blob: 1b782a2d3b3d1a7006fcc027fc7895767a04c51f [file] [log] [blame]
Christoph Lameter039363f2012-07-06 15:25:10 -05001/*
2 * Slab allocator functions that are independent of the allocator strategy
3 *
4 * (C) 2012 Christoph Lameter <cl@linux.com>
5 */
6#include <linux/slab.h>
7
8#include <linux/mm.h>
9#include <linux/poison.h>
10#include <linux/interrupt.h>
11#include <linux/memory.h>
12#include <linux/compiler.h>
13#include <linux/module.h>
Christoph Lameter20cea962012-07-06 15:25:13 -050014#include <linux/cpu.h>
15#include <linux/uaccess.h>
Glauber Costab7454ad2012-10-19 18:20:25 +040016#include <linux/seq_file.h>
17#include <linux/proc_fs.h>
Christoph Lameter039363f2012-07-06 15:25:10 -050018#include <asm/cacheflush.h>
19#include <asm/tlbflush.h>
20#include <asm/page.h>
Glauber Costa2633d7a2012-12-18 14:22:34 -080021#include <linux/memcontrol.h>
Andrey Ryabinin928cec92014-08-06 16:04:44 -070022
23#define CREATE_TRACE_POINTS
Christoph Lameterf1b6eb62013-09-04 16:35:34 +000024#include <trace/events/kmem.h>
Christoph Lameter039363f2012-07-06 15:25:10 -050025
Christoph Lameter97d06602012-07-06 15:25:11 -050026#include "slab.h"
27
28enum slab_state slab_state;
Christoph Lameter18004c52012-07-06 15:25:12 -050029LIST_HEAD(slab_caches);
30DEFINE_MUTEX(slab_mutex);
Christoph Lameter9b030cb2012-09-05 00:20:33 +000031struct kmem_cache *kmem_cache;
Christoph Lameter97d06602012-07-06 15:25:11 -050032
Joonsoo Kim07f361b2014-10-09 15:26:00 -070033/*
Joonsoo Kim423c9292014-10-09 15:26:22 -070034 * Set of flags that will prevent slab merging
35 */
36#define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
37 SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
38 SLAB_FAILSLAB)
39
40#define SLAB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
41 SLAB_CACHE_DMA | SLAB_NOTRACK)
42
43/*
44 * Merge control. If this is set then no merging of slab caches will occur.
45 * (Could be removed. This was introduced to pacify the merge skeptics.)
46 */
47static int slab_nomerge;
48
49static int __init setup_slab_nomerge(char *str)
50{
51 slab_nomerge = 1;
52 return 1;
53}
54
55#ifdef CONFIG_SLUB
56__setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
57#endif
58
59__setup("slab_nomerge", setup_slab_nomerge);
60
61/*
Joonsoo Kim07f361b2014-10-09 15:26:00 -070062 * Determine the size of a slab object
63 */
64unsigned int kmem_cache_size(struct kmem_cache *s)
65{
66 return s->object_size;
67}
68EXPORT_SYMBOL(kmem_cache_size);
69
Shuah Khan77be4b12012-08-16 00:09:46 -070070#ifdef CONFIG_DEBUG_VM
Vladimir Davydov794b1242014-04-07 15:39:26 -070071static int kmem_cache_sanity_check(const char *name, size_t size)
Shuah Khan77be4b12012-08-16 00:09:46 -070072{
73 struct kmem_cache *s = NULL;
74
75 if (!name || in_interrupt() || size < sizeof(void *) ||
76 size > KMALLOC_MAX_SIZE) {
77 pr_err("kmem_cache_create(%s) integrity check failed\n", name);
78 return -EINVAL;
79 }
80
81 list_for_each_entry(s, &slab_caches, list) {
82 char tmp;
83 int res;
84
85 /*
86 * This happens when the module gets unloaded and doesn't
87 * destroy its slab cache and no-one else reuses the vmalloc
88 * area of the module. Print a warning.
89 */
90 res = probe_kernel_address(s->name, tmp);
91 if (res) {
92 pr_err("Slab cache with size %d has lost its name\n",
93 s->object_size);
94 continue;
95 }
Shuah Khan77be4b12012-08-16 00:09:46 -070096 }
97
98 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
99 return 0;
100}
101#else
Vladimir Davydov794b1242014-04-07 15:39:26 -0700102static inline int kmem_cache_sanity_check(const char *name, size_t size)
Shuah Khan77be4b12012-08-16 00:09:46 -0700103{
104 return 0;
105}
106#endif
107
Glauber Costa55007d82012-12-18 14:22:38 -0800108#ifdef CONFIG_MEMCG_KMEM
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700109static int memcg_alloc_cache_params(struct mem_cgroup *memcg,
110 struct kmem_cache *s, struct kmem_cache *root_cache)
111{
112 size_t size;
113
114 if (!memcg_kmem_enabled())
115 return 0;
116
117 if (!memcg) {
118 size = offsetof(struct memcg_cache_params, memcg_caches);
119 size += memcg_limited_groups_array_size * sizeof(void *);
120 } else
121 size = sizeof(struct memcg_cache_params);
122
123 s->memcg_params = kzalloc(size, GFP_KERNEL);
124 if (!s->memcg_params)
125 return -ENOMEM;
126
127 if (memcg) {
128 s->memcg_params->memcg = memcg;
129 s->memcg_params->root_cache = root_cache;
130 } else
131 s->memcg_params->is_root_cache = true;
132
133 return 0;
134}
135
136static void memcg_free_cache_params(struct kmem_cache *s)
137{
138 kfree(s->memcg_params);
139}
140
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700141static int memcg_update_cache_params(struct kmem_cache *s, int num_memcgs)
142{
143 int size;
144 struct memcg_cache_params *new_params, *cur_params;
145
146 BUG_ON(!is_root_cache(s));
147
148 size = offsetof(struct memcg_cache_params, memcg_caches);
149 size += num_memcgs * sizeof(void *);
150
151 new_params = kzalloc(size, GFP_KERNEL);
152 if (!new_params)
153 return -ENOMEM;
154
155 cur_params = s->memcg_params;
156 memcpy(new_params->memcg_caches, cur_params->memcg_caches,
157 memcg_limited_groups_array_size * sizeof(void *));
158
159 new_params->is_root_cache = true;
160
161 rcu_assign_pointer(s->memcg_params, new_params);
162 if (cur_params)
163 kfree_rcu(cur_params, rcu_head);
164
165 return 0;
166}
167
Glauber Costa55007d82012-12-18 14:22:38 -0800168int memcg_update_all_caches(int num_memcgs)
169{
170 struct kmem_cache *s;
171 int ret = 0;
172 mutex_lock(&slab_mutex);
173
174 list_for_each_entry(s, &slab_caches, list) {
175 if (!is_root_cache(s))
176 continue;
177
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700178 ret = memcg_update_cache_params(s, num_memcgs);
Glauber Costa55007d82012-12-18 14:22:38 -0800179 /*
Glauber Costa55007d82012-12-18 14:22:38 -0800180 * Instead of freeing the memory, we'll just leave the caches
181 * up to this point in an updated state.
182 */
183 if (ret)
184 goto out;
185 }
186
187 memcg_update_array_size(num_memcgs);
188out:
189 mutex_unlock(&slab_mutex);
190 return ret;
191}
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700192#else
193static inline int memcg_alloc_cache_params(struct mem_cgroup *memcg,
194 struct kmem_cache *s, struct kmem_cache *root_cache)
195{
196 return 0;
197}
198
199static inline void memcg_free_cache_params(struct kmem_cache *s)
200{
201}
202#endif /* CONFIG_MEMCG_KMEM */
Glauber Costa55007d82012-12-18 14:22:38 -0800203
Christoph Lameter039363f2012-07-06 15:25:10 -0500204/*
Joonsoo Kim423c9292014-10-09 15:26:22 -0700205 * Find a mergeable slab cache
206 */
207int slab_unmergeable(struct kmem_cache *s)
208{
209 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
210 return 1;
211
212 if (!is_root_cache(s))
213 return 1;
214
215 if (s->ctor)
216 return 1;
217
218 /*
219 * We may have set a slab to be unmergeable during bootstrap.
220 */
221 if (s->refcount < 0)
222 return 1;
223
224 return 0;
225}
226
227struct kmem_cache *find_mergeable(size_t size, size_t align,
228 unsigned long flags, const char *name, void (*ctor)(void *))
229{
230 struct kmem_cache *s;
231
232 if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
233 return NULL;
234
235 if (ctor)
236 return NULL;
237
238 size = ALIGN(size, sizeof(void *));
239 align = calculate_alignment(flags, align, size);
240 size = ALIGN(size, align);
241 flags = kmem_cache_flags(size, flags, name, NULL);
242
Joonsoo Kim54362052014-12-10 15:42:18 -0800243 list_for_each_entry_reverse(s, &slab_caches, list) {
Joonsoo Kim423c9292014-10-09 15:26:22 -0700244 if (slab_unmergeable(s))
245 continue;
246
247 if (size > s->size)
248 continue;
249
250 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
251 continue;
252 /*
253 * Check if alignment is compatible.
254 * Courtesy of Adrian Drzewiecki
255 */
256 if ((s->size & ~(align - 1)) != s->size)
257 continue;
258
259 if (s->size - size >= sizeof(void *))
260 continue;
261
Joonsoo Kim95069ac82014-11-13 15:19:25 -0800262 if (IS_ENABLED(CONFIG_SLAB) && align &&
263 (align > s->align || s->align % align))
264 continue;
265
Joonsoo Kim423c9292014-10-09 15:26:22 -0700266 return s;
267 }
268 return NULL;
269}
270
271/*
Christoph Lameter45906852012-11-28 16:23:16 +0000272 * Figure out what the alignment of the objects will be given a set of
273 * flags, a user specified alignment and the size of the objects.
274 */
275unsigned long calculate_alignment(unsigned long flags,
276 unsigned long align, unsigned long size)
277{
278 /*
279 * If the user wants hardware cache aligned objects then follow that
280 * suggestion if the object is sufficiently large.
281 *
282 * The hardware cache alignment cannot override the specified
283 * alignment though. If that is greater then use it.
284 */
285 if (flags & SLAB_HWCACHE_ALIGN) {
286 unsigned long ralign = cache_line_size();
287 while (size <= ralign / 2)
288 ralign /= 2;
289 align = max(align, ralign);
290 }
291
292 if (align < ARCH_SLAB_MINALIGN)
293 align = ARCH_SLAB_MINALIGN;
294
295 return ALIGN(align, sizeof(void *));
296}
297
Vladimir Davydov794b1242014-04-07 15:39:26 -0700298static struct kmem_cache *
299do_kmem_cache_create(char *name, size_t object_size, size_t size, size_t align,
300 unsigned long flags, void (*ctor)(void *),
301 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
302{
303 struct kmem_cache *s;
304 int err;
305
306 err = -ENOMEM;
307 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
308 if (!s)
309 goto out;
310
311 s->name = name;
312 s->object_size = object_size;
313 s->size = size;
314 s->align = align;
315 s->ctor = ctor;
316
317 err = memcg_alloc_cache_params(memcg, s, root_cache);
318 if (err)
319 goto out_free_cache;
320
321 err = __kmem_cache_create(s, flags);
322 if (err)
323 goto out_free_cache;
324
325 s->refcount = 1;
326 list_add(&s->list, &slab_caches);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700327out:
328 if (err)
329 return ERR_PTR(err);
330 return s;
331
332out_free_cache:
333 memcg_free_cache_params(s);
Vaishali Thakkar7c4da062015-02-10 14:09:40 -0800334 kmem_cache_free(kmem_cache, s);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700335 goto out;
336}
Christoph Lameter45906852012-11-28 16:23:16 +0000337
338/*
Christoph Lameter039363f2012-07-06 15:25:10 -0500339 * kmem_cache_create - Create a cache.
340 * @name: A string which is used in /proc/slabinfo to identify this cache.
341 * @size: The size of objects to be created in this cache.
342 * @align: The required alignment for the objects.
343 * @flags: SLAB flags
344 * @ctor: A constructor for the objects.
345 *
346 * Returns a ptr to the cache on success, NULL on failure.
347 * Cannot be called within a interrupt, but can be interrupted.
348 * The @ctor is run when new pages are allocated by the cache.
349 *
350 * The flags are
351 *
352 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
353 * to catch references to uninitialised memory.
354 *
355 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
356 * for buffer overruns.
357 *
358 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
359 * cacheline. This can be beneficial if you're counting cycles as closely
360 * as davem.
361 */
Glauber Costa2633d7a2012-12-18 14:22:34 -0800362struct kmem_cache *
Vladimir Davydov794b1242014-04-07 15:39:26 -0700363kmem_cache_create(const char *name, size_t size, size_t align,
364 unsigned long flags, void (*ctor)(void *))
Christoph Lameter039363f2012-07-06 15:25:10 -0500365{
Vladimir Davydov794b1242014-04-07 15:39:26 -0700366 struct kmem_cache *s;
367 char *cache_name;
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800368 int err;
Christoph Lameter039363f2012-07-06 15:25:10 -0500369
Pekka Enbergb9205362012-08-16 10:12:18 +0300370 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700371 get_online_mems();
372
Pekka Enbergb9205362012-08-16 10:12:18 +0300373 mutex_lock(&slab_mutex);
Christoph Lameter686d5502012-09-05 00:20:33 +0000374
Vladimir Davydov794b1242014-04-07 15:39:26 -0700375 err = kmem_cache_sanity_check(name, size);
Andrew Morton3aa24f52014-10-09 15:25:58 -0700376 if (err) {
377 s = NULL; /* suppress uninit var warning */
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800378 goto out_unlock;
Andrew Morton3aa24f52014-10-09 15:25:58 -0700379 }
Christoph Lameter686d5502012-09-05 00:20:33 +0000380
Glauber Costad8843922012-10-17 15:36:51 +0400381 /*
382 * Some allocators will constraint the set of valid flags to a subset
383 * of all flags. We expect them to define CACHE_CREATE_MASK in this
384 * case, and we'll just provide them with a sanitized version of the
385 * passed flags.
386 */
387 flags &= CACHE_CREATE_MASK;
Christoph Lameter686d5502012-09-05 00:20:33 +0000388
Vladimir Davydov794b1242014-04-07 15:39:26 -0700389 s = __kmem_cache_alias(name, size, align, flags, ctor);
390 if (s)
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800391 goto out_unlock;
Glauber Costa2633d7a2012-12-18 14:22:34 -0800392
Vladimir Davydov794b1242014-04-07 15:39:26 -0700393 cache_name = kstrdup(name, GFP_KERNEL);
394 if (!cache_name) {
395 err = -ENOMEM;
396 goto out_unlock;
397 }
Glauber Costa2633d7a2012-12-18 14:22:34 -0800398
Vladimir Davydov794b1242014-04-07 15:39:26 -0700399 s = do_kmem_cache_create(cache_name, size, size,
400 calculate_alignment(flags, align, size),
401 flags, ctor, NULL, NULL);
402 if (IS_ERR(s)) {
403 err = PTR_ERR(s);
404 kfree(cache_name);
405 }
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800406
407out_unlock:
Christoph Lameter20cea962012-07-06 15:25:13 -0500408 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700409
410 put_online_mems();
Christoph Lameter20cea962012-07-06 15:25:13 -0500411 put_online_cpus();
412
Dave Jonesba3253c2014-01-29 14:05:48 -0800413 if (err) {
Christoph Lameter686d5502012-09-05 00:20:33 +0000414 if (flags & SLAB_PANIC)
415 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
416 name, err);
417 else {
418 printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
419 name, err);
420 dump_stack();
421 }
Christoph Lameter686d5502012-09-05 00:20:33 +0000422 return NULL;
423 }
Christoph Lameter039363f2012-07-06 15:25:10 -0500424 return s;
Glauber Costa2633d7a2012-12-18 14:22:34 -0800425}
Christoph Lameter039363f2012-07-06 15:25:10 -0500426EXPORT_SYMBOL(kmem_cache_create);
Christoph Lameter97d06602012-07-06 15:25:11 -0500427
Vladimir Davydov794b1242014-04-07 15:39:26 -0700428#ifdef CONFIG_MEMCG_KMEM
429/*
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700430 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
Vladimir Davydov794b1242014-04-07 15:39:26 -0700431 * @memcg: The memory cgroup the new cache is for.
432 * @root_cache: The parent of the new cache.
433 *
434 * This function attempts to create a kmem cache that will serve allocation
435 * requests going from @memcg to @root_cache. The new cache inherits properties
436 * from its parent.
437 */
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700438struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
Vladimir Davydov3e0350a2015-02-10 14:11:44 -0800439 struct kmem_cache *root_cache)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700440{
Vladimir Davydov3e0350a2015-02-10 14:11:44 -0800441 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
Vladimir Davydovbd673142014-06-04 16:07:40 -0700442 struct kmem_cache *s = NULL;
Vladimir Davydov794b1242014-04-07 15:39:26 -0700443 char *cache_name;
444
445 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700446 get_online_mems();
447
Vladimir Davydov794b1242014-04-07 15:39:26 -0700448 mutex_lock(&slab_mutex);
449
Vladimir Davydov3e0350a2015-02-10 14:11:44 -0800450 cgroup_name(mem_cgroup_css(memcg)->cgroup,
451 memcg_name_buf, sizeof(memcg_name_buf));
Vladimir Davydov073ee1c2014-06-04 16:08:23 -0700452 cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
Vladimir Davydov3e0350a2015-02-10 14:11:44 -0800453 memcg_cache_id(memcg), memcg_name_buf);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700454 if (!cache_name)
455 goto out_unlock;
456
457 s = do_kmem_cache_create(cache_name, root_cache->object_size,
458 root_cache->size, root_cache->align,
459 root_cache->flags, root_cache->ctor,
460 memcg, root_cache);
Vladimir Davydovbd673142014-06-04 16:07:40 -0700461 if (IS_ERR(s)) {
Vladimir Davydov794b1242014-04-07 15:39:26 -0700462 kfree(cache_name);
Vladimir Davydovbd673142014-06-04 16:07:40 -0700463 s = NULL;
464 }
Vladimir Davydov794b1242014-04-07 15:39:26 -0700465
466out_unlock:
467 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700468
469 put_online_mems();
Vladimir Davydov794b1242014-04-07 15:39:26 -0700470 put_online_cpus();
Vladimir Davydovbd673142014-06-04 16:07:40 -0700471
472 return s;
Vladimir Davydov794b1242014-04-07 15:39:26 -0700473}
Vladimir Davydovb8529902014-04-07 15:39:28 -0700474
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700475static int memcg_cleanup_cache_params(struct kmem_cache *s)
Vladimir Davydovb8529902014-04-07 15:39:28 -0700476{
477 int rc;
478
479 if (!s->memcg_params ||
480 !s->memcg_params->is_root_cache)
481 return 0;
482
483 mutex_unlock(&slab_mutex);
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700484 rc = __memcg_cleanup_cache_params(s);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700485 mutex_lock(&slab_mutex);
486
487 return rc;
488}
489#else
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700490static int memcg_cleanup_cache_params(struct kmem_cache *s)
Vladimir Davydovb8529902014-04-07 15:39:28 -0700491{
492 return 0;
493}
Vladimir Davydov794b1242014-04-07 15:39:26 -0700494#endif /* CONFIG_MEMCG_KMEM */
495
Christoph Lameter41a21282014-05-06 12:50:08 -0700496void slab_kmem_cache_release(struct kmem_cache *s)
497{
498 kfree(s->name);
499 kmem_cache_free(kmem_cache, s);
500}
501
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000502void kmem_cache_destroy(struct kmem_cache *s)
503{
504 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700505 get_online_mems();
506
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000507 mutex_lock(&slab_mutex);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700508
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000509 s->refcount--;
Vladimir Davydovb8529902014-04-07 15:39:28 -0700510 if (s->refcount)
511 goto out_unlock;
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000512
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700513 if (memcg_cleanup_cache_params(s) != 0)
Vladimir Davydovb8529902014-04-07 15:39:28 -0700514 goto out_unlock;
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000515
Vladimir Davydovb8529902014-04-07 15:39:28 -0700516 if (__kmem_cache_shutdown(s) != 0) {
Vladimir Davydovb8529902014-04-07 15:39:28 -0700517 printk(KERN_ERR "kmem_cache_destroy %s: "
518 "Slab cache still has objects\n", s->name);
519 dump_stack();
520 goto out_unlock;
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000521 }
Vladimir Davydovb8529902014-04-07 15:39:28 -0700522
Vladimir Davydov0bd62b12014-06-04 16:10:03 -0700523 list_del(&s->list);
524
Vladimir Davydovb8529902014-04-07 15:39:28 -0700525 mutex_unlock(&slab_mutex);
526 if (s->flags & SLAB_DESTROY_BY_RCU)
527 rcu_barrier();
528
529 memcg_free_cache_params(s);
Christoph Lameter41a21282014-05-06 12:50:08 -0700530#ifdef SLAB_SUPPORTS_SYSFS
531 sysfs_slab_remove(s);
532#else
533 slab_kmem_cache_release(s);
534#endif
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700535 goto out;
Vladimir Davydovb8529902014-04-07 15:39:28 -0700536
537out_unlock:
538 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700539out:
540 put_online_mems();
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000541 put_online_cpus();
542}
543EXPORT_SYMBOL(kmem_cache_destroy);
544
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700545/**
546 * kmem_cache_shrink - Shrink a cache.
547 * @cachep: The cache to shrink.
548 *
549 * Releases as many slabs as possible for a cache.
550 * To help debugging, a zero exit status indicates all slabs were released.
551 */
552int kmem_cache_shrink(struct kmem_cache *cachep)
553{
554 int ret;
555
556 get_online_cpus();
557 get_online_mems();
558 ret = __kmem_cache_shrink(cachep);
559 put_online_mems();
560 put_online_cpus();
561 return ret;
562}
563EXPORT_SYMBOL(kmem_cache_shrink);
564
Christoph Lameter97d06602012-07-06 15:25:11 -0500565int slab_is_available(void)
566{
567 return slab_state >= UP;
568}
Glauber Costab7454ad2012-10-19 18:20:25 +0400569
Christoph Lameter45530c42012-11-28 16:23:07 +0000570#ifndef CONFIG_SLOB
571/* Create a cache during boot when no slab services are available yet */
572void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
573 unsigned long flags)
574{
575 int err;
576
577 s->name = name;
578 s->size = s->object_size = size;
Christoph Lameter45906852012-11-28 16:23:16 +0000579 s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
Christoph Lameter45530c42012-11-28 16:23:07 +0000580 err = __kmem_cache_create(s, flags);
581
582 if (err)
Christoph Lameter31ba7342013-01-10 19:00:53 +0000583 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
Christoph Lameter45530c42012-11-28 16:23:07 +0000584 name, size, err);
585
586 s->refcount = -1; /* Exempt from merging for now */
587}
588
589struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
590 unsigned long flags)
591{
592 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
593
594 if (!s)
595 panic("Out of memory when creating slab %s\n", name);
596
597 create_boot_cache(s, name, size, flags);
598 list_add(&s->list, &slab_caches);
599 s->refcount = 1;
600 return s;
601}
602
Christoph Lameter9425c582013-01-10 19:12:17 +0000603struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
604EXPORT_SYMBOL(kmalloc_caches);
605
606#ifdef CONFIG_ZONE_DMA
607struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
608EXPORT_SYMBOL(kmalloc_dma_caches);
609#endif
610
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000611/*
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000612 * Conversion table for small slabs sizes / 8 to the index in the
613 * kmalloc array. This is necessary for slabs < 192 since we have non power
614 * of two cache sizes there. The size of larger slabs can be determined using
615 * fls.
616 */
617static s8 size_index[24] = {
618 3, /* 8 */
619 4, /* 16 */
620 5, /* 24 */
621 5, /* 32 */
622 6, /* 40 */
623 6, /* 48 */
624 6, /* 56 */
625 6, /* 64 */
626 1, /* 72 */
627 1, /* 80 */
628 1, /* 88 */
629 1, /* 96 */
630 7, /* 104 */
631 7, /* 112 */
632 7, /* 120 */
633 7, /* 128 */
634 2, /* 136 */
635 2, /* 144 */
636 2, /* 152 */
637 2, /* 160 */
638 2, /* 168 */
639 2, /* 176 */
640 2, /* 184 */
641 2 /* 192 */
642};
643
644static inline int size_index_elem(size_t bytes)
645{
646 return (bytes - 1) / 8;
647}
648
649/*
650 * Find the kmem_cache structure that serves a given size of
651 * allocation
652 */
653struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
654{
655 int index;
656
Joonsoo Kim9de1bc82013-08-02 11:02:42 +0900657 if (unlikely(size > KMALLOC_MAX_SIZE)) {
Sasha Levin907985f2013-06-10 15:18:00 -0400658 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
Christoph Lameter6286ae92013-05-03 15:43:18 +0000659 return NULL;
Sasha Levin907985f2013-06-10 15:18:00 -0400660 }
Christoph Lameter6286ae92013-05-03 15:43:18 +0000661
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000662 if (size <= 192) {
663 if (!size)
664 return ZERO_SIZE_PTR;
665
666 index = size_index[size_index_elem(size)];
667 } else
668 index = fls(size - 1);
669
670#ifdef CONFIG_ZONE_DMA
Joonsoo Kimb1e05412013-02-04 23:46:46 +0900671 if (unlikely((flags & GFP_DMA)))
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000672 return kmalloc_dma_caches[index];
673
674#endif
675 return kmalloc_caches[index];
676}
677
678/*
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000679 * Create the kmalloc array. Some of the regular kmalloc arrays
680 * may already have been created because they were needed to
681 * enable allocations for slab creation.
682 */
683void __init create_kmalloc_caches(unsigned long flags)
684{
685 int i;
686
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000687 /*
688 * Patch up the size_index table if we have strange large alignment
689 * requirements for the kmalloc array. This is only the case for
690 * MIPS it seems. The standard arches will not generate any code here.
691 *
692 * Largest permitted alignment is 256 bytes due to the way we
693 * handle the index determination for the smaller caches.
694 *
695 * Make sure that nothing crazy happens if someone starts tinkering
696 * around with ARCH_KMALLOC_MINALIGN
697 */
698 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
699 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
700
701 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
702 int elem = size_index_elem(i);
703
704 if (elem >= ARRAY_SIZE(size_index))
705 break;
706 size_index[elem] = KMALLOC_SHIFT_LOW;
707 }
708
709 if (KMALLOC_MIN_SIZE >= 64) {
710 /*
711 * The 96 byte size cache is not used if the alignment
712 * is 64 byte.
713 */
714 for (i = 64 + 8; i <= 96; i += 8)
715 size_index[size_index_elem(i)] = 7;
716
717 }
718
719 if (KMALLOC_MIN_SIZE >= 128) {
720 /*
721 * The 192 byte sized cache is not used if the alignment
722 * is 128 byte. Redirect kmalloc to use the 256 byte cache
723 * instead.
724 */
725 for (i = 128 + 8; i <= 192; i += 8)
726 size_index[size_index_elem(i)] = 8;
727 }
Christoph Lameter8a965b32013-05-03 18:04:18 +0000728 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
729 if (!kmalloc_caches[i]) {
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000730 kmalloc_caches[i] = create_kmalloc_cache(NULL,
731 1 << i, flags);
Christoph Lameter8a965b32013-05-03 18:04:18 +0000732 }
Chris Mason956e46e2013-05-08 15:56:28 -0400733
734 /*
735 * Caches that are not of the two-to-the-power-of size.
736 * These have to be created immediately after the
737 * earlier power of two caches
738 */
739 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
740 kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags);
741
742 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
743 kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
Christoph Lameter8a965b32013-05-03 18:04:18 +0000744 }
745
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000746 /* Kmalloc array is now usable */
747 slab_state = UP;
748
749 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
750 struct kmem_cache *s = kmalloc_caches[i];
751 char *n;
752
753 if (s) {
754 n = kasprintf(GFP_NOWAIT, "kmalloc-%d", kmalloc_size(i));
755
756 BUG_ON(!n);
757 s->name = n;
758 }
759 }
760
761#ifdef CONFIG_ZONE_DMA
762 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
763 struct kmem_cache *s = kmalloc_caches[i];
764
765 if (s) {
766 int size = kmalloc_size(i);
767 char *n = kasprintf(GFP_NOWAIT,
768 "dma-kmalloc-%d", size);
769
770 BUG_ON(!n);
771 kmalloc_dma_caches[i] = create_kmalloc_cache(n,
772 size, SLAB_CACHE_DMA | flags);
773 }
774 }
775#endif
776}
Christoph Lameter45530c42012-11-28 16:23:07 +0000777#endif /* !CONFIG_SLOB */
778
Vladimir Davydovcea371f2014-06-04 16:07:04 -0700779/*
780 * To avoid unnecessary overhead, we pass through large allocation requests
781 * directly to the page allocator. We use __GFP_COMP, because we will need to
782 * know the allocation order to free the pages properly in kfree.
783 */
Vladimir Davydov52383432014-06-04 16:06:39 -0700784void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
785{
786 void *ret;
787 struct page *page;
788
789 flags |= __GFP_COMP;
790 page = alloc_kmem_pages(flags, order);
791 ret = page ? page_address(page) : NULL;
792 kmemleak_alloc(ret, size, 1, flags);
793 return ret;
794}
795EXPORT_SYMBOL(kmalloc_order);
796
Christoph Lameterf1b6eb62013-09-04 16:35:34 +0000797#ifdef CONFIG_TRACING
798void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
799{
800 void *ret = kmalloc_order(size, flags, order);
801 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
802 return ret;
803}
804EXPORT_SYMBOL(kmalloc_order_trace);
805#endif
Christoph Lameter45530c42012-11-28 16:23:07 +0000806
Glauber Costab7454ad2012-10-19 18:20:25 +0400807#ifdef CONFIG_SLABINFO
Wanpeng Lie9b4db22013-07-04 08:33:24 +0800808
809#ifdef CONFIG_SLAB
810#define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
811#else
812#define SLABINFO_RIGHTS S_IRUSR
813#endif
814
Vladimir Davydovb0475012014-12-10 15:44:19 -0800815static void print_slabinfo_header(struct seq_file *m)
Glauber Costabcee6e22012-10-19 18:20:26 +0400816{
817 /*
818 * Output format version, so at least we can change it
819 * without _too_ many complaints.
820 */
821#ifdef CONFIG_DEBUG_SLAB
822 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
823#else
824 seq_puts(m, "slabinfo - version: 2.1\n");
825#endif
826 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
827 "<objperslab> <pagesperslab>");
828 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
829 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
830#ifdef CONFIG_DEBUG_SLAB
831 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
832 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
833 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
834#endif
835 seq_putc(m, '\n');
836}
837
Vladimir Davydov1df3b262014-12-10 15:42:16 -0800838void *slab_start(struct seq_file *m, loff_t *pos)
Glauber Costab7454ad2012-10-19 18:20:25 +0400839{
Glauber Costab7454ad2012-10-19 18:20:25 +0400840 mutex_lock(&slab_mutex);
Glauber Costab7454ad2012-10-19 18:20:25 +0400841 return seq_list_start(&slab_caches, *pos);
842}
843
Wanpeng Li276a2432013-07-08 08:08:28 +0800844void *slab_next(struct seq_file *m, void *p, loff_t *pos)
Glauber Costab7454ad2012-10-19 18:20:25 +0400845{
846 return seq_list_next(p, &slab_caches, pos);
847}
848
Wanpeng Li276a2432013-07-08 08:08:28 +0800849void slab_stop(struct seq_file *m, void *p)
Glauber Costab7454ad2012-10-19 18:20:25 +0400850{
851 mutex_unlock(&slab_mutex);
852}
853
Glauber Costa749c5412012-12-18 14:23:01 -0800854static void
855memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
Glauber Costab7454ad2012-10-19 18:20:25 +0400856{
Glauber Costa749c5412012-12-18 14:23:01 -0800857 struct kmem_cache *c;
858 struct slabinfo sinfo;
859 int i;
860
861 if (!is_root_cache(s))
862 return;
863
864 for_each_memcg_cache_index(i) {
Qiang Huang2ade4de2013-11-12 15:08:23 -0800865 c = cache_from_memcg_idx(s, i);
Glauber Costa749c5412012-12-18 14:23:01 -0800866 if (!c)
867 continue;
868
869 memset(&sinfo, 0, sizeof(sinfo));
870 get_slabinfo(c, &sinfo);
871
872 info->active_slabs += sinfo.active_slabs;
873 info->num_slabs += sinfo.num_slabs;
874 info->shared_avail += sinfo.shared_avail;
875 info->active_objs += sinfo.active_objs;
876 info->num_objs += sinfo.num_objs;
877 }
878}
879
Vladimir Davydovb0475012014-12-10 15:44:19 -0800880static void cache_show(struct kmem_cache *s, struct seq_file *m)
Glauber Costa749c5412012-12-18 14:23:01 -0800881{
Glauber Costa0d7561c2012-10-19 18:20:27 +0400882 struct slabinfo sinfo;
883
884 memset(&sinfo, 0, sizeof(sinfo));
885 get_slabinfo(s, &sinfo);
886
Glauber Costa749c5412012-12-18 14:23:01 -0800887 memcg_accumulate_slabinfo(s, &sinfo);
888
Glauber Costa0d7561c2012-10-19 18:20:27 +0400889 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
Glauber Costa749c5412012-12-18 14:23:01 -0800890 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
Glauber Costa0d7561c2012-10-19 18:20:27 +0400891 sinfo.objects_per_slab, (1 << sinfo.cache_order));
892
893 seq_printf(m, " : tunables %4u %4u %4u",
894 sinfo.limit, sinfo.batchcount, sinfo.shared);
895 seq_printf(m, " : slabdata %6lu %6lu %6lu",
896 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
897 slabinfo_show_stats(m, s);
898 seq_putc(m, '\n');
Glauber Costab7454ad2012-10-19 18:20:25 +0400899}
900
Vladimir Davydov1df3b262014-12-10 15:42:16 -0800901static int slab_show(struct seq_file *m, void *p)
Glauber Costa749c5412012-12-18 14:23:01 -0800902{
903 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
904
Vladimir Davydov1df3b262014-12-10 15:42:16 -0800905 if (p == slab_caches.next)
906 print_slabinfo_header(m);
Vladimir Davydovb0475012014-12-10 15:44:19 -0800907 if (is_root_cache(s))
908 cache_show(s, m);
909 return 0;
Glauber Costa749c5412012-12-18 14:23:01 -0800910}
911
Vladimir Davydovb0475012014-12-10 15:44:19 -0800912#ifdef CONFIG_MEMCG_KMEM
913int memcg_slab_show(struct seq_file *m, void *p)
914{
915 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
916 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
917
918 if (p == slab_caches.next)
919 print_slabinfo_header(m);
920 if (!is_root_cache(s) && s->memcg_params->memcg == memcg)
921 cache_show(s, m);
922 return 0;
923}
924#endif
925
Glauber Costab7454ad2012-10-19 18:20:25 +0400926/*
927 * slabinfo_op - iterator that generates /proc/slabinfo
928 *
929 * Output layout:
930 * cache-name
931 * num-active-objs
932 * total-objs
933 * object size
934 * num-active-slabs
935 * total-slabs
936 * num-pages-per-slab
937 * + further values on SMP and with statistics enabled
938 */
939static const struct seq_operations slabinfo_op = {
Vladimir Davydov1df3b262014-12-10 15:42:16 -0800940 .start = slab_start,
Wanpeng Li276a2432013-07-08 08:08:28 +0800941 .next = slab_next,
942 .stop = slab_stop,
Vladimir Davydov1df3b262014-12-10 15:42:16 -0800943 .show = slab_show,
Glauber Costab7454ad2012-10-19 18:20:25 +0400944};
945
946static int slabinfo_open(struct inode *inode, struct file *file)
947{
948 return seq_open(file, &slabinfo_op);
949}
950
951static const struct file_operations proc_slabinfo_operations = {
952 .open = slabinfo_open,
953 .read = seq_read,
954 .write = slabinfo_write,
955 .llseek = seq_lseek,
956 .release = seq_release,
957};
958
959static int __init slab_proc_init(void)
960{
Wanpeng Lie9b4db22013-07-04 08:33:24 +0800961 proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
962 &proc_slabinfo_operations);
Glauber Costab7454ad2012-10-19 18:20:25 +0400963 return 0;
964}
965module_init(slab_proc_init);
966#endif /* CONFIG_SLABINFO */
Andrey Ryabinin928cec92014-08-06 16:04:44 -0700967
968static __always_inline void *__do_krealloc(const void *p, size_t new_size,
969 gfp_t flags)
970{
971 void *ret;
972 size_t ks = 0;
973
974 if (p)
975 ks = ksize(p);
976
977 if (ks >= new_size)
978 return (void *)p;
979
980 ret = kmalloc_track_caller(new_size, flags);
981 if (ret && p)
982 memcpy(ret, p, ks);
983
984 return ret;
985}
986
987/**
988 * __krealloc - like krealloc() but don't free @p.
989 * @p: object to reallocate memory for.
990 * @new_size: how many bytes of memory are required.
991 * @flags: the type of memory to allocate.
992 *
993 * This function is like krealloc() except it never frees the originally
994 * allocated buffer. Use this if you don't want to free the buffer immediately
995 * like, for example, with RCU.
996 */
997void *__krealloc(const void *p, size_t new_size, gfp_t flags)
998{
999 if (unlikely(!new_size))
1000 return ZERO_SIZE_PTR;
1001
1002 return __do_krealloc(p, new_size, flags);
1003
1004}
1005EXPORT_SYMBOL(__krealloc);
1006
1007/**
1008 * krealloc - reallocate memory. The contents will remain unchanged.
1009 * @p: object to reallocate memory for.
1010 * @new_size: how many bytes of memory are required.
1011 * @flags: the type of memory to allocate.
1012 *
1013 * The contents of the object pointed to are preserved up to the
1014 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1015 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1016 * %NULL pointer, the object pointed to is freed.
1017 */
1018void *krealloc(const void *p, size_t new_size, gfp_t flags)
1019{
1020 void *ret;
1021
1022 if (unlikely(!new_size)) {
1023 kfree(p);
1024 return ZERO_SIZE_PTR;
1025 }
1026
1027 ret = __do_krealloc(p, new_size, flags);
1028 if (ret && p != ret)
1029 kfree(p);
1030
1031 return ret;
1032}
1033EXPORT_SYMBOL(krealloc);
1034
1035/**
1036 * kzfree - like kfree but zero memory
1037 * @p: object to free memory of
1038 *
1039 * The memory of the object @p points to is zeroed before freed.
1040 * If @p is %NULL, kzfree() does nothing.
1041 *
1042 * Note: this function zeroes the whole allocated buffer which can be a good
1043 * deal bigger than the requested buffer size passed to kmalloc(). So be
1044 * careful when using this function in performance sensitive code.
1045 */
1046void kzfree(const void *p)
1047{
1048 size_t ks;
1049 void *mem = (void *)p;
1050
1051 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1052 return;
1053 ks = ksize(mem);
1054 memset(mem, 0, ks);
1055 kfree(mem);
1056}
1057EXPORT_SYMBOL(kzfree);
1058
1059/* Tracepoints definitions. */
1060EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1061EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1062EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1063EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1064EXPORT_TRACEPOINT_SYMBOL(kfree);
1065EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);