blob: d88e97c10a2e31669753681efc74f6bf50fdf2ef [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
Konstantin Khlebnikov3e810ae2015-08-06 15:46:36 -070040#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | SLAB_NOTRACK)
Joonsoo Kim423c9292014-10-09 15:26:22 -070041
42/*
43 * Merge control. If this is set then no merging of slab caches will occur.
44 * (Could be removed. This was introduced to pacify the merge skeptics.)
45 */
46static int slab_nomerge;
47
48static int __init setup_slab_nomerge(char *str)
49{
50 slab_nomerge = 1;
51 return 1;
52}
53
54#ifdef CONFIG_SLUB
55__setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
56#endif
57
58__setup("slab_nomerge", setup_slab_nomerge);
59
60/*
Joonsoo Kim07f361b2014-10-09 15:26:00 -070061 * Determine the size of a slab object
62 */
63unsigned int kmem_cache_size(struct kmem_cache *s)
64{
65 return s->object_size;
66}
67EXPORT_SYMBOL(kmem_cache_size);
68
Shuah Khan77be4b12012-08-16 00:09:46 -070069#ifdef CONFIG_DEBUG_VM
Vladimir Davydov794b1242014-04-07 15:39:26 -070070static int kmem_cache_sanity_check(const char *name, size_t size)
Shuah Khan77be4b12012-08-16 00:09:46 -070071{
72 struct kmem_cache *s = NULL;
73
74 if (!name || in_interrupt() || size < sizeof(void *) ||
75 size > KMALLOC_MAX_SIZE) {
76 pr_err("kmem_cache_create(%s) integrity check failed\n", name);
77 return -EINVAL;
78 }
79
80 list_for_each_entry(s, &slab_caches, list) {
81 char tmp;
82 int res;
83
84 /*
85 * This happens when the module gets unloaded and doesn't
86 * destroy its slab cache and no-one else reuses the vmalloc
87 * area of the module. Print a warning.
88 */
89 res = probe_kernel_address(s->name, tmp);
90 if (res) {
91 pr_err("Slab cache with size %d has lost its name\n",
92 s->object_size);
93 continue;
94 }
Shuah Khan77be4b12012-08-16 00:09:46 -070095 }
96
97 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
98 return 0;
99}
100#else
Vladimir Davydov794b1242014-04-07 15:39:26 -0700101static inline int kmem_cache_sanity_check(const char *name, size_t size)
Shuah Khan77be4b12012-08-16 00:09:46 -0700102{
103 return 0;
104}
105#endif
106
Christoph Lameter484748f2015-09-04 15:45:34 -0700107void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p)
108{
109 size_t i;
110
111 for (i = 0; i < nr; i++)
112 kmem_cache_free(s, p[i]);
113}
114
115bool __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
116 void **p)
117{
118 size_t i;
119
120 for (i = 0; i < nr; i++) {
121 void *x = p[i] = kmem_cache_alloc(s, flags);
122 if (!x) {
123 __kmem_cache_free_bulk(s, i, p);
124 return false;
125 }
126 }
127 return true;
128}
129
Glauber Costa55007d82012-12-18 14:22:38 -0800130#ifdef CONFIG_MEMCG_KMEM
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800131void slab_init_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700132{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800133 s->memcg_params.is_root_cache = true;
Vladimir Davydov426589f2015-02-12 14:59:23 -0800134 INIT_LIST_HEAD(&s->memcg_params.list);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800135 RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
136}
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700137
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800138static int init_memcg_params(struct kmem_cache *s,
139 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
140{
141 struct memcg_cache_array *arr;
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700142
143 if (memcg) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800144 s->memcg_params.is_root_cache = false;
145 s->memcg_params.memcg = memcg;
146 s->memcg_params.root_cache = root_cache;
147 return 0;
148 }
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700149
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800150 slab_init_memcg_params(s);
151
152 if (!memcg_nr_cache_ids)
153 return 0;
154
155 arr = kzalloc(sizeof(struct memcg_cache_array) +
156 memcg_nr_cache_ids * sizeof(void *),
157 GFP_KERNEL);
158 if (!arr)
159 return -ENOMEM;
160
161 RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700162 return 0;
163}
164
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800165static void destroy_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700166{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800167 if (is_root_cache(s))
168 kfree(rcu_access_pointer(s->memcg_params.memcg_caches));
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700169}
170
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800171static int update_memcg_params(struct kmem_cache *s, int new_array_size)
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700172{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800173 struct memcg_cache_array *old, *new;
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700174
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800175 if (!is_root_cache(s))
176 return 0;
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700177
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800178 new = kzalloc(sizeof(struct memcg_cache_array) +
179 new_array_size * sizeof(void *), GFP_KERNEL);
180 if (!new)
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700181 return -ENOMEM;
182
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800183 old = rcu_dereference_protected(s->memcg_params.memcg_caches,
184 lockdep_is_held(&slab_mutex));
185 if (old)
186 memcpy(new->entries, old->entries,
187 memcg_nr_cache_ids * sizeof(void *));
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700188
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800189 rcu_assign_pointer(s->memcg_params.memcg_caches, new);
190 if (old)
191 kfree_rcu(old, rcu);
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700192 return 0;
193}
194
Glauber Costa55007d82012-12-18 14:22:38 -0800195int memcg_update_all_caches(int num_memcgs)
196{
197 struct kmem_cache *s;
198 int ret = 0;
Glauber Costa55007d82012-12-18 14:22:38 -0800199
Vladimir Davydov05257a12015-02-12 14:59:01 -0800200 mutex_lock(&slab_mutex);
Glauber Costa55007d82012-12-18 14:22:38 -0800201 list_for_each_entry(s, &slab_caches, list) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800202 ret = update_memcg_params(s, num_memcgs);
Glauber Costa55007d82012-12-18 14:22:38 -0800203 /*
Glauber Costa55007d82012-12-18 14:22:38 -0800204 * Instead of freeing the memory, we'll just leave the caches
205 * up to this point in an updated state.
206 */
207 if (ret)
Vladimir Davydov05257a12015-02-12 14:59:01 -0800208 break;
Glauber Costa55007d82012-12-18 14:22:38 -0800209 }
Glauber Costa55007d82012-12-18 14:22:38 -0800210 mutex_unlock(&slab_mutex);
211 return ret;
212}
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700213#else
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800214static inline int init_memcg_params(struct kmem_cache *s,
215 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700216{
217 return 0;
218}
219
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800220static inline void destroy_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700221{
222}
223#endif /* CONFIG_MEMCG_KMEM */
Glauber Costa55007d82012-12-18 14:22:38 -0800224
Christoph Lameter039363f2012-07-06 15:25:10 -0500225/*
Joonsoo Kim423c9292014-10-09 15:26:22 -0700226 * Find a mergeable slab cache
227 */
228int slab_unmergeable(struct kmem_cache *s)
229{
230 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
231 return 1;
232
233 if (!is_root_cache(s))
234 return 1;
235
236 if (s->ctor)
237 return 1;
238
239 /*
240 * We may have set a slab to be unmergeable during bootstrap.
241 */
242 if (s->refcount < 0)
243 return 1;
244
245 return 0;
246}
247
248struct kmem_cache *find_mergeable(size_t size, size_t align,
249 unsigned long flags, const char *name, void (*ctor)(void *))
250{
251 struct kmem_cache *s;
252
253 if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
254 return NULL;
255
256 if (ctor)
257 return NULL;
258
259 size = ALIGN(size, sizeof(void *));
260 align = calculate_alignment(flags, align, size);
261 size = ALIGN(size, align);
262 flags = kmem_cache_flags(size, flags, name, NULL);
263
Joonsoo Kim54362052014-12-10 15:42:18 -0800264 list_for_each_entry_reverse(s, &slab_caches, list) {
Joonsoo Kim423c9292014-10-09 15:26:22 -0700265 if (slab_unmergeable(s))
266 continue;
267
268 if (size > s->size)
269 continue;
270
271 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
272 continue;
273 /*
274 * Check if alignment is compatible.
275 * Courtesy of Adrian Drzewiecki
276 */
277 if ((s->size & ~(align - 1)) != s->size)
278 continue;
279
280 if (s->size - size >= sizeof(void *))
281 continue;
282
Joonsoo Kim95069ac82014-11-13 15:19:25 -0800283 if (IS_ENABLED(CONFIG_SLAB) && align &&
284 (align > s->align || s->align % align))
285 continue;
286
Joonsoo Kim423c9292014-10-09 15:26:22 -0700287 return s;
288 }
289 return NULL;
290}
291
292/*
Christoph Lameter45906852012-11-28 16:23:16 +0000293 * Figure out what the alignment of the objects will be given a set of
294 * flags, a user specified alignment and the size of the objects.
295 */
296unsigned long calculate_alignment(unsigned long flags,
297 unsigned long align, unsigned long size)
298{
299 /*
300 * If the user wants hardware cache aligned objects then follow that
301 * suggestion if the object is sufficiently large.
302 *
303 * The hardware cache alignment cannot override the specified
304 * alignment though. If that is greater then use it.
305 */
306 if (flags & SLAB_HWCACHE_ALIGN) {
307 unsigned long ralign = cache_line_size();
308 while (size <= ralign / 2)
309 ralign /= 2;
310 align = max(align, ralign);
311 }
312
313 if (align < ARCH_SLAB_MINALIGN)
314 align = ARCH_SLAB_MINALIGN;
315
316 return ALIGN(align, sizeof(void *));
317}
318
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800319static struct kmem_cache *create_cache(const char *name,
320 size_t object_size, size_t size, size_t align,
321 unsigned long flags, void (*ctor)(void *),
322 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700323{
324 struct kmem_cache *s;
325 int err;
326
327 err = -ENOMEM;
328 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
329 if (!s)
330 goto out;
331
332 s->name = name;
333 s->object_size = object_size;
334 s->size = size;
335 s->align = align;
336 s->ctor = ctor;
337
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800338 err = init_memcg_params(s, memcg, root_cache);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700339 if (err)
340 goto out_free_cache;
341
342 err = __kmem_cache_create(s, flags);
343 if (err)
344 goto out_free_cache;
345
346 s->refcount = 1;
347 list_add(&s->list, &slab_caches);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700348out:
349 if (err)
350 return ERR_PTR(err);
351 return s;
352
353out_free_cache:
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800354 destroy_memcg_params(s);
Vaishali Thakkar7c4da062015-02-10 14:09:40 -0800355 kmem_cache_free(kmem_cache, s);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700356 goto out;
357}
Christoph Lameter45906852012-11-28 16:23:16 +0000358
359/*
Christoph Lameter039363f2012-07-06 15:25:10 -0500360 * kmem_cache_create - Create a cache.
361 * @name: A string which is used in /proc/slabinfo to identify this cache.
362 * @size: The size of objects to be created in this cache.
363 * @align: The required alignment for the objects.
364 * @flags: SLAB flags
365 * @ctor: A constructor for the objects.
366 *
367 * Returns a ptr to the cache on success, NULL on failure.
368 * Cannot be called within a interrupt, but can be interrupted.
369 * The @ctor is run when new pages are allocated by the cache.
370 *
371 * The flags are
372 *
373 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
374 * to catch references to uninitialised memory.
375 *
376 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
377 * for buffer overruns.
378 *
379 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
380 * cacheline. This can be beneficial if you're counting cycles as closely
381 * as davem.
382 */
Glauber Costa2633d7a2012-12-18 14:22:34 -0800383struct kmem_cache *
Vladimir Davydov794b1242014-04-07 15:39:26 -0700384kmem_cache_create(const char *name, size_t size, size_t align,
385 unsigned long flags, void (*ctor)(void *))
Christoph Lameter039363f2012-07-06 15:25:10 -0500386{
Alexandru Moise40911a72015-11-05 18:45:43 -0800387 struct kmem_cache *s = NULL;
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800388 const char *cache_name;
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800389 int err;
Christoph Lameter039363f2012-07-06 15:25:10 -0500390
Pekka Enbergb9205362012-08-16 10:12:18 +0300391 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700392 get_online_mems();
Vladimir Davydov05257a12015-02-12 14:59:01 -0800393 memcg_get_cache_ids();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700394
Pekka Enbergb9205362012-08-16 10:12:18 +0300395 mutex_lock(&slab_mutex);
Christoph Lameter686d5502012-09-05 00:20:33 +0000396
Vladimir Davydov794b1242014-04-07 15:39:26 -0700397 err = kmem_cache_sanity_check(name, size);
Andrew Morton3aa24f52014-10-09 15:25:58 -0700398 if (err) {
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800399 goto out_unlock;
Andrew Morton3aa24f52014-10-09 15:25:58 -0700400 }
Christoph Lameter686d5502012-09-05 00:20:33 +0000401
Glauber Costad8843922012-10-17 15:36:51 +0400402 /*
403 * Some allocators will constraint the set of valid flags to a subset
404 * of all flags. We expect them to define CACHE_CREATE_MASK in this
405 * case, and we'll just provide them with a sanitized version of the
406 * passed flags.
407 */
408 flags &= CACHE_CREATE_MASK;
Christoph Lameter686d5502012-09-05 00:20:33 +0000409
Vladimir Davydov794b1242014-04-07 15:39:26 -0700410 s = __kmem_cache_alias(name, size, align, flags, ctor);
411 if (s)
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800412 goto out_unlock;
Glauber Costa2633d7a2012-12-18 14:22:34 -0800413
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800414 cache_name = kstrdup_const(name, GFP_KERNEL);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700415 if (!cache_name) {
416 err = -ENOMEM;
417 goto out_unlock;
418 }
Glauber Costa2633d7a2012-12-18 14:22:34 -0800419
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800420 s = create_cache(cache_name, size, size,
421 calculate_alignment(flags, align, size),
422 flags, ctor, NULL, NULL);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700423 if (IS_ERR(s)) {
424 err = PTR_ERR(s);
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800425 kfree_const(cache_name);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700426 }
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800427
428out_unlock:
Christoph Lameter20cea962012-07-06 15:25:13 -0500429 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700430
Vladimir Davydov05257a12015-02-12 14:59:01 -0800431 memcg_put_cache_ids();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700432 put_online_mems();
Christoph Lameter20cea962012-07-06 15:25:13 -0500433 put_online_cpus();
434
Dave Jonesba3253c72014-01-29 14:05:48 -0800435 if (err) {
Christoph Lameter686d5502012-09-05 00:20:33 +0000436 if (flags & SLAB_PANIC)
437 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
438 name, err);
439 else {
440 printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
441 name, err);
442 dump_stack();
443 }
Christoph Lameter686d5502012-09-05 00:20:33 +0000444 return NULL;
445 }
Christoph Lameter039363f2012-07-06 15:25:10 -0500446 return s;
Glauber Costa2633d7a2012-12-18 14:22:34 -0800447}
Christoph Lameter039363f2012-07-06 15:25:10 -0500448EXPORT_SYMBOL(kmem_cache_create);
Christoph Lameter97d06602012-07-06 15:25:11 -0500449
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800450static int shutdown_cache(struct kmem_cache *s,
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800451 struct list_head *release, bool *need_rcu_barrier)
452{
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800453 if (__kmem_cache_shutdown(s) != 0)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800454 return -EBUSY;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800455
456 if (s->flags & SLAB_DESTROY_BY_RCU)
457 *need_rcu_barrier = true;
458
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800459 list_move(&s->list, release);
460 return 0;
461}
462
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800463static void release_caches(struct list_head *release, bool need_rcu_barrier)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800464{
465 struct kmem_cache *s, *s2;
466
467 if (need_rcu_barrier)
468 rcu_barrier();
469
470 list_for_each_entry_safe(s, s2, release, list) {
471#ifdef SLAB_SUPPORTS_SYSFS
472 sysfs_slab_remove(s);
473#else
474 slab_kmem_cache_release(s);
475#endif
476 }
477}
478
Vladimir Davydov794b1242014-04-07 15:39:26 -0700479#ifdef CONFIG_MEMCG_KMEM
480/*
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700481 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
Vladimir Davydov794b1242014-04-07 15:39:26 -0700482 * @memcg: The memory cgroup the new cache is for.
483 * @root_cache: The parent of the new cache.
484 *
485 * This function attempts to create a kmem cache that will serve allocation
486 * requests going from @memcg to @root_cache. The new cache inherits properties
487 * from its parent.
488 */
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800489void memcg_create_kmem_cache(struct mem_cgroup *memcg,
490 struct kmem_cache *root_cache)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700491{
Vladimir Davydov3e0350a2015-02-10 14:11:44 -0800492 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
Michal Hocko33398cf2015-09-08 15:01:02 -0700493 struct cgroup_subsys_state *css = &memcg->css;
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800494 struct memcg_cache_array *arr;
Vladimir Davydovbd673142014-06-04 16:07:40 -0700495 struct kmem_cache *s = NULL;
Vladimir Davydov794b1242014-04-07 15:39:26 -0700496 char *cache_name;
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800497 int idx;
Vladimir Davydov794b1242014-04-07 15:39:26 -0700498
499 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700500 get_online_mems();
501
Vladimir Davydov794b1242014-04-07 15:39:26 -0700502 mutex_lock(&slab_mutex);
503
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800504 /*
505 * The memory cgroup could have been deactivated while the cache
506 * creation work was pending.
507 */
508 if (!memcg_kmem_is_active(memcg))
509 goto out_unlock;
510
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800511 idx = memcg_cache_id(memcg);
512 arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
513 lockdep_is_held(&slab_mutex));
514
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800515 /*
516 * Since per-memcg caches are created asynchronously on first
517 * allocation (see memcg_kmem_get_cache()), several threads can try to
518 * create the same cache, but only one of them may succeed.
519 */
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800520 if (arr->entries[idx])
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800521 goto out_unlock;
522
Vladimir Davydovf1008362015-02-12 14:59:29 -0800523 cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
Vladimir Davydov073ee1c2014-06-04 16:08:23 -0700524 cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
Vladimir Davydovf1008362015-02-12 14:59:29 -0800525 css->id, memcg_name_buf);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700526 if (!cache_name)
527 goto out_unlock;
528
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800529 s = create_cache(cache_name, root_cache->object_size,
530 root_cache->size, root_cache->align,
531 root_cache->flags, root_cache->ctor,
532 memcg, root_cache);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800533 /*
534 * If we could not create a memcg cache, do not complain, because
535 * that's not critical at all as we can always proceed with the root
536 * cache.
537 */
Vladimir Davydovbd673142014-06-04 16:07:40 -0700538 if (IS_ERR(s)) {
Vladimir Davydov794b1242014-04-07 15:39:26 -0700539 kfree(cache_name);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800540 goto out_unlock;
Vladimir Davydovbd673142014-06-04 16:07:40 -0700541 }
Vladimir Davydov794b1242014-04-07 15:39:26 -0700542
Vladimir Davydov426589f2015-02-12 14:59:23 -0800543 list_add(&s->memcg_params.list, &root_cache->memcg_params.list);
544
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800545 /*
546 * Since readers won't lock (see cache_from_memcg_idx()), we need a
547 * barrier here to ensure nobody will see the kmem_cache partially
548 * initialized.
549 */
550 smp_wmb();
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800551 arr->entries[idx] = s;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800552
Vladimir Davydov794b1242014-04-07 15:39:26 -0700553out_unlock:
554 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700555
556 put_online_mems();
Vladimir Davydov794b1242014-04-07 15:39:26 -0700557 put_online_cpus();
558}
Vladimir Davydovb8529902014-04-07 15:39:28 -0700559
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800560void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
561{
562 int idx;
563 struct memcg_cache_array *arr;
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800564 struct kmem_cache *s, *c;
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800565
566 idx = memcg_cache_id(memcg);
567
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800568 get_online_cpus();
569 get_online_mems();
570
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800571 mutex_lock(&slab_mutex);
572 list_for_each_entry(s, &slab_caches, list) {
573 if (!is_root_cache(s))
574 continue;
575
576 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
577 lockdep_is_held(&slab_mutex));
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800578 c = arr->entries[idx];
579 if (!c)
580 continue;
581
582 __kmem_cache_shrink(c, true);
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800583 arr->entries[idx] = NULL;
584 }
585 mutex_unlock(&slab_mutex);
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800586
587 put_online_mems();
588 put_online_cpus();
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800589}
590
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800591static int __shutdown_memcg_cache(struct kmem_cache *s,
592 struct list_head *release, bool *need_rcu_barrier)
593{
594 BUG_ON(is_root_cache(s));
595
596 if (shutdown_cache(s, release, need_rcu_barrier))
597 return -EBUSY;
598
599 list_del(&s->memcg_params.list);
600 return 0;
601}
602
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800603void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
Vladimir Davydovb8529902014-04-07 15:39:28 -0700604{
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800605 LIST_HEAD(release);
606 bool need_rcu_barrier = false;
607 struct kmem_cache *s, *s2;
Vladimir Davydovb8529902014-04-07 15:39:28 -0700608
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800609 get_online_cpus();
610 get_online_mems();
Vladimir Davydovb8529902014-04-07 15:39:28 -0700611
Vladimir Davydovb8529902014-04-07 15:39:28 -0700612 mutex_lock(&slab_mutex);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800613 list_for_each_entry_safe(s, s2, &slab_caches, list) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800614 if (is_root_cache(s) || s->memcg_params.memcg != memcg)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800615 continue;
616 /*
617 * The cgroup is about to be freed and therefore has no charges
618 * left. Hence, all its caches must be empty by now.
619 */
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800620 BUG_ON(__shutdown_memcg_cache(s, &release, &need_rcu_barrier));
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800621 }
622 mutex_unlock(&slab_mutex);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700623
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800624 put_online_mems();
625 put_online_cpus();
626
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800627 release_caches(&release, need_rcu_barrier);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700628}
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800629
630static int shutdown_memcg_caches(struct kmem_cache *s,
631 struct list_head *release, bool *need_rcu_barrier)
632{
633 struct memcg_cache_array *arr;
634 struct kmem_cache *c, *c2;
635 LIST_HEAD(busy);
636 int i;
637
638 BUG_ON(!is_root_cache(s));
639
640 /*
641 * First, shutdown active caches, i.e. caches that belong to online
642 * memory cgroups.
643 */
644 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
645 lockdep_is_held(&slab_mutex));
646 for_each_memcg_cache_index(i) {
647 c = arr->entries[i];
648 if (!c)
649 continue;
650 if (__shutdown_memcg_cache(c, release, need_rcu_barrier))
651 /*
652 * The cache still has objects. Move it to a temporary
653 * list so as not to try to destroy it for a second
654 * time while iterating over inactive caches below.
655 */
656 list_move(&c->memcg_params.list, &busy);
657 else
658 /*
659 * The cache is empty and will be destroyed soon. Clear
660 * the pointer to it in the memcg_caches array so that
661 * it will never be accessed even if the root cache
662 * stays alive.
663 */
664 arr->entries[i] = NULL;
665 }
666
667 /*
668 * Second, shutdown all caches left from memory cgroups that are now
669 * offline.
670 */
671 list_for_each_entry_safe(c, c2, &s->memcg_params.list,
672 memcg_params.list)
673 __shutdown_memcg_cache(c, release, need_rcu_barrier);
674
675 list_splice(&busy, &s->memcg_params.list);
676
677 /*
678 * A cache being destroyed must be empty. In particular, this means
679 * that all per memcg caches attached to it must be empty too.
680 */
681 if (!list_empty(&s->memcg_params.list))
682 return -EBUSY;
683 return 0;
684}
685#else
686static inline int shutdown_memcg_caches(struct kmem_cache *s,
687 struct list_head *release, bool *need_rcu_barrier)
688{
689 return 0;
690}
Vladimir Davydov794b1242014-04-07 15:39:26 -0700691#endif /* CONFIG_MEMCG_KMEM */
692
Christoph Lameter41a21282014-05-06 12:50:08 -0700693void slab_kmem_cache_release(struct kmem_cache *s)
694{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800695 destroy_memcg_params(s);
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800696 kfree_const(s->name);
Christoph Lameter41a21282014-05-06 12:50:08 -0700697 kmem_cache_free(kmem_cache, s);
698}
699
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000700void kmem_cache_destroy(struct kmem_cache *s)
701{
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800702 LIST_HEAD(release);
703 bool need_rcu_barrier = false;
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800704 int err;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800705
Sergey Senozhatsky3942d292015-09-08 15:00:50 -0700706 if (unlikely(!s))
707 return;
708
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000709 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700710 get_online_mems();
711
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000712 mutex_lock(&slab_mutex);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700713
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000714 s->refcount--;
Vladimir Davydovb8529902014-04-07 15:39:28 -0700715 if (s->refcount)
716 goto out_unlock;
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000717
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800718 err = shutdown_memcg_caches(s, &release, &need_rcu_barrier);
719 if (!err)
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800720 err = shutdown_cache(s, &release, &need_rcu_barrier);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700721
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800722 if (err) {
723 pr_err("kmem_cache_destroy %s: "
724 "Slab cache still has objects\n", s->name);
725 dump_stack();
726 }
Vladimir Davydovb8529902014-04-07 15:39:28 -0700727out_unlock:
728 mutex_unlock(&slab_mutex);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800729
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700730 put_online_mems();
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000731 put_online_cpus();
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800732
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800733 release_caches(&release, need_rcu_barrier);
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000734}
735EXPORT_SYMBOL(kmem_cache_destroy);
736
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700737/**
738 * kmem_cache_shrink - Shrink a cache.
739 * @cachep: The cache to shrink.
740 *
741 * Releases as many slabs as possible for a cache.
742 * To help debugging, a zero exit status indicates all slabs were released.
743 */
744int kmem_cache_shrink(struct kmem_cache *cachep)
745{
746 int ret;
747
748 get_online_cpus();
749 get_online_mems();
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800750 ret = __kmem_cache_shrink(cachep, false);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700751 put_online_mems();
752 put_online_cpus();
753 return ret;
754}
755EXPORT_SYMBOL(kmem_cache_shrink);
756
Denis Kirjanovfda90122015-11-05 18:44:59 -0800757bool slab_is_available(void)
Christoph Lameter97d06602012-07-06 15:25:11 -0500758{
759 return slab_state >= UP;
760}
Glauber Costab7454ad2012-10-19 18:20:25 +0400761
Christoph Lameter45530c42012-11-28 16:23:07 +0000762#ifndef CONFIG_SLOB
763/* Create a cache during boot when no slab services are available yet */
764void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
765 unsigned long flags)
766{
767 int err;
768
769 s->name = name;
770 s->size = s->object_size = size;
Christoph Lameter45906852012-11-28 16:23:16 +0000771 s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800772
773 slab_init_memcg_params(s);
774
Christoph Lameter45530c42012-11-28 16:23:07 +0000775 err = __kmem_cache_create(s, flags);
776
777 if (err)
Christoph Lameter31ba7342013-01-10 19:00:53 +0000778 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
Christoph Lameter45530c42012-11-28 16:23:07 +0000779 name, size, err);
780
781 s->refcount = -1; /* Exempt from merging for now */
782}
783
784struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
785 unsigned long flags)
786{
787 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
788
789 if (!s)
790 panic("Out of memory when creating slab %s\n", name);
791
792 create_boot_cache(s, name, size, flags);
793 list_add(&s->list, &slab_caches);
794 s->refcount = 1;
795 return s;
796}
797
Christoph Lameter9425c582013-01-10 19:12:17 +0000798struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
799EXPORT_SYMBOL(kmalloc_caches);
800
801#ifdef CONFIG_ZONE_DMA
802struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
803EXPORT_SYMBOL(kmalloc_dma_caches);
804#endif
805
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000806/*
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000807 * Conversion table for small slabs sizes / 8 to the index in the
808 * kmalloc array. This is necessary for slabs < 192 since we have non power
809 * of two cache sizes there. The size of larger slabs can be determined using
810 * fls.
811 */
812static s8 size_index[24] = {
813 3, /* 8 */
814 4, /* 16 */
815 5, /* 24 */
816 5, /* 32 */
817 6, /* 40 */
818 6, /* 48 */
819 6, /* 56 */
820 6, /* 64 */
821 1, /* 72 */
822 1, /* 80 */
823 1, /* 88 */
824 1, /* 96 */
825 7, /* 104 */
826 7, /* 112 */
827 7, /* 120 */
828 7, /* 128 */
829 2, /* 136 */
830 2, /* 144 */
831 2, /* 152 */
832 2, /* 160 */
833 2, /* 168 */
834 2, /* 176 */
835 2, /* 184 */
836 2 /* 192 */
837};
838
839static inline int size_index_elem(size_t bytes)
840{
841 return (bytes - 1) / 8;
842}
843
844/*
845 * Find the kmem_cache structure that serves a given size of
846 * allocation
847 */
848struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
849{
850 int index;
851
Joonsoo Kim9de1bc82013-08-02 11:02:42 +0900852 if (unlikely(size > KMALLOC_MAX_SIZE)) {
Sasha Levin907985f2013-06-10 15:18:00 -0400853 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
Christoph Lameter6286ae92013-05-03 15:43:18 +0000854 return NULL;
Sasha Levin907985f2013-06-10 15:18:00 -0400855 }
Christoph Lameter6286ae92013-05-03 15:43:18 +0000856
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000857 if (size <= 192) {
858 if (!size)
859 return ZERO_SIZE_PTR;
860
861 index = size_index[size_index_elem(size)];
862 } else
863 index = fls(size - 1);
864
865#ifdef CONFIG_ZONE_DMA
Joonsoo Kimb1e05412013-02-04 23:46:46 +0900866 if (unlikely((flags & GFP_DMA)))
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000867 return kmalloc_dma_caches[index];
868
869#endif
870 return kmalloc_caches[index];
871}
872
873/*
Gavin Guo4066c332015-06-24 16:55:54 -0700874 * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
875 * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
876 * kmalloc-67108864.
877 */
878static struct {
879 const char *name;
880 unsigned long size;
881} const kmalloc_info[] __initconst = {
882 {NULL, 0}, {"kmalloc-96", 96},
883 {"kmalloc-192", 192}, {"kmalloc-8", 8},
884 {"kmalloc-16", 16}, {"kmalloc-32", 32},
885 {"kmalloc-64", 64}, {"kmalloc-128", 128},
886 {"kmalloc-256", 256}, {"kmalloc-512", 512},
887 {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048},
888 {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192},
889 {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768},
890 {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072},
891 {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288},
892 {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152},
893 {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608},
894 {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432},
895 {"kmalloc-67108864", 67108864}
896};
897
898/*
Daniel Sanders34cc6992015-06-24 16:55:57 -0700899 * Patch up the size_index table if we have strange large alignment
900 * requirements for the kmalloc array. This is only the case for
901 * MIPS it seems. The standard arches will not generate any code here.
902 *
903 * Largest permitted alignment is 256 bytes due to the way we
904 * handle the index determination for the smaller caches.
905 *
906 * Make sure that nothing crazy happens if someone starts tinkering
907 * around with ARCH_KMALLOC_MINALIGN
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000908 */
Daniel Sanders34cc6992015-06-24 16:55:57 -0700909void __init setup_kmalloc_cache_index_table(void)
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000910{
911 int i;
912
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000913 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
914 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
915
916 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
917 int elem = size_index_elem(i);
918
919 if (elem >= ARRAY_SIZE(size_index))
920 break;
921 size_index[elem] = KMALLOC_SHIFT_LOW;
922 }
923
924 if (KMALLOC_MIN_SIZE >= 64) {
925 /*
926 * The 96 byte size cache is not used if the alignment
927 * is 64 byte.
928 */
929 for (i = 64 + 8; i <= 96; i += 8)
930 size_index[size_index_elem(i)] = 7;
931
932 }
933
934 if (KMALLOC_MIN_SIZE >= 128) {
935 /*
936 * The 192 byte sized cache is not used if the alignment
937 * is 128 byte. Redirect kmalloc to use the 256 byte cache
938 * instead.
939 */
940 for (i = 128 + 8; i <= 192; i += 8)
941 size_index[size_index_elem(i)] = 8;
942 }
Daniel Sanders34cc6992015-06-24 16:55:57 -0700943}
944
Christoph Lameterae6f2462015-06-30 09:01:11 -0500945static void __init new_kmalloc_cache(int idx, unsigned long flags)
Christoph Lametera9730fc2015-06-29 09:28:08 -0500946{
947 kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name,
948 kmalloc_info[idx].size, flags);
949}
950
Daniel Sanders34cc6992015-06-24 16:55:57 -0700951/*
952 * Create the kmalloc array. Some of the regular kmalloc arrays
953 * may already have been created because they were needed to
954 * enable allocations for slab creation.
955 */
956void __init create_kmalloc_caches(unsigned long flags)
957{
958 int i;
959
Christoph Lametera9730fc2015-06-29 09:28:08 -0500960 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
961 if (!kmalloc_caches[i])
962 new_kmalloc_cache(i, flags);
Chris Mason956e46e2013-05-08 15:56:28 -0400963
964 /*
Christoph Lametera9730fc2015-06-29 09:28:08 -0500965 * Caches that are not of the two-to-the-power-of size.
966 * These have to be created immediately after the
967 * earlier power of two caches
Chris Mason956e46e2013-05-08 15:56:28 -0400968 */
Christoph Lametera9730fc2015-06-29 09:28:08 -0500969 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
970 new_kmalloc_cache(1, flags);
971 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
972 new_kmalloc_cache(2, flags);
Christoph Lameter8a965b32013-05-03 18:04:18 +0000973 }
974
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000975 /* Kmalloc array is now usable */
976 slab_state = UP;
977
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000978#ifdef CONFIG_ZONE_DMA
979 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
980 struct kmem_cache *s = kmalloc_caches[i];
981
982 if (s) {
983 int size = kmalloc_size(i);
984 char *n = kasprintf(GFP_NOWAIT,
985 "dma-kmalloc-%d", size);
986
987 BUG_ON(!n);
988 kmalloc_dma_caches[i] = create_kmalloc_cache(n,
989 size, SLAB_CACHE_DMA | flags);
990 }
991 }
992#endif
993}
Christoph Lameter45530c42012-11-28 16:23:07 +0000994#endif /* !CONFIG_SLOB */
995
Vladimir Davydovcea371f2014-06-04 16:07:04 -0700996/*
997 * To avoid unnecessary overhead, we pass through large allocation requests
998 * directly to the page allocator. We use __GFP_COMP, because we will need to
999 * know the allocation order to free the pages properly in kfree.
1000 */
Vladimir Davydov52383432014-06-04 16:06:39 -07001001void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
1002{
1003 void *ret;
1004 struct page *page;
1005
1006 flags |= __GFP_COMP;
1007 page = alloc_kmem_pages(flags, order);
1008 ret = page ? page_address(page) : NULL;
1009 kmemleak_alloc(ret, size, 1, flags);
Andrey Ryabinin0316bec2015-02-13 14:39:42 -08001010 kasan_kmalloc_large(ret, size);
Vladimir Davydov52383432014-06-04 16:06:39 -07001011 return ret;
1012}
1013EXPORT_SYMBOL(kmalloc_order);
1014
Christoph Lameterf1b6eb62013-09-04 16:35:34 +00001015#ifdef CONFIG_TRACING
1016void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
1017{
1018 void *ret = kmalloc_order(size, flags, order);
1019 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
1020 return ret;
1021}
1022EXPORT_SYMBOL(kmalloc_order_trace);
1023#endif
Christoph Lameter45530c42012-11-28 16:23:07 +00001024
Glauber Costab7454ad2012-10-19 18:20:25 +04001025#ifdef CONFIG_SLABINFO
Wanpeng Lie9b4db22013-07-04 08:33:24 +08001026
1027#ifdef CONFIG_SLAB
1028#define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
1029#else
1030#define SLABINFO_RIGHTS S_IRUSR
1031#endif
1032
Vladimir Davydovb0475012014-12-10 15:44:19 -08001033static void print_slabinfo_header(struct seq_file *m)
Glauber Costabcee6e22012-10-19 18:20:26 +04001034{
1035 /*
1036 * Output format version, so at least we can change it
1037 * without _too_ many complaints.
1038 */
1039#ifdef CONFIG_DEBUG_SLAB
1040 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
1041#else
1042 seq_puts(m, "slabinfo - version: 2.1\n");
1043#endif
1044 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
1045 "<objperslab> <pagesperslab>");
1046 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
1047 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
1048#ifdef CONFIG_DEBUG_SLAB
1049 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
1050 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
1051 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
1052#endif
1053 seq_putc(m, '\n');
1054}
1055
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001056void *slab_start(struct seq_file *m, loff_t *pos)
Glauber Costab7454ad2012-10-19 18:20:25 +04001057{
Glauber Costab7454ad2012-10-19 18:20:25 +04001058 mutex_lock(&slab_mutex);
Glauber Costab7454ad2012-10-19 18:20:25 +04001059 return seq_list_start(&slab_caches, *pos);
1060}
1061
Wanpeng Li276a2432013-07-08 08:08:28 +08001062void *slab_next(struct seq_file *m, void *p, loff_t *pos)
Glauber Costab7454ad2012-10-19 18:20:25 +04001063{
1064 return seq_list_next(p, &slab_caches, pos);
1065}
1066
Wanpeng Li276a2432013-07-08 08:08:28 +08001067void slab_stop(struct seq_file *m, void *p)
Glauber Costab7454ad2012-10-19 18:20:25 +04001068{
1069 mutex_unlock(&slab_mutex);
1070}
1071
Glauber Costa749c5412012-12-18 14:23:01 -08001072static void
1073memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
Glauber Costab7454ad2012-10-19 18:20:25 +04001074{
Glauber Costa749c5412012-12-18 14:23:01 -08001075 struct kmem_cache *c;
1076 struct slabinfo sinfo;
Glauber Costa749c5412012-12-18 14:23:01 -08001077
1078 if (!is_root_cache(s))
1079 return;
1080
Vladimir Davydov426589f2015-02-12 14:59:23 -08001081 for_each_memcg_cache(c, s) {
Glauber Costa749c5412012-12-18 14:23:01 -08001082 memset(&sinfo, 0, sizeof(sinfo));
1083 get_slabinfo(c, &sinfo);
1084
1085 info->active_slabs += sinfo.active_slabs;
1086 info->num_slabs += sinfo.num_slabs;
1087 info->shared_avail += sinfo.shared_avail;
1088 info->active_objs += sinfo.active_objs;
1089 info->num_objs += sinfo.num_objs;
1090 }
1091}
1092
Vladimir Davydovb0475012014-12-10 15:44:19 -08001093static void cache_show(struct kmem_cache *s, struct seq_file *m)
Glauber Costa749c5412012-12-18 14:23:01 -08001094{
Glauber Costa0d7561c2012-10-19 18:20:27 +04001095 struct slabinfo sinfo;
1096
1097 memset(&sinfo, 0, sizeof(sinfo));
1098 get_slabinfo(s, &sinfo);
1099
Glauber Costa749c5412012-12-18 14:23:01 -08001100 memcg_accumulate_slabinfo(s, &sinfo);
1101
Glauber Costa0d7561c2012-10-19 18:20:27 +04001102 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
Glauber Costa749c5412012-12-18 14:23:01 -08001103 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
Glauber Costa0d7561c2012-10-19 18:20:27 +04001104 sinfo.objects_per_slab, (1 << sinfo.cache_order));
1105
1106 seq_printf(m, " : tunables %4u %4u %4u",
1107 sinfo.limit, sinfo.batchcount, sinfo.shared);
1108 seq_printf(m, " : slabdata %6lu %6lu %6lu",
1109 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1110 slabinfo_show_stats(m, s);
1111 seq_putc(m, '\n');
Glauber Costab7454ad2012-10-19 18:20:25 +04001112}
1113
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001114static int slab_show(struct seq_file *m, void *p)
Glauber Costa749c5412012-12-18 14:23:01 -08001115{
1116 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1117
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001118 if (p == slab_caches.next)
1119 print_slabinfo_header(m);
Vladimir Davydovb0475012014-12-10 15:44:19 -08001120 if (is_root_cache(s))
1121 cache_show(s, m);
1122 return 0;
Glauber Costa749c5412012-12-18 14:23:01 -08001123}
1124
Vladimir Davydovb0475012014-12-10 15:44:19 -08001125#ifdef CONFIG_MEMCG_KMEM
1126int memcg_slab_show(struct seq_file *m, void *p)
1127{
1128 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1129 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
1130
1131 if (p == slab_caches.next)
1132 print_slabinfo_header(m);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -08001133 if (!is_root_cache(s) && s->memcg_params.memcg == memcg)
Vladimir Davydovb0475012014-12-10 15:44:19 -08001134 cache_show(s, m);
1135 return 0;
1136}
1137#endif
1138
Glauber Costab7454ad2012-10-19 18:20:25 +04001139/*
1140 * slabinfo_op - iterator that generates /proc/slabinfo
1141 *
1142 * Output layout:
1143 * cache-name
1144 * num-active-objs
1145 * total-objs
1146 * object size
1147 * num-active-slabs
1148 * total-slabs
1149 * num-pages-per-slab
1150 * + further values on SMP and with statistics enabled
1151 */
1152static const struct seq_operations slabinfo_op = {
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001153 .start = slab_start,
Wanpeng Li276a2432013-07-08 08:08:28 +08001154 .next = slab_next,
1155 .stop = slab_stop,
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001156 .show = slab_show,
Glauber Costab7454ad2012-10-19 18:20:25 +04001157};
1158
1159static int slabinfo_open(struct inode *inode, struct file *file)
1160{
1161 return seq_open(file, &slabinfo_op);
1162}
1163
1164static const struct file_operations proc_slabinfo_operations = {
1165 .open = slabinfo_open,
1166 .read = seq_read,
1167 .write = slabinfo_write,
1168 .llseek = seq_lseek,
1169 .release = seq_release,
1170};
1171
1172static int __init slab_proc_init(void)
1173{
Wanpeng Lie9b4db22013-07-04 08:33:24 +08001174 proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
1175 &proc_slabinfo_operations);
Glauber Costab7454ad2012-10-19 18:20:25 +04001176 return 0;
1177}
1178module_init(slab_proc_init);
1179#endif /* CONFIG_SLABINFO */
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001180
1181static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1182 gfp_t flags)
1183{
1184 void *ret;
1185 size_t ks = 0;
1186
1187 if (p)
1188 ks = ksize(p);
1189
Andrey Ryabinin0316bec2015-02-13 14:39:42 -08001190 if (ks >= new_size) {
1191 kasan_krealloc((void *)p, new_size);
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001192 return (void *)p;
Andrey Ryabinin0316bec2015-02-13 14:39:42 -08001193 }
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001194
1195 ret = kmalloc_track_caller(new_size, flags);
1196 if (ret && p)
1197 memcpy(ret, p, ks);
1198
1199 return ret;
1200}
1201
1202/**
1203 * __krealloc - like krealloc() but don't free @p.
1204 * @p: object to reallocate memory for.
1205 * @new_size: how many bytes of memory are required.
1206 * @flags: the type of memory to allocate.
1207 *
1208 * This function is like krealloc() except it never frees the originally
1209 * allocated buffer. Use this if you don't want to free the buffer immediately
1210 * like, for example, with RCU.
1211 */
1212void *__krealloc(const void *p, size_t new_size, gfp_t flags)
1213{
1214 if (unlikely(!new_size))
1215 return ZERO_SIZE_PTR;
1216
1217 return __do_krealloc(p, new_size, flags);
1218
1219}
1220EXPORT_SYMBOL(__krealloc);
1221
1222/**
1223 * krealloc - reallocate memory. The contents will remain unchanged.
1224 * @p: object to reallocate memory for.
1225 * @new_size: how many bytes of memory are required.
1226 * @flags: the type of memory to allocate.
1227 *
1228 * The contents of the object pointed to are preserved up to the
1229 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1230 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1231 * %NULL pointer, the object pointed to is freed.
1232 */
1233void *krealloc(const void *p, size_t new_size, gfp_t flags)
1234{
1235 void *ret;
1236
1237 if (unlikely(!new_size)) {
1238 kfree(p);
1239 return ZERO_SIZE_PTR;
1240 }
1241
1242 ret = __do_krealloc(p, new_size, flags);
1243 if (ret && p != ret)
1244 kfree(p);
1245
1246 return ret;
1247}
1248EXPORT_SYMBOL(krealloc);
1249
1250/**
1251 * kzfree - like kfree but zero memory
1252 * @p: object to free memory of
1253 *
1254 * The memory of the object @p points to is zeroed before freed.
1255 * If @p is %NULL, kzfree() does nothing.
1256 *
1257 * Note: this function zeroes the whole allocated buffer which can be a good
1258 * deal bigger than the requested buffer size passed to kmalloc(). So be
1259 * careful when using this function in performance sensitive code.
1260 */
1261void kzfree(const void *p)
1262{
1263 size_t ks;
1264 void *mem = (void *)p;
1265
1266 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1267 return;
1268 ks = ksize(mem);
1269 memset(mem, 0, ks);
1270 kfree(mem);
1271}
1272EXPORT_SYMBOL(kzfree);
1273
1274/* Tracepoints definitions. */
1275EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1276EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1277EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1278EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1279EXPORT_TRACEPOINT_SYMBOL(kfree);
1280EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);