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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/mm/slab.c
3 * Written by Mark Hemment, 1996/97.
4 * (markhe@nextd.demon.co.uk)
5 *
6 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
7 *
8 * Major cleanup, different bufctl logic, per-cpu arrays
9 * (c) 2000 Manfred Spraul
10 *
11 * Cleanup, make the head arrays unconditional, preparation for NUMA
12 * (c) 2002 Manfred Spraul
13 *
14 * An implementation of the Slab Allocator as described in outline in;
15 * UNIX Internals: The New Frontiers by Uresh Vahalia
16 * Pub: Prentice Hall ISBN 0-13-101908-2
17 * or with a little more detail in;
18 * The Slab Allocator: An Object-Caching Kernel Memory Allocator
19 * Jeff Bonwick (Sun Microsystems).
20 * Presented at: USENIX Summer 1994 Technical Conference
21 *
22 * The memory is organized in caches, one cache for each object type.
23 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
24 * Each cache consists out of many slabs (they are small (usually one
25 * page long) and always contiguous), and each slab contains multiple
26 * initialized objects.
27 *
28 * This means, that your constructor is used only for newly allocated
29 * slabs and you must pass objects with the same intializations to
30 * kmem_cache_free.
31 *
32 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
33 * normal). If you need a special memory type, then must create a new
34 * cache for that memory type.
35 *
36 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
37 * full slabs with 0 free objects
38 * partial slabs
39 * empty slabs with no allocated objects
40 *
41 * If partial slabs exist, then new allocations come from these slabs,
42 * otherwise from empty slabs or new slabs are allocated.
43 *
44 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
45 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
46 *
47 * Each cache has a short per-cpu head array, most allocs
48 * and frees go into that array, and if that array overflows, then 1/2
49 * of the entries in the array are given back into the global cache.
50 * The head array is strictly LIFO and should improve the cache hit rates.
51 * On SMP, it additionally reduces the spinlock operations.
52 *
Andrew Mortona737b3e2006-03-22 00:08:11 -080053 * The c_cpuarray may not be read with enabled local interrupts -
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 * it's changed with a smp_call_function().
55 *
56 * SMP synchronization:
57 * constructors and destructors are called without any locking.
Pekka Enberg343e0d72006-02-01 03:05:50 -080058 * Several members in struct kmem_cache and struct slab never change, they
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 * are accessed without any locking.
60 * The per-cpu arrays are never accessed from the wrong cpu, no locking,
61 * and local interrupts are disabled so slab code is preempt-safe.
62 * The non-constant members are protected with a per-cache irq spinlock.
63 *
64 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
65 * in 2000 - many ideas in the current implementation are derived from
66 * his patch.
67 *
68 * Further notes from the original documentation:
69 *
70 * 11 April '97. Started multi-threading - markhe
Ingo Molnarfc0abb12006-01-18 17:42:33 -080071 * The global cache-chain is protected by the mutex 'cache_chain_mutex'.
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 * The sem is only needed when accessing/extending the cache-chain, which
73 * can never happen inside an interrupt (kmem_cache_create(),
74 * kmem_cache_shrink() and kmem_cache_reap()).
75 *
76 * At present, each engine can be growing a cache. This should be blocked.
77 *
Christoph Lametere498be72005-09-09 13:03:32 -070078 * 15 March 2005. NUMA slab allocator.
79 * Shai Fultheim <shai@scalex86.org>.
80 * Shobhit Dayal <shobhit@calsoftinc.com>
81 * Alok N Kataria <alokk@calsoftinc.com>
82 * Christoph Lameter <christoph@lameter.com>
83 *
84 * Modified the slab allocator to be node aware on NUMA systems.
85 * Each node has its own list of partial, free and full slabs.
86 * All object allocations for a node occur from node specific slab lists.
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 */
88
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#include <linux/slab.h>
90#include <linux/mm.h>
Randy Dunlapc9cf5522006-06-27 02:53:52 -070091#include <linux/poison.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070092#include <linux/swap.h>
93#include <linux/cache.h>
94#include <linux/interrupt.h>
95#include <linux/init.h>
96#include <linux/compiler.h>
Paul Jackson101a5002006-03-24 03:16:07 -080097#include <linux/cpuset.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070098#include <linux/seq_file.h>
99#include <linux/notifier.h>
100#include <linux/kallsyms.h>
101#include <linux/cpu.h>
102#include <linux/sysctl.h>
103#include <linux/module.h>
104#include <linux/rcupdate.h>
Paulo Marques543537b2005-06-23 00:09:02 -0700105#include <linux/string.h>
Andrew Morton138ae662006-12-06 20:36:41 -0800106#include <linux/uaccess.h>
Christoph Lametere498be72005-09-09 13:03:32 -0700107#include <linux/nodemask.h>
Christoph Lameterdc85da12006-01-18 17:42:36 -0800108#include <linux/mempolicy.h>
Ingo Molnarfc0abb12006-01-18 17:42:33 -0800109#include <linux/mutex.h>
Akinobu Mita8a8b6502006-12-08 02:39:44 -0800110#include <linux/fault-inject.h>
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700111#include <linux/rtmutex.h>
Eric Dumazet6a2d7a92006-12-13 00:34:27 -0800112#include <linux/reciprocal_div.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114#include <asm/cacheflush.h>
115#include <asm/tlbflush.h>
116#include <asm/page.h>
117
118/*
119 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
120 * SLAB_RED_ZONE & SLAB_POISON.
121 * 0 for faster, smaller code (especially in the critical paths).
122 *
123 * STATS - 1 to collect stats for /proc/slabinfo.
124 * 0 for faster, smaller code (especially in the critical paths).
125 *
126 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
127 */
128
129#ifdef CONFIG_DEBUG_SLAB
130#define DEBUG 1
131#define STATS 1
132#define FORCED_DEBUG 1
133#else
134#define DEBUG 0
135#define STATS 0
136#define FORCED_DEBUG 0
137#endif
138
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139/* Shouldn't this be in a header file somewhere? */
140#define BYTES_PER_WORD sizeof(void *)
141
142#ifndef cache_line_size
143#define cache_line_size() L1_CACHE_BYTES
144#endif
145
146#ifndef ARCH_KMALLOC_MINALIGN
147/*
148 * Enforce a minimum alignment for the kmalloc caches.
149 * Usually, the kmalloc caches are cache_line_size() aligned, except when
150 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
151 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
152 * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
153 * Note that this flag disables some debug features.
154 */
155#define ARCH_KMALLOC_MINALIGN 0
156#endif
157
158#ifndef ARCH_SLAB_MINALIGN
159/*
160 * Enforce a minimum alignment for all caches.
161 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
162 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
163 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
164 * some debug features.
165 */
166#define ARCH_SLAB_MINALIGN 0
167#endif
168
169#ifndef ARCH_KMALLOC_FLAGS
170#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
171#endif
172
173/* Legal flag mask for kmem_cache_create(). */
174#if DEBUG
175# define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
176 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
Christoph Lameterac2b8982006-03-22 00:08:15 -0800177 SLAB_CACHE_DMA | \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
179 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
Paul Jackson101a5002006-03-24 03:16:07 -0800180 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181#else
Christoph Lameterac2b8982006-03-22 00:08:15 -0800182# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
184 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
Paul Jackson101a5002006-03-24 03:16:07 -0800185 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186#endif
187
188/*
189 * kmem_bufctl_t:
190 *
191 * Bufctl's are used for linking objs within a slab
192 * linked offsets.
193 *
194 * This implementation relies on "struct page" for locating the cache &
195 * slab an object belongs to.
196 * This allows the bufctl structure to be small (one int), but limits
197 * the number of objects a slab (not a cache) can contain when off-slab
198 * bufctls are used. The limit is the size of the largest general cache
199 * that does not use off-slab slabs.
200 * For 32bit archs with 4 kB pages, is this 56.
201 * This is not serious, as it is only for large objects, when it is unwise
202 * to have too many per slab.
203 * Note: This limit can be raised by introducing a general cache whose size
204 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
205 */
206
Kyle Moffettfa5b08d2005-09-03 15:55:03 -0700207typedef unsigned int kmem_bufctl_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
209#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
Al Viro871751e2006-03-25 03:06:39 -0800210#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
211#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213/*
214 * struct slab
215 *
216 * Manages the objs in a slab. Placed either at the beginning of mem allocated
217 * for a slab, or allocated from an general cache.
218 * Slabs are chained into three list: fully used, partial, fully free slabs.
219 */
220struct slab {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800221 struct list_head list;
222 unsigned long colouroff;
223 void *s_mem; /* including colour offset */
224 unsigned int inuse; /* num of objs active in slab */
225 kmem_bufctl_t free;
226 unsigned short nodeid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227};
228
229/*
230 * struct slab_rcu
231 *
232 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
233 * arrange for kmem_freepages to be called via RCU. This is useful if
234 * we need to approach a kernel structure obliquely, from its address
235 * obtained without the usual locking. We can lock the structure to
236 * stabilize it and check it's still at the given address, only if we
237 * can be sure that the memory has not been meanwhile reused for some
238 * other kind of object (which our subsystem's lock might corrupt).
239 *
240 * rcu_read_lock before reading the address, then rcu_read_unlock after
241 * taking the spinlock within the structure expected at that address.
242 *
243 * We assume struct slab_rcu can overlay struct slab when destroying.
244 */
245struct slab_rcu {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800246 struct rcu_head head;
Pekka Enberg343e0d72006-02-01 03:05:50 -0800247 struct kmem_cache *cachep;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800248 void *addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249};
250
251/*
252 * struct array_cache
253 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 * Purpose:
255 * - LIFO ordering, to hand out cache-warm objects from _alloc
256 * - reduce the number of linked list operations
257 * - reduce spinlock operations
258 *
259 * The limit is stored in the per-cpu structure to reduce the data cache
260 * footprint.
261 *
262 */
263struct array_cache {
264 unsigned int avail;
265 unsigned int limit;
266 unsigned int batchcount;
267 unsigned int touched;
Christoph Lametere498be72005-09-09 13:03:32 -0700268 spinlock_t lock;
Andrew Mortona737b3e2006-03-22 00:08:11 -0800269 void *entry[0]; /*
270 * Must have this definition in here for the proper
271 * alignment of array_cache. Also simplifies accessing
272 * the entries.
273 * [0] is for gcc 2.95. It should really be [].
274 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275};
276
Andrew Mortona737b3e2006-03-22 00:08:11 -0800277/*
278 * bootstrap: The caches do not work without cpuarrays anymore, but the
279 * cpuarrays are allocated from the generic caches...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 */
281#define BOOT_CPUCACHE_ENTRIES 1
282struct arraycache_init {
283 struct array_cache cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800284 void *entries[BOOT_CPUCACHE_ENTRIES];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285};
286
287/*
Christoph Lametere498be72005-09-09 13:03:32 -0700288 * The slab lists for all objects.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 */
290struct kmem_list3 {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800291 struct list_head slabs_partial; /* partial list first, better asm code */
292 struct list_head slabs_full;
293 struct list_head slabs_free;
294 unsigned long free_objects;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800295 unsigned int free_limit;
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -0800296 unsigned int colour_next; /* Per-node cache coloring */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800297 spinlock_t list_lock;
298 struct array_cache *shared; /* shared per node */
299 struct array_cache **alien; /* on other nodes */
Christoph Lameter35386e32006-03-22 00:09:05 -0800300 unsigned long next_reap; /* updated without locking */
301 int free_touched; /* updated without locking */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302};
303
Christoph Lametere498be72005-09-09 13:03:32 -0700304/*
305 * Need this for bootstrapping a per node allocator.
306 */
307#define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
308struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
309#define CACHE_CACHE 0
310#define SIZE_AC 1
311#define SIZE_L3 (1 + MAX_NUMNODES)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Christoph Lametered11d9e2006-06-30 01:55:45 -0700313static int drain_freelist(struct kmem_cache *cache,
314 struct kmem_list3 *l3, int tofree);
315static void free_block(struct kmem_cache *cachep, void **objpp, int len,
316 int node);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -0700317static int enable_cpucache(struct kmem_cache *cachep);
David Howells65f27f32006-11-22 14:55:48 +0000318static void cache_reap(struct work_struct *unused);
Christoph Lametered11d9e2006-06-30 01:55:45 -0700319
Christoph Lametere498be72005-09-09 13:03:32 -0700320/*
Andrew Mortona737b3e2006-03-22 00:08:11 -0800321 * This function must be completely optimized away if a constant is passed to
322 * it. Mostly the same as what is in linux/slab.h except it returns an index.
Christoph Lametere498be72005-09-09 13:03:32 -0700323 */
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700324static __always_inline int index_of(const size_t size)
Christoph Lametere498be72005-09-09 13:03:32 -0700325{
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800326 extern void __bad_size(void);
327
Christoph Lametere498be72005-09-09 13:03:32 -0700328 if (__builtin_constant_p(size)) {
329 int i = 0;
330
331#define CACHE(x) \
332 if (size <=x) \
333 return i; \
334 else \
335 i++;
336#include "linux/kmalloc_sizes.h"
337#undef CACHE
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800338 __bad_size();
Ivan Kokshaysky7243cc02005-09-22 21:43:58 -0700339 } else
Steven Rostedt5ec8a842006-02-01 03:05:44 -0800340 __bad_size();
Christoph Lametere498be72005-09-09 13:03:32 -0700341 return 0;
342}
343
Ingo Molnare0a42722006-06-23 02:03:46 -0700344static int slab_early_init = 1;
345
Christoph Lametere498be72005-09-09 13:03:32 -0700346#define INDEX_AC index_of(sizeof(struct arraycache_init))
347#define INDEX_L3 index_of(sizeof(struct kmem_list3))
348
Pekka Enberg5295a742006-02-01 03:05:48 -0800349static void kmem_list3_init(struct kmem_list3 *parent)
Christoph Lametere498be72005-09-09 13:03:32 -0700350{
351 INIT_LIST_HEAD(&parent->slabs_full);
352 INIT_LIST_HEAD(&parent->slabs_partial);
353 INIT_LIST_HEAD(&parent->slabs_free);
354 parent->shared = NULL;
355 parent->alien = NULL;
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -0800356 parent->colour_next = 0;
Christoph Lametere498be72005-09-09 13:03:32 -0700357 spin_lock_init(&parent->list_lock);
358 parent->free_objects = 0;
359 parent->free_touched = 0;
360}
361
Andrew Mortona737b3e2006-03-22 00:08:11 -0800362#define MAKE_LIST(cachep, listp, slab, nodeid) \
363 do { \
364 INIT_LIST_HEAD(listp); \
365 list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
Christoph Lametere498be72005-09-09 13:03:32 -0700366 } while (0)
367
Andrew Mortona737b3e2006-03-22 00:08:11 -0800368#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
369 do { \
Christoph Lametere498be72005-09-09 13:03:32 -0700370 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
371 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
372 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
373 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374
375/*
Pekka Enberg343e0d72006-02-01 03:05:50 -0800376 * struct kmem_cache
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 *
378 * manages a cache.
379 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800380
Pekka J Enberg2109a2d2005-11-07 00:58:01 -0800381struct kmem_cache {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382/* 1) per-cpu data, touched during every alloc/free */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800383 struct array_cache *array[NR_CPUS];
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800384/* 2) Cache tunables. Protected by cache_chain_mutex */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800385 unsigned int batchcount;
386 unsigned int limit;
387 unsigned int shared;
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800388
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800389 unsigned int buffer_size;
Eric Dumazet6a2d7a92006-12-13 00:34:27 -0800390 u32 reciprocal_buffer_size;
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800391/* 3) touched by every alloc & free from the backend */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800392 struct kmem_list3 *nodelists[MAX_NUMNODES];
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800393
Andrew Mortona737b3e2006-03-22 00:08:11 -0800394 unsigned int flags; /* constant flags */
395 unsigned int num; /* # of objs per slab */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800397/* 4) cache_grow/shrink */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 /* order of pgs per slab (2^n) */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800399 unsigned int gfporder;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
401 /* force GFP flags, e.g. GFP_DMA */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800402 gfp_t gfpflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
Andrew Mortona737b3e2006-03-22 00:08:11 -0800404 size_t colour; /* cache colouring range */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800405 unsigned int colour_off; /* colour offset */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800406 struct kmem_cache *slabp_cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800407 unsigned int slab_size;
Andrew Mortona737b3e2006-03-22 00:08:11 -0800408 unsigned int dflags; /* dynamic flags */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
410 /* constructor func */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800411 void (*ctor) (void *, struct kmem_cache *, unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
413 /* de-constructor func */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800414 void (*dtor) (void *, struct kmem_cache *, unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800416/* 5) cache creation/removal */
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800417 const char *name;
418 struct list_head next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -0800420/* 6) statistics */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421#if STATS
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800422 unsigned long num_active;
423 unsigned long num_allocations;
424 unsigned long high_mark;
425 unsigned long grown;
426 unsigned long reaped;
427 unsigned long errors;
428 unsigned long max_freeable;
429 unsigned long node_allocs;
430 unsigned long node_frees;
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -0700431 unsigned long node_overflow;
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800432 atomic_t allochit;
433 atomic_t allocmiss;
434 atomic_t freehit;
435 atomic_t freemiss;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436#endif
437#if DEBUG
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800438 /*
439 * If debugging is enabled, then the allocator can add additional
440 * fields and/or padding to every object. buffer_size contains the total
441 * object size including these internal fields, the following two
442 * variables contain the offset to the user object and its size.
443 */
444 int obj_offset;
445 int obj_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446#endif
447};
448
449#define CFLGS_OFF_SLAB (0x80000000UL)
450#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
451
452#define BATCHREFILL_LIMIT 16
Andrew Mortona737b3e2006-03-22 00:08:11 -0800453/*
454 * Optimization question: fewer reaps means less probability for unnessary
455 * cpucache drain/refill cycles.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 *
Adrian Bunkdc6f3f22005-11-08 16:44:08 +0100457 * OTOH the cpuarrays can contain lots of objects,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 * which could lock up otherwise freeable slabs.
459 */
460#define REAPTIMEOUT_CPUC (2*HZ)
461#define REAPTIMEOUT_LIST3 (4*HZ)
462
463#if STATS
464#define STATS_INC_ACTIVE(x) ((x)->num_active++)
465#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
466#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
467#define STATS_INC_GROWN(x) ((x)->grown++)
Christoph Lametered11d9e2006-06-30 01:55:45 -0700468#define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
Andrew Mortona737b3e2006-03-22 00:08:11 -0800469#define STATS_SET_HIGH(x) \
470 do { \
471 if ((x)->num_active > (x)->high_mark) \
472 (x)->high_mark = (x)->num_active; \
473 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474#define STATS_INC_ERR(x) ((x)->errors++)
475#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
Christoph Lametere498be72005-09-09 13:03:32 -0700476#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -0700477#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
Andrew Mortona737b3e2006-03-22 00:08:11 -0800478#define STATS_SET_FREEABLE(x, i) \
479 do { \
480 if ((x)->max_freeable < i) \
481 (x)->max_freeable = i; \
482 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
484#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
485#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
486#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
487#else
488#define STATS_INC_ACTIVE(x) do { } while (0)
489#define STATS_DEC_ACTIVE(x) do { } while (0)
490#define STATS_INC_ALLOCED(x) do { } while (0)
491#define STATS_INC_GROWN(x) do { } while (0)
Christoph Lametered11d9e2006-06-30 01:55:45 -0700492#define STATS_ADD_REAPED(x,y) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493#define STATS_SET_HIGH(x) do { } while (0)
494#define STATS_INC_ERR(x) do { } while (0)
495#define STATS_INC_NODEALLOCS(x) do { } while (0)
Christoph Lametere498be72005-09-09 13:03:32 -0700496#define STATS_INC_NODEFREES(x) do { } while (0)
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -0700497#define STATS_INC_ACOVERFLOW(x) do { } while (0)
Andrew Mortona737b3e2006-03-22 00:08:11 -0800498#define STATS_SET_FREEABLE(x, i) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499#define STATS_INC_ALLOCHIT(x) do { } while (0)
500#define STATS_INC_ALLOCMISS(x) do { } while (0)
501#define STATS_INC_FREEHIT(x) do { } while (0)
502#define STATS_INC_FREEMISS(x) do { } while (0)
503#endif
504
505#if DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
Andrew Mortona737b3e2006-03-22 00:08:11 -0800507/*
508 * memory layout of objects:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 * 0 : objp
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800510 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 * the end of an object is aligned with the end of the real
512 * allocation. Catches writes behind the end of the allocation.
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800513 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 * redzone word.
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800515 * cachep->obj_offset: The real object.
516 * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
Andrew Mortona737b3e2006-03-22 00:08:11 -0800517 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
518 * [BYTES_PER_WORD long]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800520static int obj_offset(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521{
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800522 return cachep->obj_offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523}
524
Pekka Enberg343e0d72006-02-01 03:05:50 -0800525static int obj_size(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526{
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800527 return cachep->obj_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528}
529
Pekka Enberg343e0d72006-02-01 03:05:50 -0800530static unsigned long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531{
532 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800533 return (unsigned long*) (objp+obj_offset(cachep)-BYTES_PER_WORD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534}
535
Pekka Enberg343e0d72006-02-01 03:05:50 -0800536static unsigned long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537{
538 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
539 if (cachep->flags & SLAB_STORE_USER)
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800540 return (unsigned long *)(objp + cachep->buffer_size -
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800541 2 * BYTES_PER_WORD);
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800542 return (unsigned long *)(objp + cachep->buffer_size - BYTES_PER_WORD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543}
544
Pekka Enberg343e0d72006-02-01 03:05:50 -0800545static void **dbg_userword(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546{
547 BUG_ON(!(cachep->flags & SLAB_STORE_USER));
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800548 return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549}
550
551#else
552
Manfred Spraul3dafccf2006-02-01 03:05:42 -0800553#define obj_offset(x) 0
554#define obj_size(cachep) (cachep->buffer_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;})
556#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;})
557#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
558
559#endif
560
561/*
Andrew Mortona737b3e2006-03-22 00:08:11 -0800562 * Maximum size of an obj (in 2^order pages) and absolute limit for the gfp
563 * order.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 */
565#if defined(CONFIG_LARGE_ALLOCS)
566#define MAX_OBJ_ORDER 13 /* up to 32Mb */
567#define MAX_GFP_ORDER 13 /* up to 32Mb */
568#elif defined(CONFIG_MMU)
569#define MAX_OBJ_ORDER 5 /* 32 pages */
570#define MAX_GFP_ORDER 5 /* 32 pages */
571#else
572#define MAX_OBJ_ORDER 8 /* up to 1Mb */
573#define MAX_GFP_ORDER 8 /* up to 1Mb */
574#endif
575
576/*
577 * Do not go above this order unless 0 objects fit into the slab.
578 */
579#define BREAK_GFP_ORDER_HI 1
580#define BREAK_GFP_ORDER_LO 0
581static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
582
Andrew Mortona737b3e2006-03-22 00:08:11 -0800583/*
584 * Functions for storing/retrieving the cachep and or slab from the page
585 * allocator. These are used to find the slab an obj belongs to. With kfree(),
586 * these are used to find the cache which an obj belongs to.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 */
Pekka Enberg065d41c2005-11-13 16:06:46 -0800588static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
589{
590 page->lru.next = (struct list_head *)cache;
591}
592
593static inline struct kmem_cache *page_get_cache(struct page *page)
594{
Nick Piggin84097512006-03-22 00:08:34 -0800595 if (unlikely(PageCompound(page)))
596 page = (struct page *)page_private(page);
Pekka Enbergddc2e812006-06-23 02:03:40 -0700597 BUG_ON(!PageSlab(page));
Pekka Enberg065d41c2005-11-13 16:06:46 -0800598 return (struct kmem_cache *)page->lru.next;
599}
600
601static inline void page_set_slab(struct page *page, struct slab *slab)
602{
603 page->lru.prev = (struct list_head *)slab;
604}
605
606static inline struct slab *page_get_slab(struct page *page)
607{
Nick Piggin84097512006-03-22 00:08:34 -0800608 if (unlikely(PageCompound(page)))
609 page = (struct page *)page_private(page);
Pekka Enbergddc2e812006-06-23 02:03:40 -0700610 BUG_ON(!PageSlab(page));
Pekka Enberg065d41c2005-11-13 16:06:46 -0800611 return (struct slab *)page->lru.prev;
612}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
Pekka Enberg6ed5eb22006-02-01 03:05:49 -0800614static inline struct kmem_cache *virt_to_cache(const void *obj)
615{
616 struct page *page = virt_to_page(obj);
617 return page_get_cache(page);
618}
619
620static inline struct slab *virt_to_slab(const void *obj)
621{
622 struct page *page = virt_to_page(obj);
623 return page_get_slab(page);
624}
625
Pekka Enberg8fea4e92006-03-22 00:08:10 -0800626static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
627 unsigned int idx)
628{
629 return slab->s_mem + cache->buffer_size * idx;
630}
631
Eric Dumazet6a2d7a92006-12-13 00:34:27 -0800632/*
633 * We want to avoid an expensive divide : (offset / cache->buffer_size)
634 * Using the fact that buffer_size is a constant for a particular cache,
635 * we can replace (offset / cache->buffer_size) by
636 * reciprocal_divide(offset, cache->reciprocal_buffer_size)
637 */
638static inline unsigned int obj_to_index(const struct kmem_cache *cache,
639 const struct slab *slab, void *obj)
Pekka Enberg8fea4e92006-03-22 00:08:10 -0800640{
Eric Dumazet6a2d7a92006-12-13 00:34:27 -0800641 u32 offset = (obj - slab->s_mem);
642 return reciprocal_divide(offset, cache->reciprocal_buffer_size);
Pekka Enberg8fea4e92006-03-22 00:08:10 -0800643}
644
Andrew Mortona737b3e2006-03-22 00:08:11 -0800645/*
646 * These are the default caches for kmalloc. Custom caches can have other sizes.
647 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648struct cache_sizes malloc_sizes[] = {
649#define CACHE(x) { .cs_size = (x) },
650#include <linux/kmalloc_sizes.h>
651 CACHE(ULONG_MAX)
652#undef CACHE
653};
654EXPORT_SYMBOL(malloc_sizes);
655
656/* Must match cache_sizes above. Out of line to keep cache footprint low. */
657struct cache_names {
658 char *name;
659 char *name_dma;
660};
661
662static struct cache_names __initdata cache_names[] = {
663#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
664#include <linux/kmalloc_sizes.h>
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800665 {NULL,}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666#undef CACHE
667};
668
669static struct arraycache_init initarray_cache __initdata =
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800670 { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671static struct arraycache_init initarray_generic =
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800672 { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673
674/* internal cache of cache description objs */
Pekka Enberg343e0d72006-02-01 03:05:50 -0800675static struct kmem_cache cache_cache = {
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800676 .batchcount = 1,
677 .limit = BOOT_CPUCACHE_ENTRIES,
678 .shared = 1,
Pekka Enberg343e0d72006-02-01 03:05:50 -0800679 .buffer_size = sizeof(struct kmem_cache),
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800680 .name = "kmem_cache",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681#if DEBUG
Pekka Enberg343e0d72006-02-01 03:05:50 -0800682 .obj_size = sizeof(struct kmem_cache),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683#endif
684};
685
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700686#define BAD_ALIEN_MAGIC 0x01020304ul
687
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200688#ifdef CONFIG_LOCKDEP
689
690/*
691 * Slab sometimes uses the kmalloc slabs to store the slab headers
692 * for other slabs "off slab".
693 * The locking for this is tricky in that it nests within the locks
694 * of all other slabs in a few places; to deal with this special
695 * locking we put on-slab caches into a separate lock-class.
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700696 *
697 * We set lock class for alien array caches which are up during init.
698 * The lock annotation will be lost if all cpus of a node goes down and
699 * then comes back up during hotplug
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200700 */
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700701static struct lock_class_key on_slab_l3_key;
702static struct lock_class_key on_slab_alc_key;
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200703
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700704static inline void init_lock_keys(void)
705
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200706{
707 int q;
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700708 struct cache_sizes *s = malloc_sizes;
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200709
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700710 while (s->cs_size != ULONG_MAX) {
711 for_each_node(q) {
712 struct array_cache **alc;
713 int r;
714 struct kmem_list3 *l3 = s->cs_cachep->nodelists[q];
715 if (!l3 || OFF_SLAB(s->cs_cachep))
716 continue;
717 lockdep_set_class(&l3->list_lock, &on_slab_l3_key);
718 alc = l3->alien;
719 /*
720 * FIXME: This check for BAD_ALIEN_MAGIC
721 * should go away when common slab code is taught to
722 * work even without alien caches.
723 * Currently, non NUMA code returns BAD_ALIEN_MAGIC
724 * for alloc_alien_cache,
725 */
726 if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC)
727 continue;
728 for_each_node(r) {
729 if (alc[r])
730 lockdep_set_class(&alc[r]->lock,
731 &on_slab_alc_key);
732 }
733 }
734 s++;
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200735 }
736}
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200737#else
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -0700738static inline void init_lock_keys(void)
Arjan van de Venf1aaee52006-07-13 14:46:03 +0200739{
740}
741#endif
742
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -0800743/*
744 * 1. Guard access to the cache-chain.
745 * 2. Protect sanity of cpu_online_map against cpu hotplug events
746 */
Ingo Molnarfc0abb12006-01-18 17:42:33 -0800747static DEFINE_MUTEX(cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748static struct list_head cache_chain;
749
750/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 * chicken and egg problem: delay the per-cpu array allocation
752 * until the general caches are up.
753 */
754static enum {
755 NONE,
Christoph Lametere498be72005-09-09 13:03:32 -0700756 PARTIAL_AC,
757 PARTIAL_L3,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 FULL
759} g_cpucache_up;
760
Mike Kravetz39d24e62006-05-15 09:44:13 -0700761/*
762 * used by boot code to determine if it can use slab based allocator
763 */
764int slab_is_available(void)
765{
766 return g_cpucache_up == FULL;
767}
768
David Howells52bad642006-11-22 14:54:01 +0000769static DEFINE_PER_CPU(struct delayed_work, reap_work);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770
Pekka Enberg343e0d72006-02-01 03:05:50 -0800771static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772{
773 return cachep->array[smp_processor_id()];
774}
775
Andrew Mortona737b3e2006-03-22 00:08:11 -0800776static inline struct kmem_cache *__find_general_cachep(size_t size,
777 gfp_t gfpflags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778{
779 struct cache_sizes *csizep = malloc_sizes;
780
781#if DEBUG
782 /* This happens if someone tries to call
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800783 * kmem_cache_create(), or __kmalloc(), before
784 * the generic caches are initialized.
785 */
Alok Katariac7e43c72005-09-14 12:17:53 -0700786 BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787#endif
788 while (size > csizep->cs_size)
789 csizep++;
790
791 /*
Martin Hicks0abf40c2005-09-03 15:54:54 -0700792 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 * has cs_{dma,}cachep==NULL. Thus no special case
794 * for large kmalloc calls required.
795 */
Christoph Lameter4b51d662007-02-10 01:43:10 -0800796#ifdef CONFIG_ZONE_DMA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 if (unlikely(gfpflags & GFP_DMA))
798 return csizep->cs_dmacachep;
Christoph Lameter4b51d662007-02-10 01:43:10 -0800799#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 return csizep->cs_cachep;
801}
802
Adrian Bunkb2213852006-09-25 23:31:02 -0700803static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700804{
805 return __find_general_cachep(size, gfpflags);
806}
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700807
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800808static size_t slab_mgmt_size(size_t nr_objs, size_t align)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809{
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800810 return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
811}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812
Andrew Mortona737b3e2006-03-22 00:08:11 -0800813/*
814 * Calculate the number of objects and left-over bytes for a given buffer size.
815 */
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800816static void cache_estimate(unsigned long gfporder, size_t buffer_size,
817 size_t align, int flags, size_t *left_over,
818 unsigned int *num)
819{
820 int nr_objs;
821 size_t mgmt_size;
822 size_t slab_size = PAGE_SIZE << gfporder;
823
824 /*
825 * The slab management structure can be either off the slab or
826 * on it. For the latter case, the memory allocated for a
827 * slab is used for:
828 *
829 * - The struct slab
830 * - One kmem_bufctl_t for each object
831 * - Padding to respect alignment of @align
832 * - @buffer_size bytes for each object
833 *
834 * If the slab management structure is off the slab, then the
835 * alignment will already be calculated into the size. Because
836 * the slabs are all pages aligned, the objects will be at the
837 * correct alignment when allocated.
838 */
839 if (flags & CFLGS_OFF_SLAB) {
840 mgmt_size = 0;
841 nr_objs = slab_size / buffer_size;
842
843 if (nr_objs > SLAB_LIMIT)
844 nr_objs = SLAB_LIMIT;
845 } else {
846 /*
847 * Ignore padding for the initial guess. The padding
848 * is at most @align-1 bytes, and @buffer_size is at
849 * least @align. In the worst case, this result will
850 * be one greater than the number of objects that fit
851 * into the memory allocation when taking the padding
852 * into account.
853 */
854 nr_objs = (slab_size - sizeof(struct slab)) /
855 (buffer_size + sizeof(kmem_bufctl_t));
856
857 /*
858 * This calculated number will be either the right
859 * amount, or one greater than what we want.
860 */
861 if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size
862 > slab_size)
863 nr_objs--;
864
865 if (nr_objs > SLAB_LIMIT)
866 nr_objs = SLAB_LIMIT;
867
868 mgmt_size = slab_mgmt_size(nr_objs, align);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 }
Steven Rostedtfbaccac2006-02-01 03:05:45 -0800870 *num = nr_objs;
871 *left_over = slab_size - nr_objs*buffer_size - mgmt_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872}
873
874#define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
875
Andrew Mortona737b3e2006-03-22 00:08:11 -0800876static void __slab_error(const char *function, struct kmem_cache *cachep,
877 char *msg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878{
879 printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800880 function, cachep->name, msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 dump_stack();
882}
883
Paul Menage3395ee02006-12-06 20:32:16 -0800884/*
885 * By default on NUMA we use alien caches to stage the freeing of
886 * objects allocated from other nodes. This causes massive memory
887 * inefficiencies when using fake NUMA setup to split memory into a
888 * large number of small nodes, so it can be disabled on the command
889 * line
890 */
891
892static int use_alien_caches __read_mostly = 1;
893static int __init noaliencache_setup(char *s)
894{
895 use_alien_caches = 0;
896 return 1;
897}
898__setup("noaliencache", noaliencache_setup);
899
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800900#ifdef CONFIG_NUMA
901/*
902 * Special reaping functions for NUMA systems called from cache_reap().
903 * These take care of doing round robin flushing of alien caches (containing
904 * objects freed on different nodes from which they were allocated) and the
905 * flushing of remote pcps by calling drain_node_pages.
906 */
907static DEFINE_PER_CPU(unsigned long, reap_node);
908
909static void init_reap_node(int cpu)
910{
911 int node;
912
913 node = next_node(cpu_to_node(cpu), node_online_map);
914 if (node == MAX_NUMNODES)
Paul Jackson442295c2006-03-22 00:09:11 -0800915 node = first_node(node_online_map);
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800916
Daniel Yeisley7f6b8872006-11-02 22:07:14 -0800917 per_cpu(reap_node, cpu) = node;
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800918}
919
920static void next_reap_node(void)
921{
922 int node = __get_cpu_var(reap_node);
923
924 /*
925 * Also drain per cpu pages on remote zones
926 */
927 if (node != numa_node_id())
928 drain_node_pages(node);
929
930 node = next_node(node, node_online_map);
931 if (unlikely(node >= MAX_NUMNODES))
932 node = first_node(node_online_map);
933 __get_cpu_var(reap_node) = node;
934}
935
936#else
937#define init_reap_node(cpu) do { } while (0)
938#define next_reap_node(void) do { } while (0)
939#endif
940
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941/*
942 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
943 * via the workqueue/eventd.
944 * Add the CPU number into the expiration time to minimize the possibility of
945 * the CPUs getting into lockstep and contending for the global cache chain
946 * lock.
947 */
948static void __devinit start_cpu_timer(int cpu)
949{
David Howells52bad642006-11-22 14:54:01 +0000950 struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951
952 /*
953 * When this gets called from do_initcalls via cpucache_init(),
954 * init_workqueues() has already run, so keventd will be setup
955 * at that time.
956 */
David Howells52bad642006-11-22 14:54:01 +0000957 if (keventd_up() && reap_work->work.func == NULL) {
Christoph Lameter8fce4d82006-03-09 17:33:54 -0800958 init_reap_node(cpu);
David Howells65f27f32006-11-22 14:55:48 +0000959 INIT_DELAYED_WORK(reap_work, cache_reap);
Arjan van de Ven2b284212006-12-10 02:21:28 -0800960 schedule_delayed_work_on(cpu, reap_work,
961 __round_jiffies_relative(HZ, cpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 }
963}
964
Christoph Lametere498be72005-09-09 13:03:32 -0700965static struct array_cache *alloc_arraycache(int node, int entries,
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800966 int batchcount)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967{
Pekka Enbergb28a02d2006-01-08 01:00:37 -0800968 int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 struct array_cache *nc = NULL;
970
Christoph Lametere498be72005-09-09 13:03:32 -0700971 nc = kmalloc_node(memsize, GFP_KERNEL, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 if (nc) {
973 nc->avail = 0;
974 nc->limit = entries;
975 nc->batchcount = batchcount;
976 nc->touched = 0;
Christoph Lametere498be72005-09-09 13:03:32 -0700977 spin_lock_init(&nc->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 }
979 return nc;
980}
981
Christoph Lameter3ded1752006-03-25 03:06:44 -0800982/*
983 * Transfer objects in one arraycache to another.
984 * Locking must be handled by the caller.
985 *
986 * Return the number of entries transferred.
987 */
988static int transfer_objects(struct array_cache *to,
989 struct array_cache *from, unsigned int max)
990{
991 /* Figure out how many entries to transfer */
992 int nr = min(min(from->avail, max), to->limit - to->avail);
993
994 if (!nr)
995 return 0;
996
997 memcpy(to->entry + to->avail, from->entry + from->avail -nr,
998 sizeof(void *) *nr);
999
1000 from->avail -= nr;
1001 to->avail += nr;
1002 to->touched = 1;
1003 return nr;
1004}
1005
Christoph Lameter765c4502006-09-27 01:50:08 -07001006#ifndef CONFIG_NUMA
1007
1008#define drain_alien_cache(cachep, alien) do { } while (0)
1009#define reap_alien(cachep, l3) do { } while (0)
1010
1011static inline struct array_cache **alloc_alien_cache(int node, int limit)
1012{
1013 return (struct array_cache **)BAD_ALIEN_MAGIC;
1014}
1015
1016static inline void free_alien_cache(struct array_cache **ac_ptr)
1017{
1018}
1019
1020static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1021{
1022 return 0;
1023}
1024
1025static inline void *alternate_node_alloc(struct kmem_cache *cachep,
1026 gfp_t flags)
1027{
1028 return NULL;
1029}
1030
Christoph Hellwig8b98c162006-12-06 20:32:30 -08001031static inline void *____cache_alloc_node(struct kmem_cache *cachep,
Christoph Lameter765c4502006-09-27 01:50:08 -07001032 gfp_t flags, int nodeid)
1033{
1034 return NULL;
1035}
1036
1037#else /* CONFIG_NUMA */
1038
Christoph Hellwig8b98c162006-12-06 20:32:30 -08001039static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
Paul Jacksonc61afb12006-03-24 03:16:08 -08001040static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
Christoph Lameterdc85da12006-01-18 17:42:36 -08001041
Pekka Enberg5295a742006-02-01 03:05:48 -08001042static struct array_cache **alloc_alien_cache(int node, int limit)
Christoph Lametere498be72005-09-09 13:03:32 -07001043{
1044 struct array_cache **ac_ptr;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001045 int memsize = sizeof(void *) * MAX_NUMNODES;
Christoph Lametere498be72005-09-09 13:03:32 -07001046 int i;
1047
1048 if (limit > 1)
1049 limit = 12;
1050 ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node);
1051 if (ac_ptr) {
1052 for_each_node(i) {
1053 if (i == node || !node_online(i)) {
1054 ac_ptr[i] = NULL;
1055 continue;
1056 }
1057 ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d);
1058 if (!ac_ptr[i]) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001059 for (i--; i <= 0; i--)
Christoph Lametere498be72005-09-09 13:03:32 -07001060 kfree(ac_ptr[i]);
1061 kfree(ac_ptr);
1062 return NULL;
1063 }
1064 }
1065 }
1066 return ac_ptr;
1067}
1068
Pekka Enberg5295a742006-02-01 03:05:48 -08001069static void free_alien_cache(struct array_cache **ac_ptr)
Christoph Lametere498be72005-09-09 13:03:32 -07001070{
1071 int i;
1072
1073 if (!ac_ptr)
1074 return;
Christoph Lametere498be72005-09-09 13:03:32 -07001075 for_each_node(i)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001076 kfree(ac_ptr[i]);
Christoph Lametere498be72005-09-09 13:03:32 -07001077 kfree(ac_ptr);
1078}
1079
Pekka Enberg343e0d72006-02-01 03:05:50 -08001080static void __drain_alien_cache(struct kmem_cache *cachep,
Pekka Enberg5295a742006-02-01 03:05:48 -08001081 struct array_cache *ac, int node)
Christoph Lametere498be72005-09-09 13:03:32 -07001082{
1083 struct kmem_list3 *rl3 = cachep->nodelists[node];
1084
1085 if (ac->avail) {
1086 spin_lock(&rl3->list_lock);
Christoph Lametere00946f2006-03-25 03:06:45 -08001087 /*
1088 * Stuff objects into the remote nodes shared array first.
1089 * That way we could avoid the overhead of putting the objects
1090 * into the free lists and getting them back later.
1091 */
shin, jacob693f7d32006-04-28 10:54:37 -05001092 if (rl3->shared)
1093 transfer_objects(rl3->shared, ac, ac->limit);
Christoph Lametere00946f2006-03-25 03:06:45 -08001094
Christoph Lameterff694162005-09-22 21:44:02 -07001095 free_block(cachep, ac->entry, ac->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001096 ac->avail = 0;
1097 spin_unlock(&rl3->list_lock);
1098 }
1099}
1100
Christoph Lameter8fce4d82006-03-09 17:33:54 -08001101/*
1102 * Called from cache_reap() to regularly drain alien caches round robin.
1103 */
1104static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
1105{
1106 int node = __get_cpu_var(reap_node);
1107
1108 if (l3->alien) {
1109 struct array_cache *ac = l3->alien[node];
Christoph Lametere00946f2006-03-25 03:06:45 -08001110
1111 if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
Christoph Lameter8fce4d82006-03-09 17:33:54 -08001112 __drain_alien_cache(cachep, ac, node);
1113 spin_unlock_irq(&ac->lock);
1114 }
1115 }
1116}
1117
Andrew Mortona737b3e2006-03-22 00:08:11 -08001118static void drain_alien_cache(struct kmem_cache *cachep,
1119 struct array_cache **alien)
Christoph Lametere498be72005-09-09 13:03:32 -07001120{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001121 int i = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07001122 struct array_cache *ac;
1123 unsigned long flags;
1124
1125 for_each_online_node(i) {
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001126 ac = alien[i];
Christoph Lametere498be72005-09-09 13:03:32 -07001127 if (ac) {
1128 spin_lock_irqsave(&ac->lock, flags);
1129 __drain_alien_cache(cachep, ac, i);
1130 spin_unlock_irqrestore(&ac->lock, flags);
1131 }
1132 }
1133}
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001134
Ingo Molnar873623d2006-07-13 14:44:38 +02001135static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001136{
1137 struct slab *slabp = virt_to_slab(objp);
1138 int nodeid = slabp->nodeid;
1139 struct kmem_list3 *l3;
1140 struct array_cache *alien = NULL;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001141 int node;
1142
1143 node = numa_node_id();
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001144
1145 /*
1146 * Make sure we are not freeing a object from another node to the array
1147 * cache on this cpu.
1148 */
Paul Menage3395ee02006-12-06 20:32:16 -08001149 if (likely(slabp->nodeid == node) || unlikely(!use_alien_caches))
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001150 return 0;
1151
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001152 l3 = cachep->nodelists[node];
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001153 STATS_INC_NODEFREES(cachep);
1154 if (l3->alien && l3->alien[nodeid]) {
1155 alien = l3->alien[nodeid];
Ingo Molnar873623d2006-07-13 14:44:38 +02001156 spin_lock(&alien->lock);
Pekka Enberg729bd0b2006-06-23 02:03:05 -07001157 if (unlikely(alien->avail == alien->limit)) {
1158 STATS_INC_ACOVERFLOW(cachep);
1159 __drain_alien_cache(cachep, alien, nodeid);
1160 }
1161 alien->entry[alien->avail++] = objp;
1162 spin_unlock(&alien->lock);
1163 } else {
1164 spin_lock(&(cachep->nodelists[nodeid])->list_lock);
1165 free_block(cachep, &objp, 1, nodeid);
1166 spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
1167 }
1168 return 1;
1169}
Christoph Lametere498be72005-09-09 13:03:32 -07001170#endif
1171
Chandra Seetharaman8c78f302006-07-30 03:03:35 -07001172static int __cpuinit cpuup_callback(struct notifier_block *nfb,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001173 unsigned long action, void *hcpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174{
1175 long cpu = (long)hcpu;
Pekka Enberg343e0d72006-02-01 03:05:50 -08001176 struct kmem_cache *cachep;
Christoph Lametere498be72005-09-09 13:03:32 -07001177 struct kmem_list3 *l3 = NULL;
1178 int node = cpu_to_node(cpu);
1179 int memsize = sizeof(struct kmem_list3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180
1181 switch (action) {
1182 case CPU_UP_PREPARE:
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001183 mutex_lock(&cache_chain_mutex);
Andrew Mortona737b3e2006-03-22 00:08:11 -08001184 /*
1185 * We need to do this right in the beginning since
Christoph Lametere498be72005-09-09 13:03:32 -07001186 * alloc_arraycache's are going to use this list.
1187 * kmalloc_node allows us to add the slab to the right
1188 * kmem_list3 and not this cpu's kmem_list3
1189 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190
Christoph Lametere498be72005-09-09 13:03:32 -07001191 list_for_each_entry(cachep, &cache_chain, next) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08001192 /*
1193 * Set up the size64 kmemlist for cpu before we can
Christoph Lametere498be72005-09-09 13:03:32 -07001194 * begin anything. Make sure some other cpu on this
1195 * node has not already allocated this
1196 */
1197 if (!cachep->nodelists[node]) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08001198 l3 = kmalloc_node(memsize, GFP_KERNEL, node);
1199 if (!l3)
Christoph Lametere498be72005-09-09 13:03:32 -07001200 goto bad;
1201 kmem_list3_init(l3);
1202 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001203 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametere498be72005-09-09 13:03:32 -07001204
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001205 /*
1206 * The l3s don't come and go as CPUs come and
1207 * go. cache_chain_mutex is sufficient
1208 * protection here.
1209 */
Christoph Lametere498be72005-09-09 13:03:32 -07001210 cachep->nodelists[node] = l3;
1211 }
1212
1213 spin_lock_irq(&cachep->nodelists[node]->list_lock);
1214 cachep->nodelists[node]->free_limit =
Andrew Mortona737b3e2006-03-22 00:08:11 -08001215 (1 + nr_cpus_node(node)) *
1216 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07001217 spin_unlock_irq(&cachep->nodelists[node]->list_lock);
1218 }
1219
Andrew Mortona737b3e2006-03-22 00:08:11 -08001220 /*
1221 * Now we can go ahead with allocating the shared arrays and
1222 * array caches
1223 */
Christoph Lametere498be72005-09-09 13:03:32 -07001224 list_for_each_entry(cachep, &cache_chain, next) {
Tobias Klausercd105df2006-01-08 01:00:59 -08001225 struct array_cache *nc;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001226 struct array_cache *shared;
Paul Menage3395ee02006-12-06 20:32:16 -08001227 struct array_cache **alien = NULL;
Tobias Klausercd105df2006-01-08 01:00:59 -08001228
Christoph Lametere498be72005-09-09 13:03:32 -07001229 nc = alloc_arraycache(node, cachep->limit,
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001230 cachep->batchcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 if (!nc)
1232 goto bad;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001233 shared = alloc_arraycache(node,
1234 cachep->shared * cachep->batchcount,
1235 0xbaadf00d);
1236 if (!shared)
1237 goto bad;
Linus Torvalds7a21ef62006-02-05 11:26:38 -08001238
Paul Menage3395ee02006-12-06 20:32:16 -08001239 if (use_alien_caches) {
1240 alien = alloc_alien_cache(node, cachep->limit);
1241 if (!alien)
1242 goto bad;
1243 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 cachep->array[cpu] = nc;
Christoph Lametere498be72005-09-09 13:03:32 -07001245 l3 = cachep->nodelists[node];
1246 BUG_ON(!l3);
Christoph Lametere498be72005-09-09 13:03:32 -07001247
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001248 spin_lock_irq(&l3->list_lock);
1249 if (!l3->shared) {
1250 /*
1251 * We are serialised from CPU_DEAD or
1252 * CPU_UP_CANCELLED by the cpucontrol lock
1253 */
1254 l3->shared = shared;
1255 shared = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07001256 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001257#ifdef CONFIG_NUMA
1258 if (!l3->alien) {
1259 l3->alien = alien;
1260 alien = NULL;
1261 }
1262#endif
1263 spin_unlock_irq(&l3->list_lock);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001264 kfree(shared);
1265 free_alien_cache(alien);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 break;
1268 case CPU_ONLINE:
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08001269 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270 start_cpu_timer(cpu);
1271 break;
1272#ifdef CONFIG_HOTPLUG_CPU
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08001273 case CPU_DOWN_PREPARE:
1274 mutex_lock(&cache_chain_mutex);
1275 break;
1276 case CPU_DOWN_FAILED:
1277 mutex_unlock(&cache_chain_mutex);
1278 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 case CPU_DEAD:
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001280 /*
1281 * Even if all the cpus of a node are down, we don't free the
1282 * kmem_list3 of any cache. This to avoid a race between
1283 * cpu_down, and a kmalloc allocation from another cpu for
1284 * memory from the node of the cpu going down. The list3
1285 * structure is usually allocated from kmem_cache_create() and
1286 * gets destroyed at kmem_cache_destroy().
1287 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 /* fall thru */
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08001289#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290 case CPU_UP_CANCELED:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 list_for_each_entry(cachep, &cache_chain, next) {
1292 struct array_cache *nc;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001293 struct array_cache *shared;
1294 struct array_cache **alien;
Christoph Lametere498be72005-09-09 13:03:32 -07001295 cpumask_t mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296
Christoph Lametere498be72005-09-09 13:03:32 -07001297 mask = node_to_cpumask(node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298 /* cpu is dead; no one can alloc from it. */
1299 nc = cachep->array[cpu];
1300 cachep->array[cpu] = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07001301 l3 = cachep->nodelists[node];
1302
1303 if (!l3)
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001304 goto free_array_cache;
Christoph Lametere498be72005-09-09 13:03:32 -07001305
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08001306 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07001307
1308 /* Free limit for this kmem_list3 */
1309 l3->free_limit -= cachep->batchcount;
1310 if (nc)
Christoph Lameterff694162005-09-22 21:44:02 -07001311 free_block(cachep, nc->entry, nc->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001312
1313 if (!cpus_empty(mask)) {
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08001314 spin_unlock_irq(&l3->list_lock);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001315 goto free_array_cache;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001316 }
Christoph Lametere498be72005-09-09 13:03:32 -07001317
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001318 shared = l3->shared;
1319 if (shared) {
Christoph Lametere498be72005-09-09 13:03:32 -07001320 free_block(cachep, l3->shared->entry,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001321 l3->shared->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07001322 l3->shared = NULL;
1323 }
Christoph Lametere498be72005-09-09 13:03:32 -07001324
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001325 alien = l3->alien;
1326 l3->alien = NULL;
1327
1328 spin_unlock_irq(&l3->list_lock);
1329
1330 kfree(shared);
1331 if (alien) {
1332 drain_alien_cache(cachep, alien);
1333 free_alien_cache(alien);
Christoph Lametere498be72005-09-09 13:03:32 -07001334 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001335free_array_cache:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336 kfree(nc);
1337 }
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001338 /*
1339 * In the previous loop, all the objects were freed to
1340 * the respective cache's slabs, now we can go ahead and
1341 * shrink each nodelist to its limit.
1342 */
1343 list_for_each_entry(cachep, &cache_chain, next) {
1344 l3 = cachep->nodelists[node];
1345 if (!l3)
1346 continue;
Christoph Lametered11d9e2006-06-30 01:55:45 -07001347 drain_freelist(cachep, l3, l3->free_objects);
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08001348 }
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001349 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351 }
1352 return NOTIFY_OK;
Andrew Mortona737b3e2006-03-22 00:08:11 -08001353bad:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354 return NOTIFY_BAD;
1355}
1356
Chandra Seetharaman74b85f32006-06-27 02:54:09 -07001357static struct notifier_block __cpuinitdata cpucache_notifier = {
1358 &cpuup_callback, NULL, 0
1359};
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360
Christoph Lametere498be72005-09-09 13:03:32 -07001361/*
1362 * swap the static kmem_list3 with kmalloced memory
1363 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001364static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
1365 int nodeid)
Christoph Lametere498be72005-09-09 13:03:32 -07001366{
1367 struct kmem_list3 *ptr;
1368
Christoph Lametere498be72005-09-09 13:03:32 -07001369 ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid);
1370 BUG_ON(!ptr);
1371
1372 local_irq_disable();
1373 memcpy(ptr, list, sizeof(struct kmem_list3));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001374 /*
1375 * Do not assume that spinlocks can be initialized via memcpy:
1376 */
1377 spin_lock_init(&ptr->list_lock);
1378
Christoph Lametere498be72005-09-09 13:03:32 -07001379 MAKE_ALL_LISTS(cachep, ptr, nodeid);
1380 cachep->nodelists[nodeid] = ptr;
1381 local_irq_enable();
1382}
1383
Andrew Mortona737b3e2006-03-22 00:08:11 -08001384/*
1385 * Initialisation. Called after the page allocator have been initialised and
1386 * before smp_init().
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387 */
1388void __init kmem_cache_init(void)
1389{
1390 size_t left_over;
1391 struct cache_sizes *sizes;
1392 struct cache_names *names;
Christoph Lametere498be72005-09-09 13:03:32 -07001393 int i;
Jack Steiner07ed76b2006-03-07 21:55:46 -08001394 int order;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001395 int node;
Christoph Lametere498be72005-09-09 13:03:32 -07001396
1397 for (i = 0; i < NUM_INIT_LISTS; i++) {
1398 kmem_list3_init(&initkmem_list3[i]);
1399 if (i < MAX_NUMNODES)
1400 cache_cache.nodelists[i] = NULL;
1401 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402
1403 /*
1404 * Fragmentation resistance on low memory - only use bigger
1405 * page orders on machines with more than 32MB of memory.
1406 */
1407 if (num_physpages > (32 << 20) >> PAGE_SHIFT)
1408 slab_break_gfp_order = BREAK_GFP_ORDER_HI;
1409
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 /* Bootstrap is tricky, because several objects are allocated
1411 * from caches that do not exist yet:
Andrew Mortona737b3e2006-03-22 00:08:11 -08001412 * 1) initialize the cache_cache cache: it contains the struct
1413 * kmem_cache structures of all caches, except cache_cache itself:
1414 * cache_cache is statically allocated.
Christoph Lametere498be72005-09-09 13:03:32 -07001415 * Initially an __init data area is used for the head array and the
1416 * kmem_list3 structures, it's replaced with a kmalloc allocated
1417 * array at the end of the bootstrap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418 * 2) Create the first kmalloc cache.
Pekka Enberg343e0d72006-02-01 03:05:50 -08001419 * The struct kmem_cache for the new cache is allocated normally.
Christoph Lametere498be72005-09-09 13:03:32 -07001420 * An __init data area is used for the head array.
1421 * 3) Create the remaining kmalloc caches, with minimally sized
1422 * head arrays.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423 * 4) Replace the __init data head arrays for cache_cache and the first
1424 * kmalloc cache with kmalloc allocated arrays.
Christoph Lametere498be72005-09-09 13:03:32 -07001425 * 5) Replace the __init data for kmem_list3 for cache_cache and
1426 * the other cache's with kmalloc allocated memory.
1427 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428 */
1429
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001430 node = numa_node_id();
1431
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432 /* 1) create the cache_cache */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001433 INIT_LIST_HEAD(&cache_chain);
1434 list_add(&cache_cache.next, &cache_chain);
1435 cache_cache.colour_off = cache_line_size();
1436 cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001437 cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438
Andrew Mortona737b3e2006-03-22 00:08:11 -08001439 cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
1440 cache_line_size());
Eric Dumazet6a2d7a92006-12-13 00:34:27 -08001441 cache_cache.reciprocal_buffer_size =
1442 reciprocal_value(cache_cache.buffer_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443
Jack Steiner07ed76b2006-03-07 21:55:46 -08001444 for (order = 0; order < MAX_ORDER; order++) {
1445 cache_estimate(order, cache_cache.buffer_size,
1446 cache_line_size(), 0, &left_over, &cache_cache.num);
1447 if (cache_cache.num)
1448 break;
1449 }
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02001450 BUG_ON(!cache_cache.num);
Jack Steiner07ed76b2006-03-07 21:55:46 -08001451 cache_cache.gfporder = order;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001452 cache_cache.colour = left_over / cache_cache.colour_off;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001453 cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
1454 sizeof(struct slab), cache_line_size());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001455
1456 /* 2+3) create the kmalloc caches */
1457 sizes = malloc_sizes;
1458 names = cache_names;
1459
Andrew Mortona737b3e2006-03-22 00:08:11 -08001460 /*
1461 * Initialize the caches that provide memory for the array cache and the
1462 * kmem_list3 structures first. Without this, further allocations will
1463 * bug.
Christoph Lametere498be72005-09-09 13:03:32 -07001464 */
1465
1466 sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001467 sizes[INDEX_AC].cs_size,
1468 ARCH_KMALLOC_MINALIGN,
1469 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1470 NULL, NULL);
Christoph Lametere498be72005-09-09 13:03:32 -07001471
Andrew Mortona737b3e2006-03-22 00:08:11 -08001472 if (INDEX_AC != INDEX_L3) {
Christoph Lametere498be72005-09-09 13:03:32 -07001473 sizes[INDEX_L3].cs_cachep =
Andrew Mortona737b3e2006-03-22 00:08:11 -08001474 kmem_cache_create(names[INDEX_L3].name,
1475 sizes[INDEX_L3].cs_size,
1476 ARCH_KMALLOC_MINALIGN,
1477 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1478 NULL, NULL);
1479 }
Christoph Lametere498be72005-09-09 13:03:32 -07001480
Ingo Molnare0a42722006-06-23 02:03:46 -07001481 slab_early_init = 0;
1482
Linus Torvalds1da177e2005-04-16 15:20:36 -07001483 while (sizes->cs_size != ULONG_MAX) {
Christoph Lametere498be72005-09-09 13:03:32 -07001484 /*
1485 * For performance, all the general caches are L1 aligned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486 * This should be particularly beneficial on SMP boxes, as it
1487 * eliminates "false sharing".
1488 * Note for systems short on memory removing the alignment will
Christoph Lametere498be72005-09-09 13:03:32 -07001489 * allow tighter packing of the smaller caches.
1490 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001491 if (!sizes->cs_cachep) {
Christoph Lametere498be72005-09-09 13:03:32 -07001492 sizes->cs_cachep = kmem_cache_create(names->name,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001493 sizes->cs_size,
1494 ARCH_KMALLOC_MINALIGN,
1495 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1496 NULL, NULL);
1497 }
Christoph Lameter4b51d662007-02-10 01:43:10 -08001498#ifdef CONFIG_ZONE_DMA
1499 sizes->cs_dmacachep = kmem_cache_create(
1500 names->name_dma,
Andrew Mortona737b3e2006-03-22 00:08:11 -08001501 sizes->cs_size,
1502 ARCH_KMALLOC_MINALIGN,
1503 ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
1504 SLAB_PANIC,
1505 NULL, NULL);
Christoph Lameter4b51d662007-02-10 01:43:10 -08001506#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507 sizes++;
1508 names++;
1509 }
1510 /* 4) Replace the bootstrap head arrays */
1511 {
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001512 struct array_cache *ptr;
Christoph Lametere498be72005-09-09 13:03:32 -07001513
Linus Torvalds1da177e2005-04-16 15:20:36 -07001514 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
Christoph Lametere498be72005-09-09 13:03:32 -07001515
Linus Torvalds1da177e2005-04-16 15:20:36 -07001516 local_irq_disable();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001517 BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
1518 memcpy(ptr, cpu_cache_get(&cache_cache),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001519 sizeof(struct arraycache_init));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001520 /*
1521 * Do not assume that spinlocks can be initialized via memcpy:
1522 */
1523 spin_lock_init(&ptr->lock);
1524
Linus Torvalds1da177e2005-04-16 15:20:36 -07001525 cache_cache.array[smp_processor_id()] = ptr;
1526 local_irq_enable();
Christoph Lametere498be72005-09-09 13:03:32 -07001527
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
Christoph Lametere498be72005-09-09 13:03:32 -07001529
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530 local_irq_disable();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001531 BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001532 != &initarray_generic.cache);
Pekka Enberg9a2dba42006-02-01 03:05:49 -08001533 memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001534 sizeof(struct arraycache_init));
Ingo Molnar2b2d5492006-07-03 00:25:28 -07001535 /*
1536 * Do not assume that spinlocks can be initialized via memcpy:
1537 */
1538 spin_lock_init(&ptr->lock);
1539
Christoph Lametere498be72005-09-09 13:03:32 -07001540 malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001541 ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 local_irq_enable();
1543 }
Christoph Lametere498be72005-09-09 13:03:32 -07001544 /* 5) Replace the bootstrap kmem_list3's */
1545 {
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001546 int nid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001547
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001548 /* Replace the static kmem_list3 structures for the boot cpu */
1549 init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node);
1550
1551 for_each_online_node(nid) {
Christoph Lametere498be72005-09-09 13:03:32 -07001552 init_list(malloc_sizes[INDEX_AC].cs_cachep,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001553 &initkmem_list3[SIZE_AC + nid], nid);
Christoph Lametere498be72005-09-09 13:03:32 -07001554
1555 if (INDEX_AC != INDEX_L3) {
1556 init_list(malloc_sizes[INDEX_L3].cs_cachep,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07001557 &initkmem_list3[SIZE_L3 + nid], nid);
Christoph Lametere498be72005-09-09 13:03:32 -07001558 }
1559 }
1560 }
1561
1562 /* 6) resize the head arrays to their final sizes */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563 {
Pekka Enberg343e0d72006-02-01 03:05:50 -08001564 struct kmem_cache *cachep;
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001565 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566 list_for_each_entry(cachep, &cache_chain, next)
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07001567 if (enable_cpucache(cachep))
1568 BUG();
Ingo Molnarfc0abb12006-01-18 17:42:33 -08001569 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001570 }
1571
Ravikiran G Thirumalai056c6242006-09-25 23:31:38 -07001572 /* Annotate slab for lockdep -- annotate the malloc caches */
1573 init_lock_keys();
1574
1575
Linus Torvalds1da177e2005-04-16 15:20:36 -07001576 /* Done! */
1577 g_cpucache_up = FULL;
1578
Andrew Mortona737b3e2006-03-22 00:08:11 -08001579 /*
1580 * Register a cpu startup notifier callback that initializes
1581 * cpu_cache_get for all new cpus
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 */
1583 register_cpu_notifier(&cpucache_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001584
Andrew Mortona737b3e2006-03-22 00:08:11 -08001585 /*
1586 * The reap timers are started later, with a module init call: That part
1587 * of the kernel is not yet operational.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588 */
1589}
1590
1591static int __init cpucache_init(void)
1592{
1593 int cpu;
1594
Andrew Mortona737b3e2006-03-22 00:08:11 -08001595 /*
1596 * Register the timers that return unneeded pages to the page allocator
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 */
Christoph Lametere498be72005-09-09 13:03:32 -07001598 for_each_online_cpu(cpu)
Andrew Mortona737b3e2006-03-22 00:08:11 -08001599 start_cpu_timer(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600 return 0;
1601}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602__initcall(cpucache_init);
1603
1604/*
1605 * Interface to system's page allocator. No need to hold the cache-lock.
1606 *
1607 * If we requested dmaable memory, we will get it. Even if we
1608 * did not request dmaable memory, we might get it, but that
1609 * would be relatively rare and ignorable.
1610 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001611static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612{
1613 struct page *page;
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001614 int nr_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001615 int i;
1616
Luke Yangd6fef9d2006-04-10 22:52:56 -07001617#ifndef CONFIG_MMU
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001618 /*
1619 * Nommu uses slab's for process anonymous memory allocations, and thus
1620 * requires __GFP_COMP to properly refcount higher order allocations
Luke Yangd6fef9d2006-04-10 22:52:56 -07001621 */
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001622 flags |= __GFP_COMP;
Luke Yangd6fef9d2006-04-10 22:52:56 -07001623#endif
Christoph Lameter765c4502006-09-27 01:50:08 -07001624
Christoph Lameter3c517a62006-12-06 20:33:29 -08001625 flags |= cachep->gfpflags;
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001626
1627 page = alloc_pages_node(nodeid, flags, cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628 if (!page)
1629 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001630
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001631 nr_pages = (1 << cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
Christoph Lameter972d1a72006-09-25 23:31:51 -07001633 add_zone_page_state(page_zone(page),
1634 NR_SLAB_RECLAIMABLE, nr_pages);
1635 else
1636 add_zone_page_state(page_zone(page),
1637 NR_SLAB_UNRECLAIMABLE, nr_pages);
Christoph Hellwige1b6aa62006-06-23 02:03:17 -07001638 for (i = 0; i < nr_pages; i++)
1639 __SetPageSlab(page + i);
1640 return page_address(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641}
1642
1643/*
1644 * Interface to system's page release.
1645 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001646static void kmem_freepages(struct kmem_cache *cachep, void *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001648 unsigned long i = (1 << cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649 struct page *page = virt_to_page(addr);
1650 const unsigned long nr_freed = i;
1651
Christoph Lameter972d1a72006-09-25 23:31:51 -07001652 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1653 sub_zone_page_state(page_zone(page),
1654 NR_SLAB_RECLAIMABLE, nr_freed);
1655 else
1656 sub_zone_page_state(page_zone(page),
1657 NR_SLAB_UNRECLAIMABLE, nr_freed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001658 while (i--) {
Nick Pigginf205b2f2006-03-22 00:08:02 -08001659 BUG_ON(!PageSlab(page));
1660 __ClearPageSlab(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661 page++;
1662 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663 if (current->reclaim_state)
1664 current->reclaim_state->reclaimed_slab += nr_freed;
1665 free_pages((unsigned long)addr, cachep->gfporder);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666}
1667
1668static void kmem_rcu_free(struct rcu_head *head)
1669{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001670 struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
Pekka Enberg343e0d72006-02-01 03:05:50 -08001671 struct kmem_cache *cachep = slab_rcu->cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001672
1673 kmem_freepages(cachep, slab_rcu->addr);
1674 if (OFF_SLAB(cachep))
1675 kmem_cache_free(cachep->slabp_cache, slab_rcu);
1676}
1677
1678#if DEBUG
1679
1680#ifdef CONFIG_DEBUG_PAGEALLOC
Pekka Enberg343e0d72006-02-01 03:05:50 -08001681static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001682 unsigned long caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001684 int size = obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001685
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001686 addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001687
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001688 if (size < 5 * sizeof(unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689 return;
1690
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001691 *addr++ = 0x12345678;
1692 *addr++ = caller;
1693 *addr++ = smp_processor_id();
1694 size -= 3 * sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695 {
1696 unsigned long *sptr = &caller;
1697 unsigned long svalue;
1698
1699 while (!kstack_end(sptr)) {
1700 svalue = *sptr++;
1701 if (kernel_text_address(svalue)) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001702 *addr++ = svalue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703 size -= sizeof(unsigned long);
1704 if (size <= sizeof(unsigned long))
1705 break;
1706 }
1707 }
1708
1709 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001710 *addr++ = 0x87654321;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711}
1712#endif
1713
Pekka Enberg343e0d72006-02-01 03:05:50 -08001714static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001715{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001716 int size = obj_size(cachep);
1717 addr = &((char *)addr)[obj_offset(cachep)];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718
1719 memset(addr, val, size);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001720 *(unsigned char *)(addr + size - 1) = POISON_END;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721}
1722
1723static void dump_line(char *data, int offset, int limit)
1724{
1725 int i;
Dave Jonesaa83aa42006-09-29 01:59:51 -07001726 unsigned char error = 0;
1727 int bad_count = 0;
1728
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 printk(KERN_ERR "%03x:", offset);
Dave Jonesaa83aa42006-09-29 01:59:51 -07001730 for (i = 0; i < limit; i++) {
1731 if (data[offset + i] != POISON_FREE) {
1732 error = data[offset + i];
1733 bad_count++;
1734 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001735 printk(" %02x", (unsigned char)data[offset + i]);
Dave Jonesaa83aa42006-09-29 01:59:51 -07001736 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001737 printk("\n");
Dave Jonesaa83aa42006-09-29 01:59:51 -07001738
1739 if (bad_count == 1) {
1740 error ^= POISON_FREE;
1741 if (!(error & (error - 1))) {
1742 printk(KERN_ERR "Single bit error detected. Probably "
1743 "bad RAM.\n");
1744#ifdef CONFIG_X86
1745 printk(KERN_ERR "Run memtest86+ or a similar memory "
1746 "test tool.\n");
1747#else
1748 printk(KERN_ERR "Run a memory test tool.\n");
1749#endif
1750 }
1751 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752}
1753#endif
1754
1755#if DEBUG
1756
Pekka Enberg343e0d72006-02-01 03:05:50 -08001757static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001758{
1759 int i, size;
1760 char *realobj;
1761
1762 if (cachep->flags & SLAB_RED_ZONE) {
1763 printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001764 *dbg_redzone1(cachep, objp),
1765 *dbg_redzone2(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001766 }
1767
1768 if (cachep->flags & SLAB_STORE_USER) {
1769 printk(KERN_ERR "Last user: [<%p>]",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001770 *dbg_userword(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771 print_symbol("(%s)",
Andrew Mortona737b3e2006-03-22 00:08:11 -08001772 (unsigned long)*dbg_userword(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001773 printk("\n");
1774 }
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001775 realobj = (char *)objp + obj_offset(cachep);
1776 size = obj_size(cachep);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001777 for (i = 0; i < size && lines; i += 16, lines--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778 int limit;
1779 limit = 16;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001780 if (i + limit > size)
1781 limit = size - i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001782 dump_line(realobj, i, limit);
1783 }
1784}
1785
Pekka Enberg343e0d72006-02-01 03:05:50 -08001786static void check_poison_obj(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787{
1788 char *realobj;
1789 int size, i;
1790 int lines = 0;
1791
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001792 realobj = (char *)objp + obj_offset(cachep);
1793 size = obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001795 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001796 char exp = POISON_FREE;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001797 if (i == size - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001798 exp = POISON_END;
1799 if (realobj[i] != exp) {
1800 int limit;
1801 /* Mismatch ! */
1802 /* Print header */
1803 if (lines == 0) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001804 printk(KERN_ERR
Andrew Mortona737b3e2006-03-22 00:08:11 -08001805 "Slab corruption: start=%p, len=%d\n",
1806 realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807 print_objinfo(cachep, objp, 0);
1808 }
1809 /* Hexdump the affected line */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001810 i = (i / 16) * 16;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001811 limit = 16;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001812 if (i + limit > size)
1813 limit = size - i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814 dump_line(realobj, i, limit);
1815 i += 16;
1816 lines++;
1817 /* Limit to 5 lines */
1818 if (lines > 5)
1819 break;
1820 }
1821 }
1822 if (lines != 0) {
1823 /* Print some data about the neighboring objects, if they
1824 * exist:
1825 */
Pekka Enberg6ed5eb22006-02-01 03:05:49 -08001826 struct slab *slabp = virt_to_slab(objp);
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001827 unsigned int objnr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001829 objnr = obj_to_index(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001830 if (objnr) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001831 objp = index_to_obj(cachep, slabp, objnr - 1);
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001832 realobj = (char *)objp + obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001833 printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001834 realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001835 print_objinfo(cachep, objp, 2);
1836 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001837 if (objnr + 1 < cachep->num) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001838 objp = index_to_obj(cachep, slabp, objnr + 1);
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001839 realobj = (char *)objp + obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001840 printk(KERN_ERR "Next obj: start=%p, len=%d\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001841 realobj, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001842 print_objinfo(cachep, objp, 2);
1843 }
1844 }
1845}
1846#endif
1847
Linus Torvalds1da177e2005-04-16 15:20:36 -07001848#if DEBUG
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001849/**
Randy Dunlap911851e2006-03-22 00:08:14 -08001850 * slab_destroy_objs - destroy a slab and its objects
1851 * @cachep: cache pointer being destroyed
1852 * @slabp: slab pointer being destroyed
1853 *
1854 * Call the registered destructor for each object in a slab that is being
1855 * destroyed.
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001856 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001857static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001858{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001859 int i;
1860 for (i = 0; i < cachep->num; i++) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001861 void *objp = index_to_obj(cachep, slabp, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001862
1863 if (cachep->flags & SLAB_POISON) {
1864#ifdef CONFIG_DEBUG_PAGEALLOC
Andrew Mortona737b3e2006-03-22 00:08:11 -08001865 if (cachep->buffer_size % PAGE_SIZE == 0 &&
1866 OFF_SLAB(cachep))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001867 kernel_map_pages(virt_to_page(objp),
Andrew Mortona737b3e2006-03-22 00:08:11 -08001868 cachep->buffer_size / PAGE_SIZE, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001869 else
1870 check_poison_obj(cachep, objp);
1871#else
1872 check_poison_obj(cachep, objp);
1873#endif
1874 }
1875 if (cachep->flags & SLAB_RED_ZONE) {
1876 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
1877 slab_error(cachep, "start of a freed object "
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001878 "was overwritten");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
1880 slab_error(cachep, "end of a freed object "
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001881 "was overwritten");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001882 }
1883 if (cachep->dtor && !(cachep->flags & SLAB_POISON))
Manfred Spraul3dafccf2006-02-01 03:05:42 -08001884 (cachep->dtor) (objp + obj_offset(cachep), cachep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885 }
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001886}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001887#else
Pekka Enberg343e0d72006-02-01 03:05:50 -08001888static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001889{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001890 if (cachep->dtor) {
1891 int i;
1892 for (i = 0; i < cachep->num; i++) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08001893 void *objp = index_to_obj(cachep, slabp, i);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001894 (cachep->dtor) (objp, cachep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001895 }
1896 }
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001897}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001898#endif
1899
Randy Dunlap911851e2006-03-22 00:08:14 -08001900/**
1901 * slab_destroy - destroy and release all objects in a slab
1902 * @cachep: cache pointer being destroyed
1903 * @slabp: slab pointer being destroyed
1904 *
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001905 * Destroy all the objs in a slab, and release the mem back to the system.
Andrew Mortona737b3e2006-03-22 00:08:11 -08001906 * Before calling the slab must have been unlinked from the cache. The
1907 * cache-lock is not held/needed.
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001908 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001909static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
Matthew Dobson12dd36f2006-02-01 03:05:46 -08001910{
1911 void *addr = slabp->s_mem - slabp->colouroff;
1912
1913 slab_destroy_objs(cachep, slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
1915 struct slab_rcu *slab_rcu;
1916
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001917 slab_rcu = (struct slab_rcu *)slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001918 slab_rcu->cachep = cachep;
1919 slab_rcu->addr = addr;
1920 call_rcu(&slab_rcu->head, kmem_rcu_free);
1921 } else {
1922 kmem_freepages(cachep, addr);
Ingo Molnar873623d2006-07-13 14:44:38 +02001923 if (OFF_SLAB(cachep))
1924 kmem_cache_free(cachep->slabp_cache, slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925 }
1926}
1927
Andrew Mortona737b3e2006-03-22 00:08:11 -08001928/*
1929 * For setting up all the kmem_list3s for cache whose buffer_size is same as
1930 * size of kmem_list3.
1931 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08001932static void set_up_list3s(struct kmem_cache *cachep, int index)
Christoph Lametere498be72005-09-09 13:03:32 -07001933{
1934 int node;
1935
1936 for_each_online_node(node) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001937 cachep->nodelists[node] = &initkmem_list3[index + node];
Christoph Lametere498be72005-09-09 13:03:32 -07001938 cachep->nodelists[node]->next_reap = jiffies +
Pekka Enbergb28a02d2006-01-08 01:00:37 -08001939 REAPTIMEOUT_LIST3 +
1940 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametere498be72005-09-09 13:03:32 -07001941 }
1942}
1943
Christoph Lameter117f6eb2006-09-25 23:31:37 -07001944static void __kmem_cache_destroy(struct kmem_cache *cachep)
1945{
1946 int i;
1947 struct kmem_list3 *l3;
1948
1949 for_each_online_cpu(i)
1950 kfree(cachep->array[i]);
1951
1952 /* NUMA: free the list3 structures */
1953 for_each_online_node(i) {
1954 l3 = cachep->nodelists[i];
1955 if (l3) {
1956 kfree(l3->shared);
1957 free_alien_cache(l3->alien);
1958 kfree(l3);
1959 }
1960 }
1961 kmem_cache_free(&cache_cache, cachep);
1962}
1963
1964
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965/**
Randy.Dunlapa70773d2006-02-01 03:05:52 -08001966 * calculate_slab_order - calculate size (page order) of slabs
1967 * @cachep: pointer to the cache that is being created
1968 * @size: size of objects to be created in this cache.
1969 * @align: required alignment for the objects.
1970 * @flags: slab allocation flags
1971 *
1972 * Also calculates the number of objects per slab.
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001973 *
1974 * This could be made much more intelligent. For now, try to avoid using
1975 * high order pages for slabs. When the gfp() functions are more friendly
1976 * towards high-order requests, this should be changed.
1977 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08001978static size_t calculate_slab_order(struct kmem_cache *cachep,
Randy Dunlapee13d782006-02-01 03:05:53 -08001979 size_t size, size_t align, unsigned long flags)
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001980{
Ingo Molnarb1ab41c2006-06-02 15:44:58 +02001981 unsigned long offslab_limit;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001982 size_t left_over = 0;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001983 int gfporder;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001984
Andrew Mortona737b3e2006-03-22 00:08:11 -08001985 for (gfporder = 0; gfporder <= MAX_GFP_ORDER; gfporder++) {
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001986 unsigned int num;
1987 size_t remainder;
1988
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001989 cache_estimate(gfporder, size, align, flags, &remainder, &num);
Pekka Enberg4d268eb2006-01-08 01:00:36 -08001990 if (!num)
1991 continue;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08001992
Ingo Molnarb1ab41c2006-06-02 15:44:58 +02001993 if (flags & CFLGS_OFF_SLAB) {
1994 /*
1995 * Max number of objs-per-slab for caches which
1996 * use off-slab slabs. Needed to avoid a possible
1997 * looping condition in cache_grow().
1998 */
1999 offslab_limit = size - sizeof(struct slab);
2000 offslab_limit /= sizeof(kmem_bufctl_t);
2001
2002 if (num > offslab_limit)
2003 break;
2004 }
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002005
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002006 /* Found something acceptable - save it away */
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002007 cachep->num = num;
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002008 cachep->gfporder = gfporder;
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002009 left_over = remainder;
2010
2011 /*
Linus Torvaldsf78bb8a2006-03-08 10:33:05 -08002012 * A VFS-reclaimable slab tends to have most allocations
2013 * as GFP_NOFS and we really don't want to have to be allocating
2014 * higher-order pages when we are unable to shrink dcache.
2015 */
2016 if (flags & SLAB_RECLAIM_ACCOUNT)
2017 break;
2018
2019 /*
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002020 * Large number of objects is good, but very large slabs are
2021 * currently bad for the gfp()s.
2022 */
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002023 if (gfporder >= slab_break_gfp_order)
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002024 break;
2025
Linus Torvalds9888e6f2006-03-06 17:44:43 -08002026 /*
2027 * Acceptable internal fragmentation?
2028 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002029 if (left_over * 8 <= (PAGE_SIZE << gfporder))
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002030 break;
2031 }
2032 return left_over;
2033}
2034
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002035static int setup_cpu_cache(struct kmem_cache *cachep)
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002036{
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002037 if (g_cpucache_up == FULL)
2038 return enable_cpucache(cachep);
2039
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002040 if (g_cpucache_up == NONE) {
2041 /*
2042 * Note: the first kmem_cache_create must create the cache
2043 * that's used by kmalloc(24), otherwise the creation of
2044 * further caches will BUG().
2045 */
2046 cachep->array[smp_processor_id()] = &initarray_generic.cache;
2047
2048 /*
2049 * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
2050 * the first cache, then we need to set up all its list3s,
2051 * otherwise the creation of further caches will BUG().
2052 */
2053 set_up_list3s(cachep, SIZE_AC);
2054 if (INDEX_AC == INDEX_L3)
2055 g_cpucache_up = PARTIAL_L3;
2056 else
2057 g_cpucache_up = PARTIAL_AC;
2058 } else {
2059 cachep->array[smp_processor_id()] =
2060 kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
2061
2062 if (g_cpucache_up == PARTIAL_AC) {
2063 set_up_list3s(cachep, SIZE_L3);
2064 g_cpucache_up = PARTIAL_L3;
2065 } else {
2066 int node;
2067 for_each_online_node(node) {
2068 cachep->nodelists[node] =
2069 kmalloc_node(sizeof(struct kmem_list3),
2070 GFP_KERNEL, node);
2071 BUG_ON(!cachep->nodelists[node]);
2072 kmem_list3_init(cachep->nodelists[node]);
2073 }
2074 }
2075 }
2076 cachep->nodelists[numa_node_id()]->next_reap =
2077 jiffies + REAPTIMEOUT_LIST3 +
2078 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
2079
2080 cpu_cache_get(cachep)->avail = 0;
2081 cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
2082 cpu_cache_get(cachep)->batchcount = 1;
2083 cpu_cache_get(cachep)->touched = 0;
2084 cachep->batchcount = 1;
2085 cachep->limit = BOOT_CPUCACHE_ENTRIES;
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002086 return 0;
Pekka Enbergf30cf7d2006-03-22 00:08:11 -08002087}
2088
Pekka Enberg4d268eb2006-01-08 01:00:36 -08002089/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07002090 * kmem_cache_create - Create a cache.
2091 * @name: A string which is used in /proc/slabinfo to identify this cache.
2092 * @size: The size of objects to be created in this cache.
2093 * @align: The required alignment for the objects.
2094 * @flags: SLAB flags
2095 * @ctor: A constructor for the objects.
2096 * @dtor: A destructor for the objects.
2097 *
2098 * Returns a ptr to the cache on success, NULL on failure.
2099 * Cannot be called within a int, but can be interrupted.
2100 * The @ctor is run when new pages are allocated by the cache
2101 * and the @dtor is run before the pages are handed back.
2102 *
2103 * @name must be valid until the cache is destroyed. This implies that
Andrew Mortona737b3e2006-03-22 00:08:11 -08002104 * the module calling this has to destroy the cache before getting unloaded.
2105 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002106 * The flags are
2107 *
2108 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2109 * to catch references to uninitialised memory.
2110 *
2111 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2112 * for buffer overruns.
2113 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002114 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2115 * cacheline. This can be beneficial if you're counting cycles as closely
2116 * as davem.
2117 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002118struct kmem_cache *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002119kmem_cache_create (const char *name, size_t size, size_t align,
Andrew Mortona737b3e2006-03-22 00:08:11 -08002120 unsigned long flags,
2121 void (*ctor)(void*, struct kmem_cache *, unsigned long),
Pekka Enberg343e0d72006-02-01 03:05:50 -08002122 void (*dtor)(void*, struct kmem_cache *, unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002123{
2124 size_t left_over, slab_size, ralign;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07002125 struct kmem_cache *cachep = NULL, *pc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002126
2127 /*
2128 * Sanity checks... these are all serious usage bugs.
2129 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002130 if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002131 (size > (1 << MAX_OBJ_ORDER) * PAGE_SIZE) || (dtor && !ctor)) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002132 printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
2133 name);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002134 BUG();
2135 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002136
Ravikiran G Thirumalaif0188f42006-02-10 01:51:13 -08002137 /*
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002138 * We use cache_chain_mutex to ensure a consistent view of
2139 * cpu_online_map as well. Please see cpuup_callback
Ravikiran G Thirumalaif0188f42006-02-10 01:51:13 -08002140 */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002141 mutex_lock(&cache_chain_mutex);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002142
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07002143 list_for_each_entry(pc, &cache_chain, next) {
Andrew Morton4f12bb42005-11-07 00:58:00 -08002144 char tmp;
2145 int res;
2146
2147 /*
2148 * This happens when the module gets unloaded and doesn't
2149 * destroy its slab cache and no-one else reuses the vmalloc
2150 * area of the module. Print a warning.
2151 */
Andrew Morton138ae662006-12-06 20:36:41 -08002152 res = probe_kernel_address(pc->name, tmp);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002153 if (res) {
2154 printk("SLAB: cache with size %d has lost its name\n",
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002155 pc->buffer_size);
Andrew Morton4f12bb42005-11-07 00:58:00 -08002156 continue;
2157 }
2158
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002159 if (!strcmp(pc->name, name)) {
Andrew Morton4f12bb42005-11-07 00:58:00 -08002160 printk("kmem_cache_create: duplicate cache %s\n", name);
2161 dump_stack();
2162 goto oops;
2163 }
2164 }
2165
Linus Torvalds1da177e2005-04-16 15:20:36 -07002166#if DEBUG
2167 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
2168 if ((flags & SLAB_DEBUG_INITIAL) && !ctor) {
2169 /* No constructor, but inital state check requested */
2170 printk(KERN_ERR "%s: No con, but init state check "
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002171 "requested - %s\n", __FUNCTION__, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002172 flags &= ~SLAB_DEBUG_INITIAL;
2173 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002174#if FORCED_DEBUG
2175 /*
2176 * Enable redzoning and last user accounting, except for caches with
2177 * large objects, if the increased size would increase the object size
2178 * above the next power of two: caches with object sizes just above a
2179 * power of two have a significant amount of internal fragmentation.
2180 */
Andrew Mortona737b3e2006-03-22 00:08:11 -08002181 if (size < 4096 || fls(size - 1) == fls(size-1 + 3 * BYTES_PER_WORD))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002182 flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002183 if (!(flags & SLAB_DESTROY_BY_RCU))
2184 flags |= SLAB_POISON;
2185#endif
2186 if (flags & SLAB_DESTROY_BY_RCU)
2187 BUG_ON(flags & SLAB_POISON);
2188#endif
2189 if (flags & SLAB_DESTROY_BY_RCU)
2190 BUG_ON(dtor);
2191
2192 /*
Andrew Mortona737b3e2006-03-22 00:08:11 -08002193 * Always checks flags, a caller might be expecting debug support which
2194 * isn't available.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002195 */
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002196 BUG_ON(flags & ~CREATE_MASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002197
Andrew Mortona737b3e2006-03-22 00:08:11 -08002198 /*
2199 * Check that size is in terms of words. This is needed to avoid
Linus Torvalds1da177e2005-04-16 15:20:36 -07002200 * unaligned accesses for some archs when redzoning is used, and makes
2201 * sure any on-slab bufctl's are also correctly aligned.
2202 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002203 if (size & (BYTES_PER_WORD - 1)) {
2204 size += (BYTES_PER_WORD - 1);
2205 size &= ~(BYTES_PER_WORD - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002206 }
2207
Andrew Mortona737b3e2006-03-22 00:08:11 -08002208 /* calculate the final buffer alignment: */
2209
Linus Torvalds1da177e2005-04-16 15:20:36 -07002210 /* 1) arch recommendation: can be overridden for debug */
2211 if (flags & SLAB_HWCACHE_ALIGN) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002212 /*
2213 * Default alignment: as specified by the arch code. Except if
2214 * an object is really small, then squeeze multiple objects into
2215 * one cacheline.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002216 */
2217 ralign = cache_line_size();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002218 while (size <= ralign / 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002219 ralign /= 2;
2220 } else {
2221 ralign = BYTES_PER_WORD;
2222 }
Pekka Enbergca5f9702006-09-25 23:31:25 -07002223
2224 /*
2225 * Redzoning and user store require word alignment. Note this will be
2226 * overridden by architecture or caller mandated alignment if either
2227 * is greater than BYTES_PER_WORD.
2228 */
2229 if (flags & SLAB_RED_ZONE || flags & SLAB_STORE_USER)
2230 ralign = BYTES_PER_WORD;
2231
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002232 /* 2) arch mandated alignment */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002233 if (ralign < ARCH_SLAB_MINALIGN) {
2234 ralign = ARCH_SLAB_MINALIGN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002235 }
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002236 /* 3) caller mandated alignment */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002237 if (ralign < align) {
2238 ralign = align;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002239 }
Kevin Hilmana44b56d2006-12-06 20:32:11 -08002240 /* disable debug if necessary */
2241 if (ralign > BYTES_PER_WORD)
2242 flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002243 /*
Pekka Enbergca5f9702006-09-25 23:31:25 -07002244 * 4) Store it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 */
2246 align = ralign;
2247
2248 /* Get cache's description obj. */
Christoph Lametere94b1762006-12-06 20:33:17 -08002249 cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002250 if (!cachep)
Andrew Morton4f12bb42005-11-07 00:58:00 -08002251 goto oops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002252
2253#if DEBUG
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002254 cachep->obj_size = size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255
Pekka Enbergca5f9702006-09-25 23:31:25 -07002256 /*
2257 * Both debugging options require word-alignment which is calculated
2258 * into align above.
2259 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002260 if (flags & SLAB_RED_ZONE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002261 /* add space for red zone words */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002262 cachep->obj_offset += BYTES_PER_WORD;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002263 size += 2 * BYTES_PER_WORD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002264 }
2265 if (flags & SLAB_STORE_USER) {
Pekka Enbergca5f9702006-09-25 23:31:25 -07002266 /* user store requires one word storage behind the end of
2267 * the real object.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002268 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002269 size += BYTES_PER_WORD;
2270 }
2271#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002272 if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002273 && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
2274 cachep->obj_offset += PAGE_SIZE - size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002275 size = PAGE_SIZE;
2276 }
2277#endif
2278#endif
2279
Ingo Molnare0a42722006-06-23 02:03:46 -07002280 /*
2281 * Determine if the slab management is 'on' or 'off' slab.
2282 * (bootstrapping cannot cope with offslab caches so don't do
2283 * it too early on.)
2284 */
2285 if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002286 /*
2287 * Size is large, assume best to place the slab management obj
2288 * off-slab (should allow better packing of objs).
2289 */
2290 flags |= CFLGS_OFF_SLAB;
2291
2292 size = ALIGN(size, align);
2293
Linus Torvaldsf78bb8a2006-03-08 10:33:05 -08002294 left_over = calculate_slab_order(cachep, size, align, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002295
2296 if (!cachep->num) {
2297 printk("kmem_cache_create: couldn't create cache %s.\n", name);
2298 kmem_cache_free(&cache_cache, cachep);
2299 cachep = NULL;
Andrew Morton4f12bb42005-11-07 00:58:00 -08002300 goto oops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002301 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002302 slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
2303 + sizeof(struct slab), align);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002304
2305 /*
2306 * If the slab has been placed off-slab, and we have enough space then
2307 * move it on-slab. This is at the expense of any extra colouring.
2308 */
2309 if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
2310 flags &= ~CFLGS_OFF_SLAB;
2311 left_over -= slab_size;
2312 }
2313
2314 if (flags & CFLGS_OFF_SLAB) {
2315 /* really off slab. No need for manual alignment */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002316 slab_size =
2317 cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002318 }
2319
2320 cachep->colour_off = cache_line_size();
2321 /* Offset must be a multiple of the alignment. */
2322 if (cachep->colour_off < align)
2323 cachep->colour_off = align;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002324 cachep->colour = left_over / cachep->colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002325 cachep->slab_size = slab_size;
2326 cachep->flags = flags;
2327 cachep->gfpflags = 0;
Christoph Lameter4b51d662007-02-10 01:43:10 -08002328 if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002329 cachep->gfpflags |= GFP_DMA;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002330 cachep->buffer_size = size;
Eric Dumazet6a2d7a92006-12-13 00:34:27 -08002331 cachep->reciprocal_buffer_size = reciprocal_value(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002332
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002333 if (flags & CFLGS_OFF_SLAB) {
Victor Fuscob2d55072005-09-10 00:26:36 -07002334 cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002335 /*
2336 * This is a possibility for one of the malloc_sizes caches.
2337 * But since we go off slab only for object size greater than
2338 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
2339 * this should not happen at all.
2340 * But leave a BUG_ON for some lucky dude.
2341 */
2342 BUG_ON(!cachep->slabp_cache);
2343 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002344 cachep->ctor = ctor;
2345 cachep->dtor = dtor;
2346 cachep->name = name;
2347
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07002348 if (setup_cpu_cache(cachep)) {
2349 __kmem_cache_destroy(cachep);
2350 cachep = NULL;
2351 goto oops;
2352 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002353
Linus Torvalds1da177e2005-04-16 15:20:36 -07002354 /* cache setup completed, link it into the list */
2355 list_add(&cachep->next, &cache_chain);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002356oops:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002357 if (!cachep && (flags & SLAB_PANIC))
2358 panic("kmem_cache_create(): failed to create slab `%s'\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002359 name);
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002360 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002361 return cachep;
2362}
2363EXPORT_SYMBOL(kmem_cache_create);
2364
2365#if DEBUG
2366static void check_irq_off(void)
2367{
2368 BUG_ON(!irqs_disabled());
2369}
2370
2371static void check_irq_on(void)
2372{
2373 BUG_ON(irqs_disabled());
2374}
2375
Pekka Enberg343e0d72006-02-01 03:05:50 -08002376static void check_spinlock_acquired(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002377{
2378#ifdef CONFIG_SMP
2379 check_irq_off();
Christoph Lametere498be72005-09-09 13:03:32 -07002380 assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002381#endif
2382}
Christoph Lametere498be72005-09-09 13:03:32 -07002383
Pekka Enberg343e0d72006-02-01 03:05:50 -08002384static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
Christoph Lametere498be72005-09-09 13:03:32 -07002385{
2386#ifdef CONFIG_SMP
2387 check_irq_off();
2388 assert_spin_locked(&cachep->nodelists[node]->list_lock);
2389#endif
2390}
2391
Linus Torvalds1da177e2005-04-16 15:20:36 -07002392#else
2393#define check_irq_off() do { } while(0)
2394#define check_irq_on() do { } while(0)
2395#define check_spinlock_acquired(x) do { } while(0)
Christoph Lametere498be72005-09-09 13:03:32 -07002396#define check_spinlock_acquired_node(x, y) do { } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002397#endif
2398
Christoph Lameteraab22072006-03-22 00:09:06 -08002399static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
2400 struct array_cache *ac,
2401 int force, int node);
2402
Linus Torvalds1da177e2005-04-16 15:20:36 -07002403static void do_drain(void *arg)
2404{
Andrew Mortona737b3e2006-03-22 00:08:11 -08002405 struct kmem_cache *cachep = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002406 struct array_cache *ac;
Christoph Lameterff694162005-09-22 21:44:02 -07002407 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002408
2409 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08002410 ac = cpu_cache_get(cachep);
Christoph Lameterff694162005-09-22 21:44:02 -07002411 spin_lock(&cachep->nodelists[node]->list_lock);
2412 free_block(cachep, ac->entry, ac->avail, node);
2413 spin_unlock(&cachep->nodelists[node]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002414 ac->avail = 0;
2415}
2416
Pekka Enberg343e0d72006-02-01 03:05:50 -08002417static void drain_cpu_caches(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002418{
Christoph Lametere498be72005-09-09 13:03:32 -07002419 struct kmem_list3 *l3;
2420 int node;
2421
Andrew Mortona07fa392006-03-22 00:08:17 -08002422 on_each_cpu(do_drain, cachep, 1, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002423 check_irq_on();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002424 for_each_online_node(node) {
Christoph Lametere498be72005-09-09 13:03:32 -07002425 l3 = cachep->nodelists[node];
Roland Dreiera4523a82006-05-15 11:41:00 -07002426 if (l3 && l3->alien)
2427 drain_alien_cache(cachep, l3->alien);
2428 }
2429
2430 for_each_online_node(node) {
2431 l3 = cachep->nodelists[node];
2432 if (l3)
Christoph Lameteraab22072006-03-22 00:09:06 -08002433 drain_array(cachep, l3, l3->shared, 1, node);
Christoph Lametere498be72005-09-09 13:03:32 -07002434 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002435}
2436
Christoph Lametered11d9e2006-06-30 01:55:45 -07002437/*
2438 * Remove slabs from the list of free slabs.
2439 * Specify the number of slabs to drain in tofree.
2440 *
2441 * Returns the actual number of slabs released.
2442 */
2443static int drain_freelist(struct kmem_cache *cache,
2444 struct kmem_list3 *l3, int tofree)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002445{
Christoph Lametered11d9e2006-06-30 01:55:45 -07002446 struct list_head *p;
2447 int nr_freed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002448 struct slab *slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002449
Christoph Lametered11d9e2006-06-30 01:55:45 -07002450 nr_freed = 0;
2451 while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002452
Christoph Lametered11d9e2006-06-30 01:55:45 -07002453 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07002454 p = l3->slabs_free.prev;
Christoph Lametered11d9e2006-06-30 01:55:45 -07002455 if (p == &l3->slabs_free) {
2456 spin_unlock_irq(&l3->list_lock);
2457 goto out;
2458 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002459
Christoph Lametered11d9e2006-06-30 01:55:45 -07002460 slabp = list_entry(p, struct slab, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002461#if DEBUG
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002462 BUG_ON(slabp->inuse);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002463#endif
2464 list_del(&slabp->list);
Christoph Lametered11d9e2006-06-30 01:55:45 -07002465 /*
2466 * Safe to drop the lock. The slab is no longer linked
2467 * to the cache.
2468 */
2469 l3->free_objects -= cache->num;
Christoph Lametere498be72005-09-09 13:03:32 -07002470 spin_unlock_irq(&l3->list_lock);
Christoph Lametered11d9e2006-06-30 01:55:45 -07002471 slab_destroy(cache, slabp);
2472 nr_freed++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002473 }
Christoph Lametered11d9e2006-06-30 01:55:45 -07002474out:
2475 return nr_freed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002476}
2477
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002478/* Called with cache_chain_mutex held to protect against cpu hotplug */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002479static int __cache_shrink(struct kmem_cache *cachep)
Christoph Lametere498be72005-09-09 13:03:32 -07002480{
2481 int ret = 0, i = 0;
2482 struct kmem_list3 *l3;
2483
2484 drain_cpu_caches(cachep);
2485
2486 check_irq_on();
2487 for_each_online_node(i) {
2488 l3 = cachep->nodelists[i];
Christoph Lametered11d9e2006-06-30 01:55:45 -07002489 if (!l3)
2490 continue;
2491
2492 drain_freelist(cachep, l3, l3->free_objects);
2493
2494 ret += !list_empty(&l3->slabs_full) ||
2495 !list_empty(&l3->slabs_partial);
Christoph Lametere498be72005-09-09 13:03:32 -07002496 }
2497 return (ret ? 1 : 0);
2498}
2499
Linus Torvalds1da177e2005-04-16 15:20:36 -07002500/**
2501 * kmem_cache_shrink - Shrink a cache.
2502 * @cachep: The cache to shrink.
2503 *
2504 * Releases as many slabs as possible for a cache.
2505 * To help debugging, a zero exit status indicates all slabs were released.
2506 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002507int kmem_cache_shrink(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002508{
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002509 int ret;
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002510 BUG_ON(!cachep || in_interrupt());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002511
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002512 mutex_lock(&cache_chain_mutex);
2513 ret = __cache_shrink(cachep);
2514 mutex_unlock(&cache_chain_mutex);
2515 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002516}
2517EXPORT_SYMBOL(kmem_cache_shrink);
2518
2519/**
2520 * kmem_cache_destroy - delete a cache
2521 * @cachep: the cache to destroy
2522 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08002523 * Remove a &struct kmem_cache object from the slab cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002524 *
2525 * It is expected this function will be called by a module when it is
2526 * unloaded. This will remove the cache completely, and avoid a duplicate
2527 * cache being allocated each time a module is loaded and unloaded, if the
2528 * module doesn't have persistent in-kernel storage across loads and unloads.
2529 *
2530 * The cache must be empty before calling this function.
2531 *
2532 * The caller must guarantee that noone will allocate memory from the cache
2533 * during the kmem_cache_destroy().
2534 */
Alexey Dobriyan133d2052006-09-27 01:49:41 -07002535void kmem_cache_destroy(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002536{
Eric Sesterhenn40094fa2006-04-02 13:49:25 +02002537 BUG_ON(!cachep || in_interrupt());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538
Linus Torvalds1da177e2005-04-16 15:20:36 -07002539 /* Find the cache in the chain of caches. */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002540 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002541 /*
2542 * the chain is never empty, cache_cache is never destroyed
2543 */
2544 list_del(&cachep->next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002545 if (__cache_shrink(cachep)) {
2546 slab_error(cachep, "Can't free all objects");
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002547 list_add(&cachep->next, &cache_chain);
Ingo Molnarfc0abb12006-01-18 17:42:33 -08002548 mutex_unlock(&cache_chain_mutex);
Alexey Dobriyan133d2052006-09-27 01:49:41 -07002549 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002550 }
2551
2552 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07002553 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002554
Christoph Lameter117f6eb2006-09-25 23:31:37 -07002555 __kmem_cache_destroy(cachep);
Ravikiran G Thirumalai8f5be202006-12-06 20:32:14 -08002556 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002557}
2558EXPORT_SYMBOL(kmem_cache_destroy);
2559
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07002560/*
2561 * Get the memory for a slab management obj.
2562 * For a slab cache when the slab descriptor is off-slab, slab descriptors
2563 * always come from malloc_sizes caches. The slab descriptor cannot
2564 * come from the same cache which is getting created because,
2565 * when we are searching for an appropriate cache for these
2566 * descriptors in kmem_cache_create, we search through the malloc_sizes array.
2567 * If we are creating a malloc_sizes cache here it would not be visible to
2568 * kmem_find_general_cachep till the initialization is complete.
2569 * Hence we cannot have slabp_cache same as the original cache.
2570 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08002571static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002572 int colour_off, gfp_t local_flags,
2573 int nodeid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002574{
2575 struct slab *slabp;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002576
Linus Torvalds1da177e2005-04-16 15:20:36 -07002577 if (OFF_SLAB(cachep)) {
2578 /* Slab management obj is off-slab. */
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002579 slabp = kmem_cache_alloc_node(cachep->slabp_cache,
Christoph Lameter3c517a62006-12-06 20:33:29 -08002580 local_flags & ~GFP_THISNODE, nodeid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002581 if (!slabp)
2582 return NULL;
2583 } else {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002584 slabp = objp + colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002585 colour_off += cachep->slab_size;
2586 }
2587 slabp->inuse = 0;
2588 slabp->colouroff = colour_off;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002589 slabp->s_mem = objp + colour_off;
Ravikiran G Thirumalai5b74ada2006-04-10 22:52:53 -07002590 slabp->nodeid = nodeid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002591 return slabp;
2592}
2593
2594static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
2595{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002596 return (kmem_bufctl_t *) (slabp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002597}
2598
Pekka Enberg343e0d72006-02-01 03:05:50 -08002599static void cache_init_objs(struct kmem_cache *cachep,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002600 struct slab *slabp, unsigned long ctor_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002601{
2602 int i;
2603
2604 for (i = 0; i < cachep->num; i++) {
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002605 void *objp = index_to_obj(cachep, slabp, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002606#if DEBUG
2607 /* need to poison the objs? */
2608 if (cachep->flags & SLAB_POISON)
2609 poison_obj(cachep, objp, POISON_FREE);
2610 if (cachep->flags & SLAB_STORE_USER)
2611 *dbg_userword(cachep, objp) = NULL;
2612
2613 if (cachep->flags & SLAB_RED_ZONE) {
2614 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2615 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2616 }
2617 /*
Andrew Mortona737b3e2006-03-22 00:08:11 -08002618 * Constructors are not allowed to allocate memory from the same
2619 * cache which they are a constructor for. Otherwise, deadlock.
2620 * They must also be threaded.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002621 */
2622 if (cachep->ctor && !(cachep->flags & SLAB_POISON))
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002623 cachep->ctor(objp + obj_offset(cachep), cachep,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002624 ctor_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002625
2626 if (cachep->flags & SLAB_RED_ZONE) {
2627 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
2628 slab_error(cachep, "constructor overwrote the"
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002629 " end of an object");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002630 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
2631 slab_error(cachep, "constructor overwrote the"
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002632 " start of an object");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002633 }
Andrew Mortona737b3e2006-03-22 00:08:11 -08002634 if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
2635 OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002636 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002637 cachep->buffer_size / PAGE_SIZE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002638#else
2639 if (cachep->ctor)
2640 cachep->ctor(objp, cachep, ctor_flags);
2641#endif
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002642 slab_bufctl(slabp)[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002643 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002644 slab_bufctl(slabp)[i - 1] = BUFCTL_END;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002645 slabp->free = 0;
2646}
2647
Pekka Enberg343e0d72006-02-01 03:05:50 -08002648static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002649{
Christoph Lameter4b51d662007-02-10 01:43:10 -08002650 if (CONFIG_ZONE_DMA_FLAG) {
2651 if (flags & GFP_DMA)
2652 BUG_ON(!(cachep->gfpflags & GFP_DMA));
2653 else
2654 BUG_ON(cachep->gfpflags & GFP_DMA);
2655 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002656}
2657
Andrew Mortona737b3e2006-03-22 00:08:11 -08002658static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
2659 int nodeid)
Matthew Dobson78d382d2006-02-01 03:05:47 -08002660{
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002661 void *objp = index_to_obj(cachep, slabp, slabp->free);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002662 kmem_bufctl_t next;
2663
2664 slabp->inuse++;
2665 next = slab_bufctl(slabp)[slabp->free];
2666#if DEBUG
2667 slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
2668 WARN_ON(slabp->nodeid != nodeid);
2669#endif
2670 slabp->free = next;
2671
2672 return objp;
2673}
2674
Andrew Mortona737b3e2006-03-22 00:08:11 -08002675static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
2676 void *objp, int nodeid)
Matthew Dobson78d382d2006-02-01 03:05:47 -08002677{
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002678 unsigned int objnr = obj_to_index(cachep, slabp, objp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002679
2680#if DEBUG
2681 /* Verify that the slab belongs to the intended node */
2682 WARN_ON(slabp->nodeid != nodeid);
2683
Al Viro871751e2006-03-25 03:06:39 -08002684 if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
Matthew Dobson78d382d2006-02-01 03:05:47 -08002685 printk(KERN_ERR "slab: double free detected in cache "
Andrew Mortona737b3e2006-03-22 00:08:11 -08002686 "'%s', objp %p\n", cachep->name, objp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08002687 BUG();
2688 }
2689#endif
2690 slab_bufctl(slabp)[objnr] = slabp->free;
2691 slabp->free = objnr;
2692 slabp->inuse--;
2693}
2694
Pekka Enberg47768742006-06-23 02:03:07 -07002695/*
2696 * Map pages beginning at addr to the given cache and slab. This is required
2697 * for the slab allocator to be able to lookup the cache and slab of a
2698 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
2699 */
2700static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
2701 void *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002702{
Pekka Enberg47768742006-06-23 02:03:07 -07002703 int nr_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002704 struct page *page;
2705
Pekka Enberg47768742006-06-23 02:03:07 -07002706 page = virt_to_page(addr);
Nick Piggin84097512006-03-22 00:08:34 -08002707
Pekka Enberg47768742006-06-23 02:03:07 -07002708 nr_pages = 1;
Nick Piggin84097512006-03-22 00:08:34 -08002709 if (likely(!PageCompound(page)))
Pekka Enberg47768742006-06-23 02:03:07 -07002710 nr_pages <<= cache->gfporder;
2711
Linus Torvalds1da177e2005-04-16 15:20:36 -07002712 do {
Pekka Enberg47768742006-06-23 02:03:07 -07002713 page_set_cache(page, cache);
2714 page_set_slab(page, slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002715 page++;
Pekka Enberg47768742006-06-23 02:03:07 -07002716 } while (--nr_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002717}
2718
2719/*
2720 * Grow (by 1) the number of slabs within a cache. This is called by
2721 * kmem_cache_alloc() when there are no active objs left in a cache.
2722 */
Christoph Lameter3c517a62006-12-06 20:33:29 -08002723static int cache_grow(struct kmem_cache *cachep,
2724 gfp_t flags, int nodeid, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002725{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002726 struct slab *slabp;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002727 size_t offset;
2728 gfp_t local_flags;
2729 unsigned long ctor_flags;
Christoph Lametere498be72005-09-09 13:03:32 -07002730 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002731
Andrew Mortona737b3e2006-03-22 00:08:11 -08002732 /*
2733 * Be lazy and only check for valid flags here, keeping it out of the
2734 * critical path in kmem_cache_alloc().
Linus Torvalds1da177e2005-04-16 15:20:36 -07002735 */
Christoph Lameter441e1432006-12-06 20:33:19 -08002736 BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK | __GFP_NO_GROW));
Christoph Lameter6e0eaa42006-12-06 20:33:10 -08002737 if (flags & __GFP_NO_GROW)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002738 return 0;
2739
2740 ctor_flags = SLAB_CTOR_CONSTRUCTOR;
Christoph Lametera06d72c2006-12-06 20:33:12 -08002741 local_flags = (flags & GFP_LEVEL_MASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002742 if (!(local_flags & __GFP_WAIT))
2743 /*
2744 * Not allowed to sleep. Need to tell a constructor about
2745 * this - it might need to know...
2746 */
2747 ctor_flags |= SLAB_CTOR_ATOMIC;
2748
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002749 /* Take the l3 list lock to change the colour_next on this node */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002750 check_irq_off();
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002751 l3 = cachep->nodelists[nodeid];
2752 spin_lock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002753
2754 /* Get colour for the slab, and cal the next value. */
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002755 offset = l3->colour_next;
2756 l3->colour_next++;
2757 if (l3->colour_next >= cachep->colour)
2758 l3->colour_next = 0;
2759 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002760
Ravikiran G Thirumalai2e1217c2006-02-04 23:27:56 -08002761 offset *= cachep->colour_off;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002762
2763 if (local_flags & __GFP_WAIT)
2764 local_irq_enable();
2765
2766 /*
2767 * The test for missing atomic flag is performed here, rather than
2768 * the more obvious place, simply to reduce the critical path length
2769 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2770 * will eventually be caught here (where it matters).
2771 */
2772 kmem_flagcheck(cachep, flags);
2773
Andrew Mortona737b3e2006-03-22 00:08:11 -08002774 /*
2775 * Get mem for the objs. Attempt to allocate a physical page from
2776 * 'nodeid'.
Christoph Lametere498be72005-09-09 13:03:32 -07002777 */
Christoph Lameter3c517a62006-12-06 20:33:29 -08002778 if (!objp)
2779 objp = kmem_getpages(cachep, flags, nodeid);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002780 if (!objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002781 goto failed;
2782
2783 /* Get slab management. */
Christoph Lameter3c517a62006-12-06 20:33:29 -08002784 slabp = alloc_slabmgmt(cachep, objp, offset,
2785 local_flags & ~GFP_THISNODE, nodeid);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002786 if (!slabp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002787 goto opps1;
2788
Christoph Lametere498be72005-09-09 13:03:32 -07002789 slabp->nodeid = nodeid;
Pekka Enberg47768742006-06-23 02:03:07 -07002790 slab_map_pages(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002791
2792 cache_init_objs(cachep, slabp, ctor_flags);
2793
2794 if (local_flags & __GFP_WAIT)
2795 local_irq_disable();
2796 check_irq_off();
Christoph Lametere498be72005-09-09 13:03:32 -07002797 spin_lock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002798
2799 /* Make slab active. */
Christoph Lametere498be72005-09-09 13:03:32 -07002800 list_add_tail(&slabp->list, &(l3->slabs_free));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002801 STATS_INC_GROWN(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07002802 l3->free_objects += cachep->num;
2803 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002804 return 1;
Andrew Mortona737b3e2006-03-22 00:08:11 -08002805opps1:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002806 kmem_freepages(cachep, objp);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002807failed:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002808 if (local_flags & __GFP_WAIT)
2809 local_irq_disable();
2810 return 0;
2811}
2812
2813#if DEBUG
2814
2815/*
2816 * Perform extra freeing checks:
2817 * - detect bad pointers.
2818 * - POISON/RED_ZONE checking
2819 * - destructor calls, for caches with POISON+dtor
2820 */
2821static void kfree_debugcheck(const void *objp)
2822{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002823 if (!virt_addr_valid(objp)) {
2824 printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002825 (unsigned long)objp);
2826 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002827 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002828}
2829
Pekka Enberg58ce1fd2006-06-23 02:03:24 -07002830static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
2831{
2832 unsigned long redzone1, redzone2;
2833
2834 redzone1 = *dbg_redzone1(cache, obj);
2835 redzone2 = *dbg_redzone2(cache, obj);
2836
2837 /*
2838 * Redzone is ok.
2839 */
2840 if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
2841 return;
2842
2843 if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
2844 slab_error(cache, "double free detected");
2845 else
2846 slab_error(cache, "memory outside object was overwritten");
2847
2848 printk(KERN_ERR "%p: redzone 1:0x%lx, redzone 2:0x%lx.\n",
2849 obj, redzone1, redzone2);
2850}
2851
Pekka Enberg343e0d72006-02-01 03:05:50 -08002852static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002853 void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002854{
2855 struct page *page;
2856 unsigned int objnr;
2857 struct slab *slabp;
2858
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002859 objp -= obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002860 kfree_debugcheck(objp);
2861 page = virt_to_page(objp);
2862
Pekka Enberg065d41c2005-11-13 16:06:46 -08002863 slabp = page_get_slab(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002864
2865 if (cachep->flags & SLAB_RED_ZONE) {
Pekka Enberg58ce1fd2006-06-23 02:03:24 -07002866 verify_redzone_free(cachep, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002867 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2868 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2869 }
2870 if (cachep->flags & SLAB_STORE_USER)
2871 *dbg_userword(cachep, objp) = caller;
2872
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002873 objnr = obj_to_index(cachep, slabp, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002874
2875 BUG_ON(objnr >= cachep->num);
Pekka Enberg8fea4e92006-03-22 00:08:10 -08002876 BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002877
2878 if (cachep->flags & SLAB_DEBUG_INITIAL) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002879 /*
2880 * Need to call the slab's constructor so the caller can
2881 * perform a verify of its state (debugging). Called without
2882 * the cache-lock held.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002883 */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002884 cachep->ctor(objp + obj_offset(cachep),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002885 cachep, SLAB_CTOR_CONSTRUCTOR | SLAB_CTOR_VERIFY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002886 }
2887 if (cachep->flags & SLAB_POISON && cachep->dtor) {
2888 /* we want to cache poison the object,
2889 * call the destruction callback
2890 */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002891 cachep->dtor(objp + obj_offset(cachep), cachep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002892 }
Al Viro871751e2006-03-25 03:06:39 -08002893#ifdef CONFIG_DEBUG_SLAB_LEAK
2894 slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
2895#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002896 if (cachep->flags & SLAB_POISON) {
2897#ifdef CONFIG_DEBUG_PAGEALLOC
Andrew Mortona737b3e2006-03-22 00:08:11 -08002898 if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002899 store_stackinfo(cachep, objp, (unsigned long)caller);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002900 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08002901 cachep->buffer_size / PAGE_SIZE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002902 } else {
2903 poison_obj(cachep, objp, POISON_FREE);
2904 }
2905#else
2906 poison_obj(cachep, objp, POISON_FREE);
2907#endif
2908 }
2909 return objp;
2910}
2911
Pekka Enberg343e0d72006-02-01 03:05:50 -08002912static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002913{
2914 kmem_bufctl_t i;
2915 int entries = 0;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002916
Linus Torvalds1da177e2005-04-16 15:20:36 -07002917 /* Check slab's freelist to see if this obj is there. */
2918 for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
2919 entries++;
2920 if (entries > cachep->num || i >= cachep->num)
2921 goto bad;
2922 }
2923 if (entries != cachep->num - slabp->inuse) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002924bad:
2925 printk(KERN_ERR "slab: Internal list corruption detected in "
2926 "cache '%s'(%d), slabp %p(%d). Hexdump:\n",
2927 cachep->name, cachep->num, slabp, slabp->inuse);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002928 for (i = 0;
Linus Torvalds264132b2006-03-06 12:10:07 -08002929 i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002930 i++) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002931 if (i % 16 == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002932 printk("\n%03x:", i);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08002933 printk(" %02x", ((unsigned char *)slabp)[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002934 }
2935 printk("\n");
2936 BUG();
2937 }
2938}
2939#else
2940#define kfree_debugcheck(x) do { } while(0)
2941#define cache_free_debugcheck(x,objp,z) (objp)
2942#define check_slabp(x,y) do { } while(0)
2943#endif
2944
Pekka Enberg343e0d72006-02-01 03:05:50 -08002945static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002946{
2947 int batchcount;
2948 struct kmem_list3 *l3;
2949 struct array_cache *ac;
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002950 int node;
2951
2952 node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002953
2954 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08002955 ac = cpu_cache_get(cachep);
Andrew Mortona737b3e2006-03-22 00:08:11 -08002956retry:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002957 batchcount = ac->batchcount;
2958 if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08002959 /*
2960 * If there was little recent activity on this cache, then
2961 * perform only a partial refill. Otherwise we could generate
2962 * refill bouncing.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002963 */
2964 batchcount = BATCHREFILL_LIMIT;
2965 }
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002966 l3 = cachep->nodelists[node];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002967
Christoph Lametere498be72005-09-09 13:03:32 -07002968 BUG_ON(ac->avail > 0 || !l3);
2969 spin_lock(&l3->list_lock);
2970
Christoph Lameter3ded1752006-03-25 03:06:44 -08002971 /* See if we can refill from the shared array */
2972 if (l3->shared && transfer_objects(ac, l3->shared, batchcount))
2973 goto alloc_done;
2974
Linus Torvalds1da177e2005-04-16 15:20:36 -07002975 while (batchcount > 0) {
2976 struct list_head *entry;
2977 struct slab *slabp;
2978 /* Get slab alloc is to come from. */
2979 entry = l3->slabs_partial.next;
2980 if (entry == &l3->slabs_partial) {
2981 l3->free_touched = 1;
2982 entry = l3->slabs_free.next;
2983 if (entry == &l3->slabs_free)
2984 goto must_grow;
2985 }
2986
2987 slabp = list_entry(entry, struct slab, list);
2988 check_slabp(cachep, slabp);
2989 check_spinlock_acquired(cachep);
2990 while (slabp->inuse < cachep->num && batchcount--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002991 STATS_INC_ALLOCED(cachep);
2992 STATS_INC_ACTIVE(cachep);
2993 STATS_SET_HIGH(cachep);
2994
Matthew Dobson78d382d2006-02-01 03:05:47 -08002995 ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
Pekka Enberg1ca4cb22006-10-06 00:43:52 -07002996 node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002997 }
2998 check_slabp(cachep, slabp);
2999
3000 /* move slabp to correct slabp list: */
3001 list_del(&slabp->list);
3002 if (slabp->free == BUFCTL_END)
3003 list_add(&slabp->list, &l3->slabs_full);
3004 else
3005 list_add(&slabp->list, &l3->slabs_partial);
3006 }
3007
Andrew Mortona737b3e2006-03-22 00:08:11 -08003008must_grow:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003009 l3->free_objects -= ac->avail;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003010alloc_done:
Christoph Lametere498be72005-09-09 13:03:32 -07003011 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003012
3013 if (unlikely(!ac->avail)) {
3014 int x;
Christoph Lameter3c517a62006-12-06 20:33:29 -08003015 x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
Christoph Lametere498be72005-09-09 13:03:32 -07003016
Andrew Mortona737b3e2006-03-22 00:08:11 -08003017 /* cache_grow can reenable interrupts, then ac could change. */
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003018 ac = cpu_cache_get(cachep);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003019 if (!x && ac->avail == 0) /* no objects in sight? abort */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003020 return NULL;
3021
Andrew Mortona737b3e2006-03-22 00:08:11 -08003022 if (!ac->avail) /* objects refilled by interrupt? */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003023 goto retry;
3024 }
3025 ac->touched = 1;
Christoph Lametere498be72005-09-09 13:03:32 -07003026 return ac->entry[--ac->avail];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003027}
3028
Andrew Mortona737b3e2006-03-22 00:08:11 -08003029static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
3030 gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003031{
3032 might_sleep_if(flags & __GFP_WAIT);
3033#if DEBUG
3034 kmem_flagcheck(cachep, flags);
3035#endif
3036}
3037
3038#if DEBUG
Andrew Mortona737b3e2006-03-22 00:08:11 -08003039static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
3040 gfp_t flags, void *objp, void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003041{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003042 if (!objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003043 return objp;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003044 if (cachep->flags & SLAB_POISON) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003045#ifdef CONFIG_DEBUG_PAGEALLOC
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003046 if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003047 kernel_map_pages(virt_to_page(objp),
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003048 cachep->buffer_size / PAGE_SIZE, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003049 else
3050 check_poison_obj(cachep, objp);
3051#else
3052 check_poison_obj(cachep, objp);
3053#endif
3054 poison_obj(cachep, objp, POISON_INUSE);
3055 }
3056 if (cachep->flags & SLAB_STORE_USER)
3057 *dbg_userword(cachep, objp) = caller;
3058
3059 if (cachep->flags & SLAB_RED_ZONE) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08003060 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
3061 *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
3062 slab_error(cachep, "double free, or memory outside"
3063 " object was overwritten");
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003064 printk(KERN_ERR
Andrew Mortona737b3e2006-03-22 00:08:11 -08003065 "%p: redzone 1:0x%lx, redzone 2:0x%lx\n",
3066 objp, *dbg_redzone1(cachep, objp),
3067 *dbg_redzone2(cachep, objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003068 }
3069 *dbg_redzone1(cachep, objp) = RED_ACTIVE;
3070 *dbg_redzone2(cachep, objp) = RED_ACTIVE;
3071 }
Al Viro871751e2006-03-25 03:06:39 -08003072#ifdef CONFIG_DEBUG_SLAB_LEAK
3073 {
3074 struct slab *slabp;
3075 unsigned objnr;
3076
3077 slabp = page_get_slab(virt_to_page(objp));
3078 objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
3079 slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
3080 }
3081#endif
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003082 objp += obj_offset(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003083 if (cachep->ctor && cachep->flags & SLAB_POISON) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003084 unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003085
3086 if (!(flags & __GFP_WAIT))
3087 ctor_flags |= SLAB_CTOR_ATOMIC;
3088
3089 cachep->ctor(objp, cachep, ctor_flags);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003090 }
Kevin Hilmana44b56d2006-12-06 20:32:11 -08003091#if ARCH_SLAB_MINALIGN
3092 if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
3093 printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
3094 objp, ARCH_SLAB_MINALIGN);
3095 }
3096#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07003097 return objp;
3098}
3099#else
3100#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
3101#endif
3102
Akinobu Mita8a8b6502006-12-08 02:39:44 -08003103#ifdef CONFIG_FAILSLAB
3104
3105static struct failslab_attr {
3106
3107 struct fault_attr attr;
3108
3109 u32 ignore_gfp_wait;
3110#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3111 struct dentry *ignore_gfp_wait_file;
3112#endif
3113
3114} failslab = {
3115 .attr = FAULT_ATTR_INITIALIZER,
Don Mullis6b1b60f2006-12-08 02:39:53 -08003116 .ignore_gfp_wait = 1,
Akinobu Mita8a8b6502006-12-08 02:39:44 -08003117};
3118
3119static int __init setup_failslab(char *str)
3120{
3121 return setup_fault_attr(&failslab.attr, str);
3122}
3123__setup("failslab=", setup_failslab);
3124
3125static int should_failslab(struct kmem_cache *cachep, gfp_t flags)
3126{
3127 if (cachep == &cache_cache)
3128 return 0;
3129 if (flags & __GFP_NOFAIL)
3130 return 0;
3131 if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT))
3132 return 0;
3133
3134 return should_fail(&failslab.attr, obj_size(cachep));
3135}
3136
3137#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3138
3139static int __init failslab_debugfs(void)
3140{
3141 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
3142 struct dentry *dir;
3143 int err;
3144
3145 err = init_fault_attr_dentries(&failslab.attr, "failslab");
3146 if (err)
3147 return err;
3148 dir = failslab.attr.dentries.dir;
3149
3150 failslab.ignore_gfp_wait_file =
3151 debugfs_create_bool("ignore-gfp-wait", mode, dir,
3152 &failslab.ignore_gfp_wait);
3153
3154 if (!failslab.ignore_gfp_wait_file) {
3155 err = -ENOMEM;
3156 debugfs_remove(failslab.ignore_gfp_wait_file);
3157 cleanup_fault_attr_dentries(&failslab.attr);
3158 }
3159
3160 return err;
3161}
3162
3163late_initcall(failslab_debugfs);
3164
3165#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3166
3167#else /* CONFIG_FAILSLAB */
3168
3169static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags)
3170{
3171 return 0;
3172}
3173
3174#endif /* CONFIG_FAILSLAB */
3175
Pekka Enberg343e0d72006-02-01 03:05:50 -08003176static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003177{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003178 void *objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003179 struct array_cache *ac;
3180
Alok N Kataria5c382302005-09-27 21:45:46 -07003181 check_irq_off();
Akinobu Mita8a8b6502006-12-08 02:39:44 -08003182
3183 if (should_failslab(cachep, flags))
3184 return NULL;
3185
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003186 ac = cpu_cache_get(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003187 if (likely(ac->avail)) {
3188 STATS_INC_ALLOCHIT(cachep);
3189 ac->touched = 1;
Christoph Lametere498be72005-09-09 13:03:32 -07003190 objp = ac->entry[--ac->avail];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003191 } else {
3192 STATS_INC_ALLOCMISS(cachep);
3193 objp = cache_alloc_refill(cachep, flags);
3194 }
Alok N Kataria5c382302005-09-27 21:45:46 -07003195 return objp;
3196}
3197
Christoph Lametere498be72005-09-09 13:03:32 -07003198#ifdef CONFIG_NUMA
3199/*
Paul Jacksonb2455392006-03-24 03:16:12 -08003200 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
Paul Jacksonc61afb12006-03-24 03:16:08 -08003201 *
3202 * If we are in_interrupt, then process context, including cpusets and
3203 * mempolicy, may not apply and should not be used for allocation policy.
3204 */
3205static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
3206{
3207 int nid_alloc, nid_here;
3208
Christoph Lameter765c4502006-09-27 01:50:08 -07003209 if (in_interrupt() || (flags & __GFP_THISNODE))
Paul Jacksonc61afb12006-03-24 03:16:08 -08003210 return NULL;
3211 nid_alloc = nid_here = numa_node_id();
3212 if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
3213 nid_alloc = cpuset_mem_spread_node();
3214 else if (current->mempolicy)
3215 nid_alloc = slab_node(current->mempolicy);
3216 if (nid_alloc != nid_here)
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003217 return ____cache_alloc_node(cachep, flags, nid_alloc);
Paul Jacksonc61afb12006-03-24 03:16:08 -08003218 return NULL;
3219}
3220
3221/*
Christoph Lameter765c4502006-09-27 01:50:08 -07003222 * Fallback function if there was no memory available and no objects on a
Christoph Lameter3c517a62006-12-06 20:33:29 -08003223 * certain node and fall back is permitted. First we scan all the
3224 * available nodelists for available objects. If that fails then we
3225 * perform an allocation without specifying a node. This allows the page
3226 * allocator to do its reclaim / fallback magic. We then insert the
3227 * slab into the proper nodelist and then allocate from it.
Christoph Lameter765c4502006-09-27 01:50:08 -07003228 */
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003229static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
Christoph Lameter765c4502006-09-27 01:50:08 -07003230{
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003231 struct zonelist *zonelist;
3232 gfp_t local_flags;
Christoph Lameter765c4502006-09-27 01:50:08 -07003233 struct zone **z;
3234 void *obj = NULL;
Christoph Lameter3c517a62006-12-06 20:33:29 -08003235 int nid;
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003236
3237 if (flags & __GFP_THISNODE)
3238 return NULL;
3239
3240 zonelist = &NODE_DATA(slab_node(current->mempolicy))
3241 ->node_zonelists[gfp_zone(flags)];
3242 local_flags = (flags & GFP_LEVEL_MASK);
Christoph Lameter765c4502006-09-27 01:50:08 -07003243
Christoph Lameter3c517a62006-12-06 20:33:29 -08003244retry:
3245 /*
3246 * Look through allowed nodes for objects available
3247 * from existing per node queues.
3248 */
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003249 for (z = zonelist->zones; *z && !obj; z++) {
Christoph Lameter3c517a62006-12-06 20:33:29 -08003250 nid = zone_to_nid(*z);
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003251
Paul Jackson02a0e532006-12-13 00:34:25 -08003252 if (cpuset_zone_allowed_hardwall(*z, flags) &&
Christoph Lameter3c517a62006-12-06 20:33:29 -08003253 cache->nodelists[nid] &&
3254 cache->nodelists[nid]->free_objects)
3255 obj = ____cache_alloc_node(cache,
3256 flags | GFP_THISNODE, nid);
3257 }
3258
Hugh Dickinsb6a60452007-01-05 16:36:36 -08003259 if (!obj && !(flags & __GFP_NO_GROW)) {
Christoph Lameter3c517a62006-12-06 20:33:29 -08003260 /*
3261 * This allocation will be performed within the constraints
3262 * of the current cpuset / memory policy requirements.
3263 * We may trigger various forms of reclaim on the allowed
3264 * set and go into memory reserves if necessary.
3265 */
Christoph Lameterdd47ea72006-12-13 00:34:11 -08003266 if (local_flags & __GFP_WAIT)
3267 local_irq_enable();
3268 kmem_flagcheck(cache, flags);
Christoph Lameter3c517a62006-12-06 20:33:29 -08003269 obj = kmem_getpages(cache, flags, -1);
Christoph Lameterdd47ea72006-12-13 00:34:11 -08003270 if (local_flags & __GFP_WAIT)
3271 local_irq_disable();
Christoph Lameter3c517a62006-12-06 20:33:29 -08003272 if (obj) {
3273 /*
3274 * Insert into the appropriate per node queues
3275 */
3276 nid = page_to_nid(virt_to_page(obj));
3277 if (cache_grow(cache, flags, nid, obj)) {
3278 obj = ____cache_alloc_node(cache,
3279 flags | GFP_THISNODE, nid);
3280 if (!obj)
3281 /*
3282 * Another processor may allocate the
3283 * objects in the slab since we are
3284 * not holding any locks.
3285 */
3286 goto retry;
3287 } else {
Hugh Dickinsb6a60452007-01-05 16:36:36 -08003288 /* cache_grow already freed obj */
Christoph Lameter3c517a62006-12-06 20:33:29 -08003289 obj = NULL;
3290 }
3291 }
Christoph Lameteraedb0eb2006-10-21 10:24:16 -07003292 }
Christoph Lameter765c4502006-09-27 01:50:08 -07003293 return obj;
3294}
3295
3296/*
Christoph Lametere498be72005-09-09 13:03:32 -07003297 * A interface to enable slab creation on nodeid
Linus Torvalds1da177e2005-04-16 15:20:36 -07003298 */
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003299static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003300 int nodeid)
Christoph Lametere498be72005-09-09 13:03:32 -07003301{
3302 struct list_head *entry;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003303 struct slab *slabp;
3304 struct kmem_list3 *l3;
3305 void *obj;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003306 int x;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003307
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003308 l3 = cachep->nodelists[nodeid];
3309 BUG_ON(!l3);
Christoph Lametere498be72005-09-09 13:03:32 -07003310
Andrew Mortona737b3e2006-03-22 00:08:11 -08003311retry:
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08003312 check_irq_off();
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003313 spin_lock(&l3->list_lock);
3314 entry = l3->slabs_partial.next;
3315 if (entry == &l3->slabs_partial) {
3316 l3->free_touched = 1;
3317 entry = l3->slabs_free.next;
3318 if (entry == &l3->slabs_free)
3319 goto must_grow;
3320 }
Christoph Lametere498be72005-09-09 13:03:32 -07003321
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003322 slabp = list_entry(entry, struct slab, list);
3323 check_spinlock_acquired_node(cachep, nodeid);
3324 check_slabp(cachep, slabp);
Christoph Lametere498be72005-09-09 13:03:32 -07003325
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003326 STATS_INC_NODEALLOCS(cachep);
3327 STATS_INC_ACTIVE(cachep);
3328 STATS_SET_HIGH(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003329
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003330 BUG_ON(slabp->inuse == cachep->num);
Christoph Lametere498be72005-09-09 13:03:32 -07003331
Matthew Dobson78d382d2006-02-01 03:05:47 -08003332 obj = slab_get_obj(cachep, slabp, nodeid);
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003333 check_slabp(cachep, slabp);
3334 l3->free_objects--;
3335 /* move slabp to correct slabp list: */
3336 list_del(&slabp->list);
Christoph Lametere498be72005-09-09 13:03:32 -07003337
Andrew Mortona737b3e2006-03-22 00:08:11 -08003338 if (slabp->free == BUFCTL_END)
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003339 list_add(&slabp->list, &l3->slabs_full);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003340 else
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003341 list_add(&slabp->list, &l3->slabs_partial);
Christoph Lametere498be72005-09-09 13:03:32 -07003342
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003343 spin_unlock(&l3->list_lock);
3344 goto done;
Christoph Lametere498be72005-09-09 13:03:32 -07003345
Andrew Mortona737b3e2006-03-22 00:08:11 -08003346must_grow:
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003347 spin_unlock(&l3->list_lock);
Christoph Lameter3c517a62006-12-06 20:33:29 -08003348 x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
Christoph Lameter765c4502006-09-27 01:50:08 -07003349 if (x)
3350 goto retry;
Christoph Lametere498be72005-09-09 13:03:32 -07003351
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003352 return fallback_alloc(cachep, flags);
Christoph Lameter765c4502006-09-27 01:50:08 -07003353
Andrew Mortona737b3e2006-03-22 00:08:11 -08003354done:
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003355 return obj;
Christoph Lametere498be72005-09-09 13:03:32 -07003356}
Pekka Enberg8c8cc2c2007-02-10 01:42:53 -08003357
3358/**
3359 * kmem_cache_alloc_node - Allocate an object on the specified node
3360 * @cachep: The cache to allocate from.
3361 * @flags: See kmalloc().
3362 * @nodeid: node number of the target node.
3363 * @caller: return address of caller, used for debug information
3364 *
3365 * Identical to kmem_cache_alloc but it will allocate memory on the given
3366 * node, which can improve the performance for cpu bound structures.
3367 *
3368 * Fallback to other node is possible if __GFP_THISNODE is not set.
3369 */
3370static __always_inline void *
3371__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
3372 void *caller)
3373{
3374 unsigned long save_flags;
3375 void *ptr;
3376
3377 cache_alloc_debugcheck_before(cachep, flags);
3378 local_irq_save(save_flags);
3379
3380 if (unlikely(nodeid == -1))
3381 nodeid = numa_node_id();
3382
3383 if (unlikely(!cachep->nodelists[nodeid])) {
3384 /* Node not bootstrapped yet */
3385 ptr = fallback_alloc(cachep, flags);
3386 goto out;
3387 }
3388
3389 if (nodeid == numa_node_id()) {
3390 /*
3391 * Use the locally cached objects if possible.
3392 * However ____cache_alloc does not allow fallback
3393 * to other nodes. It may fail while we still have
3394 * objects on other nodes available.
3395 */
3396 ptr = ____cache_alloc(cachep, flags);
3397 if (ptr)
3398 goto out;
3399 }
3400 /* ___cache_alloc_node can fall back to other nodes */
3401 ptr = ____cache_alloc_node(cachep, flags, nodeid);
3402 out:
3403 local_irq_restore(save_flags);
3404 ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
3405
3406 return ptr;
3407}
3408
3409static __always_inline void *
3410__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
3411{
3412 void *objp;
3413
3414 if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
3415 objp = alternate_node_alloc(cache, flags);
3416 if (objp)
3417 goto out;
3418 }
3419 objp = ____cache_alloc(cache, flags);
3420
3421 /*
3422 * We may just have run out of memory on the local node.
3423 * ____cache_alloc_node() knows how to locate memory on other nodes
3424 */
3425 if (!objp)
3426 objp = ____cache_alloc_node(cache, flags, numa_node_id());
3427
3428 out:
3429 return objp;
3430}
3431#else
3432
3433static __always_inline void *
3434__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3435{
3436 return ____cache_alloc(cachep, flags);
3437}
3438
3439#endif /* CONFIG_NUMA */
3440
3441static __always_inline void *
3442__cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
3443{
3444 unsigned long save_flags;
3445 void *objp;
3446
3447 cache_alloc_debugcheck_before(cachep, flags);
3448 local_irq_save(save_flags);
3449 objp = __do_cache_alloc(cachep, flags);
3450 local_irq_restore(save_flags);
3451 objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
3452 prefetchw(objp);
3453
3454 return objp;
3455}
Christoph Lametere498be72005-09-09 13:03:32 -07003456
3457/*
3458 * Caller needs to acquire correct kmem_list's list_lock
3459 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003460static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003461 int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003462{
3463 int i;
Christoph Lametere498be72005-09-09 13:03:32 -07003464 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003465
3466 for (i = 0; i < nr_objects; i++) {
3467 void *objp = objpp[i];
3468 struct slab *slabp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003469
Pekka Enberg6ed5eb22006-02-01 03:05:49 -08003470 slabp = virt_to_slab(objp);
Christoph Lameterff694162005-09-22 21:44:02 -07003471 l3 = cachep->nodelists[node];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003472 list_del(&slabp->list);
Christoph Lameterff694162005-09-22 21:44:02 -07003473 check_spinlock_acquired_node(cachep, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003474 check_slabp(cachep, slabp);
Matthew Dobson78d382d2006-02-01 03:05:47 -08003475 slab_put_obj(cachep, slabp, objp, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003476 STATS_DEC_ACTIVE(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003477 l3->free_objects++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003478 check_slabp(cachep, slabp);
3479
3480 /* fixup slab chains */
3481 if (slabp->inuse == 0) {
Christoph Lametere498be72005-09-09 13:03:32 -07003482 if (l3->free_objects > l3->free_limit) {
3483 l3->free_objects -= cachep->num;
Ravikiran G Thirumalaie5ac9c52006-09-25 23:31:34 -07003484 /* No need to drop any previously held
3485 * lock here, even if we have a off-slab slab
3486 * descriptor it is guaranteed to come from
3487 * a different cache, refer to comments before
3488 * alloc_slabmgmt.
3489 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003490 slab_destroy(cachep, slabp);
3491 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07003492 list_add(&slabp->list, &l3->slabs_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003493 }
3494 } else {
3495 /* Unconditionally move a slab to the end of the
3496 * partial list on free - maximum time for the
3497 * other objects to be freed, too.
3498 */
Christoph Lametere498be72005-09-09 13:03:32 -07003499 list_add_tail(&slabp->list, &l3->slabs_partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003500 }
3501 }
3502}
3503
Pekka Enberg343e0d72006-02-01 03:05:50 -08003504static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003505{
3506 int batchcount;
Christoph Lametere498be72005-09-09 13:03:32 -07003507 struct kmem_list3 *l3;
Christoph Lameterff694162005-09-22 21:44:02 -07003508 int node = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003509
3510 batchcount = ac->batchcount;
3511#if DEBUG
3512 BUG_ON(!batchcount || batchcount > ac->avail);
3513#endif
3514 check_irq_off();
Christoph Lameterff694162005-09-22 21:44:02 -07003515 l3 = cachep->nodelists[node];
Ingo Molnar873623d2006-07-13 14:44:38 +02003516 spin_lock(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07003517 if (l3->shared) {
3518 struct array_cache *shared_array = l3->shared;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003519 int max = shared_array->limit - shared_array->avail;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003520 if (max) {
3521 if (batchcount > max)
3522 batchcount = max;
Christoph Lametere498be72005-09-09 13:03:32 -07003523 memcpy(&(shared_array->entry[shared_array->avail]),
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003524 ac->entry, sizeof(void *) * batchcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003525 shared_array->avail += batchcount;
3526 goto free_done;
3527 }
3528 }
3529
Christoph Lameterff694162005-09-22 21:44:02 -07003530 free_block(cachep, ac->entry, batchcount, node);
Andrew Mortona737b3e2006-03-22 00:08:11 -08003531free_done:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003532#if STATS
3533 {
3534 int i = 0;
3535 struct list_head *p;
3536
Christoph Lametere498be72005-09-09 13:03:32 -07003537 p = l3->slabs_free.next;
3538 while (p != &(l3->slabs_free)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003539 struct slab *slabp;
3540
3541 slabp = list_entry(p, struct slab, list);
3542 BUG_ON(slabp->inuse);
3543
3544 i++;
3545 p = p->next;
3546 }
3547 STATS_SET_FREEABLE(cachep, i);
3548 }
3549#endif
Christoph Lametere498be72005-09-09 13:03:32 -07003550 spin_unlock(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003551 ac->avail -= batchcount;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003552 memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003553}
3554
3555/*
Andrew Mortona737b3e2006-03-22 00:08:11 -08003556 * Release an obj back to its cache. If the obj has a constructed state, it must
3557 * be in this state _before_ it is released. Called with disabled ints.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003558 */
Ingo Molnar873623d2006-07-13 14:44:38 +02003559static inline void __cache_free(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003560{
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003561 struct array_cache *ac = cpu_cache_get(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003562
3563 check_irq_off();
3564 objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
3565
Ingo Molnar873623d2006-07-13 14:44:38 +02003566 if (cache_free_alien(cachep, objp))
Pekka Enberg729bd0b2006-06-23 02:03:05 -07003567 return;
Christoph Lametere498be72005-09-09 13:03:32 -07003568
Linus Torvalds1da177e2005-04-16 15:20:36 -07003569 if (likely(ac->avail < ac->limit)) {
3570 STATS_INC_FREEHIT(cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003571 ac->entry[ac->avail++] = objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003572 return;
3573 } else {
3574 STATS_INC_FREEMISS(cachep);
3575 cache_flusharray(cachep, ac);
Christoph Lametere498be72005-09-09 13:03:32 -07003576 ac->entry[ac->avail++] = objp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003577 }
3578}
3579
3580/**
3581 * kmem_cache_alloc - Allocate an object
3582 * @cachep: The cache to allocate from.
3583 * @flags: See kmalloc().
3584 *
3585 * Allocate an object from this cache. The flags are only relevant
3586 * if the cache has no available objects.
3587 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003588void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003589{
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003590 return __cache_alloc(cachep, flags, __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003591}
3592EXPORT_SYMBOL(kmem_cache_alloc);
3593
3594/**
Rolf Eike Beerb8008b22006-07-30 03:04:04 -07003595 * kmem_cache_zalloc - Allocate an object. The memory is set to zero.
Pekka Enberga8c0f9a2006-03-25 03:06:42 -08003596 * @cache: The cache to allocate from.
3597 * @flags: See kmalloc().
3598 *
3599 * Allocate an object from this cache and set the allocated memory to zero.
3600 * The flags are only relevant if the cache has no available objects.
3601 */
3602void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags)
3603{
3604 void *ret = __cache_alloc(cache, flags, __builtin_return_address(0));
3605 if (ret)
3606 memset(ret, 0, obj_size(cache));
3607 return ret;
3608}
3609EXPORT_SYMBOL(kmem_cache_zalloc);
3610
3611/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07003612 * kmem_ptr_validate - check if an untrusted pointer might
3613 * be a slab entry.
3614 * @cachep: the cache we're checking against
3615 * @ptr: pointer to validate
3616 *
3617 * This verifies that the untrusted pointer looks sane:
3618 * it is _not_ a guarantee that the pointer is actually
3619 * part of the slab cache in question, but it at least
3620 * validates that the pointer can be dereferenced and
3621 * looks half-way sane.
3622 *
3623 * Currently only used for dentry validation.
3624 */
Christoph Lameterb7f869a2006-12-22 01:06:44 -08003625int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003626{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003627 unsigned long addr = (unsigned long)ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003628 unsigned long min_addr = PAGE_OFFSET;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003629 unsigned long align_mask = BYTES_PER_WORD - 1;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003630 unsigned long size = cachep->buffer_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003631 struct page *page;
3632
3633 if (unlikely(addr < min_addr))
3634 goto out;
3635 if (unlikely(addr > (unsigned long)high_memory - size))
3636 goto out;
3637 if (unlikely(addr & align_mask))
3638 goto out;
3639 if (unlikely(!kern_addr_valid(addr)))
3640 goto out;
3641 if (unlikely(!kern_addr_valid(addr + size - 1)))
3642 goto out;
3643 page = virt_to_page(ptr);
3644 if (unlikely(!PageSlab(page)))
3645 goto out;
Pekka Enberg065d41c2005-11-13 16:06:46 -08003646 if (unlikely(page_get_cache(page) != cachep))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003647 goto out;
3648 return 1;
Andrew Mortona737b3e2006-03-22 00:08:11 -08003649out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003650 return 0;
3651}
3652
3653#ifdef CONFIG_NUMA
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003654void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
3655{
3656 return __cache_alloc_node(cachep, flags, nodeid,
3657 __builtin_return_address(0));
3658}
Linus Torvalds1da177e2005-04-16 15:20:36 -07003659EXPORT_SYMBOL(kmem_cache_alloc_node);
3660
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003661static __always_inline void *
3662__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003663{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003664 struct kmem_cache *cachep;
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003665
3666 cachep = kmem_find_general_cachep(size, flags);
3667 if (unlikely(cachep == NULL))
3668 return NULL;
3669 return kmem_cache_alloc_node(cachep, flags, node);
3670}
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003671
3672#ifdef CONFIG_DEBUG_SLAB
3673void *__kmalloc_node(size_t size, gfp_t flags, int node)
3674{
3675 return __do_kmalloc_node(size, flags, node,
3676 __builtin_return_address(0));
3677}
Christoph Hellwigdbe5e692006-09-25 23:31:36 -07003678EXPORT_SYMBOL(__kmalloc_node);
Christoph Hellwig8b98c162006-12-06 20:32:30 -08003679
3680void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
3681 int node, void *caller)
3682{
3683 return __do_kmalloc_node(size, flags, node, caller);
3684}
3685EXPORT_SYMBOL(__kmalloc_node_track_caller);
3686#else
3687void *__kmalloc_node(size_t size, gfp_t flags, int node)
3688{
3689 return __do_kmalloc_node(size, flags, node, NULL);
3690}
3691EXPORT_SYMBOL(__kmalloc_node);
3692#endif /* CONFIG_DEBUG_SLAB */
3693#endif /* CONFIG_NUMA */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003694
3695/**
Paul Drynoff800590f2006-06-23 02:03:48 -07003696 * __do_kmalloc - allocate memory
Linus Torvalds1da177e2005-04-16 15:20:36 -07003697 * @size: how many bytes of memory are required.
Paul Drynoff800590f2006-06-23 02:03:48 -07003698 * @flags: the type of memory to allocate (see kmalloc).
Randy Dunlap911851e2006-03-22 00:08:14 -08003699 * @caller: function caller for debug tracking of the caller
Linus Torvalds1da177e2005-04-16 15:20:36 -07003700 */
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003701static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
3702 void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003703{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003704 struct kmem_cache *cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003705
Manfred Spraul97e2bde2005-05-01 08:58:38 -07003706 /* If you want to save a few bytes .text space: replace
3707 * __ with kmem_.
3708 * Then kmalloc uses the uninlined functions instead of the inline
3709 * functions.
3710 */
3711 cachep = __find_general_cachep(size, flags);
Andrew Mortondbdb9042005-09-23 13:24:10 -07003712 if (unlikely(cachep == NULL))
3713 return NULL;
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003714 return __cache_alloc(cachep, flags, caller);
3715}
3716
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003717
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -07003718#ifdef CONFIG_DEBUG_SLAB
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003719void *__kmalloc(size_t size, gfp_t flags)
3720{
Al Viro871751e2006-03-25 03:06:39 -08003721 return __do_kmalloc(size, flags, __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003722}
3723EXPORT_SYMBOL(__kmalloc);
3724
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003725void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
3726{
3727 return __do_kmalloc(size, flags, caller);
3728}
3729EXPORT_SYMBOL(__kmalloc_track_caller);
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -07003730
3731#else
3732void *__kmalloc(size_t size, gfp_t flags)
3733{
3734 return __do_kmalloc(size, flags, NULL);
3735}
3736EXPORT_SYMBOL(__kmalloc);
Pekka Enberg7fd6b142006-02-01 03:05:52 -08003737#endif
3738
Linus Torvalds1da177e2005-04-16 15:20:36 -07003739/**
3740 * kmem_cache_free - Deallocate an object
3741 * @cachep: The cache the allocation was from.
3742 * @objp: The previously allocated object.
3743 *
3744 * Free an object which was previously allocated from this
3745 * cache.
3746 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003747void kmem_cache_free(struct kmem_cache *cachep, void *objp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003748{
3749 unsigned long flags;
3750
Pekka Enbergddc2e812006-06-23 02:03:40 -07003751 BUG_ON(virt_to_cache(objp) != cachep);
3752
Linus Torvalds1da177e2005-04-16 15:20:36 -07003753 local_irq_save(flags);
Ingo Molnar898552c2007-02-10 01:44:57 -08003754 debug_check_no_locks_freed(objp, obj_size(cachep));
Ingo Molnar873623d2006-07-13 14:44:38 +02003755 __cache_free(cachep, objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003756 local_irq_restore(flags);
3757}
3758EXPORT_SYMBOL(kmem_cache_free);
3759
3760/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07003761 * kfree - free previously allocated memory
3762 * @objp: pointer returned by kmalloc.
3763 *
Pekka Enberg80e93ef2005-09-09 13:10:16 -07003764 * If @objp is NULL, no operation is performed.
3765 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003766 * Don't free memory not originally allocated by kmalloc()
3767 * or you will run into trouble.
3768 */
3769void kfree(const void *objp)
3770{
Pekka Enberg343e0d72006-02-01 03:05:50 -08003771 struct kmem_cache *c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003772 unsigned long flags;
3773
3774 if (unlikely(!objp))
3775 return;
3776 local_irq_save(flags);
3777 kfree_debugcheck(objp);
Pekka Enberg6ed5eb22006-02-01 03:05:49 -08003778 c = virt_to_cache(objp);
Ingo Molnarf9b84042006-06-27 02:54:49 -07003779 debug_check_no_locks_freed(objp, obj_size(c));
Ingo Molnar873623d2006-07-13 14:44:38 +02003780 __cache_free(c, (void *)objp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003781 local_irq_restore(flags);
3782}
3783EXPORT_SYMBOL(kfree);
3784
Pekka Enberg343e0d72006-02-01 03:05:50 -08003785unsigned int kmem_cache_size(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003786{
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003787 return obj_size(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003788}
3789EXPORT_SYMBOL(kmem_cache_size);
3790
Pekka Enberg343e0d72006-02-01 03:05:50 -08003791const char *kmem_cache_name(struct kmem_cache *cachep)
Arnaldo Carvalho de Melo19449722005-06-18 22:46:19 -07003792{
3793 return cachep->name;
3794}
3795EXPORT_SYMBOL_GPL(kmem_cache_name);
3796
Christoph Lametere498be72005-09-09 13:03:32 -07003797/*
Christoph Lameter0718dc22006-03-25 03:06:47 -08003798 * This initializes kmem_list3 or resizes varioius caches for all nodes.
Christoph Lametere498be72005-09-09 13:03:32 -07003799 */
Pekka Enberg343e0d72006-02-01 03:05:50 -08003800static int alloc_kmemlist(struct kmem_cache *cachep)
Christoph Lametere498be72005-09-09 13:03:32 -07003801{
3802 int node;
3803 struct kmem_list3 *l3;
Christoph Lametercafeb022006-03-25 03:06:46 -08003804 struct array_cache *new_shared;
Paul Menage3395ee02006-12-06 20:32:16 -08003805 struct array_cache **new_alien = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07003806
3807 for_each_online_node(node) {
Christoph Lametercafeb022006-03-25 03:06:46 -08003808
Paul Menage3395ee02006-12-06 20:32:16 -08003809 if (use_alien_caches) {
3810 new_alien = alloc_alien_cache(node, cachep->limit);
3811 if (!new_alien)
3812 goto fail;
3813 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003814
Christoph Lameter0718dc22006-03-25 03:06:47 -08003815 new_shared = alloc_arraycache(node,
3816 cachep->shared*cachep->batchcount,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003817 0xbaadf00d);
Christoph Lameter0718dc22006-03-25 03:06:47 -08003818 if (!new_shared) {
3819 free_alien_cache(new_alien);
Christoph Lametere498be72005-09-09 13:03:32 -07003820 goto fail;
Christoph Lameter0718dc22006-03-25 03:06:47 -08003821 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003822
Andrew Mortona737b3e2006-03-22 00:08:11 -08003823 l3 = cachep->nodelists[node];
3824 if (l3) {
Christoph Lametercafeb022006-03-25 03:06:46 -08003825 struct array_cache *shared = l3->shared;
3826
Christoph Lametere498be72005-09-09 13:03:32 -07003827 spin_lock_irq(&l3->list_lock);
3828
Christoph Lametercafeb022006-03-25 03:06:46 -08003829 if (shared)
Christoph Lameter0718dc22006-03-25 03:06:47 -08003830 free_block(cachep, shared->entry,
3831 shared->avail, node);
Christoph Lametere498be72005-09-09 13:03:32 -07003832
Christoph Lametercafeb022006-03-25 03:06:46 -08003833 l3->shared = new_shared;
3834 if (!l3->alien) {
Christoph Lametere498be72005-09-09 13:03:32 -07003835 l3->alien = new_alien;
3836 new_alien = NULL;
3837 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003838 l3->free_limit = (1 + nr_cpus_node(node)) *
Andrew Mortona737b3e2006-03-22 00:08:11 -08003839 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07003840 spin_unlock_irq(&l3->list_lock);
Christoph Lametercafeb022006-03-25 03:06:46 -08003841 kfree(shared);
Christoph Lametere498be72005-09-09 13:03:32 -07003842 free_alien_cache(new_alien);
3843 continue;
3844 }
Andrew Mortona737b3e2006-03-22 00:08:11 -08003845 l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
Christoph Lameter0718dc22006-03-25 03:06:47 -08003846 if (!l3) {
3847 free_alien_cache(new_alien);
3848 kfree(new_shared);
Christoph Lametere498be72005-09-09 13:03:32 -07003849 goto fail;
Christoph Lameter0718dc22006-03-25 03:06:47 -08003850 }
Christoph Lametere498be72005-09-09 13:03:32 -07003851
3852 kmem_list3_init(l3);
3853 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
Andrew Mortona737b3e2006-03-22 00:08:11 -08003854 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
Christoph Lametercafeb022006-03-25 03:06:46 -08003855 l3->shared = new_shared;
Christoph Lametere498be72005-09-09 13:03:32 -07003856 l3->alien = new_alien;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003857 l3->free_limit = (1 + nr_cpus_node(node)) *
Andrew Mortona737b3e2006-03-22 00:08:11 -08003858 cachep->batchcount + cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07003859 cachep->nodelists[node] = l3;
3860 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003861 return 0;
Christoph Lameter0718dc22006-03-25 03:06:47 -08003862
Andrew Mortona737b3e2006-03-22 00:08:11 -08003863fail:
Christoph Lameter0718dc22006-03-25 03:06:47 -08003864 if (!cachep->next.next) {
3865 /* Cache is not active yet. Roll back what we did */
3866 node--;
3867 while (node >= 0) {
3868 if (cachep->nodelists[node]) {
3869 l3 = cachep->nodelists[node];
3870
3871 kfree(l3->shared);
3872 free_alien_cache(l3->alien);
3873 kfree(l3);
3874 cachep->nodelists[node] = NULL;
3875 }
3876 node--;
3877 }
3878 }
Christoph Lametercafeb022006-03-25 03:06:46 -08003879 return -ENOMEM;
Christoph Lametere498be72005-09-09 13:03:32 -07003880}
3881
Linus Torvalds1da177e2005-04-16 15:20:36 -07003882struct ccupdate_struct {
Pekka Enberg343e0d72006-02-01 03:05:50 -08003883 struct kmem_cache *cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003884 struct array_cache *new[NR_CPUS];
3885};
3886
3887static void do_ccupdate_local(void *info)
3888{
Andrew Mortona737b3e2006-03-22 00:08:11 -08003889 struct ccupdate_struct *new = info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003890 struct array_cache *old;
3891
3892 check_irq_off();
Pekka Enberg9a2dba42006-02-01 03:05:49 -08003893 old = cpu_cache_get(new->cachep);
Christoph Lametere498be72005-09-09 13:03:32 -07003894
Linus Torvalds1da177e2005-04-16 15:20:36 -07003895 new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
3896 new->new[smp_processor_id()] = old;
3897}
3898
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -08003899/* Always called with the cache_chain_mutex held */
Andrew Mortona737b3e2006-03-22 00:08:11 -08003900static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
3901 int batchcount, int shared)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003902{
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003903 struct ccupdate_struct *new;
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003904 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003905
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003906 new = kzalloc(sizeof(*new), GFP_KERNEL);
3907 if (!new)
3908 return -ENOMEM;
3909
Christoph Lametere498be72005-09-09 13:03:32 -07003910 for_each_online_cpu(i) {
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003911 new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
Andrew Mortona737b3e2006-03-22 00:08:11 -08003912 batchcount);
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003913 if (!new->new[i]) {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003914 for (i--; i >= 0; i--)
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003915 kfree(new->new[i]);
3916 kfree(new);
Christoph Lametere498be72005-09-09 13:03:32 -07003917 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003918 }
3919 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003920 new->cachep = cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003921
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003922 on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
Christoph Lametere498be72005-09-09 13:03:32 -07003923
Linus Torvalds1da177e2005-04-16 15:20:36 -07003924 check_irq_on();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003925 cachep->batchcount = batchcount;
3926 cachep->limit = limit;
Christoph Lametere498be72005-09-09 13:03:32 -07003927 cachep->shared = shared;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003928
Christoph Lametere498be72005-09-09 13:03:32 -07003929 for_each_online_cpu(i) {
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003930 struct array_cache *ccold = new->new[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07003931 if (!ccold)
3932 continue;
Christoph Lametere498be72005-09-09 13:03:32 -07003933 spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
Christoph Lameterff694162005-09-22 21:44:02 -07003934 free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
Christoph Lametere498be72005-09-09 13:03:32 -07003935 spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003936 kfree(ccold);
3937 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07003938 kfree(new);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003939 return alloc_kmemlist(cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003940}
3941
Ravikiran G Thirumalaib5d8ca72006-03-22 00:08:12 -08003942/* Called with cache_chain_mutex held always */
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003943static int enable_cpucache(struct kmem_cache *cachep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003944{
3945 int err;
3946 int limit, shared;
3947
Andrew Mortona737b3e2006-03-22 00:08:11 -08003948 /*
3949 * The head array serves three purposes:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003950 * - create a LIFO ordering, i.e. return objects that are cache-warm
3951 * - reduce the number of spinlock operations.
Andrew Mortona737b3e2006-03-22 00:08:11 -08003952 * - reduce the number of linked list operations on the slab and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003953 * bufctl chains: array operations are cheaper.
3954 * The numbers are guessed, we should auto-tune as described by
3955 * Bonwick.
3956 */
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003957 if (cachep->buffer_size > 131072)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003958 limit = 1;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003959 else if (cachep->buffer_size > PAGE_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003960 limit = 8;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003961 else if (cachep->buffer_size > 1024)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003962 limit = 24;
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003963 else if (cachep->buffer_size > 256)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003964 limit = 54;
3965 else
3966 limit = 120;
3967
Andrew Mortona737b3e2006-03-22 00:08:11 -08003968 /*
3969 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
Linus Torvalds1da177e2005-04-16 15:20:36 -07003970 * allocation behaviour: Most allocs on one cpu, most free operations
3971 * on another cpu. For these cases, an efficient object passing between
3972 * cpus is necessary. This is provided by a shared array. The array
3973 * replaces Bonwick's magazine layer.
3974 * On uniprocessor, it's functionally equivalent (but less efficient)
3975 * to a larger limit. Thus disabled by default.
3976 */
3977 shared = 0;
3978#ifdef CONFIG_SMP
Manfred Spraul3dafccf2006-02-01 03:05:42 -08003979 if (cachep->buffer_size <= PAGE_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003980 shared = 8;
3981#endif
3982
3983#if DEBUG
Andrew Mortona737b3e2006-03-22 00:08:11 -08003984 /*
3985 * With debugging enabled, large batchcount lead to excessively long
3986 * periods with disabled local interrupts. Limit the batchcount
Linus Torvalds1da177e2005-04-16 15:20:36 -07003987 */
3988 if (limit > 32)
3989 limit = 32;
3990#endif
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003991 err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003992 if (err)
3993 printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08003994 cachep->name, -err);
Christoph Lameter2ed3a4e2006-09-25 23:31:38 -07003995 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003996}
3997
Christoph Lameter1b552532006-03-22 00:09:07 -08003998/*
3999 * Drain an array if it contains any elements taking the l3 lock only if
Christoph Lameterb18e7e62006-03-22 00:09:07 -08004000 * necessary. Note that the l3 listlock also protects the array_cache
4001 * if drain_array() is used on the shared array.
Christoph Lameter1b552532006-03-22 00:09:07 -08004002 */
4003void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
4004 struct array_cache *ac, int force, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004005{
4006 int tofree;
4007
Christoph Lameter1b552532006-03-22 00:09:07 -08004008 if (!ac || !ac->avail)
4009 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004010 if (ac->touched && !force) {
4011 ac->touched = 0;
Christoph Lameterb18e7e62006-03-22 00:09:07 -08004012 } else {
Christoph Lameter1b552532006-03-22 00:09:07 -08004013 spin_lock_irq(&l3->list_lock);
Christoph Lameterb18e7e62006-03-22 00:09:07 -08004014 if (ac->avail) {
4015 tofree = force ? ac->avail : (ac->limit + 4) / 5;
4016 if (tofree > ac->avail)
4017 tofree = (ac->avail + 1) / 2;
4018 free_block(cachep, ac->entry, tofree, node);
4019 ac->avail -= tofree;
4020 memmove(ac->entry, &(ac->entry[tofree]),
4021 sizeof(void *) * ac->avail);
4022 }
Christoph Lameter1b552532006-03-22 00:09:07 -08004023 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004024 }
4025}
4026
4027/**
4028 * cache_reap - Reclaim memory from caches.
Randy Dunlap1e5d5332005-11-07 01:01:06 -08004029 * @unused: unused parameter
Linus Torvalds1da177e2005-04-16 15:20:36 -07004030 *
4031 * Called from workqueue/eventd every few seconds.
4032 * Purpose:
4033 * - clear the per-cpu caches for this CPU.
4034 * - return freeable pages to the main free memory pool.
4035 *
Andrew Mortona737b3e2006-03-22 00:08:11 -08004036 * If we cannot acquire the cache chain mutex then just give up - we'll try
4037 * again on the next iteration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004038 */
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004039static void cache_reap(struct work_struct *w)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004040{
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004041 struct kmem_cache *searchp;
Christoph Lametere498be72005-09-09 13:03:32 -07004042 struct kmem_list3 *l3;
Christoph Lameteraab22072006-03-22 00:09:06 -08004043 int node = numa_node_id();
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004044 struct delayed_work *work =
4045 container_of(w, struct delayed_work, work);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004046
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004047 if (!mutex_trylock(&cache_chain_mutex))
Linus Torvalds1da177e2005-04-16 15:20:36 -07004048 /* Give up. Setup the next iteration. */
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004049 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004050
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004051 list_for_each_entry(searchp, &cache_chain, next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004052 check_irq_on();
4053
Christoph Lameter35386e32006-03-22 00:09:05 -08004054 /*
4055 * We only take the l3 lock if absolutely necessary and we
4056 * have established with reasonable certainty that
4057 * we can do some work if the lock was obtained.
4058 */
Christoph Lameteraab22072006-03-22 00:09:06 -08004059 l3 = searchp->nodelists[node];
Christoph Lameter35386e32006-03-22 00:09:05 -08004060
Christoph Lameter8fce4d82006-03-09 17:33:54 -08004061 reap_alien(searchp, l3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004062
Christoph Lameteraab22072006-03-22 00:09:06 -08004063 drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004064
Christoph Lameter35386e32006-03-22 00:09:05 -08004065 /*
4066 * These are racy checks but it does not matter
4067 * if we skip one check or scan twice.
4068 */
Christoph Lametere498be72005-09-09 13:03:32 -07004069 if (time_after(l3->next_reap, jiffies))
Christoph Lameter35386e32006-03-22 00:09:05 -08004070 goto next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004071
Christoph Lametere498be72005-09-09 13:03:32 -07004072 l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004073
Christoph Lameteraab22072006-03-22 00:09:06 -08004074 drain_array(searchp, l3, l3->shared, 0, node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004075
Christoph Lametered11d9e2006-06-30 01:55:45 -07004076 if (l3->free_touched)
Christoph Lametere498be72005-09-09 13:03:32 -07004077 l3->free_touched = 0;
Christoph Lametered11d9e2006-06-30 01:55:45 -07004078 else {
4079 int freed;
4080
4081 freed = drain_freelist(searchp, l3, (l3->free_limit +
4082 5 * searchp->num - 1) / (5 * searchp->num));
4083 STATS_ADD_REAPED(searchp, freed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004084 }
Christoph Lameter35386e32006-03-22 00:09:05 -08004085next:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004086 cond_resched();
4087 }
4088 check_irq_on();
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004089 mutex_unlock(&cache_chain_mutex);
Christoph Lameter8fce4d82006-03-09 17:33:54 -08004090 next_reap_node();
Christoph Lameter2244b952006-06-30 01:55:33 -07004091 refresh_cpu_vm_stats(smp_processor_id());
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004092out:
Andrew Mortona737b3e2006-03-22 00:08:11 -08004093 /* Set up the next iteration */
Christoph Lameter7c5cae32007-02-10 01:42:55 -08004094 schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004095}
4096
4097#ifdef CONFIG_PROC_FS
4098
Pekka Enberg85289f92006-01-08 01:00:36 -08004099static void print_slabinfo_header(struct seq_file *m)
4100{
4101 /*
4102 * Output format version, so at least we can change it
4103 * without _too_ many complaints.
4104 */
4105#if STATS
4106 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
4107#else
4108 seq_puts(m, "slabinfo - version: 2.1\n");
4109#endif
4110 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4111 "<objperslab> <pagesperslab>");
4112 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4113 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4114#if STATS
4115 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004116 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
Pekka Enberg85289f92006-01-08 01:00:36 -08004117 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
4118#endif
4119 seq_putc(m, '\n');
4120}
4121
Linus Torvalds1da177e2005-04-16 15:20:36 -07004122static void *s_start(struct seq_file *m, loff_t *pos)
4123{
4124 loff_t n = *pos;
4125 struct list_head *p;
4126
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004127 mutex_lock(&cache_chain_mutex);
Pekka Enberg85289f92006-01-08 01:00:36 -08004128 if (!n)
4129 print_slabinfo_header(m);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004130 p = cache_chain.next;
4131 while (n--) {
4132 p = p->next;
4133 if (p == &cache_chain)
4134 return NULL;
4135 }
Pekka Enberg343e0d72006-02-01 03:05:50 -08004136 return list_entry(p, struct kmem_cache, next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004137}
4138
4139static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4140{
Pekka Enberg343e0d72006-02-01 03:05:50 -08004141 struct kmem_cache *cachep = p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004142 ++*pos;
Andrew Mortona737b3e2006-03-22 00:08:11 -08004143 return cachep->next.next == &cache_chain ?
4144 NULL : list_entry(cachep->next.next, struct kmem_cache, next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004145}
4146
4147static void s_stop(struct seq_file *m, void *p)
4148{
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004149 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004150}
4151
4152static int s_show(struct seq_file *m, void *p)
4153{
Pekka Enberg343e0d72006-02-01 03:05:50 -08004154 struct kmem_cache *cachep = p;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004155 struct slab *slabp;
4156 unsigned long active_objs;
4157 unsigned long num_objs;
4158 unsigned long active_slabs = 0;
4159 unsigned long num_slabs, free_objects = 0, shared_avail = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07004160 const char *name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004161 char *error = NULL;
Christoph Lametere498be72005-09-09 13:03:32 -07004162 int node;
4163 struct kmem_list3 *l3;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004164
Linus Torvalds1da177e2005-04-16 15:20:36 -07004165 active_objs = 0;
4166 num_slabs = 0;
Christoph Lametere498be72005-09-09 13:03:32 -07004167 for_each_online_node(node) {
4168 l3 = cachep->nodelists[node];
4169 if (!l3)
4170 continue;
4171
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08004172 check_irq_on();
4173 spin_lock_irq(&l3->list_lock);
Christoph Lametere498be72005-09-09 13:03:32 -07004174
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004175 list_for_each_entry(slabp, &l3->slabs_full, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004176 if (slabp->inuse != cachep->num && !error)
4177 error = "slabs_full accounting error";
4178 active_objs += cachep->num;
4179 active_slabs++;
4180 }
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004181 list_for_each_entry(slabp, &l3->slabs_partial, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004182 if (slabp->inuse == cachep->num && !error)
4183 error = "slabs_partial inuse accounting error";
4184 if (!slabp->inuse && !error)
4185 error = "slabs_partial/inuse accounting error";
4186 active_objs += slabp->inuse;
4187 active_slabs++;
4188 }
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004189 list_for_each_entry(slabp, &l3->slabs_free, list) {
Christoph Lametere498be72005-09-09 13:03:32 -07004190 if (slabp->inuse && !error)
4191 error = "slabs_free/inuse accounting error";
4192 num_slabs++;
4193 }
4194 free_objects += l3->free_objects;
Ravikiran G Thirumalai4484ebf2006-02-04 23:27:59 -08004195 if (l3->shared)
4196 shared_avail += l3->shared->avail;
Christoph Lametere498be72005-09-09 13:03:32 -07004197
Ravikiran G Thirumalaica3b9b92006-02-04 23:27:58 -08004198 spin_unlock_irq(&l3->list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004199 }
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004200 num_slabs += active_slabs;
4201 num_objs = num_slabs * cachep->num;
Christoph Lametere498be72005-09-09 13:03:32 -07004202 if (num_objs - active_objs != free_objects && !error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004203 error = "free_objects accounting error";
4204
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004205 name = cachep->name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004206 if (error)
4207 printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
4208
4209 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
Manfred Spraul3dafccf2006-02-01 03:05:42 -08004210 name, active_objs, num_objs, cachep->buffer_size,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004211 cachep->num, (1 << cachep->gfporder));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004212 seq_printf(m, " : tunables %4u %4u %4u",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004213 cachep->limit, cachep->batchcount, cachep->shared);
Christoph Lametere498be72005-09-09 13:03:32 -07004214 seq_printf(m, " : slabdata %6lu %6lu %6lu",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004215 active_slabs, num_slabs, shared_avail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004216#if STATS
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004217 { /* list3 stats */
Linus Torvalds1da177e2005-04-16 15:20:36 -07004218 unsigned long high = cachep->high_mark;
4219 unsigned long allocs = cachep->num_allocations;
4220 unsigned long grown = cachep->grown;
4221 unsigned long reaped = cachep->reaped;
4222 unsigned long errors = cachep->errors;
4223 unsigned long max_freeable = cachep->max_freeable;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004224 unsigned long node_allocs = cachep->node_allocs;
Christoph Lametere498be72005-09-09 13:03:32 -07004225 unsigned long node_frees = cachep->node_frees;
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004226 unsigned long overflows = cachep->node_overflow;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004227
Christoph Lametere498be72005-09-09 13:03:32 -07004228 seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004229 %4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
Andrew Mortona737b3e2006-03-22 00:08:11 -08004230 reaped, errors, max_freeable, node_allocs,
Ravikiran G Thirumalaifb7faf32006-04-10 22:52:54 -07004231 node_frees, overflows);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004232 }
4233 /* cpu stats */
4234 {
4235 unsigned long allochit = atomic_read(&cachep->allochit);
4236 unsigned long allocmiss = atomic_read(&cachep->allocmiss);
4237 unsigned long freehit = atomic_read(&cachep->freehit);
4238 unsigned long freemiss = atomic_read(&cachep->freemiss);
4239
4240 seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004241 allochit, allocmiss, freehit, freemiss);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004242 }
4243#endif
4244 seq_putc(m, '\n');
Linus Torvalds1da177e2005-04-16 15:20:36 -07004245 return 0;
4246}
4247
4248/*
4249 * slabinfo_op - iterator that generates /proc/slabinfo
4250 *
4251 * Output layout:
4252 * cache-name
4253 * num-active-objs
4254 * total-objs
4255 * object size
4256 * num-active-slabs
4257 * total-slabs
4258 * num-pages-per-slab
4259 * + further values on SMP and with statistics enabled
4260 */
4261
Helge Deller15ad7cd2006-12-06 20:40:36 -08004262const struct seq_operations slabinfo_op = {
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004263 .start = s_start,
4264 .next = s_next,
4265 .stop = s_stop,
4266 .show = s_show,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004267};
4268
4269#define MAX_SLABINFO_WRITE 128
4270/**
4271 * slabinfo_write - Tuning for the slab allocator
4272 * @file: unused
4273 * @buffer: user buffer
4274 * @count: data length
4275 * @ppos: unused
4276 */
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004277ssize_t slabinfo_write(struct file *file, const char __user * buffer,
4278 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004279{
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004280 char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004281 int limit, batchcount, shared, res;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004282 struct kmem_cache *cachep;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004283
Linus Torvalds1da177e2005-04-16 15:20:36 -07004284 if (count > MAX_SLABINFO_WRITE)
4285 return -EINVAL;
4286 if (copy_from_user(&kbuf, buffer, count))
4287 return -EFAULT;
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004288 kbuf[MAX_SLABINFO_WRITE] = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -07004289
4290 tmp = strchr(kbuf, ' ');
4291 if (!tmp)
4292 return -EINVAL;
4293 *tmp = '\0';
4294 tmp++;
4295 if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
4296 return -EINVAL;
4297
4298 /* Find the cache in the chain of caches. */
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004299 mutex_lock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004300 res = -EINVAL;
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004301 list_for_each_entry(cachep, &cache_chain, next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004302 if (!strcmp(cachep->name, kbuf)) {
Andrew Mortona737b3e2006-03-22 00:08:11 -08004303 if (limit < 1 || batchcount < 1 ||
4304 batchcount > limit || shared < 0) {
Christoph Lametere498be72005-09-09 13:03:32 -07004305 res = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004306 } else {
Christoph Lametere498be72005-09-09 13:03:32 -07004307 res = do_tune_cpucache(cachep, limit,
Pekka Enbergb28a02d2006-01-08 01:00:37 -08004308 batchcount, shared);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004309 }
4310 break;
4311 }
4312 }
Ingo Molnarfc0abb12006-01-18 17:42:33 -08004313 mutex_unlock(&cache_chain_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004314 if (res >= 0)
4315 res = count;
4316 return res;
4317}
Al Viro871751e2006-03-25 03:06:39 -08004318
4319#ifdef CONFIG_DEBUG_SLAB_LEAK
4320
4321static void *leaks_start(struct seq_file *m, loff_t *pos)
4322{
4323 loff_t n = *pos;
4324 struct list_head *p;
4325
4326 mutex_lock(&cache_chain_mutex);
4327 p = cache_chain.next;
4328 while (n--) {
4329 p = p->next;
4330 if (p == &cache_chain)
4331 return NULL;
4332 }
4333 return list_entry(p, struct kmem_cache, next);
4334}
4335
4336static inline int add_caller(unsigned long *n, unsigned long v)
4337{
4338 unsigned long *p;
4339 int l;
4340 if (!v)
4341 return 1;
4342 l = n[1];
4343 p = n + 2;
4344 while (l) {
4345 int i = l/2;
4346 unsigned long *q = p + 2 * i;
4347 if (*q == v) {
4348 q[1]++;
4349 return 1;
4350 }
4351 if (*q > v) {
4352 l = i;
4353 } else {
4354 p = q + 2;
4355 l -= i + 1;
4356 }
4357 }
4358 if (++n[1] == n[0])
4359 return 0;
4360 memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n));
4361 p[0] = v;
4362 p[1] = 1;
4363 return 1;
4364}
4365
4366static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
4367{
4368 void *p;
4369 int i;
4370 if (n[0] == n[1])
4371 return;
4372 for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) {
4373 if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
4374 continue;
4375 if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
4376 return;
4377 }
4378}
4379
4380static void show_symbol(struct seq_file *m, unsigned long address)
4381{
4382#ifdef CONFIG_KALLSYMS
4383 char *modname;
4384 const char *name;
4385 unsigned long offset, size;
4386 char namebuf[KSYM_NAME_LEN+1];
4387
4388 name = kallsyms_lookup(address, &size, &offset, &modname, namebuf);
4389
4390 if (name) {
4391 seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
4392 if (modname)
4393 seq_printf(m, " [%s]", modname);
4394 return;
4395 }
4396#endif
4397 seq_printf(m, "%p", (void *)address);
4398}
4399
4400static int leaks_show(struct seq_file *m, void *p)
4401{
4402 struct kmem_cache *cachep = p;
Al Viro871751e2006-03-25 03:06:39 -08004403 struct slab *slabp;
4404 struct kmem_list3 *l3;
4405 const char *name;
4406 unsigned long *n = m->private;
4407 int node;
4408 int i;
4409
4410 if (!(cachep->flags & SLAB_STORE_USER))
4411 return 0;
4412 if (!(cachep->flags & SLAB_RED_ZONE))
4413 return 0;
4414
4415 /* OK, we can do it */
4416
4417 n[1] = 0;
4418
4419 for_each_online_node(node) {
4420 l3 = cachep->nodelists[node];
4421 if (!l3)
4422 continue;
4423
4424 check_irq_on();
4425 spin_lock_irq(&l3->list_lock);
4426
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004427 list_for_each_entry(slabp, &l3->slabs_full, list)
Al Viro871751e2006-03-25 03:06:39 -08004428 handle_slab(n, cachep, slabp);
Christoph Hellwig7a7c3812006-06-23 02:03:17 -07004429 list_for_each_entry(slabp, &l3->slabs_partial, list)
Al Viro871751e2006-03-25 03:06:39 -08004430 handle_slab(n, cachep, slabp);
Al Viro871751e2006-03-25 03:06:39 -08004431 spin_unlock_irq(&l3->list_lock);
4432 }
4433 name = cachep->name;
4434 if (n[0] == n[1]) {
4435 /* Increase the buffer size */
4436 mutex_unlock(&cache_chain_mutex);
4437 m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
4438 if (!m->private) {
4439 /* Too bad, we are really out */
4440 m->private = n;
4441 mutex_lock(&cache_chain_mutex);
4442 return -ENOMEM;
4443 }
4444 *(unsigned long *)m->private = n[0] * 2;
4445 kfree(n);
4446 mutex_lock(&cache_chain_mutex);
4447 /* Now make sure this entry will be retried */
4448 m->count = m->size;
4449 return 0;
4450 }
4451 for (i = 0; i < n[1]; i++) {
4452 seq_printf(m, "%s: %lu ", name, n[2*i+3]);
4453 show_symbol(m, n[2*i+2]);
4454 seq_putc(m, '\n');
4455 }
Siddha, Suresh Bd2e7b7d2006-09-25 23:31:47 -07004456
Al Viro871751e2006-03-25 03:06:39 -08004457 return 0;
4458}
4459
Helge Deller15ad7cd2006-12-06 20:40:36 -08004460const struct seq_operations slabstats_op = {
Al Viro871751e2006-03-25 03:06:39 -08004461 .start = leaks_start,
4462 .next = s_next,
4463 .stop = s_stop,
4464 .show = leaks_show,
4465};
4466#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07004467#endif
4468
Manfred Spraul00e145b2005-09-03 15:55:07 -07004469/**
4470 * ksize - get the actual amount of memory allocated for a given object
4471 * @objp: Pointer to the object
4472 *
4473 * kmalloc may internally round up allocations and return more memory
4474 * than requested. ksize() can be used to determine the actual amount of
4475 * memory allocated. The caller may use this additional memory, even though
4476 * a smaller amount of memory was initially specified with the kmalloc call.
4477 * The caller must guarantee that objp points to a valid object previously
4478 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4479 * must not be freed during the duration of the call.
4480 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07004481unsigned int ksize(const void *objp)
4482{
Manfred Spraul00e145b2005-09-03 15:55:07 -07004483 if (unlikely(objp == NULL))
4484 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004485
Pekka Enberg6ed5eb22006-02-01 03:05:49 -08004486 return obj_size(virt_to_cache(objp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004487}