHE_CACHE 0
308#define SIZE_AC 1
309#define SIZE_L3 (1 + MAX_NUMNODES)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
Christoph Lametered11d9e2006-06-30 01:55:45 -0700311static int drain_freelist(struct kmem_cache *cache,
312 struct kmem_list3 *l3, int tofree);
313static void free_block(struct kmem_cache *cachep, void **objpp, int len,
314 int node);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -0700315static int enable_cpucache(struct kmem_cache *cachep);
David Howells65f27f32006-11-22 14:55:48 +0000316static void cache_reap(struct work_struct *unused);
Christoph Lametered11d9e2006-06-30 01:55:45 -0700317
Christoph Lametere498be72005-09-09 13:03:32 -0700318/*
Andrew Mortona737b3e2006-03-22 00:08:11 -0800319 * This function must be completely optimized away if a constant is passed to
320 * it. Mostly the same as what is in linux/slab.h except it returns an index.
Christoph Lametere498be72005-09-09 13:03:32 -0700321 */
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700322static __always_inline int index_of(const size_t size)
Christoph Lametere498be72005-09-09 13:03:32 -0700323{
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800324 extern void __bad_size(void);
325
Christoph Lametere498be72005-09-09 13:03:32 -0700326 if (__builtin_constant_p(size)) {
327 int i = 0;
328
329#define CACHE(x) \
330 if (size <=x) \
331 return i; \
332 else \
333 i++;
334#include "linux/kmalloc_sizes.h"
335#undef CACHE
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800336 __bad_size();
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700337 } else
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800338 __bad_size();
Christoph Lametere498be72005-09-09 13:03:32 -0700339 return 0;
340}
341
Ingo Molnare0a42722006-06-23 02:03:46 -0700342static int slab_early_init = 1;
343
Christoph Lametere498be72005-09-09 13:03:32 -0700344#define INDEX_AC index_of(sizeof(struct arraycache_init))
345#define INDEX_L3 index_of(sizeof(struct kmem_list3))
346
Pekka Enberg5295a742006-02-01 03:05:48 -0800347static void kmem_list3_init(struct kmem_list3 *parent)
Christoph Lametere498be72005-09-09 13:03:32 -0700348{
349 INIT_LIST_HEAD(&parent->slabs_full);
350 INIT_LIST_HEAD(&parent->slabs_partial);
351 INIT_LIST_HEAD(&parent->slabs_free);
352 parent->shared = NULL;
353 parent->alien = NULL;
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -0800354 parent->colour_next = 0;
Christoph Lametere498be72005-09-09 13:03:32 -0700355 spin_lock_init(&parent->list_lock);
356 parent->free_objects = 0;
357 parent->free_touched = 0;
358}
359
Andrew Mortona737b3e2006-03-22 00:08:11 -0800360#define MAKE_LIST(cachep, listp, slab, nodeid) \
361 do { \
362 INIT_LIST_HEAD(listp); \
363 list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
Christoph Lametere498be72005-09-09 13:03:32 -0700364 } while (0)
365
Andrew Mortona737b3e2006-03-22 00:08:11 -0800366#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
367 do { \
Christoph Lametere498be72005-09-09 13:03:32 -0700368 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
369 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
370 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
371 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
373/*
Pekka Enberg343e0d72006-02-01 03:05:50 -0800374 * struct kmem_cache
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 *
376 * manages a cache.
377 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800378
Pekka J Enberg2109a2d2005-11-07 00:58:01 -0800379struct kmem_cache {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380/* 1) per-cpu data, touched during every alloc/free */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800381 struct array_cache *array[NR_CPUS];
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800382/* 2) Cache tunables. Protected by cache_chain_mutex */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800383 unsigned int batchcount;
384 unsigned int limit;
385 unsigned int shared;
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800386
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800387 unsigned int buffer_size;
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800388/* 3) touched by every alloc & free from the backend */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800389 struct kmem_list3 *nodelists[MAX_NUMNODES];
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800390
Andrew Mortona737b3e2006-03-22 00:08:11 -0800391 unsigned int flags; /* constant flags */
392 unsigned int num; /* # of objs per slab */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800394/* 4) cache_grow/shrink */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 /* order of pgs per slab (2^n) */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800396 unsigned int gfporder;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
398 /* force GFP flags, e.g. GFP_DMA */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800399 gfp_t gfpflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
Andrew Mortona737b3e2006-03-22 00:08:11 -0800401 size_t colour; /* cache colouring range */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800402 unsigned int colour_off; /* colour offset */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800403 struct kmem_cache *slabp_cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800404 unsigned int slab_size;
Andrew Mortona737b3e2006-03-22 00:08:11 -0800405 unsigned int dflags; /* dynamic flags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406
407 /* constructor func */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800408 void (*ctor) (void *, struct kmem_cache *, unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
410 /* de-constructor func */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800411 void (*dtor) (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
444};
445
446#define CFLGS_OFF_SLAB (0x80000000UL)
447#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
448
449#define BATCHREFILL_LIMIT 16
Andrew Mortona737b3e2006-03-22 00:08:11 -0800450/*
451 * Optimization question: fewer reaps means less probability for unnessary
452 * cpucache drain/refill cycles.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 *
Adrian Bunkdc6f3f22005-11-08 16:44:08 +0100454 * OTOH the cpuarrays can contain lots of objects,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 * which could lock up otherwise freeable slabs.
456 */
457#define REAPTIMEOUT_CPUC (2*HZ)
458#define REAPTIMEOUT_LIST3 (4*HZ)
459
460#if STATS
461#define STATS_INC_ACTIVE(x) ((x)->num_active++)
462#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
463#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
464#define STATS_INC_GROWN(x) ((x)->grown++)
Christoph Lametered11d9e2006-06-30 01:55:45 -0700465#define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
Andrew Mortona737b3e2006-03-22 00:08:11 -0800466#define STATS_SET_HIGH(x) \
467 do { \
468 if ((x)->num_active > (x)->high_mark) \
469 (x)->high_mark = (x)->num_active; \
470 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471#define STATS_INC_ERR(x) ((x)->errors++)
472#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
Christoph Lametere498be72005-09-09 13:03:32 -0700473#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -0700474#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
Andrew Mortona737b3e2006-03-22 00:08:11 -0800475#define STATS_SET_FREEABLE(x, i) \
476 do { \
477 if ((x)->max_freeable < i) \
478 (x)->max_freeable = i; \
479 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
481#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
482#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
483#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
484#else
485#define STATS_INC_ACTIVE(x) do { } while (0)
486#define STATS_DEC_ACTIVE(x) do { } while (0)
487#define STATS_INC_ALLOCED(x) do { } while (0)
488#define STATS_INC_GROWN(x) do { } while (0)
Christoph Lametered11d9e2006-06-30 01:55:45 -0700489#define STATS_ADD_REAPED(x,y) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490#define STATS_SET_HIGH(x) do { } while (0)
491#define STATS_INC_ERR(x) do { } while (0)
492#define STATS_INC_NODEALLOCS(x) do { } while (0)
Christoph Lametere498be72005-09-09 13:03:32 -0700493#define STATS_INC_NODEFREES(x) do { } while (0)
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -0700494#define STATS_INC_ACOVERFLOW(x) do { } while (0)
Andrew Mortona737b3e2006-03-22 00:08:11 -0800495#define STATS_SET_FREEABLE(x, i) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496#define STATS_INC_ALLOCHIT(x) do { } while (0)
497#define STATS_INC_ALLOCMISS(x) do { } while (0)
498#define STATS_INC_FREEHIT(x) do { } while (0)
499#define STATS_INC_FREEMISS(x) do { } while (0)
500#endif
501
502#if DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503
Andrew Mortona737b3e2006-03-22 00:08:11 -0800504/*
505 * memory layout of objects:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 * 0 : objp
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800507 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 * the end of an object is aligned with the end of the real
509 * allocation. Catches writes behind the end of the allocation.
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800510 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 * redzone word.
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800512 * cachep->obj_offset: The real object.
513 * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
Andrew Mortona737b3e2006-03-22 00:08:11 -0800514 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
515 * [BYTES_PER_WORD long]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800517static int obj_offset(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518{
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800519 return cachep->obj_offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520}
521
Pekka Enberg343e0d72006-02-01 03:05:50 -0800522static int obj_size(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523{
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800524 return cachep->obj_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525}
526
Pekka Enberg343e0d72006-02-01 03:05:50 -0800527static unsigned long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528{
529 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800530 return (unsigned long*) (objp+obj_offset(cachep)-BYTES_PER_WORD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531}
532
Pekka Enberg343e0d72006-02-01 03:05:50 -0800533static unsigned long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534{
535 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
536 if (cachep->flags & SLAB_STORE_USER)
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800537 return (unsigned long *)(objp + cachep->buffer_size -
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800538 2 * BYTES_PER_WORD);
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800539 return (unsigned long *)(objp + cachep->buffer_size - BYTES_PER_WORD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540}
541
Pekka Enberg343e0d72006-02-01 03:05:50 -0800542static void **dbg_userword(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543{
544 BUG_ON(!(cachep->flags & SLAB_STORE_USER));
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800545 return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546}
547
548#else
549
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800550#define obj_offset(x) 0
551#define obj_size(cachep) (cachep->buffer_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;})
553#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;})
554#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
555
556#endif
557
558/*
Andrew Mortona737b3e2006-03-22 00:08:11 -0800559 * Maximum size of an obj (in 2^order pages) and absolute limit for the gfp
560 * order.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 */
562#if defined(CONFIG_LARGE_ALLOCS)
563#define MAX_OBJ_ORDER 13 /* up to 32Mb */
564#define MAX_GFP_ORDER 13 /* up to 32Mb */
565#elif defined(CONFIG_MMU)
566#define MAX_OBJ_ORDER 5 /* 32 pages */
567#define MAX_GFP_ORDER 5 /* 32 pages */
568#else
569#define MAX_OBJ_ORDER 8 /* up to 1Mb */
570#define MAX_GFP_ORDER 8 /* up to 1Mb */
571#endif
572
573/*
574 * Do not go above this order unless 0 objects fit into the slab.
575 */
576#define BREAK_GFP_ORDER_HI 1
577#define BREAK_GFP_ORDER_LO 0
578static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
579
Andrew Mortona737b3e2006-03-22 00:08:11 -0800580/*
581 * Functions for storing/retrieving the cachep and or slab from the page
582 * allocator. These are used to find the slab an obj belongs to. With kfree(),
583 * these are used to find the cache which an obj belongs to.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 */
Pekka Enberg065d41c2005-11-13 16:06:46 -0800585static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
586{
587 page->lru.next = (struct list_head *)cache;
588}
589
590static inline struct kmem_cache *page_get_cache(struct page *page)
591{
Nick Piggin84097512006-03-22 00:08:34 -0800592 if (unlikely(PageCompound(page)))
593 page = (struct page *)page_private(page);
Pekka Enbergddc2e812006-06-23 02:03:40 -0700594 BUG_ON(!PageSlab(page));
Pekka Enberg065d41c2005-11-13 16:06:46 -0800595 return (struct kmem_cache *)page->lru.next;
596}
597
598static inline void page_set_slab(struct page *page, struct slab *slab)
599{
600 page->lru.prev = (struct list_head *)slab;
601}
602
603static inline struct slab *page_get_slab(struct page *page)
604{
Nick Piggin84097512006-03-22 00:08:34 -0800605 if (unlikely(PageCompound(page)))
606 page = (struct page *)page_private(page);
Pekka Enbergddc2e812006-06-23 02:03:40 -0700607 BUG_ON(!PageSlab(page));
Pekka Enberg065d41c2005-11-13 16:06:46 -0800608 return (struct slab *)page->lru.prev;
609}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -0800611static inline struct kmem_cache *virt_to_cache(const void *obj)
612{
613 struct page *page = virt_to_page(obj);
614 return page_get_cache(page);
615}
616
617static inline struct slab *virt_to_slab(const void *obj)
618{
619 struct page *page = virt_to_page(obj);
620 return page_get_slab(page);
621}
622
Pekka Enberg8fea4e92006-03-22 00:08:10 -0800623static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
624 unsigned int idx)
625{
626 return slab->s_mem + cache->buffer_size * idx;
627}
628
629static inline unsigned int obj_to_index(struct kmem_cache *cache,
630 struct slab *slab, void *obj)
631{
632 return (unsigned)(obj - slab->s_mem) / cache->buffer_size;
633}
634
Andrew Mortona737b3e2006-03-22 00:08:11 -0800635/*
636 * These are the default caches for kmalloc. Custom caches can have other sizes.
637 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638struct cache_sizes malloc_sizes[] = {
639#define CACHE(x) { .cs_size = (x) },
640#include <linux/kmalloc_sizes.h>
641 CACHE(ULONG_MAX)
642#undef CACHE
643};
644EXPORT_SYMBOL(malloc_sizes);
645
646/* Must match cache_sizes above. Out of line to keep cache footprint low. */
647struct cache_names {
648 char *name;
649 char *name_dma;
650};
651
652static struct cache_names __initdata cache_names[] = {
653#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
654#include <linux/kmalloc_sizes.h>
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800655 {NULL,}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656#undef CACHE
657};
658
659static struct arraycache_init initarray_cache __initdata =
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800660 { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661static struct arraycache_init initarray_generic =
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800662 { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663
664/* internal cache of cache description objs */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800665static struct kmem_cache cache_cache = {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800666 .batchcount = 1,
667 .limit = BOOT_CPUCACHE_ENTRIES,
668 .shared = 1,
Pekka Enberg343e0d72006-02-01 03:05:50 -0800669 .buffer_size = sizeof(struct kmem_cache),
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800670 .name = "kmem_cache",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671#if DEBUG
Pekka Enberg343e0d72006-02-01 03:05:50 -0800672 .obj_size = sizeof(struct kmem_cache),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673#endif
674};
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
778 while (size > csizep->cs_size)
779 csizep++;
780
781 /*
Martin Hicks0abf40c2005-09-03 15:54:54 -0700782 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 * has cs_{dma,}cachep==NULL. Thus no special case
784 * for large kmalloc calls required.
785 */
786 if (unlikely(gfpflags & GFP_DMA))
787 return csizep->cs_dmacachep;
788 return csizep->cs_cachep;
789}
790
Adrian Bunkb2213852006-09-25 23:31:02 -0700791static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700792{
793 return __find_general_cachep(size, gfpflags);
794}
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700795
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800796static size_t slab_mgmt_size(size_t nr_objs, size_t align)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797{
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800798 return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
799}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
Andrew Mortona737b3e2006-03-22 00:08:11 -0800801/*
802 * Calculate the number of objects and left-over bytes for a given buffer size.
803 */
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800804static void cache_estimate(unsigned long gfporder, size_t buffer_size,
805 size_t align, int flags, size_t *left_over,
806 unsigned int *num)
807{
808 int nr_objs;
809 size_t mgmt_size;
810 size_t slab_size = PAGE_SIZE << gfporder;
811
812 /*
813 * The slab management structure can be either off the slab or
814 * on it. For the latter case, the memory allocated for a
815 * slab is used for:
816 *
817 * - The struct slab
818 * - One kmem_bufctl_t for each object
819 * - Padding to respect alignment of @align
820 * - @buffer_size bytes for each object
821 *
822 * If the slab management structure is off the slab, then the
823 * alignment will already be calculated into the size. Because
824 * the slabs are all pages aligned, the objects will be at the
825 * correct alignment when allocated.
826 */
827 if (flags & CFLGS_OFF_SLAB) {
828 mgmt_size = 0;
829 nr_objs = slab_size / buffer_size;
830
831 if (nr_objs > SLAB_LIMIT)
832 nr_objs = SLAB_LIMIT;
833 } else {
834 /*
835 * Ignore padding for the initial guess. The padding
836 * is at most @align-1 bytes, and @buffer_size is at
837 * least @align. In the worst case, this result will
838 * be one greater than the number of objects that fit
839 * into the memory allocation when taking the padding
840 * into account.
841 */
842 nr_objs = (slab_size - sizeof(struct slab)) /
843 (buffer_size + sizeof(kmem_bufctl_t));
844
845 /*
846 * This calculated number will be either the right
847 * amount, or one greater than what we want.
848 */
849 if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size
850 > slab_size)
851 nr_objs--;
852
853 if (nr_objs > SLAB_LIMIT)
854 nr_objs = SLAB_LIMIT;
855
856 mgmt_size = slab_mgmt_size(nr_objs, align);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 }
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800858 *num = nr_objs;
859 *left_over = slab_size - nr_objs*buffer_size - mgmt_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860}
861
862#define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
863
Andrew Mortona737b3e2006-03-22 00:08:11 -0800864static void __slab_error(const char *function, struct kmem_cache *cachep,
865 char *msg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866{
867 printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800868 function, cachep->name, msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 dump_stack();
870}
871
Paul Menage3395ee02006-12-06 20:32:16 -0800872/*
873 * By default on NUMA we use alien caches to stage the freeing of
874 * objects allocated from other nodes. This causes massive memory
875 * inefficiencies when using fake NUMA setup to split memory into a
876 * large number of small nodes, so it can be disabled on the command
877 * line
878 */
879
880static int use_alien_caches __read_mostly = 1;
881static int __init noaliencache_setup(char *s)
882{
883 use_alien_caches = 0;
884 return 1;
885}
886__setup("noaliencache", noaliencache_setup);
887
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800888#ifdef CONFIG_NUMA
889/*
890 * Special reaping functions for NUMA systems called from cache_reap().
891 * These take care of doing round robin flushing of alien caches (containing
892 * objects freed on different nodes from which they were allocated) and the
893 * flushing of remote pcps by calling drain_node_pages.
894 */
895static DEFINE_PER_CPU(unsigned long, reap_node);
896
897static void init_reap_node(int cpu)
898{
899 int node;
900
901 node = next_node(cpu_to_node(cpu), node_online_map);
902 if (node == MAX_NUMNODES)
Paul Jackson442295c2006-03-22 00:09:11 -0800903 node = first_node(node_online_map);
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800904
Daniel Yeisley7f6b8872006-11-02 22:07:14 -0800905 per_cpu(reap_node, cpu) = node;
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800906}
907
908static void next_reap_node(void)
909{
910 int node = __get_cpu_var(reap_node);
911
912 /*
913 * Also drain per cpu pages on remote zones
914 */
915 if (node != numa_node_id())
916 drain_node_pages(node);
917
918 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 */
936static void __devinit start_cpu_timer(int cpu)
937{
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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
949 }
950}
951
Christoph Lametere498be72005-09-09 13:03:32 -0700952static struct array_cache *alloc_arraycache(int node, int entries,
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800953 int batchcount)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954{
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800955 int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 struct array_cache *nc = NULL;
957
Christoph Lametere498be72005-09-09 13:03:32 -0700958 nc = kmalloc_node(memsize, GFP_KERNEL, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 if (nc) {
960 nc->avail = 0;
961 nc->limit = entries;
962 nc->batchcount = batchcount;
963 nc->touched = 0;
Christoph Lametere498be72005-09-09 13:03:32 -0700964 spin_lock_init(&nc->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 }
966 return nc;
967}
968
Christoph Lameter3ded1752006-03-25 03:06:44 -0800969/*
970 * Transfer objects in one arraycache to another.
971 * Locking must be handled by the caller.
972 *
973 * Return the number of entries transferred.
974 */
975static int transfer_objects(struct array_cache *to,
976 struct array_cache *from, unsigned int max)
977{
978 /* Figure out how many entries to transfer */
979 int nr = min(min(from->avail, max), to->limit - to->avail);
980
981 if (!nr)
982 return 0;
983
984 memcpy(to->entry + to->avail, from->entry + from->avail -nr,
985 sizeof(void *) *nr);
986
987 from->avail -= nr;
988 to->avail += nr;
989 to->touched = 1;
990 return nr;
991}
992
Christoph Lameter765c4502006-09-27 01:50:08 -0700993#ifndef CONFIG_NUMA
994
995#define drain_alien_cache(cachep, alien) do { } while (0)
996#define reap_alien(cachep, l3) do { } while (0)
997
998static inline struct array_cache **alloc_alien_cache(int node, int limit)
999{
1000 return (struct array_cache **)BAD_ALIEN_MAGIC;
1001}
1002
1003static inline void free_alien_cache(struct array_cache **ac_ptr)
1004{
1005}
1006
1007static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1008{
1009 return 0;
1010}
1011
1012static inline void *alternate_node_alloc(struct kmem_cache *cachep,
1013 gfp_t flags)
1014{
1015 return NULL;
1016}
1017
Christoph Hellwig8b98c162006-12-06 20:32:30 -08001018static inline void *____cache_alloc_node(struct kmem_cache *cachep,
Christoph Lameter765c4502006-09-27 01:50:08 -07001019 gfp_t flags, int nodeid)
1020{
1021 return NULL;
1022}
1023
1024#else /* CONFIG_NUMA */
1025
Christoph Hellwig8b98c162006-12-06 20:32:30 -08001026static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
Paul Jacksonc61afb12006-03-24 03:16:08 -08001027static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
Christoph Lameterdc85da12006-01-18 17:42:36 -08001028
Pekka Enberg5295a742006-02-01 03:05:48 -08001029static struct array_cache **alloc_alien_cache(int node, int limit)
Christoph Lametere498be72005-09-09 13:03:32 -07001030{
1031 struct array_cache **ac_ptr;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001032 int memsize = sizeof(void *) * MAX_NUMNODES;
Christoph Lametere498be72005-09-09 13:03:32 -07001033 int i;
1034
1035 if (limit > 1)
1036 limit = 12;
1037 ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node);
1038 if (ac_ptr) {
1039 for_each_node(i) {
1040 if (i == node || !node_online(i)) {
1041 ac_ptr[i] = NULL;
1042 continue;
1043 }
1044 ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d);
1045 if (!ac_ptr[i]) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001046 for (i--; i <= 0; i--)
Christoph Lametere498be72005-09-09 13:03:32 -07001047 kfree(ac_ptr[i]);
1048 kfree(ac_ptr);
1049 return NULL;
1050 }
1051 }
1052 }
1053 return ac_ptr;
1054}
1055
Pekka Enberg5295a742006-02-01 03:05:48 -08001056static void free_alien_cache(struct array_cache **ac_ptr)
Christoph Lametere498be72005-09-09 13:03:32 -07001057{
1058 int i;
1059
1060 if (!ac_ptr)
1061 return;
Christoph Lametere498be72005-09-09 13:03:32 -07001062 for_each_node(i)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001063 kfree(ac_ptr[i]);
Christoph Lametere498be72005-09-09 13:03:32 -07001064 kfree(ac_ptr);
1065}
1066
Pekka Enberg343e0d72006-02-01 03:05:50 -08001067static void __drain_alien_cache(struct kmem_cache *cachep,
Pekka Enberg5295a742006-02-01 03:05:48 -08001068 struct array_cache *ac, int node)
Christoph Lametere498be72005-09-09 13:03:32 -07001069{
1070 struct kmem_list3 *rl3 = cachep->nodelists[node];
1071
1072 if (ac->avail) {
1073 spin_lock(&rl3->list_lock);
Christoph Lametere00946f2006-03-25 03:06:45 -08001074 /*
1075 * Stuff objects into the remote nodes shared array first.
1076 * That way we could avoid the overhead of putting the objects
1077 * into the free lists and getting them back later.
1078 */
shin, jacob693f7d32006-04-28 10:54:37 -05001079 if (rl3->shared)
1080 transfer_objects(rl3->shared, ac, ac->limit);
Christoph Lametere00946f2006-03-25 03:06:45 -08001081
Christoph Lameterff694162005-09-22 21:44:02 -07001082 free_block(cachep, ac->entry, ac->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001083 ac->avail = 0;
1084 spin_unlock(&rl3->list_lock);
1085 }
1086}
1087
Christoph Lameter8fce4d82006-03-09 17:33:54 -08001088/*
1089 * Called from cache_reap() to regularly drain alien caches round robin.
1090 */
1091static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
1092{
1093 int node = __get_cpu_var(reap_node);
1094
1095 if (l3->alien) {
1096 struct array_cache *ac = l3->alien[node];
Christoph Lametere00946f2006-03-25 03:06:45 -08001097
1098 if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
Christoph Lameter8fce4d82006-03-09 17:33:54 -08001099 __drain_alien_cache(cachep, ac, node);
1100 spin_unlock_irq(&ac->lock);
1101 }
1102 }
1103}
1104
Andrew Mortona737b3e2006-03-22 00:08:11 -08001105static void drain_alien_cache(struct kmem_cache *cachep,
1106 struct array_cache **alien)
Christoph Lametere498be72005-09-09 13:03:32 -07001107{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001108 int i = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07001109 struct array_cache *ac;
1110 unsigned long flags;
1111
1112 for_each_online_node(i) {
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001113 ac = alien[i];
Christoph Lametere498be72005-09-09 13:03:32 -07001114 if (ac) {
1115 spin_lock_irqsave(&ac->lock, flags);
1116 __drain_alien_cache(cachep, ac, i);
1117 spin_unlock_irqrestore(&ac->lock, flags);
1118 }
1119 }
1120}
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001121
Ingo Molnar873623d2006-07-13 14:44:38 +02001122static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001123{
1124 struct slab *slabp = virt_to_slab(objp);
1125 int nodeid = slabp->nodeid;
1126 struct kmem_list3 *l3;
1127 struct array_cache *alien = NULL;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001128 int node;
1129
1130 node = numa_node_id();
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001131
1132 /*
1133 * Make sure we are not freeing a object from another node to the array
1134 * cache on this cpu.
1135 */
Paul Menage3395ee02006-12-06 20:32:16 -08001136 if (likely(slabp->nodeid == node) || unlikely(!use_alien_caches))
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001137 return 0;
1138
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001139 l3 = cachep->nodelists[node];
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001140 STATS_INC_NODEFREES(cachep);
1141 if (l3->alien && l3->alien[nodeid]) {
1142 alien = l3->alien[nodeid];
Ingo Molnar873623d2006-07-13 14:44:38 +02001143 spin_lock(&alien->lock);
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001144 if (unlikely(alien->avail == alien->limit)) {
1145 STATS_INC_ACOVERFLOW(cachep);
1146 __drain_alien_cache(cachep, alien, nodeid);
1147 }
1148 alien->entry[alien->avail++] = objp;
1149 spin_unlock(&alien->lock);
1150 } else {
1151 spin_lock(&(cachep->nodelists[nodeid])->list_lock);
1152 free_block(cachep, &objp, 1, nodeid);
1153 spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
1154 }
1155 return 1;
1156}
Christoph Lametere498be72005-09-09 13:03:32 -07001157#endif
1158
Chandra Seetharaman8c78f302006-07-30 03:03:35 -07001159static int __cpuinit cpuup_callback(struct notifier_block *nfb,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001160 unsigned long action, void *hcpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161{
1162 long cpu = (long)hcpu;
Pekka Enberg343e0d72006-02-01 03:05:50 -08001163 struct kmem_cache *cachep;
Christoph Lametere498be72005-09-09 13:03:32 -07001164 struct kmem_list3 *l3 = NULL;
1165 int node = cpu_to_node(cpu);
1166 int memsize = sizeof(struct kmem_list3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167
1168 switch (action) {
1169 case CPU_UP_PREPARE:
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001170 mutex_lock(&cache_chain_mutex);
Andrew Mortona737b3e2006-03-22 00:08:11 -08001171 /*
1172 * We need to do this right in the beginning since
Christoph Lametere498be72005-09-09 13:03:32 -07001173 * alloc_arraycache's are going to use this list.
1174 * kmalloc_node allows us to add the slab to the right
1175 * kmem_list3 and not this cpu's kmem_list3
1176 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177
Christoph Lametere498be72005-09-09 13:03:32 -07001178 list_for_each_entry(cachep, &cache_chain, next) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08001179 /*
1180 * Set up the size64 kmemlist for cpu before we can
Christoph Lametere498be72005-09-09 13:03:32 -07001181 * begin anything. Make sure some other cpu on this
1182 * node has not already allocated this
1183 */
1184 if (!cachep->nodelists[node]) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08001185 l3 = kmalloc_node(memsize, GFP_KERNEL, node);
1186 if (!l3)
Christoph Lametere498be72005-09-09 13:03:32 -07001187 goto bad;
1188 kmem_list3_init(l3);
1189 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001190 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametere498be72005-09-09 13:03:32 -07001191
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001192 /*
1193 * The l3s don't come and go as CPUs come and
1194 * go. cache_chain_mutex is sufficient
1195 * protection here.
1196 */
Christoph Lametere498be72005-09-09 13:03:32 -07001197 cachep->nodelists[node] = l3;
1198 }
1199
1200 spin_lock_irq(&cachep->nodelists[node]->list_lock);
1201 cachep->nodelists[node]->free_limit =
Andrew Mortona737b3e2006-03-22 00:08:11 -08001202 (1 + nr_cpus_node(node)) *
1203 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07001204 spin_unlock_irq(&cachep->nodelists[node]->list_lock);
1205 }
1206
Andrew Mortona737b3e2006-03-22 00:08:11 -08001207 /*
1208 * Now we can go ahead with allocating the shared arrays and
1209 * array caches
1210 */
Christoph Lametere498be72005-09-09 13:03:32 -07001211 list_for_each_entry(cachep, &cache_chain, next) {
Tobias Klausercd105df2006-01-08 01:00:59 -08001212 struct array_cache *nc;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001213 struct array_cache *shared;
Paul Menage3395ee02006-12-06 20:32:16 -08001214 struct array_cache **alien = NULL;
Tobias Klausercd105df2006-01-08 01:00:59 -08001215
Christoph Lametere498be72005-09-09 13:03:32 -07001216 nc = alloc_arraycache(node, cachep->limit,
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001217 cachep->batchcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 if (!nc)
1219 goto bad;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001220 shared = alloc_arraycache(node,
1221 cachep->shared * cachep->batchcount,
1222 0xbaadf00d);
1223 if (!shared)
1224 goto bad;
Linus Torvalds7a21ef62006-02-05 11:26:38 -08001225
Paul Menage3395ee02006-12-06 20:32:16 -08001226 if (use_alien_caches) {
1227 alien = alloc_alien_cache(node, cachep->limit);
1228 if (!alien)
1229 goto bad;
1230 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 cachep->array[cpu] = nc;
Christoph Lametere498be72005-09-09 13:03:32 -07001232 l3 = cachep->nodelists[node];
1233 BUG_ON(!l3);
Christoph Lametere498be72005-09-09 13:03:32 -07001234
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001235 spin_lock_irq(&l3->list_lock);
1236 if (!l3->shared) {
1237 /*
1238 * We are serialised from CPU_DEAD or
1239 * CPU_UP_CANCELLED by the cpucontrol lock
1240 */
1241 l3->shared = shared;
1242 shared = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07001243 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001244#ifdef CONFIG_NUMA
1245 if (!l3->alien) {
1246 l3->alien = alien;
1247 alien = NULL;
1248 }
1249#endif
1250 spin_unlock_irq(&l3->list_lock);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001251 kfree(shared);
1252 free_alien_cache(alien);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 break;
1255 case CPU_ONLINE:
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08001256 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257 start_cpu_timer(cpu);
1258 break;
1259#ifdef CONFIG_HOTPLUG_CPU
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08001260 case CPU_DOWN_PREPARE:
1261 mutex_lock(&cache_chain_mutex);
1262 break;
1263 case CPU_DOWN_FAILED:
1264 mutex_unlock(&cache_chain_mutex);
1265 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 case CPU_DEAD:
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001267 /*
1268 * Even if all the cpus of a node are down, we don't free the
1269 * kmem_list3 of any cache. This to avoid a race between
1270 * cpu_down, and a kmalloc allocation from another cpu for
1271 * memory from the node of the cpu going down. The list3
1272 * structure is usually allocated from kmem_cache_create() and
1273 * gets destroyed at kmem_cache_destroy().
1274 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275 /* fall thru */
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08001276#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 case CPU_UP_CANCELED:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 list_for_each_entry(cachep, &cache_chain, next) {
1279 struct array_cache *nc;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001280 struct array_cache *shared;
1281 struct array_cache **alien;
Christoph Lametere498be72005-09-09 13:03:32 -07001282 cpumask_t mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283
Christoph Lametere498be72005-09-09 13:03:32 -07001284 mask = node_to_cpumask(node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 /* cpu is dead; no one can alloc from it. */
1286 nc = cachep->array[cpu];
1287 cachep->array[cpu] = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07001288 l3 = cachep->nodelists[node];
1289
1290 if (!l3)
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001291 goto free_array_cache;
Christoph Lametere498be72005-09-09 13:03:32 -07001292
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08001293 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07001294
1295 /* Free limit for this kmem_list3 */
1296 l3->free_limit -= cachep->batchcount;
1297 if (nc)
Christoph Lameterff694162005-09-22 21:44:02 -07001298 free_block(cachep, nc->entry, nc->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001299
1300 if (!cpus_empty(mask)) {
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08001301 spin_unlock_irq(&l3->list_lock);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001302 goto free_array_cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001303 }
Christoph Lametere498be72005-09-09 13:03:32 -07001304
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001305 shared = l3->shared;
1306 if (shared) {
Christoph Lametere498be72005-09-09 13:03:32 -07001307 free_block(cachep, l3->shared->entry,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001308 l3->shared->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001309 l3->shared = NULL;
1310 }
Christoph Lametere498be72005-09-09 13:03:32 -07001311
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001312 alien = l3->alien;
1313 l3->alien = NULL;
1314
1315 spin_unlock_irq(&l3->list_lock);
1316
1317 kfree(shared);
1318 if (alien) {
1319 drain_alien_cache(cachep, alien);
1320 free_alien_cache(alien);
Christoph Lametere498be72005-09-09 13:03:32 -07001321 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001322free_array_cache:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 kfree(nc);
1324 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001325 /*
1326 * In the previous loop, all the objects were freed to
1327 * the respective cache's slabs, now we can go ahead and
1328 * shrink each nodelist to its limit.
1329 */
1330 list_for_each_entry(cachep, &cache_chain, next) {
1331 l3 = cachep->nodelists[node];
1332 if (!l3)
1333 continue;
Christoph Lametered11d9e2006-06-30 01:55:45 -07001334 drain_freelist(cachep, l3, l3->free_objects);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001335 }
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001336 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338 }
1339 return NOTIFY_OK;
Andrew Mortona737b3e2006-03-22 00:08:11 -08001340bad:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341 return NOTIFY_BAD;
1342}
1343
Chandra Seetharaman74b85f32006-06-27 02:54:09 -07001344static struct notifier_block __cpuinitdata cpucache_notifier = {
1345 &cpuup_callback, NULL, 0
1346};
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347
Christoph Lametere498be72005-09-09 13:03:32 -07001348/*
1349 * swap the static kmem_list3 with kmalloced memory
1350 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001351static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
1352 int nodeid)
Christoph Lametere498be72005-09-09 13:03:32 -07001353{
1354 struct kmem_list3 *ptr;
1355
Christoph Lametere498be72005-09-09 13:03:32 -07001356 ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid);
1357 BUG_ON(!ptr);
1358
1359 local_irq_disable();
1360 memcpy(ptr, list, sizeof(struct kmem_list3));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001361 /*
1362 * Do not assume that spinlocks can be initialized via memcpy:
1363 */
1364 spin_lock_init(&ptr->list_lock);
1365
Christoph Lametere498be72005-09-09 13:03:32 -07001366 MAKE_ALL_LISTS(cachep, ptr, nodeid);
1367 cachep->nodelists[nodeid] = ptr;
1368 local_irq_enable();
1369}
1370
Andrew Mortona737b3e2006-03-22 00:08:11 -08001371/*
1372 * Initialisation. Called after the page allocator have been initialised and
1373 * before smp_init().
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374 */
1375void __init kmem_cache_init(void)
1376{
1377 size_t left_over;
1378 struct cache_sizes *sizes;
1379 struct cache_names *names;
Christoph Lametere498be72005-09-09 13:03:32 -07001380 int i;
Jack Steiner07ed76b2006-03-07 21:55:46 -08001381 int order;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001382 int node;
Christoph Lametere498be72005-09-09 13:03:32 -07001383
1384 for (i = 0; i < NUM_INIT_LISTS; i++) {
1385 kmem_list3_init(&initkmem_list3[i]);
1386 if (i < MAX_NUMNODES)
1387 cache_cache.nodelists[i] = NULL;
1388 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389
1390 /*
1391 * Fragmentation resistance on low memory - only use bigger
1392 * page orders on machines with more than 32MB of memory.
1393 */
1394 if (num_physpages > (32 << 20) >> PAGE_SHIFT)
1395 slab_break_gfp_order = BREAK_GFP_ORDER_HI;
1396
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397 /* Bootstrap is tricky, because several objects are allocated
1398 * from caches that do not exist yet:
Andrew Mortona737b3e2006-03-22 00:08:11 -08001399 * 1) initialize the cache_cache cache: it contains the struct
1400 * kmem_cache structures of all caches, except cache_cache itself:
1401 * cache_cache is statically allocated.
Christoph Lametere498be72005-09-09 13:03:32 -07001402 * Initially an __init data area is used for the head array and the
1403 * kmem_list3 structures, it's replaced with a kmalloc allocated
1404 * array at the end of the bootstrap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405 * 2) Create the first kmalloc cache.
Pekka Enberg343e0d72006-02-01 03:05:50 -08001406 * The struct kmem_cache for the new cache is allocated normally.
Christoph Lametere498be72005-09-09 13:03:32 -07001407 * An __init data area is used for the head array.
1408 * 3) Create the remaining kmalloc caches, with minimally sized
1409 * head arrays.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 * 4) Replace the __init data head arrays for cache_cache and the first
1411 * kmalloc cache with kmalloc allocated arrays.
Christoph Lametere498be72005-09-09 13:03:32 -07001412 * 5) Replace the __init data for kmem_list3 for cache_cache and
1413 * the other cache's with kmalloc allocated memory.
1414 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415 */
1416
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001417 node = numa_node_id();
1418
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419 /* 1) create the cache_cache */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001420 INIT_LIST_HEAD(&cache_chain);
1421 list_add(&cache_cache.next, &cache_chain);
1422 cache_cache.colour_off = cache_line_size();
1423 cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001424 cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425
Andrew Mortona737b3e2006-03-22 00:08:11 -08001426 cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
1427 cache_line_size());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428
Jack Steiner07ed76b2006-03-07 21:55:46 -08001429 for (order = 0; order < MAX_ORDER; order++) {
1430 cache_estimate(order, cache_cache.buffer_size,
1431 cache_line_size(), 0, &left_over, &cache_cache.num);
1432 if (cache_cache.num)
1433 break;
1434 }
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02001435 BUG_ON(!cache_cache.num);
Jack Steiner07ed76b2006-03-07 21:55:46 -08001436 cache_cache.gfporder = order;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001437 cache_cache.colour = left_over / cache_cache.colour_off;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001438 cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
1439 sizeof(struct slab), cache_line_size());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440
1441 /* 2+3) create the kmalloc caches */
1442 sizes = malloc_sizes;
1443 names = cache_names;
1444
Andrew Mortona737b3e2006-03-22 00:08:11 -08001445 /*
1446 * Initialize the caches that provide memory for the array cache and the
1447 * kmem_list3 structures first. Without this, further allocations will
1448 * bug.
Christoph Lametere498be72005-09-09 13:03:32 -07001449 */
1450
1451 sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001452 sizes[INDEX_AC].cs_size,
1453 ARCH_KMALLOC_MINALIGN,
1454 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1455 NULL, NULL);
Christoph Lametere498be72005-09-09 13:03:32 -07001456
Andrew Mortona737b3e2006-03-22 00:08:11 -08001457 if (INDEX_AC != INDEX_L3) {
Christoph Lametere498be72005-09-09 13:03:32 -07001458 sizes[INDEX_L3].cs_cachep =
Andrew Mortona737b3e2006-03-22 00:08:11 -08001459 kmem_cache_create(names[INDEX_L3].name,
1460 sizes[INDEX_L3].cs_size,
1461 ARCH_KMALLOC_MINALIGN,
1462 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1463 NULL, NULL);
1464 }
Christoph Lametere498be72005-09-09 13:03:32 -07001465
Ingo Molnare0a42722006-06-23 02:03:46 -07001466 slab_early_init = 0;
1467
Linus Torvalds1da177e2005-04-16 15:20:36 -07001468 while (sizes->cs_size != ULONG_MAX) {
Christoph Lametere498be72005-09-09 13:03:32 -07001469 /*
1470 * For performance, all the general caches are L1 aligned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471 * This should be particularly beneficial on SMP boxes, as it
1472 * eliminates "false sharing".
1473 * Note for systems short on memory removing the alignment will
Christoph Lametere498be72005-09-09 13:03:32 -07001474 * allow tighter packing of the smaller caches.
1475 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001476 if (!sizes->cs_cachep) {
Christoph Lametere498be72005-09-09 13:03:32 -07001477 sizes->cs_cachep = kmem_cache_create(names->name,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001478 sizes->cs_size,
1479 ARCH_KMALLOC_MINALIGN,
1480 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1481 NULL, NULL);
1482 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001483
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001485 sizes->cs_size,
1486 ARCH_KMALLOC_MINALIGN,
1487 ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
1488 SLAB_PANIC,
1489 NULL, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 sizes++;
1491 names++;
1492 }
1493 /* 4) Replace the bootstrap head arrays */
1494 {
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001495 struct array_cache *ptr;
Christoph Lametere498be72005-09-09 13:03:32 -07001496
Linus Torvalds1da177e2005-04-16 15:20:36 -07001497 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
Christoph Lametere498be72005-09-09 13:03:32 -07001498
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 local_irq_disable();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001500 BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
1501 memcpy(ptr, cpu_cache_get(&cache_cache),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001502 sizeof(struct arraycache_init));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001503 /*
1504 * Do not assume that spinlocks can be initialized via memcpy:
1505 */
1506 spin_lock_init(&ptr->lock);
1507
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508 cache_cache.array[smp_processor_id()] = ptr;
1509 local_irq_enable();
Christoph Lametere498be72005-09-09 13:03:32 -07001510
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
Christoph Lametere498be72005-09-09 13:03:32 -07001512
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513 local_irq_disable();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001514 BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001515 != &initarray_generic.cache);
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001516 memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001517 sizeof(struct arraycache_init));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001518 /*
1519 * Do not assume that spinlocks can be initialized via memcpy:
1520 */
1521 spin_lock_init(&ptr->lock);
1522
Christoph Lametere498be72005-09-09 13:03:32 -07001523 malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001524 ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001525 local_irq_enable();
1526 }
Christoph Lametere498be72005-09-09 13:03:32 -07001527 /* 5) Replace the bootstrap kmem_list3's */
1528 {
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001529 int nid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001531 /* Replace the static kmem_list3 structures for the boot cpu */
1532 init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node);
1533
1534 for_each_online_node(nid) {
Christoph Lametere498be72005-09-09 13:03:32 -07001535 init_list(malloc_sizes[INDEX_AC].cs_cachep,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001536 &initkmem_list3[SIZE_AC + nid], nid);
Christoph Lametere498be72005-09-09 13:03:32 -07001537
1538 if (INDEX_AC != INDEX_L3) {
1539 init_list(malloc_sizes[INDEX_L3].cs_cachep,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001540 &initkmem_list3[SIZE_L3 + nid], nid);
Christoph Lametere498be72005-09-09 13:03:32 -07001541 }
1542 }
1543 }
1544
1545 /* 6) resize the head arrays to their final sizes */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546 {
Pekka Enberg343e0d72006-02-01 03:05:50 -08001547 struct kmem_cache *cachep;
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001548 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549 list_for_each_entry(cachep, &cache_chain, next)
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07001550 if (enable_cpucache(cachep))
1551 BUG();
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001552 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553 }
1554
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -07001555 /* Annotate slab for lockdep -- annotate the malloc caches */
1556 init_lock_keys();
1557
1558
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559 /* Done! */
1560 g_cpucache_up = FULL;
1561
Andrew Mortona737b3e2006-03-22 00:08:11 -08001562 /*
1563 * Register a cpu startup notifier callback that initializes
1564 * cpu_cache_get for all new cpus
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 */
1566 register_cpu_notifier(&cpucache_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567
Andrew Mortona737b3e2006-03-22 00:08:11 -08001568 /*
1569 * The reap timers are started later, with a module init call: That part
1570 * of the kernel is not yet operational.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571 */
1572}
1573
1574static int __init cpucache_init(void)
1575{
1576 int cpu;
1577
Andrew Mortona737b3e2006-03-22 00:08:11 -08001578 /*
1579 * Register the timers that return unneeded pages to the page allocator
Linus Torvalds1da177e2005-04-16 15:20:36 -07001580 */
Christoph Lametere498be72005-09-09 13:03:32 -07001581 for_each_online_cpu(cpu)
Andrew Mortona737b3e2006-03-22 00:08:11 -08001582 start_cpu_timer(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 return 0;
1584}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585__initcall(cpucache_init);
1586
1587/*
1588 * Interface to system's page allocator. No need to hold the cache-lock.
1589 *
1590 * If we requested dmaable memory, we will get it. Even if we
1591 * did not request dmaable memory, we might get it, but that
1592 * would be relatively rare and ignorable.
1593 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001594static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595{
1596 struct page *page;
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001597 int nr_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001598 int i;
1599
Luke Yangd6fef9d2006-04-10 22:52:56 -07001600#ifndef CONFIG_MMU
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001601 /*
1602 * Nommu uses slab's for process anonymous memory allocations, and thus
1603 * requires __GFP_COMP to properly refcount higher order allocations
Luke Yangd6fef9d2006-04-10 22:52:56 -07001604 */
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001605 flags |= __GFP_COMP;
Luke Yangd6fef9d2006-04-10 22:52:56 -07001606#endif
Christoph Lameter765c4502006-09-27 01:50:08 -07001607
1608 /*
1609 * Under NUMA we want memory on the indicated node. We will handle
1610 * the needed fallback ourselves since we want to serve from our
1611 * per node object lists first for other nodes.
1612 */
1613 flags |= cachep->gfpflags | GFP_THISNODE;
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001614
1615 page = alloc_pages_node(nodeid, flags, cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616 if (!page)
1617 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001619 nr_pages = (1 << cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
Christoph Lameter972d1a72006-09-25 23:31:51 -07001621 add_zone_page_state(page_zone(page),
1622 NR_SLAB_RECLAIMABLE, nr_pages);
1623 else
1624 add_zone_page_state(page_zone(page),
1625 NR_SLAB_UNRECLAIMABLE, nr_pages);
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001626 for (i = 0; i < nr_pages; i++)
1627 __SetPageSlab(page + i);
1628 return page_address(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629}
1630
1631/*
1632 * Interface to system's page release.
1633 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001634static void kmem_freepages(struct kmem_cache *cachep, void *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001635{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001636 unsigned long i = (1 << cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637 struct page *page = virt_to_page(addr);
1638 const unsigned long nr_freed = i;
1639
Christoph Lameter972d1a72006-09-25 23:31:51 -07001640 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1641 sub_zone_page_state(page_zone(page),
1642 NR_SLAB_RECLAIMABLE, nr_freed);
1643 else
1644 sub_zone_page_state(page_zone(page),
1645 NR_SLAB_UNRECLAIMABLE, nr_freed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001646 while (i--) {
Nick Pigginf205b2f2006-03-22 00:08:02 -08001647 BUG_ON(!PageSlab(page));
1648 __ClearPageSlab(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649 page++;
1650 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651 if (current->reclaim_state)
1652 current->reclaim_state->reclaimed_slab += nr_freed;
1653 free_pages((unsigned long)addr, cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001654}
1655
1656static void kmem_rcu_free(struct rcu_head *head)
1657{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001658 struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
Pekka Enberg343e0d72006-02-01 03:05:50 -08001659 struct kmem_cache *cachep = slab_rcu->cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001660
1661 kmem_freepages(cachep, slab_rcu->addr);
1662 if (OFF_SLAB(cachep))
1663 kmem_cache_free(cachep->slabp_cache, slab_rcu);
1664}
1665
1666#if DEBUG
1667
1668#ifdef CONFIG_DEBUG_PAGEALLOC
Pekka Enberg343e0d72006-02-01 03:05:50 -08001669static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001670 unsigned long caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001672 int size = obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001674 addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001676 if (size < 5 * sizeof(unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677 return;
1678
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001679 *addr++ = 0x12345678;
1680 *addr++ = caller;
1681 *addr++ = smp_processor_id();
1682 size -= 3 * sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683 {
1684 unsigned long *sptr = &caller;
1685 unsigned long svalue;
1686
1687 while (!kstack_end(sptr)) {
1688 svalue = *sptr++;
1689 if (kernel_text_address(svalue)) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001690 *addr++ = svalue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691 size -= sizeof(unsigned long);
1692 if (size <= sizeof(unsigned long))
1693 break;
1694 }
1695 }
1696
1697 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001698 *addr++ = 0x87654321;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699}
1700#endif
1701
Pekka Enberg343e0d72006-02-01 03:05:50 -08001702static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001704 int size = obj_size(cachep);
1705 addr = &((char *)addr)[obj_offset(cachep)];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706
1707 memset(addr, val, size);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001708 *(unsigned char *)(addr + size - 1) = POISON_END;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709}
1710
1711static void dump_line(char *data, int offset, int limit)
1712{
1713 int i;
Dave Jonesaa83aa42006-09-29 01:59:51 -07001714 unsigned char error = 0;
1715 int bad_count = 0;
1716
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717 printk(KERN_ERR "%03x:", offset);
Dave Jonesaa83aa42006-09-29 01:59:51 -07001718 for (i = 0; i < limit; i++) {
1719 if (data[offset + i] != POISON_FREE) {
1720 error = data[offset + i];
1721 bad_count++;
1722 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001723 printk(" %02x", (unsigned char)data[offset + i]);
Dave Jonesaa83aa42006-09-29 01:59:51 -07001724 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725 printk("\n");
Dave Jonesaa83aa42006-09-29 01:59:51 -07001726
1727 if (bad_count == 1) {
1728 error ^= POISON_FREE;
1729 if (!(error & (error - 1))) {
1730 printk(KERN_ERR "Single bit error detected. Probably "
1731 "bad RAM.\n");
1732#ifdef CONFIG_X86
1733 printk(KERN_ERR "Run memtest86+ or a similar memory "
1734 "test tool.\n");
1735#else
1736 printk(KERN_ERR "Run a memory test tool.\n");
1737#endif
1738 }
1739 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001740}
1741#endif
1742
1743#if DEBUG
1744
Pekka Enberg343e0d72006-02-01 03:05:50 -08001745static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001746{
1747 int i, size;
1748 char *realobj;
1749
1750 if (cachep->flags & SLAB_RED_ZONE) {
1751 printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001752 *dbg_redzone1(cachep, objp),
1753 *dbg_redzone2(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754 }
1755
1756 if (cachep->flags & SLAB_STORE_USER) {
1757 printk(KERN_ERR "Last user: [<%p>]",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001758 *dbg_userword(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759 print_symbol("(%s)",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001760 (unsigned long)*dbg_userword(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001761 printk("\n");
1762 }
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001763 realobj = (char *)objp + obj_offset(cachep);
1764 size = obj_size(cachep);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001765 for (i = 0; i < size && lines; i += 16, lines--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001766 int limit;
1767 limit = 16;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001768 if (i + limit > size)
1769 limit = size - i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001770 dump_line(realobj, i, limit);
1771 }
1772}
1773
Pekka Enberg343e0d72006-02-01 03:05:50 -08001774static void check_poison_obj(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001775{
1776 char *realobj;
1777 int size, i;
1778 int lines = 0;
1779
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001780 realobj = (char *)objp + obj_offset(cachep);
1781 size = obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001782
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001783 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784 char exp = POISON_FREE;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001785 if (i == size - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786 exp = POISON_END;
1787 if (realobj[i] != exp) {
1788 int limit;
1789 /* Mismatch ! */
1790 /* Print header */
1791 if (lines == 0) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001792 printk(KERN_ERR
Andrew Mortona737b3e2006-03-22 00:08:11 -08001793 "Slab corruption: start=%p, len=%d\n",
1794 realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 print_objinfo(cachep, objp, 0);
1796 }
1797 /* Hexdump the affected line */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001798 i = (i / 16) * 16;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001799 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 i += 16;
1804 lines++;
1805 /* Limit to 5 lines */
1806 if (lines > 5)
1807 break;
1808 }
1809 }
1810 if (lines != 0) {
1811 /* Print some data about the neighboring objects, if they
1812 * exist:
1813 */
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -08001814 struct slab *slabp = virt_to_slab(objp);
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001815 unsigned int objnr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001816
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001817 objnr = obj_to_index(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818 if (objnr) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001819 objp = index_to_obj(cachep, slabp, objnr - 1);
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001820 realobj = (char *)objp + obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001821 printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001822 realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001823 print_objinfo(cachep, objp, 2);
1824 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001825 if (objnr + 1 < cachep->num) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001826 objp = index_to_obj(cachep, slabp, objnr + 1);
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001827 realobj = (char *)objp + obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828 printk(KERN_ERR "Next obj: start=%p, len=%d\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001829 realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001830 print_objinfo(cachep, objp, 2);
1831 }
1832 }
1833}
1834#endif
1835
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836#if DEBUG
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001837/**
Randy Dunlap911851e2006-03-22 00:08:14 -08001838 * slab_destroy_objs - destroy a slab and its objects
1839 * @cachep: cache pointer being destroyed
1840 * @slabp: slab pointer being destroyed
1841 *
1842 * Call the registered destructor for each object in a slab that is being
1843 * destroyed.
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001844 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001845static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001846{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001847 int i;
1848 for (i = 0; i < cachep->num; i++) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001849 void *objp = index_to_obj(cachep, slabp, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001850
1851 if (cachep->flags & SLAB_POISON) {
1852#ifdef CONFIG_DEBUG_PAGEALLOC
Andrew Mortona737b3e2006-03-22 00:08:11 -08001853 if (cachep->buffer_size % PAGE_SIZE == 0 &&
1854 OFF_SLAB(cachep))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001855 kernel_map_pages(virt_to_page(objp),
Andrew Mortona737b3e2006-03-22 00:08:11 -08001856 cachep->buffer_size / PAGE_SIZE, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001857 else
1858 check_poison_obj(cachep, objp);
1859#else
1860 check_poison_obj(cachep, objp);
1861#endif
1862 }
1863 if (cachep->flags & SLAB_RED_ZONE) {
1864 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
1865 slab_error(cachep, "start of a freed object "
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001866 "was overwritten");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001867 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
1868 slab_error(cachep, "end of a freed object "
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001869 "was overwritten");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001870 }
1871 if (cachep->dtor && !(cachep->flags & SLAB_POISON))
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001872 (cachep->dtor) (objp + obj_offset(cachep), cachep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873 }
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001874}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001875#else
Pekka Enberg343e0d72006-02-01 03:05:50 -08001876static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001877{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001878 if (cachep->dtor) {
1879 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);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001882 (cachep->dtor) (objp, cachep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883 }
1884 }
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001885}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001886#endif
1887
Randy Dunlap911851e2006-03-22 00:08:14 -08001888/**
1889 * slab_destroy - destroy and release all objects in a slab
1890 * @cachep: cache pointer being destroyed
1891 * @slabp: slab pointer being destroyed
1892 *
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001893 * Destroy all the objs in a slab, and release the mem back to the system.
Andrew Mortona737b3e2006-03-22 00:08:11 -08001894 * Before calling the slab must have been unlinked from the cache. The
1895 * cache-lock is not held/needed.
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001896 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001897static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001898{
1899 void *addr = slabp->s_mem - slabp->colouroff;
1900
1901 slab_destroy_objs(cachep, slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001902 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
1903 struct slab_rcu *slab_rcu;
1904
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001905 slab_rcu = (struct slab_rcu *)slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001906 slab_rcu->cachep = cachep;
1907 slab_rcu->addr = addr;
1908 call_rcu(&slab_rcu->head, kmem_rcu_free);
1909 } else {
1910 kmem_freepages(cachep, addr);
Ingo Molnar873623d2006-07-13 14:44:38 +02001911 if (OFF_SLAB(cachep))
1912 kmem_cache_free(cachep->slabp_cache, slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913 }
1914}
1915
Andrew Mortona737b3e2006-03-22 00:08:11 -08001916/*
1917 * For setting up all the kmem_list3s for cache whose buffer_size is same as
1918 * size of kmem_list3.
1919 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001920static void set_up_list3s(struct kmem_cache *cachep, int index)
Christoph Lametere498be72005-09-09 13:03:32 -07001921{
1922 int node;
1923
1924 for_each_online_node(node) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001925 cachep->nodelists[node] = &initkmem_list3[index + node];
Christoph Lametere498be72005-09-09 13:03:32 -07001926 cachep->nodelists[node]->next_reap = jiffies +
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001927 REAPTIMEOUT_LIST3 +
1928 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametere498be72005-09-09 13:03:32 -07001929 }
1930}
1931
Christoph Lameter117f6eb2006-09-25 23:31:37 -07001932static void __kmem_cache_destroy(struct kmem_cache *cachep)
1933{
1934 int i;
1935 struct kmem_list3 *l3;
1936
1937 for_each_online_cpu(i)
1938 kfree(cachep->array[i]);
1939
1940 /* NUMA: free the list3 structures */
1941 for_each_online_node(i) {
1942 l3 = cachep->nodelists[i];
1943 if (l3) {
1944 kfree(l3->shared);
1945 free_alien_cache(l3->alien);
1946 kfree(l3);
1947 }
1948 }
1949 kmem_cache_free(&cache_cache, cachep);
1950}
1951
1952
Linus Torvalds1da177e2005-04-16 15:20:36 -07001953/**
Randy.Dunlapa70773d2006-02-01 03:05:52 -08001954 * calculate_slab_order - calculate size (page order) of slabs
1955 * @cachep: pointer to the cache that is being created
1956 * @size: size of objects to be created in this cache.
1957 * @align: required alignment for the objects.
1958 * @flags: slab allocation flags
1959 *
1960 * Also calculates the number of objects per slab.
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001961 *
1962 * This could be made much more intelligent. For now, try to avoid using
1963 * high order pages for slabs. When the gfp() functions are more friendly
1964 * towards high-order requests, this should be changed.
1965 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001966static size_t calculate_slab_order(struct kmem_cache *cachep,
Randy Dunlapee13d782006-02-01 03:05:53 -08001967 size_t size, size_t align, unsigned long flags)
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001968{
Ingo Molnarb1ab41c2006-06-02 15:44:58 +02001969 unsigned long offslab_limit;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001970 size_t left_over = 0;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001971 int gfporder;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001972
Andrew Mortona737b3e2006-03-22 00:08:11 -08001973 for (gfporder = 0; gfporder <= MAX_GFP_ORDER; gfporder++) {
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001974 unsigned int num;
1975 size_t remainder;
1976
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001977 cache_estimate(gfporder, size, align, flags, &remainder, &num);
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001978 if (!num)
1979 continue;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001980
Ingo Molnarb1ab41c2006-06-02 15:44:58 +02001981 if (flags & CFLGS_OFF_SLAB) {
1982 /*
1983 * Max number of objs-per-slab for caches which
1984 * use off-slab slabs. Needed to avoid a possible
1985 * looping condition in cache_grow().
1986 */
1987 offslab_limit = size - sizeof(struct slab);
1988 offslab_limit /= sizeof(kmem_bufctl_t);
1989
1990 if (num > offslab_limit)
1991 break;
1992 }
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001993
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001994 /* Found something acceptable - save it away */
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001995 cachep->num = num;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001996 cachep->gfporder = gfporder;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001997 left_over = remainder;
1998
1999 /*
Linus Torvaldsf78bb8a2006-03-08 10:33:05 -08002000 * A VFS-reclaimable slab tends to have most allocations
2001 * as GFP_NOFS and we really don't want to have to be allocating
2002 * higher-order pages when we are unable to shrink dcache.
2003 */
2004 if (flags & SLAB_RECLAIM_ACCOUNT)
2005 break;
2006
2007 /*
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002008 * Large number of objects is good, but very large slabs are
2009 * currently bad for the gfp()s.
2010 */
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002011 if (gfporder >= slab_break_gfp_order)
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002012 break;
2013
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002014 /*
2015 * Acceptable internal fragmentation?
2016 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002017 if (left_over * 8 <= (PAGE_SIZE << gfporder))
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002018 break;
2019 }
2020 return left_over;
2021}
2022
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002023static int setup_cpu_cache(struct kmem_cache *cachep)
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002024{
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002025 if (g_cpucache_up == FULL)
2026 return enable_cpucache(cachep);
2027
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002028 if (g_cpucache_up == NONE) {
2029 /*
2030 * Note: the first kmem_cache_create must create the cache
2031 * that's used by kmalloc(24), otherwise the creation of
2032 * further caches will BUG().
2033 */
2034 cachep->array[smp_processor_id()] = &initarray_generic.cache;
2035
2036 /*
2037 * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
2038 * the first cache, then we need to set up all its list3s,
2039 * otherwise the creation of further caches will BUG().
2040 */
2041 set_up_list3s(cachep, SIZE_AC);
2042 if (INDEX_AC == INDEX_L3)
2043 g_cpucache_up = PARTIAL_L3;
2044 else
2045 g_cpucache_up = PARTIAL_AC;
2046 } else {
2047 cachep->array[smp_processor_id()] =
2048 kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
2049
2050 if (g_cpucache_up == PARTIAL_AC) {
2051 set_up_list3s(cachep, SIZE_L3);
2052 g_cpucache_up = PARTIAL_L3;
2053 } else {
2054 int node;
2055 for_each_online_node(node) {
2056 cachep->nodelists[node] =
2057 kmalloc_node(sizeof(struct kmem_list3),
2058 GFP_KERNEL, node);
2059 BUG_ON(!cachep->nodelists[node]);
2060 kmem_list3_init(cachep->nodelists[node]);
2061 }
2062 }
2063 }
2064 cachep->nodelists[numa_node_id()]->next_reap =
2065 jiffies + REAPTIMEOUT_LIST3 +
2066 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
2067
2068 cpu_cache_get(cachep)->avail = 0;
2069 cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
2070 cpu_cache_get(cachep)->batchcount = 1;
2071 cpu_cache_get(cachep)->touched = 0;
2072 cachep->batchcount = 1;
2073 cachep->limit = BOOT_CPUCACHE_ENTRIES;
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002074 return 0;
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002075}
2076
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002077/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07002078 * kmem_cache_create - Create a cache.
2079 * @name: A string which is used in /proc/slabinfo to identify this cache.
2080 * @size: The size of objects to be created in this cache.
2081 * @align: The required alignment for the objects.
2082 * @flags: SLAB flags
2083 * @ctor: A constructor for the objects.
2084 * @dtor: A destructor for the objects.
2085 *
2086 * Returns a ptr to the cache on success, NULL on failure.
2087 * Cannot be called within a int, but can be interrupted.
2088 * The @ctor is run when new pages are allocated by the cache
2089 * and the @dtor is run before the pages are handed back.
2090 *
2091 * @name must be valid until the cache is destroyed. This implies that
Andrew Mortona737b3e2006-03-22 00:08:11 -08002092 * the module calling this has to destroy the cache before getting unloaded.
2093 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002094 * The flags are
2095 *
2096 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2097 * to catch references to uninitialised memory.
2098 *
2099 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2100 * for buffer overruns.
2101 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002102 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2103 * cacheline. This can be beneficial if you're counting cycles as closely
2104 * as davem.
2105 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002106struct kmem_cache *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002107kmem_cache_create (const char *name, size_t size, size_t align,
Andrew Mortona737b3e2006-03-22 00:08:11 -08002108 unsigned long flags,
2109 void (*ctor)(void*, struct kmem_cache *, unsigned long),
Pekka Enberg343e0d72006-02-01 03:05:50 -08002110 void (*dtor)(void*, struct kmem_cache *, unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002111{
2112 size_t left_over, slab_size, ralign;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07002113 struct kmem_cache *cachep = NULL, *pc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002114
2115 /*
2116 * Sanity checks... these are all serious usage bugs.
2117 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002118 if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002119 (size > (1 << MAX_OBJ_ORDER) * PAGE_SIZE) || (dtor && !ctor)) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002120 printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
2121 name);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002122 BUG();
2123 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002124
Ravikiran G Thirumalaif0188f42006-02-10 01:51:13 -08002125 /*
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002126 * We use cache_chain_mutex to ensure a consistent view of
2127 * cpu_online_map as well. Please see cpuup_callback
Ravikiran G Thirumalaif0188f42006-02-10 01:51:13 -08002128 */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002129 mutex_lock(&cache_chain_mutex);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002130
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07002131 list_for_each_entry(pc, &cache_chain, next) {
Andrew Morton4f12bb42005-11-07 00:58:00 -08002132 mm_segment_t old_fs = get_fs();
2133 char tmp;
2134 int res;
2135
2136 /*
2137 * This happens when the module gets unloaded and doesn't
2138 * destroy its slab cache and no-one else reuses the vmalloc
2139 * area of the module. Print a warning.
2140 */
2141 set_fs(KERNEL_DS);
2142 res = __get_user(tmp, pc->name);
2143 set_fs(old_fs);
2144 if (res) {
2145 printk("SLAB: cache with size %d has lost its name\n",
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002146 pc->buffer_size);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002147 continue;
2148 }
2149
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002150 if (!strcmp(pc->name, name)) {
Andrew Morton4f12bb42005-11-07 00:58:00 -08002151 printk("kmem_cache_create: duplicate cache %s\n", name);
2152 dump_stack();
2153 goto oops;
2154 }
2155 }
2156
Linus Torvalds1da177e2005-04-16 15:20:36 -07002157#if DEBUG
2158 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
2159 if ((flags & SLAB_DEBUG_INITIAL) && !ctor) {
2160 /* No constructor, but inital state check requested */
2161 printk(KERN_ERR "%s: No con, but init state check "
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002162 "requested - %s\n", __FUNCTION__, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002163 flags &= ~SLAB_DEBUG_INITIAL;
2164 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002165#if FORCED_DEBUG
2166 /*
2167 * Enable redzoning and last user accounting, except for caches with
2168 * large objects, if the increased size would increase the object size
2169 * above the next power of two: caches with object sizes just above a
2170 * power of two have a significant amount of internal fragmentation.
2171 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002172 if (size < 4096 || fls(size - 1) == fls(size-1 + 3 * BYTES_PER_WORD))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002173 flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002174 if (!(flags & SLAB_DESTROY_BY_RCU))
2175 flags |= SLAB_POISON;
2176#endif
2177 if (flags & SLAB_DESTROY_BY_RCU)
2178 BUG_ON(flags & SLAB_POISON);
2179#endif
2180 if (flags & SLAB_DESTROY_BY_RCU)
2181 BUG_ON(dtor);
2182
2183 /*
Andrew Mortona737b3e2006-03-22 00:08:11 -08002184 * Always checks flags, a caller might be expecting debug support which
2185 * isn't available.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002186 */
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002187 BUG_ON(flags & ~CREATE_MASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002188
Andrew Mortona737b3e2006-03-22 00:08:11 -08002189 /*
2190 * Check that size is in terms of words. This is needed to avoid
Linus Torvalds1da177e2005-04-16 15:20:36 -07002191 * unaligned accesses for some archs when redzoning is used, and makes
2192 * sure any on-slab bufctl's are also correctly aligned.
2193 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002194 if (size & (BYTES_PER_WORD - 1)) {
2195 size += (BYTES_PER_WORD - 1);
2196 size &= ~(BYTES_PER_WORD - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002197 }
2198
Andrew Mortona737b3e2006-03-22 00:08:11 -08002199 /* calculate the final buffer alignment: */
2200
Linus Torvalds1da177e2005-04-16 15:20:36 -07002201 /* 1) arch recommendation: can be overridden for debug */
2202 if (flags & SLAB_HWCACHE_ALIGN) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002203 /*
2204 * Default alignment: as specified by the arch code. Except if
2205 * an object is really small, then squeeze multiple objects into
2206 * one cacheline.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002207 */
2208 ralign = cache_line_size();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002209 while (size <= ralign / 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002210 ralign /= 2;
2211 } else {
2212 ralign = BYTES_PER_WORD;
2213 }
Pekka Enbergca5f9702006-09-25 23:31:25 -07002214
2215 /*
2216 * Redzoning and user store require word alignment. Note this will be
2217 * overridden by architecture or caller mandated alignment if either
2218 * is greater than BYTES_PER_WORD.
2219 */
2220 if (flags & SLAB_RED_ZONE || flags & SLAB_STORE_USER)
2221 ralign = BYTES_PER_WORD;
2222
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002223 /* 2) arch mandated alignment */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002224 if (ralign < ARCH_SLAB_MINALIGN) {
2225 ralign = ARCH_SLAB_MINALIGN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002226 }
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002227 /* 3) caller mandated alignment */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002228 if (ralign < align) {
2229 ralign = align;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002230 }
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002231 /* disable debug if necessary */
2232 if (ralign > BYTES_PER_WORD)
2233 flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002234 /*
Pekka Enbergca5f9702006-09-25 23:31:25 -07002235 * 4) Store it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002236 */
2237 align = ralign;
2238
2239 /* Get cache's description obj. */
Pekka Enbergc5e3b832006-03-25 03:06:43 -08002240 cachep = kmem_cache_zalloc(&cache_cache, SLAB_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002241 if (!cachep)
Andrew Morton4f12bb42005-11-07 00:58:00 -08002242 goto oops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002243
2244#if DEBUG
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002245 cachep->obj_size = size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002246
Pekka Enbergca5f9702006-09-25 23:31:25 -07002247 /*
2248 * Both debugging options require word-alignment which is calculated
2249 * into align above.
2250 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002251 if (flags & SLAB_RED_ZONE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002252 /* add space for red zone words */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002253 cachep->obj_offset += BYTES_PER_WORD;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002254 size += 2 * BYTES_PER_WORD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255 }
2256 if (flags & SLAB_STORE_USER) {
Pekka Enbergca5f9702006-09-25 23:31:25 -07002257 /* user store requires one word storage behind the end of
2258 * the real object.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002259 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002260 size += BYTES_PER_WORD;
2261 }
2262#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002263 if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002264 && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
2265 cachep->obj_offset += PAGE_SIZE - size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002266 size = PAGE_SIZE;
2267 }
2268#endif
2269#endif
2270
Ingo Molnare0a42722006-06-23 02:03:46 -07002271 /*
2272 * Determine if the slab management is 'on' or 'off' slab.
2273 * (bootstrapping cannot cope with offslab caches so don't do
2274 * it too early on.)
2275 */
2276 if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002277 /*
2278 * Size is large, assume best to place the slab management obj
2279 * off-slab (should allow better packing of objs).
2280 */
2281 flags |= CFLGS_OFF_SLAB;
2282
2283 size = ALIGN(size, align);
2284
Linus Torvaldsf78bb8a2006-03-08 10:33:05 -08002285 left_over = calculate_slab_order(cachep, size, align, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002286
2287 if (!cachep->num) {
2288 printk("kmem_cache_create: couldn't create cache %s.\n", name);
2289 kmem_cache_free(&cache_cache, cachep);
2290 cachep = NULL;
Andrew Morton4f12bb42005-11-07 00:58:00 -08002291 goto oops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002292 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002293 slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
2294 + sizeof(struct slab), align);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002295
2296 /*
2297 * If the slab has been placed off-slab, and we have enough space then
2298 * move it on-slab. This is at the expense of any extra colouring.
2299 */
2300 if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
2301 flags &= ~CFLGS_OFF_SLAB;
2302 left_over -= slab_size;
2303 }
2304
2305 if (flags & CFLGS_OFF_SLAB) {
2306 /* really off slab. No need for manual alignment */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002307 slab_size =
2308 cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002309 }
2310
2311 cachep->colour_off = cache_line_size();
2312 /* Offset must be a multiple of the alignment. */
2313 if (cachep->colour_off < align)
2314 cachep->colour_off = align;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002315 cachep->colour = left_over / cachep->colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002316 cachep->slab_size = slab_size;
2317 cachep->flags = flags;
2318 cachep->gfpflags = 0;
2319 if (flags & SLAB_CACHE_DMA)
2320 cachep->gfpflags |= GFP_DMA;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002321 cachep->buffer_size = size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002322
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002323 if (flags & CFLGS_OFF_SLAB) {
Victor Fuscob2d55072005-09-10 00:26:36 -07002324 cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002325 /*
2326 * This is a possibility for one of the malloc_sizes caches.
2327 * But since we go off slab only for object size greater than
2328 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
2329 * this should not happen at all.
2330 * But leave a BUG_ON for some lucky dude.
2331 */
2332 BUG_ON(!cachep->slabp_cache);
2333 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002334 cachep->ctor = ctor;
2335 cachep->dtor = dtor;
2336 cachep->name = name;
2337
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002338 if (setup_cpu_cache(cachep)) {
2339 __kmem_cache_destroy(cachep);
2340 cachep = NULL;
2341 goto oops;
2342 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002343
Linus Torvalds1da177e2005-04-16 15:20:36 -07002344 /* cache setup completed, link it into the list */
2345 list_add(&cachep->next, &cache_chain);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002346oops:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002347 if (!cachep && (flags & SLAB_PANIC))
2348 panic("kmem_cache_create(): failed to create slab `%s'\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002349 name);
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002350 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002351 return cachep;
2352}
2353EXPORT_SYMBOL(kmem_cache_create);
2354
2355#if DEBUG
2356static void check_irq_off(void)
2357{
2358 BUG_ON(!irqs_disabled());
2359}
2360
2361static void check_irq_on(void)
2362{
2363 BUG_ON(irqs_disabled());
2364}
2365
Pekka Enberg343e0d72006-02-01 03:05:50 -08002366static void check_spinlock_acquired(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002367{
2368#ifdef CONFIG_SMP
2369 check_irq_off();
Christoph Lametere498be72005-09-09 13:03:32 -07002370 assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002371#endif
2372}
Christoph Lametere498be72005-09-09 13:03:32 -07002373
Pekka Enberg343e0d72006-02-01 03:05:50 -08002374static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
Christoph Lametere498be72005-09-09 13:03:32 -07002375{
2376#ifdef CONFIG_SMP
2377 check_irq_off();
2378 assert_spin_locked(&cachep->nodelists[node]->list_lock);
2379#endif
2380}
2381
Linus Torvalds1da177e2005-04-16 15:20:36 -07002382#else
2383#define check_irq_off() do { } while(0)
2384#define check_irq_on() do { } while(0)
2385#define check_spinlock_acquired(x) do { } while(0)
Christoph Lametere498be72005-09-09 13:03:32 -07002386#define check_spinlock_acquired_node(x, y) do { } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002387#endif
2388
Christoph Lameteraab22072006-03-22 00:09:06 -08002389static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
2390 struct array_cache *ac,
2391 int force, int node);
2392
Linus Torvalds1da177e2005-04-16 15:20:36 -07002393static void do_drain(void *arg)
2394{
Andrew Mortona737b3e2006-03-22 00:08:11 -08002395 struct kmem_cache *cachep = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002396 struct array_cache *ac;
Christoph Lameterff694162005-09-22 21:44:02 -07002397 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002398
2399 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08002400 ac = cpu_cache_get(cachep);
Christoph Lameterff694162005-09-22 21:44:02 -07002401 spin_lock(&cachep->nodelists[node]->list_lock);
2402 free_block(cachep, ac->entry, ac->avail, node);
2403 spin_unlock(&cachep->nodelists[node]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002404 ac->avail = 0;
2405}
2406
Pekka Enberg343e0d72006-02-01 03:05:50 -08002407static void drain_cpu_caches(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002408{
Christoph Lametere498be72005-09-09 13:03:32 -07002409 struct kmem_list3 *l3;
2410 int node;
2411
Andrew Mortona07fa392006-03-22 00:08:17 -08002412 on_each_cpu(do_drain, cachep, 1, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002413 check_irq_on();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002414 for_each_online_node(node) {
Christoph Lametere498be72005-09-09 13:03:32 -07002415 l3 = cachep->nodelists[node];
Roland Dreiera4523a82006-05-15 11:41:00 -07002416 if (l3 && l3->alien)
2417 drain_alien_cache(cachep, l3->alien);
2418 }
2419
2420 for_each_online_node(node) {
2421 l3 = cachep->nodelists[node];
2422 if (l3)
Christoph Lameteraab22072006-03-22 00:09:06 -08002423 drain_array(cachep, l3, l3->shared, 1, node);
Christoph Lametere498be72005-09-09 13:03:32 -07002424 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002425}
2426
Christoph Lametered11d9e2006-06-30 01:55:45 -07002427/*
2428 * Remove slabs from the list of free slabs.
2429 * Specify the number of slabs to drain in tofree.
2430 *
2431 * Returns the actual number of slabs released.
2432 */
2433static int drain_freelist(struct kmem_cache *cache,
2434 struct kmem_list3 *l3, int tofree)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002435{
Christoph Lametered11d9e2006-06-30 01:55:45 -07002436 struct list_head *p;
2437 int nr_freed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002438 struct slab *slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002439
Christoph Lametered11d9e2006-06-30 01:55:45 -07002440 nr_freed = 0;
2441 while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002442
Christoph Lametered11d9e2006-06-30 01:55:45 -07002443 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07002444 p = l3->slabs_free.prev;
Christoph Lametered11d9e2006-06-30 01:55:45 -07002445 if (p == &l3->slabs_free) {
2446 spin_unlock_irq(&l3->list_lock);
2447 goto out;
2448 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002449
Christoph Lametered11d9e2006-06-30 01:55:45 -07002450 slabp = list_entry(p, struct slab, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002451#if DEBUG
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002452 BUG_ON(slabp->inuse);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002453#endif
2454 list_del(&slabp->list);
Christoph Lametered11d9e2006-06-30 01:55:45 -07002455 /*
2456 * Safe to drop the lock. The slab is no longer linked
2457 * to the cache.
2458 */
2459 l3->free_objects -= cache->num;
Christoph Lametere498be72005-09-09 13:03:32 -07002460 spin_unlock_irq(&l3->list_lock);
Christoph Lametered11d9e2006-06-30 01:55:45 -07002461 slab_destroy(cache, slabp);
2462 nr_freed++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002463 }
Christoph Lametered11d9e2006-06-30 01:55:45 -07002464out:
2465 return nr_freed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002466}
2467
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002468/* Called with cache_chain_mutex held to protect against cpu hotplug */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002469static int __cache_shrink(struct kmem_cache *cachep)
Christoph Lametere498be72005-09-09 13:03:32 -07002470{
2471 int ret = 0, i = 0;
2472 struct kmem_list3 *l3;
2473
2474 drain_cpu_caches(cachep);
2475
2476 check_irq_on();
2477 for_each_online_node(i) {
2478 l3 = cachep->nodelists[i];
Christoph Lametered11d9e2006-06-30 01:55:45 -07002479 if (!l3)
2480 continue;
2481
2482 drain_freelist(cachep, l3, l3->free_objects);
2483
2484 ret += !list_empty(&l3->slabs_full) ||
2485 !list_empty(&l3->slabs_partial);
Christoph Lametere498be72005-09-09 13:03:32 -07002486 }
2487 return (ret ? 1 : 0);
2488}
2489
Linus Torvalds1da177e2005-04-16 15:20:36 -07002490/**
2491 * kmem_cache_shrink - Shrink a cache.
2492 * @cachep: The cache to shrink.
2493 *
2494 * Releases as many slabs as possible for a cache.
2495 * To help debugging, a zero exit status indicates all slabs were released.
2496 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002497int kmem_cache_shrink(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002498{
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002499 int ret;
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002500 BUG_ON(!cachep || in_interrupt());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002501
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002502 mutex_lock(&cache_chain_mutex);
2503 ret = __cache_shrink(cachep);
2504 mutex_unlock(&cache_chain_mutex);
2505 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002506}
2507EXPORT_SYMBOL(kmem_cache_shrink);
2508
2509/**
2510 * kmem_cache_destroy - delete a cache
2511 * @cachep: the cache to destroy
2512 *
Pekka Enberg343e0d72006-02-01 03:05:50 -08002513 * Remove a struct kmem_cache object from the slab cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002514 *
2515 * It is expected this function will be called by a module when it is
2516 * unloaded. This will remove the cache completely, and avoid a duplicate
2517 * cache being allocated each time a module is loaded and unloaded, if the
2518 * module doesn't have persistent in-kernel storage across loads and unloads.
2519 *
2520 * The cache must be empty before calling this function.
2521 *
2522 * The caller must guarantee that noone will allocate memory from the cache
2523 * during the kmem_cache_destroy().
2524 */
Alexey Dobriyan133d2052006-09-27 01:49:41 -07002525void kmem_cache_destroy(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002526{
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002527 BUG_ON(!cachep || in_interrupt());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002528
Linus Torvalds1da177e2005-04-16 15:20:36 -07002529 /* Find the cache in the chain of caches. */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002530 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002531 /*
2532 * the chain is never empty, cache_cache is never destroyed
2533 */
2534 list_del(&cachep->next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002535 if (__cache_shrink(cachep)) {
2536 slab_error(cachep, "Can't free all objects");
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002537 list_add(&cachep->next, &cache_chain);
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002538 mutex_unlock(&cache_chain_mutex);
Alexey Dobriyan133d2052006-09-27 01:49:41 -07002539 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002540 }
2541
2542 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07002543 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002544
Christoph Lameter117f6eb2006-09-25 23:31:37 -07002545 __kmem_cache_destroy(cachep);
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002546 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002547}
2548EXPORT_SYMBOL(kmem_cache_destroy);
2549
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002550/*
2551 * Get the memory for a slab management obj.
2552 * For a slab cache when the slab descriptor is off-slab, slab descriptors
2553 * always come from malloc_sizes caches. The slab descriptor cannot
2554 * come from the same cache which is getting created because,
2555 * when we are searching for an appropriate cache for these
2556 * descriptors in kmem_cache_create, we search through the malloc_sizes array.
2557 * If we are creating a malloc_sizes cache here it would not be visible to
2558 * kmem_find_general_cachep till the initialization is complete.
2559 * Hence we cannot have slabp_cache same as the original cache.
2560 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002561static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002562 int colour_off, gfp_t local_flags,
2563 int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002564{
2565 struct slab *slabp;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002566
Linus Torvalds1da177e2005-04-16 15:20:36 -07002567 if (OFF_SLAB(cachep)) {
2568 /* Slab management obj is off-slab. */
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002569 slabp = kmem_cache_alloc_node(cachep->slabp_cache,
2570 local_flags, nodeid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002571 if (!slabp)
2572 return NULL;
2573 } else {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002574 slabp = objp + colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002575 colour_off += cachep->slab_size;
2576 }
2577 slabp->inuse = 0;
2578 slabp->colouroff = colour_off;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002579 slabp->s_mem = objp + colour_off;
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002580 slabp->nodeid = nodeid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002581 return slabp;
2582}
2583
2584static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
2585{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002586 return (kmem_bufctl_t *) (slabp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002587}
2588
Pekka Enberg343e0d72006-02-01 03:05:50 -08002589static void cache_init_objs(struct kmem_cache *cachep,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002590 struct slab *slabp, unsigned long ctor_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002591{
2592 int i;
2593
2594 for (i = 0; i < cachep->num; i++) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002595 void *objp = index_to_obj(cachep, slabp, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002596#if DEBUG
2597 /* need to poison the objs? */
2598 if (cachep->flags & SLAB_POISON)
2599 poison_obj(cachep, objp, POISON_FREE);
2600 if (cachep->flags & SLAB_STORE_USER)
2601 *dbg_userword(cachep, objp) = NULL;
2602
2603 if (cachep->flags & SLAB_RED_ZONE) {
2604 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2605 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2606 }
2607 /*
Andrew Mortona737b3e2006-03-22 00:08:11 -08002608 * Constructors are not allowed to allocate memory from the same
2609 * cache which they are a constructor for. Otherwise, deadlock.
2610 * They must also be threaded.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002611 */
2612 if (cachep->ctor && !(cachep->flags & SLAB_POISON))
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002613 cachep->ctor(objp + obj_offset(cachep), cachep,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002614 ctor_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002615
2616 if (cachep->flags & SLAB_RED_ZONE) {
2617 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
2618 slab_error(cachep, "constructor overwrote the"
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002619 " end of an object");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002620 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
2621 slab_error(cachep, "constructor overwrote the"
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002622 " start of an object");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002623 }
Andrew Mortona737b3e2006-03-22 00:08:11 -08002624 if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
2625 OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002626 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002627 cachep->buffer_size / PAGE_SIZE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002628#else
2629 if (cachep->ctor)
2630 cachep->ctor(objp, cachep, ctor_flags);
2631#endif
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002632 slab_bufctl(slabp)[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002633 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002634 slab_bufctl(slabp)[i - 1] = BUFCTL_END;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002635 slabp->free = 0;
2636}
2637
Pekka Enberg343e0d72006-02-01 03:05:50 -08002638static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002639{
Andrew Mortona737b3e2006-03-22 00:08:11 -08002640 if (flags & SLAB_DMA)
2641 BUG_ON(!(cachep->gfpflags & GFP_DMA));
2642 else
2643 BUG_ON(cachep->gfpflags & GFP_DMA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002644}
2645
Andrew Mortona737b3e2006-03-22 00:08:11 -08002646static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
2647 int nodeid)
Matthew Dobson78d382d2006-02-01 03:05:47 -08002648{
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002649 void *objp = index_to_obj(cachep, slabp, slabp->free);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002650 kmem_bufctl_t next;
2651
2652 slabp->inuse++;
2653 next = slab_bufctl(slabp)[slabp->free];
2654#if DEBUG
2655 slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
2656 WARN_ON(slabp->nodeid != nodeid);
2657#endif
2658 slabp->free = next;
2659
2660 return objp;
2661}
2662
Andrew Mortona737b3e2006-03-22 00:08:11 -08002663static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
2664 void *objp, int nodeid)
Matthew Dobson78d382d2006-02-01 03:05:47 -08002665{
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002666 unsigned int objnr = obj_to_index(cachep, slabp, objp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002667
2668#if DEBUG
2669 /* Verify that the slab belongs to the intended node */
2670 WARN_ON(slabp->nodeid != nodeid);
2671
Al Viro871751e2006-03-25 03:06:39 -08002672 if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
Matthew Dobson78d382d2006-02-01 03:05:47 -08002673 printk(KERN_ERR "slab: double free detected in cache "
Andrew Mortona737b3e2006-03-22 00:08:11 -08002674 "'%s', objp %p\n", cachep->name, objp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002675 BUG();
2676 }
2677#endif
2678 slab_bufctl(slabp)[objnr] = slabp->free;
2679 slabp->free = objnr;
2680 slabp->inuse--;
2681}
2682
Pekka Enberg47768742006-06-23 02:03:07 -07002683/*
2684 * Map pages beginning at addr to the given cache and slab. This is required
2685 * for the slab allocator to be able to lookup the cache and slab of a
2686 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
2687 */
2688static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
2689 void *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002690{
Pekka Enberg47768742006-06-23 02:03:07 -07002691 int nr_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002692 struct page *page;
2693
Pekka Enberg47768742006-06-23 02:03:07 -07002694 page = virt_to_page(addr);
Nick Piggin84097512006-03-22 00:08:34 -08002695
Pekka Enberg47768742006-06-23 02:03:07 -07002696 nr_pages = 1;
Nick Piggin84097512006-03-22 00:08:34 -08002697 if (likely(!PageCompound(page)))
Pekka Enberg47768742006-06-23 02:03:07 -07002698 nr_pages <<= cache->gfporder;
2699
Linus Torvalds1da177e2005-04-16 15:20:36 -07002700 do {
Pekka Enberg47768742006-06-23 02:03:07 -07002701 page_set_cache(page, cache);
2702 page_set_slab(page, slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002703 page++;
Pekka Enberg47768742006-06-23 02:03:07 -07002704 } while (--nr_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002705}
2706
2707/*
2708 * Grow (by 1) the number of slabs within a cache. This is called by
2709 * kmem_cache_alloc() when there are no active objs left in a cache.
2710 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002711static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002712{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002713 struct slab *slabp;
2714 void *objp;
2715 size_t offset;
2716 gfp_t local_flags;
2717 unsigned long ctor_flags;
Christoph Lametere498be72005-09-09 13:03:32 -07002718 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002719
Andrew Mortona737b3e2006-03-22 00:08:11 -08002720 /*
2721 * Be lazy and only check for valid flags here, keeping it out of the
2722 * critical path in kmem_cache_alloc().
Linus Torvalds1da177e2005-04-16 15:20:36 -07002723 */
Christoph Lameter6e0eaa42006-12-06 20:33:10 -08002724 BUG_ON(flags & ~(SLAB_DMA | SLAB_LEVEL_MASK | __GFP_NO_GROW));
2725 if (flags & __GFP_NO_GROW)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002726 return 0;
2727
2728 ctor_flags = SLAB_CTOR_CONSTRUCTOR;
2729 local_flags = (flags & SLAB_LEVEL_MASK);
2730 if (!(local_flags & __GFP_WAIT))
2731 /*
2732 * Not allowed to sleep. Need to tell a constructor about
2733 * this - it might need to know...
2734 */
2735 ctor_flags |= SLAB_CTOR_ATOMIC;
2736
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002737 /* Take the l3 list lock to change the colour_next on this node */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002738 check_irq_off();
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002739 l3 = cachep->nodelists[nodeid];
2740 spin_lock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002741
2742 /* Get colour for the slab, and cal the next value. */
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002743 offset = l3->colour_next;
2744 l3->colour_next++;
2745 if (l3->colour_next >= cachep->colour)
2746 l3->colour_next = 0;
2747 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002748
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002749 offset *= cachep->colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002750
2751 if (local_flags & __GFP_WAIT)
2752 local_irq_enable();
2753
2754 /*
2755 * The test for missing atomic flag is performed here, rather than
2756 * the more obvious place, simply to reduce the critical path length
2757 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2758 * will eventually be caught here (where it matters).
2759 */
2760 kmem_flagcheck(cachep, flags);
2761
Andrew Mortona737b3e2006-03-22 00:08:11 -08002762 /*
2763 * Get mem for the objs. Attempt to allocate a physical page from
2764 * 'nodeid'.
Christoph Lametere498be72005-09-09 13:03:32 -07002765 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002766 objp = kmem_getpages(cachep, flags, nodeid);
2767 if (!objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002768 goto failed;
2769
2770 /* Get slab management. */
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002771 slabp = alloc_slabmgmt(cachep, objp, offset, local_flags, nodeid);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002772 if (!slabp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002773 goto opps1;
2774
Christoph Lametere498be72005-09-09 13:03:32 -07002775 slabp->nodeid = nodeid;
Pekka Enberg47768742006-06-23 02:03:07 -07002776 slab_map_pages(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002777
2778 cache_init_objs(cachep, slabp, ctor_flags);
2779
2780 if (local_flags & __GFP_WAIT)
2781 local_irq_disable();
2782 check_irq_off();
Christoph Lametere498be72005-09-09 13:03:32 -07002783 spin_lock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002784
2785 /* Make slab active. */
Christoph Lametere498be72005-09-09 13:03:32 -07002786 list_add_tail(&slabp->list, &(l3->slabs_free));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002787 STATS_INC_GROWN(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07002788 l3->free_objects += cachep->num;
2789 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002790 return 1;
Andrew Mortona737b3e2006-03-22 00:08:11 -08002791opps1:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002792 kmem_freepages(cachep, objp);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002793failed:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002794 if (local_flags & __GFP_WAIT)
2795 local_irq_disable();
2796 return 0;
2797}
2798
2799#if DEBUG
2800
2801/*
2802 * Perform extra freeing checks:
2803 * - detect bad pointers.
2804 * - POISON/RED_ZONE checking
2805 * - destructor calls, for caches with POISON+dtor
2806 */
2807static void kfree_debugcheck(const void *objp)
2808{
2809 struct page *page;
2810
2811 if (!virt_addr_valid(objp)) {
2812 printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002813 (unsigned long)objp);
2814 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002815 }
2816 page = virt_to_page(objp);
2817 if (!PageSlab(page)) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002818 printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n",
2819 (unsigned long)objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002820 BUG();
2821 }
2822}
2823
Pekka Enberg58ce1fd2006-06-23 02:03:24 -07002824static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
2825{
2826 unsigned long redzone1, redzone2;
2827
2828 redzone1 = *dbg_redzone1(cache, obj);
2829 redzone2 = *dbg_redzone2(cache, obj);
2830
2831 /*
2832 * Redzone is ok.
2833 */
2834 if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
2835 return;
2836
2837 if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
2838 slab_error(cache, "double free detected");
2839 else
2840 slab_error(cache, "memory outside object was overwritten");
2841
2842 printk(KERN_ERR "%p: redzone 1:0x%lx, redzone 2:0x%lx.\n",
2843 obj, redzone1, redzone2);
2844}
2845
Pekka Enberg343e0d72006-02-01 03:05:50 -08002846static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002847 void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002848{
2849 struct page *page;
2850 unsigned int objnr;
2851 struct slab *slabp;
2852
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002853 objp -= obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002854 kfree_debugcheck(objp);
2855 page = virt_to_page(objp);
2856
Pekka Enberg065d41c2005-11-13 16:06:46 -08002857 slabp = page_get_slab(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002858
2859 if (cachep->flags & SLAB_RED_ZONE) {
Pekka Enberg58ce1fd2006-06-23 02:03:24 -07002860 verify_redzone_free(cachep, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002861 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2862 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2863 }
2864 if (cachep->flags & SLAB_STORE_USER)
2865 *dbg_userword(cachep, objp) = caller;
2866
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002867 objnr = obj_to_index(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002868
2869 BUG_ON(objnr >= cachep->num);
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002870 BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002871
2872 if (cachep->flags & SLAB_DEBUG_INITIAL) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002873 /*
2874 * Need to call the slab's constructor so the caller can
2875 * perform a verify of its state (debugging). Called without
2876 * the cache-lock held.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002877 */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002878 cachep->ctor(objp + obj_offset(cachep),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002879 cachep, SLAB_CTOR_CONSTRUCTOR | SLAB_CTOR_VERIFY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002880 }
2881 if (cachep->flags & SLAB_POISON && cachep->dtor) {
2882 /* we want to cache poison the object,
2883 * call the destruction callback
2884 */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002885 cachep->dtor(objp + obj_offset(cachep), cachep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002886 }
Al Viro871751e2006-03-25 03:06:39 -08002887#ifdef CONFIG_DEBUG_SLAB_LEAK
2888 slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
2889#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002890 if (cachep->flags & SLAB_POISON) {
2891#ifdef CONFIG_DEBUG_PAGEALLOC
Andrew Mortona737b3e2006-03-22 00:08:11 -08002892 if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002893 store_stackinfo(cachep, objp, (unsigned long)caller);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002894 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002895 cachep->buffer_size / PAGE_SIZE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002896 } else {
2897 poison_obj(cachep, objp, POISON_FREE);
2898 }
2899#else
2900 poison_obj(cachep, objp, POISON_FREE);
2901#endif
2902 }
2903 return objp;
2904}
2905
Pekka Enberg343e0d72006-02-01 03:05:50 -08002906static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002907{
2908 kmem_bufctl_t i;
2909 int entries = 0;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002910
Linus Torvalds1da177e2005-04-16 15:20:36 -07002911 /* Check slab's freelist to see if this obj is there. */
2912 for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
2913 entries++;
2914 if (entries > cachep->num || i >= cachep->num)
2915 goto bad;
2916 }
2917 if (entries != cachep->num - slabp->inuse) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002918bad:
2919 printk(KERN_ERR "slab: Internal list corruption detected in "
2920 "cache '%s'(%d), slabp %p(%d). Hexdump:\n",
2921 cachep->name, cachep->num, slabp, slabp->inuse);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002922 for (i = 0;
Linus Torvalds264132b2006-03-06 12:10:07 -08002923 i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002924 i++) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002925 if (i % 16 == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002926 printk("\n%03x:", i);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002927 printk(" %02x", ((unsigned char *)slabp)[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002928 }
2929 printk("\n");
2930 BUG();
2931 }
2932}
2933#else
2934#define kfree_debugcheck(x) do { } while(0)
2935#define cache_free_debugcheck(x,objp,z) (objp)
2936#define check_slabp(x,y) do { } while(0)
2937#endif
2938
Pekka Enberg343e0d72006-02-01 03:05:50 -08002939static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002940{
2941 int batchcount;
2942 struct kmem_list3 *l3;
2943 struct array_cache *ac;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002944 int node;
2945
2946 node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002947
2948 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08002949 ac = cpu_cache_get(cachep);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002950retry:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002951 batchcount = ac->batchcount;
2952 if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002953 /*
2954 * If there was little recent activity on this cache, then
2955 * perform only a partial refill. Otherwise we could generate
2956 * refill bouncing.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002957 */
2958 batchcount = BATCHREFILL_LIMIT;
2959 }
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002960 l3 = cachep->nodelists[node];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002961
Christoph Lametere498be72005-09-09 13:03:32 -07002962 BUG_ON(ac->avail > 0 || !l3);
2963 spin_lock(&l3->list_lock);
2964
Christoph Lameter3ded1752006-03-25 03:06:44 -08002965 /* See if we can refill from the shared array */
2966 if (l3->shared && transfer_objects(ac, l3->shared, batchcount))
2967 goto alloc_done;
2968
Linus Torvalds1da177e2005-04-16 15:20:36 -07002969 while (batchcount > 0) {
2970 struct list_head *entry;
2971 struct slab *slabp;
2972 /* Get slab alloc is to come from. */
2973 entry = l3->slabs_partial.next;
2974 if (entry == &l3->slabs_partial) {
2975 l3->free_touched = 1;
2976 entry = l3->slabs_free.next;
2977 if (entry == &l3->slabs_free)
2978 goto must_grow;
2979 }
2980
2981 slabp = list_entry(entry, struct slab, list);
2982 check_slabp(cachep, slabp);
2983 check_spinlock_acquired(cachep);
2984 while (slabp->inuse < cachep->num && batchcount--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002985 STATS_INC_ALLOCED(cachep);
2986 STATS_INC_ACTIVE(cachep);
2987 STATS_SET_HIGH(cachep);
2988
Matthew Dobson78d382d2006-02-01 03:05:47 -08002989 ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002990 node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002991 }
2992 check_slabp(cachep, slabp);
2993
2994 /* move slabp to correct slabp list: */
2995 list_del(&slabp->list);
2996 if (slabp->free == BUFCTL_END)
2997 list_add(&slabp->list, &l3->slabs_full);
2998 else
2999 list_add(&slabp->list, &l3->slabs_partial);
3000 }
3001
Andrew Mortona737b3e2006-03-22 00:08:11 -08003002must_grow:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003003 l3->free_objects -= ac->avail;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003004alloc_done:
Christoph Lametere498be72005-09-09 13:03:32 -07003005 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003006
3007 if (unlikely(!ac->avail)) {
3008 int x;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07003009 x = cache_grow(cachep, flags, node);
Christoph Lametere498be72005-09-09 13:03:32 -07003010
Andrew Mortona737b3e2006-03-22 00:08:11 -08003011 /* cache_grow can reenable interrupts, then ac could change. */
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003012 ac = cpu_cache_get(cachep);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003013 if (!x && ac->avail == 0) /* no objects in sight? abort */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003014 return NULL;
3015
Andrew Mortona737b3e2006-03-22 00:08:11 -08003016 if (!ac->avail) /* objects refilled by interrupt? */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003017 goto retry;
3018 }
3019 ac->touched = 1;
Christoph Lametere498be72005-09-09 13:03:32 -07003020 return ac->entry[--ac->avail];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003021}
3022
Andrew Mortona737b3e2006-03-22 00:08:11 -08003023static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
3024 gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003025{
3026 might_sleep_if(flags & __GFP_WAIT);
3027#if DEBUG
3028 kmem_flagcheck(cachep, flags);
3029#endif
3030}
3031
3032#if DEBUG
Andrew Mortona737b3e2006-03-22 00:08:11 -08003033static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
3034 gfp_t flags, void *objp, void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003035{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003036 if (!objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003037 return objp;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003038 if (cachep->flags & SLAB_POISON) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003039#ifdef CONFIG_DEBUG_PAGEALLOC
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003040 if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003041 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003042 cachep->buffer_size / PAGE_SIZE, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003043 else
3044 check_poison_obj(cachep, objp);
3045#else
3046 check_poison_obj(cachep, objp);
3047#endif
3048 poison_obj(cachep, objp, POISON_INUSE);
3049 }
3050 if (cachep->flags & SLAB_STORE_USER)
3051 *dbg_userword(cachep, objp) = caller;
3052
3053 if (cachep->flags & SLAB_RED_ZONE) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08003054 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
3055 *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
3056 slab_error(cachep, "double free, or memory outside"
3057 " object was overwritten");
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003058 printk(KERN_ERR
Andrew Mortona737b3e2006-03-22 00:08:11 -08003059 "%p: redzone 1:0x%lx, redzone 2:0x%lx\n",
3060 objp, *dbg_redzone1(cachep, objp),
3061 *dbg_redzone2(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003062 }
3063 *dbg_redzone1(cachep, objp) = RED_ACTIVE;
3064 *dbg_redzone2(cachep, objp) = RED_ACTIVE;
3065 }
Al Viro871751e2006-03-25 03:06:39 -08003066#ifdef CONFIG_DEBUG_SLAB_LEAK
3067 {
3068 struct slab *slabp;
3069 unsigned objnr;
3070
3071 slabp = page_get_slab(virt_to_page(objp));
3072 objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
3073 slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
3074 }
3075#endif
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003076 objp += obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003077 if (cachep->ctor && cachep->flags & SLAB_POISON) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003078 unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003079
3080 if (!(flags & __GFP_WAIT))
3081 ctor_flags |= SLAB_CTOR_ATOMIC;
3082
3083 cachep->ctor(objp, cachep, ctor_flags);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003084 }
Kevin Hilmana44b56d2006-12-06 20:32:11 -08003085#if ARCH_SLAB_MINALIGN
3086 if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
3087 printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
3088 objp, ARCH_SLAB_MINALIGN);
3089 }
3090#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07003091 return objp;
3092}
3093#else
3094#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
3095#endif
3096
Pekka Enberg343e0d72006-02-01 03:05:50 -08003097static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003098{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003099 void *objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003100 struct array_cache *ac;
3101
Alok N Kataria5c382302005-09-27 21:45:46 -07003102 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003103 ac = cpu_cache_get(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003104 if (likely(ac->avail)) {
3105 STATS_INC_ALLOCHIT(cachep);
3106 ac->touched = 1;
Christoph Lametere498be72005-09-09 13:03:32 -07003107 objp = ac->entry[--ac->avail];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003108 } else {
3109 STATS_INC_ALLOCMISS(cachep);
3110 objp = cache_alloc_refill(cachep, flags);
3111 }
Alok N Kataria5c382302005-09-27 21:45:46 -07003112 return objp;
3113}
3114
Andrew Mortona737b3e2006-03-22 00:08:11 -08003115static __always_inline void *__cache_alloc(struct kmem_cache *cachep,
3116 gfp_t flags, void *caller)
Alok N Kataria5c382302005-09-27 21:45:46 -07003117{
3118 unsigned long save_flags;
Christoph Lameterde3083e2006-09-27 01:50:03 -07003119 void *objp = NULL;
Alok N Kataria5c382302005-09-27 21:45:46 -07003120
3121 cache_alloc_debugcheck_before(cachep, flags);
3122
3123 local_irq_save(save_flags);
Christoph Lameterde3083e2006-09-27 01:50:03 -07003124
Christoph Lameter765c4502006-09-27 01:50:08 -07003125 if (unlikely(NUMA_BUILD &&
3126 current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY)))
Christoph Lameterde3083e2006-09-27 01:50:03 -07003127 objp = alternate_node_alloc(cachep, flags);
Christoph Lameterde3083e2006-09-27 01:50:03 -07003128
3129 if (!objp)
3130 objp = ____cache_alloc(cachep, flags);
Christoph Lameter765c4502006-09-27 01:50:08 -07003131 /*
3132 * We may just have run out of memory on the local node.
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003133 * ____cache_alloc_node() knows how to locate memory on other nodes
Christoph Lameter765c4502006-09-27 01:50:08 -07003134 */
3135 if (NUMA_BUILD && !objp)
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003136 objp = ____cache_alloc_node(cachep, flags, numa_node_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003137 local_irq_restore(save_flags);
Eric Dumazet34342e82005-09-03 15:55:06 -07003138 objp = cache_alloc_debugcheck_after(cachep, flags, objp,
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003139 caller);
Eric Dumazet34342e82005-09-03 15:55:06 -07003140 prefetchw(objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003141 return objp;
3142}
3143
Christoph Lametere498be72005-09-09 13:03:32 -07003144#ifdef CONFIG_NUMA
3145/*
Paul Jacksonb2455392006-03-24 03:16:12 -08003146 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
Paul Jacksonc61afb12006-03-24 03:16:08 -08003147 *
3148 * If we are in_interrupt, then process context, including cpusets and
3149 * mempolicy, may not apply and should not be used for allocation policy.
3150 */
3151static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
3152{
3153 int nid_alloc, nid_here;
3154
Christoph Lameter765c4502006-09-27 01:50:08 -07003155 if (in_interrupt() || (flags & __GFP_THISNODE))
Paul Jacksonc61afb12006-03-24 03:16:08 -08003156 return NULL;
3157 nid_alloc = nid_here = numa_node_id();
3158 if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
3159 nid_alloc = cpuset_mem_spread_node();
3160 else if (current->mempolicy)
3161 nid_alloc = slab_node(current->mempolicy);
3162 if (nid_alloc != nid_here)
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003163 return ____cache_alloc_node(cachep, flags, nid_alloc);
Paul Jacksonc61afb12006-03-24 03:16:08 -08003164 return NULL;
3165}
3166
3167/*
Christoph Lameter765c4502006-09-27 01:50:08 -07003168 * Fallback function if there was no memory available and no objects on a
3169 * certain node and we are allowed to fall back. We mimick the behavior of
3170 * the page allocator. We fall back according to a zonelist determined by
3171 * the policy layer while obeying cpuset constraints.
3172 */
3173void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
3174{
3175 struct zonelist *zonelist = &NODE_DATA(slab_node(current->mempolicy))
3176 ->node_zonelists[gfp_zone(flags)];
3177 struct zone **z;
3178 void *obj = NULL;
3179
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003180 for (z = zonelist->zones; *z && !obj; z++) {
3181 int nid = zone_to_nid(*z);
3182
Christoph Lameter765c4502006-09-27 01:50:08 -07003183 if (zone_idx(*z) <= ZONE_NORMAL &&
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003184 cpuset_zone_allowed(*z, flags) &&
3185 cache->nodelists[nid])
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003186 obj = ____cache_alloc_node(cache,
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003187 flags | __GFP_THISNODE, nid);
3188 }
Christoph Lameter765c4502006-09-27 01:50:08 -07003189 return obj;
3190}
3191
3192/*
Christoph Lametere498be72005-09-09 13:03:32 -07003193 * A interface to enable slab creation on nodeid
Linus Torvalds1da177e2005-04-16 15:20:36 -07003194 */
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003195static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003196 int nodeid)
Christoph Lametere498be72005-09-09 13:03:32 -07003197{
3198 struct list_head *entry;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003199 struct slab *slabp;
3200 struct kmem_list3 *l3;
3201 void *obj;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003202 int x;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003203
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003204 l3 = cachep->nodelists[nodeid];
3205 BUG_ON(!l3);
Christoph Lametere498be72005-09-09 13:03:32 -07003206
Andrew Mortona737b3e2006-03-22 00:08:11 -08003207retry:
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08003208 check_irq_off();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003209 spin_lock(&l3->list_lock);
3210 entry = l3->slabs_partial.next;
3211 if (entry == &l3->slabs_partial) {
3212 l3->free_touched = 1;
3213 entry = l3->slabs_free.next;
3214 if (entry == &l3->slabs_free)
3215 goto must_grow;
3216 }
Christoph Lametere498be72005-09-09 13:03:32 -07003217
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003218 slabp = list_entry(entry, struct slab, list);
3219 check_spinlock_acquired_node(cachep, nodeid);
3220 check_slabp(cachep, slabp);
Christoph Lametere498be72005-09-09 13:03:32 -07003221
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003222 STATS_INC_NODEALLOCS(cachep);
3223 STATS_INC_ACTIVE(cachep);
3224 STATS_SET_HIGH(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003225
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003226 BUG_ON(slabp->inuse == cachep->num);
Christoph Lametere498be72005-09-09 13:03:32 -07003227
Matthew Dobson78d382d2006-02-01 03:05:47 -08003228 obj = slab_get_obj(cachep, slabp, nodeid);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003229 check_slabp(cachep, slabp);
3230 l3->free_objects--;
3231 /* move slabp to correct slabp list: */
3232 list_del(&slabp->list);
Christoph Lametere498be72005-09-09 13:03:32 -07003233
Andrew Mortona737b3e2006-03-22 00:08:11 -08003234 if (slabp->free == BUFCTL_END)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003235 list_add(&slabp->list, &l3->slabs_full);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003236 else
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003237 list_add(&slabp->list, &l3->slabs_partial);
Christoph Lametere498be72005-09-09 13:03:32 -07003238
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003239 spin_unlock(&l3->list_lock);
3240 goto done;
Christoph Lametere498be72005-09-09 13:03:32 -07003241
Andrew Mortona737b3e2006-03-22 00:08:11 -08003242must_grow:
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003243 spin_unlock(&l3->list_lock);
3244 x = cache_grow(cachep, flags, nodeid);
Christoph Lameter765c4502006-09-27 01:50:08 -07003245 if (x)
3246 goto retry;
Christoph Lametere498be72005-09-09 13:03:32 -07003247
Christoph Lameter765c4502006-09-27 01:50:08 -07003248 if (!(flags & __GFP_THISNODE))
3249 /* Unable to grow the cache. Fall back to other nodes. */
3250 return fallback_alloc(cachep, flags);
Christoph Lametere498be72005-09-09 13:03:32 -07003251
Christoph Lameter765c4502006-09-27 01:50:08 -07003252 return NULL;
3253
Andrew Mortona737b3e2006-03-22 00:08:11 -08003254done:
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003255 return obj;
Christoph Lametere498be72005-09-09 13:03:32 -07003256}
3257#endif
3258
3259/*
3260 * Caller needs to acquire correct kmem_list's list_lock
3261 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003262static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003263 int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003264{
3265 int i;
Christoph Lametere498be72005-09-09 13:03:32 -07003266 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003267
3268 for (i = 0; i < nr_objects; i++) {
3269 void *objp = objpp[i];
3270 struct slab *slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003271
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -08003272 slabp = virt_to_slab(objp);
Christoph Lameterff694162005-09-22 21:44:02 -07003273 l3 = cachep->nodelists[node];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003274 list_del(&slabp->list);
Christoph Lameterff694162005-09-22 21:44:02 -07003275 check_spinlock_acquired_node(cachep, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003276 check_slabp(cachep, slabp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08003277 slab_put_obj(cachep, slabp, objp, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003278 STATS_DEC_ACTIVE(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003279 l3->free_objects++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003280 check_slabp(cachep, slabp);
3281
3282 /* fixup slab chains */
3283 if (slabp->inuse == 0) {
Christoph Lametere498be72005-09-09 13:03:32 -07003284 if (l3->free_objects > l3->free_limit) {
3285 l3->free_objects -= cachep->num;
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07003286 /* No need to drop any previously held
3287 * lock here, even if we have a off-slab slab
3288 * descriptor it is guaranteed to come from
3289 * a different cache, refer to comments before
3290 * alloc_slabmgmt.
3291 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003292 slab_destroy(cachep, slabp);
3293 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07003294 list_add(&slabp->list, &l3->slabs_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003295 }
3296 } else {
3297 /* Unconditionally move a slab to the end of the
3298 * partial list on free - maximum time for the
3299 * other objects to be freed, too.
3300 */
Christoph Lametere498be72005-09-09 13:03:32 -07003301 list_add_tail(&slabp->list, &l3->slabs_partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003302 }
3303 }
3304}
3305
Pekka Enberg343e0d72006-02-01 03:05:50 -08003306static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003307{
3308 int batchcount;
Christoph Lametere498be72005-09-09 13:03:32 -07003309 struct kmem_list3 *l3;
Christoph Lameterff694162005-09-22 21:44:02 -07003310 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003311
3312 batchcount = ac->batchcount;
3313#if DEBUG
3314 BUG_ON(!batchcount || batchcount > ac->avail);
3315#endif
3316 check_irq_off();
Christoph Lameterff694162005-09-22 21:44:02 -07003317 l3 = cachep->nodelists[node];
Ingo Molnar873623d2006-07-13 14:44:38 +02003318 spin_lock(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07003319 if (l3->shared) {
3320 struct array_cache *shared_array = l3->shared;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003321 int max = shared_array->limit - shared_array->avail;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003322 if (max) {
3323 if (batchcount > max)
3324 batchcount = max;
Christoph Lametere498be72005-09-09 13:03:32 -07003325 memcpy(&(shared_array->entry[shared_array->avail]),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003326 ac->entry, sizeof(void *) * batchcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003327 shared_array->avail += batchcount;
3328 goto free_done;
3329 }
3330 }
3331
Christoph Lameterff694162005-09-22 21:44:02 -07003332 free_block(cachep, ac->entry, batchcount, node);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003333free_done:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003334#if STATS
3335 {
3336 int i = 0;
3337 struct list_head *p;
3338
Christoph Lametere498be72005-09-09 13:03:32 -07003339 p = l3->slabs_free.next;
3340 while (p != &(l3->slabs_free)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003341 struct slab *slabp;
3342
3343 slabp = list_entry(p, struct slab, list);
3344 BUG_ON(slabp->inuse);
3345
3346 i++;
3347 p = p->next;
3348 }
3349 STATS_SET_FREEABLE(cachep, i);
3350 }
3351#endif
Christoph Lametere498be72005-09-09 13:03:32 -07003352 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003353 ac->avail -= batchcount;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003354 memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003355}
3356
3357/*
Andrew Mortona737b3e2006-03-22 00:08:11 -08003358 * Release an obj back to its cache. If the obj has a constructed state, it must
3359 * be in this state _before_ it is released. Called with disabled ints.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003360 */
Ingo Molnar873623d2006-07-13 14:44:38 +02003361static inline void __cache_free(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003362{
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003363 struct array_cache *ac = cpu_cache_get(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003364
3365 check_irq_off();
3366 objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
3367
Ingo Molnar873623d2006-07-13 14:44:38 +02003368 if (cache_free_alien(cachep, objp))
Pekka Enberg729bd0b2006-06-23 02:03:05 -07003369 return;
Christoph Lametere498be72005-09-09 13:03:32 -07003370
Linus Torvalds1da177e2005-04-16 15:20:36 -07003371 if (likely(ac->avail < ac->limit)) {
3372 STATS_INC_FREEHIT(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003373 ac->entry[ac->avail++] = objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003374 return;
3375 } else {
3376 STATS_INC_FREEMISS(cachep);
3377 cache_flusharray(cachep, ac);
Christoph Lametere498be72005-09-09 13:03:32 -07003378 ac->entry[ac->avail++] = objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003379 }
3380}
3381
3382/**
3383 * kmem_cache_alloc - Allocate an object
3384 * @cachep: The cache to allocate from.
3385 * @flags: See kmalloc().
3386 *
3387 * Allocate an object from this cache. The flags are only relevant
3388 * if the cache has no available objects.
3389 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003390void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003391{
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003392 return __cache_alloc(cachep, flags, __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003393}
3394EXPORT_SYMBOL(kmem_cache_alloc);
3395
3396/**
Rolf Eike Beerb8008b22006-07-30 03:04:04 -07003397 * kmem_cache_zalloc - Allocate an object. The memory is set to zero.
Pekka Enberga8c0f9a2006-03-25 03:06:42 -08003398 * @cache: The cache to allocate from.
3399 * @flags: See kmalloc().
3400 *
3401 * Allocate an object from this cache and set the allocated memory to zero.
3402 * The flags are only relevant if the cache has no available objects.
3403 */
3404void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags)
3405{
3406 void *ret = __cache_alloc(cache, flags, __builtin_return_address(0));
3407 if (ret)
3408 memset(ret, 0, obj_size(cache));
3409 return ret;
3410}
3411EXPORT_SYMBOL(kmem_cache_zalloc);
3412
3413/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07003414 * kmem_ptr_validate - check if an untrusted pointer might
3415 * be a slab entry.
3416 * @cachep: the cache we're checking against
3417 * @ptr: pointer to validate
3418 *
3419 * This verifies that the untrusted pointer looks sane:
3420 * it is _not_ a guarantee that the pointer is actually
3421 * part of the slab cache in question, but it at least
3422 * validates that the pointer can be dereferenced and
3423 * looks half-way sane.
3424 *
3425 * Currently only used for dentry validation.
3426 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003427int fastcall kmem_ptr_validate(struct kmem_cache *cachep, void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003428{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003429 unsigned long addr = (unsigned long)ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003430 unsigned long min_addr = PAGE_OFFSET;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003431 unsigned long align_mask = BYTES_PER_WORD - 1;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003432 unsigned long size = cachep->buffer_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003433 struct page *page;
3434
3435 if (unlikely(addr < min_addr))
3436 goto out;
3437 if (unlikely(addr > (unsigned long)high_memory - size))
3438 goto out;
3439 if (unlikely(addr & align_mask))
3440 goto out;
3441 if (unlikely(!kern_addr_valid(addr)))
3442 goto out;
3443 if (unlikely(!kern_addr_valid(addr + size - 1)))
3444 goto out;
3445 page = virt_to_page(ptr);
3446 if (unlikely(!PageSlab(page)))
3447 goto out;
Pekka Enberg065d41c2005-11-13 16:06:46 -08003448 if (unlikely(page_get_cache(page) != cachep))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003449 goto out;
3450 return 1;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003451out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003452 return 0;
3453}
3454
3455#ifdef CONFIG_NUMA
3456/**
3457 * kmem_cache_alloc_node - Allocate an object on the specified node
3458 * @cachep: The cache to allocate from.
3459 * @flags: See kmalloc().
3460 * @nodeid: node number of the target node.
3461 *
3462 * Identical to kmem_cache_alloc, except that this function is slow
3463 * and can sleep. And it will allocate memory on the given node, which
3464 * can improve the performance for cpu bound structures.
Christoph Lametere498be72005-09-09 13:03:32 -07003465 * New and improved: it will now make sure that the object gets
3466 * put on the correct node list so that there is no false sharing.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003467 */
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003468static __always_inline void *
3469__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
3470 int nodeid, void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003471{
Christoph Lametere498be72005-09-09 13:03:32 -07003472 unsigned long save_flags;
3473 void *ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003474
Christoph Lametere498be72005-09-09 13:03:32 -07003475 cache_alloc_debugcheck_before(cachep, flags);
3476 local_irq_save(save_flags);
Christoph Lameter18f820f2006-02-01 03:05:43 -08003477
3478 if (nodeid == -1 || nodeid == numa_node_id() ||
Andrew Mortona737b3e2006-03-22 00:08:11 -08003479 !cachep->nodelists[nodeid])
Alok N Kataria5c382302005-09-27 21:45:46 -07003480 ptr = ____cache_alloc(cachep, flags);
3481 else
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003482 ptr = ____cache_alloc_node(cachep, flags, nodeid);
Christoph Lametere498be72005-09-09 13:03:32 -07003483 local_irq_restore(save_flags);
Christoph Lameter18f820f2006-02-01 03:05:43 -08003484
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003485 ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003486
Christoph Lametere498be72005-09-09 13:03:32 -07003487 return ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003488}
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003489
3490void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
3491{
3492 return __cache_alloc_node(cachep, flags, nodeid,
3493 __builtin_return_address(0));
3494}
Linus Torvalds1da177e2005-04-16 15:20:36 -07003495EXPORT_SYMBOL(kmem_cache_alloc_node);
3496
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003497static __always_inline void *
3498__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003499{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003500 struct kmem_cache *cachep;
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003501
3502 cachep = kmem_find_general_cachep(size, flags);
3503 if (unlikely(cachep == NULL))
3504 return NULL;
3505 return kmem_cache_alloc_node(cachep, flags, node);
3506}
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003507
3508#ifdef CONFIG_DEBUG_SLAB
3509void *__kmalloc_node(size_t size, gfp_t flags, int node)
3510{
3511 return __do_kmalloc_node(size, flags, node,
3512 __builtin_return_address(0));
3513}
Christoph Hellwigdbe5e692006-09-25 23:31:36 -07003514EXPORT_SYMBOL(__kmalloc_node);
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003515
3516void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
3517 int node, void *caller)
3518{
3519 return __do_kmalloc_node(size, flags, node, caller);
3520}
3521EXPORT_SYMBOL(__kmalloc_node_track_caller);
3522#else
3523void *__kmalloc_node(size_t size, gfp_t flags, int node)
3524{
3525 return __do_kmalloc_node(size, flags, node, NULL);
3526}
3527EXPORT_SYMBOL(__kmalloc_node);
3528#endif /* CONFIG_DEBUG_SLAB */
3529#endif /* CONFIG_NUMA */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003530
3531/**
Paul Drynoff800590f2006-06-23 02:03:48 -07003532 * __do_kmalloc - allocate memory
Linus Torvalds1da177e2005-04-16 15:20:36 -07003533 * @size: how many bytes of memory are required.
Paul Drynoff800590f2006-06-23 02:03:48 -07003534 * @flags: the type of memory to allocate (see kmalloc).
Randy Dunlap911851e2006-03-22 00:08:14 -08003535 * @caller: function caller for debug tracking of the caller
Linus Torvalds1da177e2005-04-16 15:20:36 -07003536 */
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003537static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
3538 void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003539{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003540 struct kmem_cache *cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003541
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003542 /* If you want to save a few bytes .text space: replace
3543 * __ with kmem_.
3544 * Then kmalloc uses the uninlined functions instead of the inline
3545 * functions.
3546 */
3547 cachep = __find_general_cachep(size, flags);
Andrew Mortondbdb9042005-09-23 13:24:10 -07003548 if (unlikely(cachep == NULL))
3549 return NULL;
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003550 return __cache_alloc(cachep, flags, caller);
3551}
3552
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003553
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -07003554#ifdef CONFIG_DEBUG_SLAB
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003555void *__kmalloc(size_t size, gfp_t flags)
3556{
Al Viro871751e2006-03-25 03:06:39 -08003557 return __do_kmalloc(size, flags, __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003558}
3559EXPORT_SYMBOL(__kmalloc);
3560
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003561void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
3562{
3563 return __do_kmalloc(size, flags, caller);
3564}
3565EXPORT_SYMBOL(__kmalloc_track_caller);
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -07003566
3567#else
3568void *__kmalloc(size_t size, gfp_t flags)
3569{
3570 return __do_kmalloc(size, flags, NULL);
3571}
3572EXPORT_SYMBOL(__kmalloc);
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003573#endif
3574
Linus Torvalds1da177e2005-04-16 15:20:36 -07003575/**
3576 * kmem_cache_free - Deallocate an object
3577 * @cachep: The cache the allocation was from.
3578 * @objp: The previously allocated object.
3579 *
3580 * Free an object which was previously allocated from this
3581 * cache.
3582 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003583void kmem_cache_free(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003584{
3585 unsigned long flags;
3586
Pekka Enbergddc2e812006-06-23 02:03:40 -07003587 BUG_ON(virt_to_cache(objp) != cachep);
3588
Linus Torvalds1da177e2005-04-16 15:20:36 -07003589 local_irq_save(flags);
Ingo Molnar873623d2006-07-13 14:44:38 +02003590 __cache_free(cachep, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003591 local_irq_restore(flags);
3592}
3593EXPORT_SYMBOL(kmem_cache_free);
3594
3595/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07003596 * kfree - free previously allocated memory
3597 * @objp: pointer returned by kmalloc.
3598 *
Pekka Enberg80e93ef2005-09-09 13:10:16 -07003599 * If @objp is NULL, no operation is performed.
3600 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003601 * Don't free memory not originally allocated by kmalloc()
3602 * or you will run into trouble.
3603 */
3604void kfree(const void *objp)
3605{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003606 struct kmem_cache *c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003607 unsigned long flags;
3608
3609 if (unlikely(!objp))
3610 return;
3611 local_irq_save(flags);
3612 kfree_debugcheck(objp);
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -08003613 c = virt_to_cache(objp);
Ingo Molnarf9b84042006-06-27 02:54:49 -07003614 debug_check_no_locks_freed(objp, obj_size(c));
Ingo Molnar873623d2006-07-13 14:44:38 +02003615 __cache_free(c, (void *)objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003616 local_irq_restore(flags);
3617}
3618EXPORT_SYMBOL(kfree);
3619
Pekka Enberg343e0d72006-02-01 03:05:50 -08003620unsigned int kmem_cache_size(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003621{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003622 return obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003623}
3624EXPORT_SYMBOL(kmem_cache_size);
3625
Pekka Enberg343e0d72006-02-01 03:05:50 -08003626const char *kmem_cache_name(struct kmem_cache *cachep)
Arnaldo Carvalho de Melo19449722005-06-18 22:46:19 -07003627{
3628 return cachep->name;
3629}
3630EXPORT_SYMBOL_GPL(kmem_cache_name);
3631
Christoph Lametere498be72005-09-09 13:03:32 -07003632/*
Christoph Lameter0718dc22006-03-25 03:06:47 -08003633 * This initializes kmem_list3 or resizes varioius caches for all nodes.
Christoph Lametere498be72005-09-09 13:03:32 -07003634 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003635static int alloc_kmemlist(struct kmem_cache *cachep)
Christoph Lametere498be72005-09-09 13:03:32 -07003636{
3637 int node;
3638 struct kmem_list3 *l3;
Christoph Lametercafeb022006-03-25 03:06:46 -08003639 struct array_cache *new_shared;
Paul Menage3395ee02006-12-06 20:32:16 -08003640 struct array_cache **new_alien = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07003641
3642 for_each_online_node(node) {
Christoph Lametercafeb022006-03-25 03:06:46 -08003643
Paul Menage3395ee02006-12-06 20:32:16 -08003644 if (use_alien_caches) {
3645 new_alien = alloc_alien_cache(node, cachep->limit);
3646 if (!new_alien)
3647 goto fail;
3648 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003649
Christoph Lameter0718dc22006-03-25 03:06:47 -08003650 new_shared = alloc_arraycache(node,
3651 cachep->shared*cachep->batchcount,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003652 0xbaadf00d);
Christoph Lameter0718dc22006-03-25 03:06:47 -08003653 if (!new_shared) {
3654 free_alien_cache(new_alien);
Christoph Lametere498be72005-09-09 13:03:32 -07003655 goto fail;
Christoph Lameter0718dc22006-03-25 03:06:47 -08003656 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003657
Andrew Mortona737b3e2006-03-22 00:08:11 -08003658 l3 = cachep->nodelists[node];
3659 if (l3) {
Christoph Lametercafeb022006-03-25 03:06:46 -08003660 struct array_cache *shared = l3->shared;
3661
Christoph Lametere498be72005-09-09 13:03:32 -07003662 spin_lock_irq(&l3->list_lock);
3663
Christoph Lametercafeb022006-03-25 03:06:46 -08003664 if (shared)
Christoph Lameter0718dc22006-03-25 03:06:47 -08003665 free_block(cachep, shared->entry,
3666 shared->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07003667
Christoph Lametercafeb022006-03-25 03:06:46 -08003668 l3->shared = new_shared;
3669 if (!l3->alien) {
Christoph Lametere498be72005-09-09 13:03:32 -07003670 l3->alien = new_alien;
3671 new_alien = NULL;
3672 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003673 l3->free_limit = (1 + nr_cpus_node(node)) *
Andrew Mortona737b3e2006-03-22 00:08:11 -08003674 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07003675 spin_unlock_irq(&l3->list_lock);
Christoph Lametercafeb022006-03-25 03:06:46 -08003676 kfree(shared);
Christoph Lametere498be72005-09-09 13:03:32 -07003677 free_alien_cache(new_alien);
3678 continue;
3679 }
Andrew Mortona737b3e2006-03-22 00:08:11 -08003680 l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
Christoph Lameter0718dc22006-03-25 03:06:47 -08003681 if (!l3) {
3682 free_alien_cache(new_alien);
3683 kfree(new_shared);
Christoph Lametere498be72005-09-09 13:03:32 -07003684 goto fail;
Christoph Lameter0718dc22006-03-25 03:06:47 -08003685 }
Christoph Lametere498be72005-09-09 13:03:32 -07003686
3687 kmem_list3_init(l3);
3688 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
Andrew Mortona737b3e2006-03-22 00:08:11 -08003689 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametercafeb022006-03-25 03:06:46 -08003690 l3->shared = new_shared;
Christoph Lametere498be72005-09-09 13:03:32 -07003691 l3->alien = new_alien;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003692 l3->free_limit = (1 + nr_cpus_node(node)) *
Andrew Mortona737b3e2006-03-22 00:08:11 -08003693 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07003694 cachep->nodelists[node] = l3;
3695 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003696 return 0;
Christoph Lameter0718dc22006-03-25 03:06:47 -08003697
Andrew Mortona737b3e2006-03-22 00:08:11 -08003698fail:
Christoph Lameter0718dc22006-03-25 03:06:47 -08003699 if (!cachep->next.next) {
3700 /* Cache is not active yet. Roll back what we did */
3701 node--;
3702 while (node >= 0) {
3703 if (cachep->nodelists[node]) {
3704 l3 = cachep->nodelists[node];
3705
3706 kfree(l3->shared);
3707 free_alien_cache(l3->alien);
3708 kfree(l3);
3709 cachep->nodelists[node] = NULL;
3710 }
3711 node--;
3712 }
3713 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003714 return -ENOMEM;
Christoph Lametere498be72005-09-09 13:03:32 -07003715}
3716
Linus Torvalds1da177e2005-04-16 15:20:36 -07003717struct ccupdate_struct {
Pekka Enberg343e0d72006-02-01 03:05:50 -08003718 struct kmem_cache *cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003719 struct array_cache *new[NR_CPUS];
3720};
3721
3722static void do_ccupdate_local(void *info)
3723{
Andrew Mortona737b3e2006-03-22 00:08:11 -08003724 struct ccupdate_struct *new = info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003725 struct array_cache *old;
3726
3727 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003728 old = cpu_cache_get(new->cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003729
Linus Torvalds1da177e2005-04-16 15:20:36 -07003730 new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
3731 new->new[smp_processor_id()] = old;
3732}
3733
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -08003734/* Always called with the cache_chain_mutex held */
Andrew Mortona737b3e2006-03-22 00:08:11 -08003735static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
3736 int batchcount, int shared)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003737{
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003738 struct ccupdate_struct *new;
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003739 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003740
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003741 new = kzalloc(sizeof(*new), GFP_KERNEL);
3742 if (!new)
3743 return -ENOMEM;
3744
Christoph Lametere498be72005-09-09 13:03:32 -07003745 for_each_online_cpu(i) {
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003746 new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003747 batchcount);
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003748 if (!new->new[i]) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003749 for (i--; i >= 0; i--)
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003750 kfree(new->new[i]);
3751 kfree(new);
Christoph Lametere498be72005-09-09 13:03:32 -07003752 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003753 }
3754 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003755 new->cachep = cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003756
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003757 on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
Christoph Lametere498be72005-09-09 13:03:32 -07003758
Linus Torvalds1da177e2005-04-16 15:20:36 -07003759 check_irq_on();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003760 cachep->batchcount = batchcount;
3761 cachep->limit = limit;
Christoph Lametere498be72005-09-09 13:03:32 -07003762 cachep->shared = shared;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003763
Christoph Lametere498be72005-09-09 13:03:32 -07003764 for_each_online_cpu(i) {
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003765 struct array_cache *ccold = new->new[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003766 if (!ccold)
3767 continue;
Christoph Lametere498be72005-09-09 13:03:32 -07003768 spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
Christoph Lameterff694162005-09-22 21:44:02 -07003769 free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
Christoph Lametere498be72005-09-09 13:03:32 -07003770 spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003771 kfree(ccold);
3772 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003773 kfree(new);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003774 return alloc_kmemlist(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003775}
3776
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -08003777/* Called with cache_chain_mutex held always */
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003778static int enable_cpucache(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003779{
3780 int err;
3781 int limit, shared;
3782
Andrew Mortona737b3e2006-03-22 00:08:11 -08003783 /*
3784 * The head array serves three purposes:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003785 * - create a LIFO ordering, i.e. return objects that are cache-warm
3786 * - reduce the number of spinlock operations.
Andrew Mortona737b3e2006-03-22 00:08:11 -08003787 * - reduce the number of linked list operations on the slab and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003788 * bufctl chains: array operations are cheaper.
3789 * The numbers are guessed, we should auto-tune as described by
3790 * Bonwick.
3791 */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003792 if (cachep->buffer_size > 131072)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003793 limit = 1;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003794 else if (cachep->buffer_size > PAGE_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003795 limit = 8;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003796 else if (cachep->buffer_size > 1024)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003797 limit = 24;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003798 else if (cachep->buffer_size > 256)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003799 limit = 54;
3800 else
3801 limit = 120;
3802
Andrew Mortona737b3e2006-03-22 00:08:11 -08003803 /*
3804 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
Linus Torvalds1da177e2005-04-16 15:20:36 -07003805 * allocation behaviour: Most allocs on one cpu, most free operations
3806 * on another cpu. For these cases, an efficient object passing between
3807 * cpus is necessary. This is provided by a shared array. The array
3808 * replaces Bonwick's magazine layer.
3809 * On uniprocessor, it's functionally equivalent (but less efficient)
3810 * to a larger limit. Thus disabled by default.
3811 */
3812 shared = 0;
3813#ifdef CONFIG_SMP
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003814 if (cachep->buffer_size <= PAGE_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003815 shared = 8;
3816#endif
3817
3818#if DEBUG
Andrew Mortona737b3e2006-03-22 00:08:11 -08003819 /*
3820 * With debugging enabled, large batchcount lead to excessively long
3821 * periods with disabled local interrupts. Limit the batchcount
Linus Torvalds1da177e2005-04-16 15:20:36 -07003822 */
3823 if (limit > 32)
3824 limit = 32;
3825#endif
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003826 err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003827 if (err)
3828 printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003829 cachep->name, -err);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003830 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003831}
3832
Christoph Lameter1b552532006-03-22 00:09:07 -08003833/*
3834 * Drain an array if it contains any elements taking the l3 lock only if
Christoph Lameterb18e7e62006-03-22 00:09:07 -08003835 * necessary. Note that the l3 listlock also protects the array_cache
3836 * if drain_array() is used on the shared array.
Christoph Lameter1b552532006-03-22 00:09:07 -08003837 */
3838void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
3839 struct array_cache *ac, int force, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003840{
3841 int tofree;
3842
Christoph Lameter1b552532006-03-22 00:09:07 -08003843 if (!ac || !ac->avail)
3844 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003845 if (ac->touched && !force) {
3846 ac->touched = 0;
Christoph Lameterb18e7e62006-03-22 00:09:07 -08003847 } else {
Christoph Lameter1b552532006-03-22 00:09:07 -08003848 spin_lock_irq(&l3->list_lock);
Christoph Lameterb18e7e62006-03-22 00:09:07 -08003849 if (ac->avail) {
3850 tofree = force ? ac->avail : (ac->limit + 4) / 5;
3851 if (tofree > ac->avail)
3852 tofree = (ac->avail + 1) / 2;
3853 free_block(cachep, ac->entry, tofree, node);
3854 ac->avail -= tofree;
3855 memmove(ac->entry, &(ac->entry[tofree]),
3856 sizeof(void *) * ac->avail);
3857 }
Christoph Lameter1b552532006-03-22 00:09:07 -08003858 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003859 }
3860}
3861
3862/**
3863 * cache_reap - Reclaim memory from caches.
Randy Dunlap1e5d5332005-11-07 01:01:06 -08003864 * @unused: unused parameter
Linus Torvalds1da177e2005-04-16 15:20:36 -07003865 *
3866 * Called from workqueue/eventd every few seconds.
3867 * Purpose:
3868 * - clear the per-cpu caches for this CPU.
3869 * - return freeable pages to the main free memory pool.
3870 *
Andrew Mortona737b3e2006-03-22 00:08:11 -08003871 * If we cannot acquire the cache chain mutex then just give up - we'll try
3872 * again on the next iteration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003873 */
David Howells65f27f32006-11-22 14:55:48 +00003874static void cache_reap(struct work_struct *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003875{
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07003876 struct kmem_cache *searchp;
Christoph Lametere498be72005-09-09 13:03:32 -07003877 struct kmem_list3 *l3;
Christoph Lameteraab22072006-03-22 00:09:06 -08003878 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003879
Ingo Molnarfc0abb12006-01-18 17:42:33 -08003880 if (!mutex_trylock(&cache_chain_mutex)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003881 /* Give up. Setup the next iteration. */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003882 schedule_delayed_work(&__get_cpu_var(reap_work),
3883 REAPTIMEOUT_CPUC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003884 return;
3885 }
3886
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07003887 list_for_each_entry(searchp, &cache_chain, next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003888 check_irq_on();
3889
Christoph Lameter35386e32006-03-22 00:09:05 -08003890 /*
3891 * We only take the l3 lock if absolutely necessary and we
3892 * have established with reasonable certainty that
3893 * we can do some work if the lock was obtained.
3894 */
Christoph Lameteraab22072006-03-22 00:09:06 -08003895 l3 = searchp->nodelists[node];
Christoph Lameter35386e32006-03-22 00:09:05 -08003896
Christoph Lameter8fce4d82006-03-09 17:33:54 -08003897 reap_alien(searchp, l3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003898
Christoph Lameteraab22072006-03-22 00:09:06 -08003899 drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003900
Christoph Lameter35386e32006-03-22 00:09:05 -08003901 /*
3902 * These are racy checks but it does not matter
3903 * if we skip one check or scan twice.
3904 */
Christoph Lametere498be72005-09-09 13:03:32 -07003905 if (time_after(l3->next_reap, jiffies))
Christoph Lameter35386e32006-03-22 00:09:05 -08003906 goto next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003907
Christoph Lametere498be72005-09-09 13:03:32 -07003908 l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003909
Christoph Lameteraab22072006-03-22 00:09:06 -08003910 drain_array(searchp, l3, l3->shared, 0, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003911
Christoph Lametered11d9e2006-06-30 01:55:45 -07003912 if (l3->free_touched)
Christoph Lametere498be72005-09-09 13:03:32 -07003913 l3->free_touched = 0;
Christoph Lametered11d9e2006-06-30 01:55:45 -07003914 else {
3915 int freed;
3916
3917 freed = drain_freelist(searchp, l3, (l3->free_limit +
3918 5 * searchp->num - 1) / (5 * searchp->num));
3919 STATS_ADD_REAPED(searchp, freed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003920 }
Christoph Lameter35386e32006-03-22 00:09:05 -08003921next:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003922 cond_resched();
3923 }
3924 check_irq_on();
Ingo Molnarfc0abb12006-01-18 17:42:33 -08003925 mutex_unlock(&cache_chain_mutex);
Christoph Lameter8fce4d82006-03-09 17:33:54 -08003926 next_reap_node();
Christoph Lameter2244b952006-06-30 01:55:33 -07003927 refresh_cpu_vm_stats(smp_processor_id());
Andrew Mortona737b3e2006-03-22 00:08:11 -08003928 /* Set up the next iteration */
Manfred Spraulcd61ef62005-11-07 00:58:02 -08003929 schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003930}
3931
3932#ifdef CONFIG_PROC_FS
3933
Pekka Enberg85289f92006-01-08 01:00:36 -08003934static void print_slabinfo_header(struct seq_file *m)
3935{
3936 /*
3937 * Output format version, so at least we can change it
3938 * without _too_ many complaints.
3939 */
3940#if STATS
3941 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
3942#else
3943 seq_puts(m, "slabinfo - version: 2.1\n");
3944#endif
3945 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
3946 "<objperslab> <pagesperslab>");
3947 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
3948 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
3949#if STATS
3950 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07003951 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
Pekka Enberg85289f92006-01-08 01:00:36 -08003952 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
3953#endif
3954 seq_putc(m, '\n');
3955}
3956
Linus Torvalds1da177e2005-04-16 15:20:36 -07003957static void *s_start(struct seq_file *m, loff_t *pos)
3958{
3959 loff_t n = *pos;
3960 struct list_head *p;
3961
Ingo Molnarfc0abb12006-01-18 17:42:33 -08003962 mutex_lock(&cache_chain_mutex);
Pekka Enberg85289f92006-01-08 01:00:36 -08003963 if (!n)
3964 print_slabinfo_header(m);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003965 p = cache_chain.next;
3966 while (n--) {
3967 p = p->next;
3968 if (p == &cache_chain)
3969 return NULL;
3970 }
Pekka Enberg343e0d72006-02-01 03:05:50 -08003971 return list_entry(p, struct kmem_cache, next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003972}
3973
3974static void *s_next(struct seq_file *m, void *p, loff_t *pos)
3975{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003976 struct kmem_cache *cachep = p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003977 ++*pos;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003978 return cachep->next.next == &cache_chain ?
3979 NULL : list_entry(cachep->next.next, struct kmem_cache, next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003980}
3981
3982static void s_stop(struct seq_file *m, void *p)
3983{
Ingo Molnarfc0abb12006-01-18 17:42:33 -08003984 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003985}
3986
3987static int s_show(struct seq_file *m, void *p)
3988{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003989 struct kmem_cache *cachep = p;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003990 struct slab *slabp;
3991 unsigned long active_objs;
3992 unsigned long num_objs;
3993 unsigned long active_slabs = 0;
3994 unsigned long num_slabs, free_objects = 0, shared_avail = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07003995 const char *name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003996 char *error = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07003997 int node;
3998 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003999
Linus Torvalds1da177e2005-04-16 15:20:36 -07004000 active_objs = 0;
4001 num_slabs = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07004002 for_each_online_node(node) {
4003 l3 = cachep->nodelists[node];
4004 if (!l3)
4005 continue;
4006
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08004007 check_irq_on();
4008 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07004009
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004010 list_for_each_entry(slabp, &l3->slabs_full, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004011 if (slabp->inuse != cachep->num && !error)
4012 error = "slabs_full accounting error";
4013 active_objs += cachep->num;
4014 active_slabs++;
4015 }
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004016 list_for_each_entry(slabp, &l3->slabs_partial, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004017 if (slabp->inuse == cachep->num && !error)
4018 error = "slabs_partial inuse accounting error";
4019 if (!slabp->inuse && !error)
4020 error = "slabs_partial/inuse accounting error";
4021 active_objs += slabp->inuse;
4022 active_slabs++;
4023 }
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004024 list_for_each_entry(slabp, &l3->slabs_free, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004025 if (slabp->inuse && !error)
4026 error = "slabs_free/inuse accounting error";
4027 num_slabs++;
4028 }
4029 free_objects += l3->free_objects;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08004030 if (l3->shared)
4031 shared_avail += l3->shared->avail;
Christoph Lametere498be72005-09-09 13:03:32 -07004032
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08004033 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004034 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004035 num_slabs += active_slabs;
4036 num_objs = num_slabs * cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07004037 if (num_objs - active_objs != free_objects && !error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004038 error = "free_objects accounting error";
4039
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004040 name = cachep->name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004041 if (error)
4042 printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
4043
4044 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
Manfred Spraul3dafccf2006-02-01 03:05:42 -08004045 name, active_objs, num_objs, cachep->buffer_size,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004046 cachep->num, (1 << cachep->gfporder));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004047 seq_printf(m, " : tunables %4u %4u %4u",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004048 cachep->limit, cachep->batchcount, cachep->shared);
Christoph Lametere498be72005-09-09 13:03:32 -07004049 seq_printf(m, " : slabdata %6lu %6lu %6lu",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004050 active_slabs, num_slabs, shared_avail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004051#if STATS
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004052 { /* list3 stats */
Linus Torvalds1da177e2005-04-16 15:20:36 -07004053 unsigned long high = cachep->high_mark;
4054 unsigned long allocs = cachep->num_allocations;
4055 unsigned long grown = cachep->grown;
4056 unsigned long reaped = cachep->reaped;
4057 unsigned long errors = cachep->errors;
4058 unsigned long max_freeable = cachep->max_freeable;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004059 unsigned long node_allocs = cachep->node_allocs;
Christoph Lametere498be72005-09-09 13:03:32 -07004060 unsigned long node_frees = cachep->node_frees;
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004061 unsigned long overflows = cachep->node_overflow;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004062
Christoph Lametere498be72005-09-09 13:03:32 -07004063 seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004064 %4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
Andrew Mortona737b3e2006-03-22 00:08:11 -08004065 reaped, errors, max_freeable, node_allocs,
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004066 node_frees, overflows);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004067 }
4068 /* cpu stats */
4069 {
4070 unsigned long allochit = atomic_read(&cachep->allochit);
4071 unsigned long allocmiss = atomic_read(&cachep->allocmiss);
4072 unsigned long freehit = atomic_read(&cachep->freehit);
4073 unsigned long freemiss = atomic_read(&cachep->freemiss);
4074
4075 seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004076 allochit, allocmiss, freehit, freemiss);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004077 }
4078#endif
4079 seq_putc(m, '\n');
Linus Torvalds1da177e2005-04-16 15:20:36 -07004080 return 0;
4081}
4082
4083/*
4084 * slabinfo_op - iterator that generates /proc/slabinfo
4085 *
4086 * Output layout:
4087 * cache-name
4088 * num-active-objs
4089 * total-objs
4090 * object size
4091 * num-active-slabs
4092 * total-slabs
4093 * num-pages-per-slab
4094 * + further values on SMP and with statistics enabled
4095 */
4096
4097struct seq_operations slabinfo_op = {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004098 .start = s_start,
4099 .next = s_next,
4100 .stop = s_stop,
4101 .show = s_show,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004102};
4103
4104#define MAX_SLABINFO_WRITE 128
4105/**
4106 * slabinfo_write - Tuning for the slab allocator
4107 * @file: unused
4108 * @buffer: user buffer
4109 * @count: data length
4110 * @ppos: unused
4111 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004112ssize_t slabinfo_write(struct file *file, const char __user * buffer,
4113 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004114{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004115 char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004116 int limit, batchcount, shared, res;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004117 struct kmem_cache *cachep;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004118
Linus Torvalds1da177e2005-04-16 15:20:36 -07004119 if (count > MAX_SLABINFO_WRITE)
4120 return -EINVAL;
4121 if (copy_from_user(&kbuf, buffer, count))
4122 return -EFAULT;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004123 kbuf[MAX_SLABINFO_WRITE] = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -07004124
4125 tmp = strchr(kbuf, ' ');
4126 if (!tmp)
4127 return -EINVAL;
4128 *tmp = '\0';
4129 tmp++;
4130 if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
4131 return -EINVAL;
4132
4133 /* Find the cache in the chain of caches. */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004134 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004135 res = -EINVAL;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004136 list_for_each_entry(cachep, &cache_chain, next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004137 if (!strcmp(cachep->name, kbuf)) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08004138 if (limit < 1 || batchcount < 1 ||
4139 batchcount > limit || shared < 0) {
Christoph Lametere498be72005-09-09 13:03:32 -07004140 res = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004141 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07004142 res = do_tune_cpucache(cachep, limit,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004143 batchcount, shared);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004144 }
4145 break;
4146 }
4147 }
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004148 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004149 if (res >= 0)
4150 res = count;
4151 return res;
4152}
Al Viro871751e2006-03-25 03:06:39 -08004153
4154#ifdef CONFIG_DEBUG_SLAB_LEAK
4155
4156static void *leaks_start(struct seq_file *m, loff_t *pos)
4157{
4158 loff_t n = *pos;
4159 struct list_head *p;
4160
4161 mutex_lock(&cache_chain_mutex);
4162 p = cache_chain.next;
4163 while (n--) {
4164 p = p->next;
4165 if (p == &cache_chain)
4166 return NULL;
4167 }
4168 return list_entry(p, struct kmem_cache, next);
4169}
4170
4171static inline int add_caller(unsigned long *n, unsigned long v)
4172{
4173 unsigned long *p;
4174 int l;
4175 if (!v)
4176 return 1;
4177 l = n[1];
4178 p = n + 2;
4179 while (l) {
4180 int i = l/2;
4181 unsigned long *q = p + 2 * i;
4182 if (*q == v) {
4183 q[1]++;
4184 return 1;
4185 }
4186 if (*q > v) {
4187 l = i;
4188 } else {
4189 p = q + 2;
4190 l -= i + 1;
4191 }
4192 }
4193 if (++n[1] == n[0])
4194 return 0;
4195 memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n));
4196 p[0] = v;
4197 p[1] = 1;
4198 return 1;
4199}
4200
4201static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
4202{
4203 void *p;
4204 int i;
4205 if (n[0] == n[1])
4206 return;
4207 for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) {
4208 if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
4209 continue;
4210 if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
4211 return;
4212 }
4213}
4214
4215static void show_symbol(struct seq_file *m, unsigned long address)
4216{
4217#ifdef CONFIG_KALLSYMS
4218 char *modname;
4219 const char *name;
4220 unsigned long offset, size;
4221 char namebuf[KSYM_NAME_LEN+1];
4222
4223 name = kallsyms_lookup(address, &size, &offset, &modname, namebuf);
4224
4225 if (name) {
4226 seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
4227 if (modname)
4228 seq_printf(m, " [%s]", modname);
4229 return;
4230 }
4231#endif
4232 seq_printf(m, "%p", (void *)address);
4233}
4234
4235static int leaks_show(struct seq_file *m, void *p)
4236{
4237 struct kmem_cache *cachep = p;
Al Viro871751e2006-03-25 03:06:39 -08004238 struct slab *slabp;
4239 struct kmem_list3 *l3;
4240 const char *name;
4241 unsigned long *n = m->private;
4242 int node;
4243 int i;
4244
4245 if (!(cachep->flags & SLAB_STORE_USER))
4246 return 0;
4247 if (!(cachep->flags & SLAB_RED_ZONE))
4248 return 0;
4249
4250 /* OK, we can do it */
4251
4252 n[1] = 0;
4253
4254 for_each_online_node(node) {
4255 l3 = cachep->nodelists[node];
4256 if (!l3)
4257 continue;
4258
4259 check_irq_on();
4260 spin_lock_irq(&l3->list_lock);
4261
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004262 list_for_each_entry(slabp, &l3->slabs_full, list)
Al Viro871751e2006-03-25 03:06:39 -08004263 handle_slab(n, cachep, slabp);
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004264 list_for_each_entry(slabp, &l3->slabs_partial, list)
Al Viro871751e2006-03-25 03:06:39 -08004265 handle_slab(n, cachep, slabp);
Al Viro871751e2006-03-25 03:06:39 -08004266 spin_unlock_irq(&l3->list_lock);
4267 }
4268 name = cachep->name;
4269 if (n[0] == n[1]) {
4270 /* Increase the buffer size */
4271 mutex_unlock(&cache_chain_mutex);
4272 m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
4273 if (!m->private) {
4274 /* Too bad, we are really out */
4275 m->private = n;
4276 mutex_lock(&cache_chain_mutex);
4277 return -ENOMEM;
4278 }
4279 *(unsigned long *)m->private = n[0] * 2;
4280 kfree(n);
4281 mutex_lock(&cache_chain_mutex);
4282 /* Now make sure this entry will be retried */
4283 m->count = m->size;
4284 return 0;
4285 }
4286 for (i = 0; i < n[1]; i++) {
4287 seq_printf(m, "%s: %lu ", name, n[2*i+3]);
4288 show_symbol(m, n[2*i+2]);
4289 seq_putc(m, '\n');
4290 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07004291
Al Viro871751e2006-03-25 03:06:39 -08004292 return 0;
4293}
4294
4295struct seq_operations slabstats_op = {
4296 .start = leaks_start,
4297 .next = s_next,
4298 .stop = s_stop,
4299 .show = leaks_show,
4300};
4301#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07004302#endif
4303
Manfred Spraul00e145b2005-09-03 15:55:07 -07004304/**
4305 * ksize - get the actual amount of memory allocated for a given object
4306 * @objp: Pointer to the object
4307 *
4308 * kmalloc may internally round up allocations and return more memory
4309 * than requested. ksize() can be used to determine the actual amount of
4310 * memory allocated. The caller may use this additional memory, even though
4311 * a smaller amount of memory was initially specified with the kmalloc call.
4312 * The caller must guarantee that objp points to a valid object previously
4313 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4314 * must not be freed during the duration of the call.
4315 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07004316unsigned int ksize(const void *objp)
4317{
Manfred Spraul00e145b2005-09-03 15:55:07 -07004318 if (unlikely(objp == NULL))
4319 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004320
Pekka Enberg6ed5eb2212006-02-01 03:05:49 -08004321 return obj_size(virt_to_cache(objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004322}