blob: 71f0b28a1bec8bc58a479f7c53343b647bcf5f24 [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 | \
Alexander Potapenko7ed2f9e2016-03-25 14:21:59 -070038 SLAB_FAILSLAB | SLAB_KASAN)
Joonsoo Kim423c9292014-10-09 15:26:22 -070039
Vladimir Davydov230e9fc2016-01-14 15:18:15 -080040#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \
41 SLAB_NOTRACK | SLAB_ACCOUNT)
Joonsoo Kim423c9292014-10-09 15:26:22 -070042
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
Christoph Lameter484748f2015-09-04 15:45:34 -0700108void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p)
109{
110 size_t i;
111
Jesper Dangaard Brouerca257192016-03-15 14:54:00 -0700112 for (i = 0; i < nr; i++) {
113 if (s)
114 kmem_cache_free(s, p[i]);
115 else
116 kfree(p[i]);
117 }
Christoph Lameter484748f2015-09-04 15:45:34 -0700118}
119
Jesper Dangaard Brouer865762a2015-11-20 15:57:58 -0800120int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
Christoph Lameter484748f2015-09-04 15:45:34 -0700121 void **p)
122{
123 size_t i;
124
125 for (i = 0; i < nr; i++) {
126 void *x = p[i] = kmem_cache_alloc(s, flags);
127 if (!x) {
128 __kmem_cache_free_bulk(s, i, p);
Jesper Dangaard Brouer865762a2015-11-20 15:57:58 -0800129 return 0;
Christoph Lameter484748f2015-09-04 15:45:34 -0700130 }
131 }
Jesper Dangaard Brouer865762a2015-11-20 15:57:58 -0800132 return i;
Christoph Lameter484748f2015-09-04 15:45:34 -0700133}
134
Johannes Weiner127424c2016-01-20 15:02:32 -0800135#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800136void slab_init_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700137{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800138 s->memcg_params.is_root_cache = true;
Vladimir Davydov426589f2015-02-12 14:59:23 -0800139 INIT_LIST_HEAD(&s->memcg_params.list);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800140 RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
141}
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700142
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800143static int init_memcg_params(struct kmem_cache *s,
144 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
145{
146 struct memcg_cache_array *arr;
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700147
148 if (memcg) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800149 s->memcg_params.is_root_cache = false;
150 s->memcg_params.memcg = memcg;
151 s->memcg_params.root_cache = root_cache;
152 return 0;
153 }
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700154
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800155 slab_init_memcg_params(s);
156
157 if (!memcg_nr_cache_ids)
158 return 0;
159
160 arr = kzalloc(sizeof(struct memcg_cache_array) +
161 memcg_nr_cache_ids * sizeof(void *),
162 GFP_KERNEL);
163 if (!arr)
164 return -ENOMEM;
165
166 RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700167 return 0;
168}
169
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800170static void destroy_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700171{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800172 if (is_root_cache(s))
173 kfree(rcu_access_pointer(s->memcg_params.memcg_caches));
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700174}
175
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800176static int update_memcg_params(struct kmem_cache *s, int new_array_size)
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700177{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800178 struct memcg_cache_array *old, *new;
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700179
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800180 if (!is_root_cache(s))
181 return 0;
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700182
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800183 new = kzalloc(sizeof(struct memcg_cache_array) +
184 new_array_size * sizeof(void *), GFP_KERNEL);
185 if (!new)
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700186 return -ENOMEM;
187
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800188 old = rcu_dereference_protected(s->memcg_params.memcg_caches,
189 lockdep_is_held(&slab_mutex));
190 if (old)
191 memcpy(new->entries, old->entries,
192 memcg_nr_cache_ids * sizeof(void *));
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700193
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800194 rcu_assign_pointer(s->memcg_params.memcg_caches, new);
195 if (old)
196 kfree_rcu(old, rcu);
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700197 return 0;
198}
199
Glauber Costa55007d82012-12-18 14:22:38 -0800200int memcg_update_all_caches(int num_memcgs)
201{
202 struct kmem_cache *s;
203 int ret = 0;
Glauber Costa55007d82012-12-18 14:22:38 -0800204
Vladimir Davydov05257a12015-02-12 14:59:01 -0800205 mutex_lock(&slab_mutex);
Glauber Costa55007d82012-12-18 14:22:38 -0800206 list_for_each_entry(s, &slab_caches, list) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800207 ret = update_memcg_params(s, num_memcgs);
Glauber Costa55007d82012-12-18 14:22:38 -0800208 /*
Glauber Costa55007d82012-12-18 14:22:38 -0800209 * Instead of freeing the memory, we'll just leave the caches
210 * up to this point in an updated state.
211 */
212 if (ret)
Vladimir Davydov05257a12015-02-12 14:59:01 -0800213 break;
Glauber Costa55007d82012-12-18 14:22:38 -0800214 }
Glauber Costa55007d82012-12-18 14:22:38 -0800215 mutex_unlock(&slab_mutex);
216 return ret;
217}
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700218#else
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800219static inline int init_memcg_params(struct kmem_cache *s,
220 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700221{
222 return 0;
223}
224
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800225static inline void destroy_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700226{
227}
Johannes Weiner127424c2016-01-20 15:02:32 -0800228#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
Glauber Costa55007d82012-12-18 14:22:38 -0800229
Christoph Lameter039363f2012-07-06 15:25:10 -0500230/*
Joonsoo Kim423c9292014-10-09 15:26:22 -0700231 * Find a mergeable slab cache
232 */
233int slab_unmergeable(struct kmem_cache *s)
234{
235 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
236 return 1;
237
238 if (!is_root_cache(s))
239 return 1;
240
241 if (s->ctor)
242 return 1;
243
244 /*
245 * We may have set a slab to be unmergeable during bootstrap.
246 */
247 if (s->refcount < 0)
248 return 1;
249
250 return 0;
251}
252
253struct kmem_cache *find_mergeable(size_t size, size_t align,
254 unsigned long flags, const char *name, void (*ctor)(void *))
255{
256 struct kmem_cache *s;
257
258 if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
259 return NULL;
260
261 if (ctor)
262 return NULL;
263
264 size = ALIGN(size, sizeof(void *));
265 align = calculate_alignment(flags, align, size);
266 size = ALIGN(size, align);
267 flags = kmem_cache_flags(size, flags, name, NULL);
268
Joonsoo Kim54362052014-12-10 15:42:18 -0800269 list_for_each_entry_reverse(s, &slab_caches, list) {
Joonsoo Kim423c9292014-10-09 15:26:22 -0700270 if (slab_unmergeable(s))
271 continue;
272
273 if (size > s->size)
274 continue;
275
276 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
277 continue;
278 /*
279 * Check if alignment is compatible.
280 * Courtesy of Adrian Drzewiecki
281 */
282 if ((s->size & ~(align - 1)) != s->size)
283 continue;
284
285 if (s->size - size >= sizeof(void *))
286 continue;
287
Joonsoo Kim95069ac82014-11-13 15:19:25 -0800288 if (IS_ENABLED(CONFIG_SLAB) && align &&
289 (align > s->align || s->align % align))
290 continue;
291
Joonsoo Kim423c9292014-10-09 15:26:22 -0700292 return s;
293 }
294 return NULL;
295}
296
297/*
Christoph Lameter45906852012-11-28 16:23:16 +0000298 * Figure out what the alignment of the objects will be given a set of
299 * flags, a user specified alignment and the size of the objects.
300 */
301unsigned long calculate_alignment(unsigned long flags,
302 unsigned long align, unsigned long size)
303{
304 /*
305 * If the user wants hardware cache aligned objects then follow that
306 * suggestion if the object is sufficiently large.
307 *
308 * The hardware cache alignment cannot override the specified
309 * alignment though. If that is greater then use it.
310 */
311 if (flags & SLAB_HWCACHE_ALIGN) {
312 unsigned long ralign = cache_line_size();
313 while (size <= ralign / 2)
314 ralign /= 2;
315 align = max(align, ralign);
316 }
317
318 if (align < ARCH_SLAB_MINALIGN)
319 align = ARCH_SLAB_MINALIGN;
320
321 return ALIGN(align, sizeof(void *));
322}
323
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800324static struct kmem_cache *create_cache(const char *name,
325 size_t object_size, size_t size, size_t align,
326 unsigned long flags, void (*ctor)(void *),
327 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700328{
329 struct kmem_cache *s;
330 int err;
331
332 err = -ENOMEM;
333 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
334 if (!s)
335 goto out;
336
337 s->name = name;
338 s->object_size = object_size;
339 s->size = size;
340 s->align = align;
341 s->ctor = ctor;
342
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800343 err = init_memcg_params(s, memcg, root_cache);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700344 if (err)
345 goto out_free_cache;
346
347 err = __kmem_cache_create(s, flags);
348 if (err)
349 goto out_free_cache;
350
351 s->refcount = 1;
352 list_add(&s->list, &slab_caches);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700353out:
354 if (err)
355 return ERR_PTR(err);
356 return s;
357
358out_free_cache:
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800359 destroy_memcg_params(s);
Vaishali Thakkar7c4da062015-02-10 14:09:40 -0800360 kmem_cache_free(kmem_cache, s);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700361 goto out;
362}
Christoph Lameter45906852012-11-28 16:23:16 +0000363
364/*
Christoph Lameter039363f2012-07-06 15:25:10 -0500365 * kmem_cache_create - Create a cache.
366 * @name: A string which is used in /proc/slabinfo to identify this cache.
367 * @size: The size of objects to be created in this cache.
368 * @align: The required alignment for the objects.
369 * @flags: SLAB flags
370 * @ctor: A constructor for the objects.
371 *
372 * Returns a ptr to the cache on success, NULL on failure.
373 * Cannot be called within a interrupt, but can be interrupted.
374 * The @ctor is run when new pages are allocated by the cache.
375 *
376 * The flags are
377 *
378 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
379 * to catch references to uninitialised memory.
380 *
381 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
382 * for buffer overruns.
383 *
384 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
385 * cacheline. This can be beneficial if you're counting cycles as closely
386 * as davem.
387 */
Glauber Costa2633d7a2012-12-18 14:22:34 -0800388struct kmem_cache *
Vladimir Davydov794b1242014-04-07 15:39:26 -0700389kmem_cache_create(const char *name, size_t size, size_t align,
390 unsigned long flags, void (*ctor)(void *))
Christoph Lameter039363f2012-07-06 15:25:10 -0500391{
Alexandru Moise40911a72015-11-05 18:45:43 -0800392 struct kmem_cache *s = NULL;
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800393 const char *cache_name;
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800394 int err;
Christoph Lameter039363f2012-07-06 15:25:10 -0500395
Pekka Enbergb9205362012-08-16 10:12:18 +0300396 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700397 get_online_mems();
Vladimir Davydov05257a12015-02-12 14:59:01 -0800398 memcg_get_cache_ids();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700399
Pekka Enbergb9205362012-08-16 10:12:18 +0300400 mutex_lock(&slab_mutex);
Christoph Lameter686d5502012-09-05 00:20:33 +0000401
Vladimir Davydov794b1242014-04-07 15:39:26 -0700402 err = kmem_cache_sanity_check(name, size);
Andrew Morton3aa24f52014-10-09 15:25:58 -0700403 if (err) {
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800404 goto out_unlock;
Andrew Morton3aa24f52014-10-09 15:25:58 -0700405 }
Christoph Lameter686d5502012-09-05 00:20:33 +0000406
Glauber Costad8843922012-10-17 15:36:51 +0400407 /*
408 * Some allocators will constraint the set of valid flags to a subset
409 * of all flags. We expect them to define CACHE_CREATE_MASK in this
410 * case, and we'll just provide them with a sanitized version of the
411 * passed flags.
412 */
413 flags &= CACHE_CREATE_MASK;
Christoph Lameter686d5502012-09-05 00:20:33 +0000414
Vladimir Davydov794b1242014-04-07 15:39:26 -0700415 s = __kmem_cache_alias(name, size, align, flags, ctor);
416 if (s)
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800417 goto out_unlock;
Glauber Costa2633d7a2012-12-18 14:22:34 -0800418
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800419 cache_name = kstrdup_const(name, GFP_KERNEL);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700420 if (!cache_name) {
421 err = -ENOMEM;
422 goto out_unlock;
423 }
Glauber Costa2633d7a2012-12-18 14:22:34 -0800424
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800425 s = create_cache(cache_name, size, size,
426 calculate_alignment(flags, align, size),
427 flags, ctor, NULL, NULL);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700428 if (IS_ERR(s)) {
429 err = PTR_ERR(s);
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800430 kfree_const(cache_name);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700431 }
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800432
433out_unlock:
Christoph Lameter20cea962012-07-06 15:25:13 -0500434 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700435
Vladimir Davydov05257a12015-02-12 14:59:01 -0800436 memcg_put_cache_ids();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700437 put_online_mems();
Christoph Lameter20cea962012-07-06 15:25:13 -0500438 put_online_cpus();
439
Dave Jonesba3253c2014-01-29 14:05:48 -0800440 if (err) {
Christoph Lameter686d5502012-09-05 00:20:33 +0000441 if (flags & SLAB_PANIC)
442 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
443 name, err);
444 else {
Joe Perches11705322016-03-17 14:19:50 -0700445 pr_warn("kmem_cache_create(%s) failed with error %d\n",
Christoph Lameter686d5502012-09-05 00:20:33 +0000446 name, err);
447 dump_stack();
448 }
Christoph Lameter686d5502012-09-05 00:20:33 +0000449 return NULL;
450 }
Christoph Lameter039363f2012-07-06 15:25:10 -0500451 return s;
Glauber Costa2633d7a2012-12-18 14:22:34 -0800452}
Christoph Lameter039363f2012-07-06 15:25:10 -0500453EXPORT_SYMBOL(kmem_cache_create);
Christoph Lameter97d06602012-07-06 15:25:11 -0500454
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800455static int shutdown_cache(struct kmem_cache *s,
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800456 struct list_head *release, bool *need_rcu_barrier)
457{
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800458 if (__kmem_cache_shutdown(s) != 0)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800459 return -EBUSY;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800460
461 if (s->flags & SLAB_DESTROY_BY_RCU)
462 *need_rcu_barrier = true;
463
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800464 list_move(&s->list, release);
465 return 0;
466}
467
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800468static void release_caches(struct list_head *release, bool need_rcu_barrier)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800469{
470 struct kmem_cache *s, *s2;
471
472 if (need_rcu_barrier)
473 rcu_barrier();
474
475 list_for_each_entry_safe(s, s2, release, list) {
476#ifdef SLAB_SUPPORTS_SYSFS
477 sysfs_slab_remove(s);
478#else
479 slab_kmem_cache_release(s);
480#endif
481 }
482}
483
Johannes Weiner127424c2016-01-20 15:02:32 -0800484#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700485/*
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700486 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
Vladimir Davydov794b1242014-04-07 15:39:26 -0700487 * @memcg: The memory cgroup the new cache is for.
488 * @root_cache: The parent of the new cache.
489 *
490 * This function attempts to create a kmem cache that will serve allocation
491 * requests going from @memcg to @root_cache. The new cache inherits properties
492 * from its parent.
493 */
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800494void memcg_create_kmem_cache(struct mem_cgroup *memcg,
495 struct kmem_cache *root_cache)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700496{
Vladimir Davydov3e0350a2015-02-10 14:11:44 -0800497 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
Michal Hocko33398cf2015-09-08 15:01:02 -0700498 struct cgroup_subsys_state *css = &memcg->css;
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800499 struct memcg_cache_array *arr;
Vladimir Davydovbd673142014-06-04 16:07:40 -0700500 struct kmem_cache *s = NULL;
Vladimir Davydov794b1242014-04-07 15:39:26 -0700501 char *cache_name;
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800502 int idx;
Vladimir Davydov794b1242014-04-07 15:39:26 -0700503
504 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700505 get_online_mems();
506
Vladimir Davydov794b1242014-04-07 15:39:26 -0700507 mutex_lock(&slab_mutex);
508
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800509 /*
Johannes Weiner567e9ab2016-01-20 15:02:24 -0800510 * The memory cgroup could have been offlined while the cache
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800511 * creation work was pending.
512 */
Vladimir Davydovb6ecd2d2016-03-17 14:18:33 -0700513 if (memcg->kmem_state != KMEM_ONLINE)
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800514 goto out_unlock;
515
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800516 idx = memcg_cache_id(memcg);
517 arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
518 lockdep_is_held(&slab_mutex));
519
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800520 /*
521 * Since per-memcg caches are created asynchronously on first
522 * allocation (see memcg_kmem_get_cache()), several threads can try to
523 * create the same cache, but only one of them may succeed.
524 */
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800525 if (arr->entries[idx])
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800526 goto out_unlock;
527
Vladimir Davydovf1008362015-02-12 14:59:29 -0800528 cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
Johannes Weiner73f576c2016-07-20 15:44:57 -0700529 cache_name = kasprintf(GFP_KERNEL, "%s(%llu:%s)", root_cache->name,
530 css->serial_nr, memcg_name_buf);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700531 if (!cache_name)
532 goto out_unlock;
533
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800534 s = create_cache(cache_name, root_cache->object_size,
535 root_cache->size, root_cache->align,
536 root_cache->flags, root_cache->ctor,
537 memcg, root_cache);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800538 /*
539 * If we could not create a memcg cache, do not complain, because
540 * that's not critical at all as we can always proceed with the root
541 * cache.
542 */
Vladimir Davydovbd673142014-06-04 16:07:40 -0700543 if (IS_ERR(s)) {
Vladimir Davydov794b1242014-04-07 15:39:26 -0700544 kfree(cache_name);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800545 goto out_unlock;
Vladimir Davydovbd673142014-06-04 16:07:40 -0700546 }
Vladimir Davydov794b1242014-04-07 15:39:26 -0700547
Vladimir Davydov426589f2015-02-12 14:59:23 -0800548 list_add(&s->memcg_params.list, &root_cache->memcg_params.list);
549
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800550 /*
551 * Since readers won't lock (see cache_from_memcg_idx()), we need a
552 * barrier here to ensure nobody will see the kmem_cache partially
553 * initialized.
554 */
555 smp_wmb();
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800556 arr->entries[idx] = s;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800557
Vladimir Davydov794b1242014-04-07 15:39:26 -0700558out_unlock:
559 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700560
561 put_online_mems();
Vladimir Davydov794b1242014-04-07 15:39:26 -0700562 put_online_cpus();
563}
Vladimir Davydovb8529902014-04-07 15:39:28 -0700564
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800565void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
566{
567 int idx;
568 struct memcg_cache_array *arr;
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800569 struct kmem_cache *s, *c;
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800570
571 idx = memcg_cache_id(memcg);
572
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800573 get_online_cpus();
574 get_online_mems();
575
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800576 mutex_lock(&slab_mutex);
577 list_for_each_entry(s, &slab_caches, list) {
578 if (!is_root_cache(s))
579 continue;
580
581 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
582 lockdep_is_held(&slab_mutex));
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800583 c = arr->entries[idx];
584 if (!c)
585 continue;
586
587 __kmem_cache_shrink(c, true);
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800588 arr->entries[idx] = NULL;
589 }
590 mutex_unlock(&slab_mutex);
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800591
592 put_online_mems();
593 put_online_cpus();
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800594}
595
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800596static int __shutdown_memcg_cache(struct kmem_cache *s,
597 struct list_head *release, bool *need_rcu_barrier)
598{
599 BUG_ON(is_root_cache(s));
600
601 if (shutdown_cache(s, release, need_rcu_barrier))
602 return -EBUSY;
603
604 list_del(&s->memcg_params.list);
605 return 0;
606}
607
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800608void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
Vladimir Davydovb8529902014-04-07 15:39:28 -0700609{
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800610 LIST_HEAD(release);
611 bool need_rcu_barrier = false;
612 struct kmem_cache *s, *s2;
Vladimir Davydovb8529902014-04-07 15:39:28 -0700613
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800614 get_online_cpus();
615 get_online_mems();
Vladimir Davydovb8529902014-04-07 15:39:28 -0700616
Vladimir Davydovb8529902014-04-07 15:39:28 -0700617 mutex_lock(&slab_mutex);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800618 list_for_each_entry_safe(s, s2, &slab_caches, list) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800619 if (is_root_cache(s) || s->memcg_params.memcg != memcg)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800620 continue;
621 /*
622 * The cgroup is about to be freed and therefore has no charges
623 * left. Hence, all its caches must be empty by now.
624 */
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800625 BUG_ON(__shutdown_memcg_cache(s, &release, &need_rcu_barrier));
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800626 }
627 mutex_unlock(&slab_mutex);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700628
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800629 put_online_mems();
630 put_online_cpus();
631
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800632 release_caches(&release, need_rcu_barrier);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700633}
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800634
635static int shutdown_memcg_caches(struct kmem_cache *s,
636 struct list_head *release, bool *need_rcu_barrier)
637{
638 struct memcg_cache_array *arr;
639 struct kmem_cache *c, *c2;
640 LIST_HEAD(busy);
641 int i;
642
643 BUG_ON(!is_root_cache(s));
644
645 /*
646 * First, shutdown active caches, i.e. caches that belong to online
647 * memory cgroups.
648 */
649 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
650 lockdep_is_held(&slab_mutex));
651 for_each_memcg_cache_index(i) {
652 c = arr->entries[i];
653 if (!c)
654 continue;
655 if (__shutdown_memcg_cache(c, release, need_rcu_barrier))
656 /*
657 * The cache still has objects. Move it to a temporary
658 * list so as not to try to destroy it for a second
659 * time while iterating over inactive caches below.
660 */
661 list_move(&c->memcg_params.list, &busy);
662 else
663 /*
664 * The cache is empty and will be destroyed soon. Clear
665 * the pointer to it in the memcg_caches array so that
666 * it will never be accessed even if the root cache
667 * stays alive.
668 */
669 arr->entries[i] = NULL;
670 }
671
672 /*
673 * Second, shutdown all caches left from memory cgroups that are now
674 * offline.
675 */
676 list_for_each_entry_safe(c, c2, &s->memcg_params.list,
677 memcg_params.list)
678 __shutdown_memcg_cache(c, release, need_rcu_barrier);
679
680 list_splice(&busy, &s->memcg_params.list);
681
682 /*
683 * A cache being destroyed must be empty. In particular, this means
684 * that all per memcg caches attached to it must be empty too.
685 */
686 if (!list_empty(&s->memcg_params.list))
687 return -EBUSY;
688 return 0;
689}
690#else
691static inline int shutdown_memcg_caches(struct kmem_cache *s,
692 struct list_head *release, bool *need_rcu_barrier)
693{
694 return 0;
695}
Johannes Weiner127424c2016-01-20 15:02:32 -0800696#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
Vladimir Davydov794b1242014-04-07 15:39:26 -0700697
Christoph Lameter41a21282014-05-06 12:50:08 -0700698void slab_kmem_cache_release(struct kmem_cache *s)
699{
Dmitry Safonov52b4b952016-02-17 13:11:37 -0800700 __kmem_cache_release(s);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800701 destroy_memcg_params(s);
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800702 kfree_const(s->name);
Christoph Lameter41a21282014-05-06 12:50:08 -0700703 kmem_cache_free(kmem_cache, s);
704}
705
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000706void kmem_cache_destroy(struct kmem_cache *s)
707{
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800708 LIST_HEAD(release);
709 bool need_rcu_barrier = false;
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800710 int err;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800711
Sergey Senozhatsky3942d292015-09-08 15:00:50 -0700712 if (unlikely(!s))
713 return;
714
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000715 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700716 get_online_mems();
717
Alexander Potapenko55834c52016-05-20 16:59:11 -0700718 kasan_cache_destroy(s);
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000719 mutex_lock(&slab_mutex);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700720
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000721 s->refcount--;
Vladimir Davydovb8529902014-04-07 15:39:28 -0700722 if (s->refcount)
723 goto out_unlock;
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000724
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800725 err = shutdown_memcg_caches(s, &release, &need_rcu_barrier);
726 if (!err)
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800727 err = shutdown_cache(s, &release, &need_rcu_barrier);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700728
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800729 if (err) {
Joe Perches756a0252016-03-17 14:19:47 -0700730 pr_err("kmem_cache_destroy %s: Slab cache still has objects\n",
731 s->name);
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800732 dump_stack();
733 }
Vladimir Davydovb8529902014-04-07 15:39:28 -0700734out_unlock:
735 mutex_unlock(&slab_mutex);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800736
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700737 put_online_mems();
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000738 put_online_cpus();
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800739
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800740 release_caches(&release, need_rcu_barrier);
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000741}
742EXPORT_SYMBOL(kmem_cache_destroy);
743
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700744/**
745 * kmem_cache_shrink - Shrink a cache.
746 * @cachep: The cache to shrink.
747 *
748 * Releases as many slabs as possible for a cache.
749 * To help debugging, a zero exit status indicates all slabs were released.
750 */
751int kmem_cache_shrink(struct kmem_cache *cachep)
752{
753 int ret;
754
755 get_online_cpus();
756 get_online_mems();
Alexander Potapenko55834c52016-05-20 16:59:11 -0700757 kasan_cache_shrink(cachep);
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800758 ret = __kmem_cache_shrink(cachep, false);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700759 put_online_mems();
760 put_online_cpus();
761 return ret;
762}
763EXPORT_SYMBOL(kmem_cache_shrink);
764
Denis Kirjanovfda90122015-11-05 18:44:59 -0800765bool slab_is_available(void)
Christoph Lameter97d06602012-07-06 15:25:11 -0500766{
767 return slab_state >= UP;
768}
Glauber Costab7454ad2012-10-19 18:20:25 +0400769
Christoph Lameter45530c42012-11-28 16:23:07 +0000770#ifndef CONFIG_SLOB
771/* Create a cache during boot when no slab services are available yet */
772void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
773 unsigned long flags)
774{
775 int err;
776
777 s->name = name;
778 s->size = s->object_size = size;
Christoph Lameter45906852012-11-28 16:23:16 +0000779 s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800780
781 slab_init_memcg_params(s);
782
Christoph Lameter45530c42012-11-28 16:23:07 +0000783 err = __kmem_cache_create(s, flags);
784
785 if (err)
Christoph Lameter31ba7342013-01-10 19:00:53 +0000786 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
Christoph Lameter45530c42012-11-28 16:23:07 +0000787 name, size, err);
788
789 s->refcount = -1; /* Exempt from merging for now */
790}
791
792struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
793 unsigned long flags)
794{
795 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
796
797 if (!s)
798 panic("Out of memory when creating slab %s\n", name);
799
800 create_boot_cache(s, name, size, flags);
801 list_add(&s->list, &slab_caches);
802 s->refcount = 1;
803 return s;
804}
805
Christoph Lameter9425c582013-01-10 19:12:17 +0000806struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
807EXPORT_SYMBOL(kmalloc_caches);
808
809#ifdef CONFIG_ZONE_DMA
810struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
811EXPORT_SYMBOL(kmalloc_dma_caches);
812#endif
813
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000814/*
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000815 * Conversion table for small slabs sizes / 8 to the index in the
816 * kmalloc array. This is necessary for slabs < 192 since we have non power
817 * of two cache sizes there. The size of larger slabs can be determined using
818 * fls.
819 */
820static s8 size_index[24] = {
821 3, /* 8 */
822 4, /* 16 */
823 5, /* 24 */
824 5, /* 32 */
825 6, /* 40 */
826 6, /* 48 */
827 6, /* 56 */
828 6, /* 64 */
829 1, /* 72 */
830 1, /* 80 */
831 1, /* 88 */
832 1, /* 96 */
833 7, /* 104 */
834 7, /* 112 */
835 7, /* 120 */
836 7, /* 128 */
837 2, /* 136 */
838 2, /* 144 */
839 2, /* 152 */
840 2, /* 160 */
841 2, /* 168 */
842 2, /* 176 */
843 2, /* 184 */
844 2 /* 192 */
845};
846
847static inline int size_index_elem(size_t bytes)
848{
849 return (bytes - 1) / 8;
850}
851
852/*
853 * Find the kmem_cache structure that serves a given size of
854 * allocation
855 */
856struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
857{
858 int index;
859
Joonsoo Kim9de1bc82013-08-02 11:02:42 +0900860 if (unlikely(size > KMALLOC_MAX_SIZE)) {
Sasha Levin907985f2013-06-10 15:18:00 -0400861 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
Christoph Lameter6286ae92013-05-03 15:43:18 +0000862 return NULL;
Sasha Levin907985f2013-06-10 15:18:00 -0400863 }
Christoph Lameter6286ae92013-05-03 15:43:18 +0000864
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000865 if (size <= 192) {
866 if (!size)
867 return ZERO_SIZE_PTR;
868
869 index = size_index[size_index_elem(size)];
870 } else
871 index = fls(size - 1);
872
873#ifdef CONFIG_ZONE_DMA
Joonsoo Kimb1e05412013-02-04 23:46:46 +0900874 if (unlikely((flags & GFP_DMA)))
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000875 return kmalloc_dma_caches[index];
876
877#endif
878 return kmalloc_caches[index];
879}
880
881/*
Gavin Guo4066c332015-06-24 16:55:54 -0700882 * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
883 * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
884 * kmalloc-67108864.
885 */
886static struct {
887 const char *name;
888 unsigned long size;
889} const kmalloc_info[] __initconst = {
890 {NULL, 0}, {"kmalloc-96", 96},
891 {"kmalloc-192", 192}, {"kmalloc-8", 8},
892 {"kmalloc-16", 16}, {"kmalloc-32", 32},
893 {"kmalloc-64", 64}, {"kmalloc-128", 128},
894 {"kmalloc-256", 256}, {"kmalloc-512", 512},
895 {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048},
896 {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192},
897 {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768},
898 {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072},
899 {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288},
900 {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152},
901 {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608},
902 {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432},
903 {"kmalloc-67108864", 67108864}
904};
905
906/*
Daniel Sanders34cc6992015-06-24 16:55:57 -0700907 * Patch up the size_index table if we have strange large alignment
908 * requirements for the kmalloc array. This is only the case for
909 * MIPS it seems. The standard arches will not generate any code here.
910 *
911 * Largest permitted alignment is 256 bytes due to the way we
912 * handle the index determination for the smaller caches.
913 *
914 * Make sure that nothing crazy happens if someone starts tinkering
915 * around with ARCH_KMALLOC_MINALIGN
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000916 */
Daniel Sanders34cc6992015-06-24 16:55:57 -0700917void __init setup_kmalloc_cache_index_table(void)
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000918{
919 int i;
920
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000921 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
922 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
923
924 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
925 int elem = size_index_elem(i);
926
927 if (elem >= ARRAY_SIZE(size_index))
928 break;
929 size_index[elem] = KMALLOC_SHIFT_LOW;
930 }
931
932 if (KMALLOC_MIN_SIZE >= 64) {
933 /*
934 * The 96 byte size cache is not used if the alignment
935 * is 64 byte.
936 */
937 for (i = 64 + 8; i <= 96; i += 8)
938 size_index[size_index_elem(i)] = 7;
939
940 }
941
942 if (KMALLOC_MIN_SIZE >= 128) {
943 /*
944 * The 192 byte sized cache is not used if the alignment
945 * is 128 byte. Redirect kmalloc to use the 256 byte cache
946 * instead.
947 */
948 for (i = 128 + 8; i <= 192; i += 8)
949 size_index[size_index_elem(i)] = 8;
950 }
Daniel Sanders34cc6992015-06-24 16:55:57 -0700951}
952
Christoph Lameterae6f2462015-06-30 09:01:11 -0500953static void __init new_kmalloc_cache(int idx, unsigned long flags)
Christoph Lametera9730fc2015-06-29 09:28:08 -0500954{
955 kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name,
956 kmalloc_info[idx].size, flags);
957}
958
Daniel Sanders34cc6992015-06-24 16:55:57 -0700959/*
960 * Create the kmalloc array. Some of the regular kmalloc arrays
961 * may already have been created because they were needed to
962 * enable allocations for slab creation.
963 */
964void __init create_kmalloc_caches(unsigned long flags)
965{
966 int i;
967
Christoph Lametera9730fc2015-06-29 09:28:08 -0500968 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
969 if (!kmalloc_caches[i])
970 new_kmalloc_cache(i, flags);
Chris Mason956e46e2013-05-08 15:56:28 -0400971
972 /*
Christoph Lametera9730fc2015-06-29 09:28:08 -0500973 * Caches that are not of the two-to-the-power-of size.
974 * These have to be created immediately after the
975 * earlier power of two caches
Chris Mason956e46e2013-05-08 15:56:28 -0400976 */
Christoph Lametera9730fc2015-06-29 09:28:08 -0500977 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
978 new_kmalloc_cache(1, flags);
979 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
980 new_kmalloc_cache(2, flags);
Christoph Lameter8a965b32013-05-03 18:04:18 +0000981 }
982
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000983 /* Kmalloc array is now usable */
984 slab_state = UP;
985
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000986#ifdef CONFIG_ZONE_DMA
987 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
988 struct kmem_cache *s = kmalloc_caches[i];
989
990 if (s) {
991 int size = kmalloc_size(i);
992 char *n = kasprintf(GFP_NOWAIT,
993 "dma-kmalloc-%d", size);
994
995 BUG_ON(!n);
996 kmalloc_dma_caches[i] = create_kmalloc_cache(n,
997 size, SLAB_CACHE_DMA | flags);
998 }
999 }
1000#endif
1001}
Christoph Lameter45530c42012-11-28 16:23:07 +00001002#endif /* !CONFIG_SLOB */
1003
Vladimir Davydovcea371f2014-06-04 16:07:04 -07001004/*
1005 * To avoid unnecessary overhead, we pass through large allocation requests
1006 * directly to the page allocator. We use __GFP_COMP, because we will need to
1007 * know the allocation order to free the pages properly in kfree.
1008 */
Vladimir Davydov52383432014-06-04 16:06:39 -07001009void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
1010{
1011 void *ret;
1012 struct page *page;
1013
1014 flags |= __GFP_COMP;
Vladimir Davydov49491482016-07-26 15:24:24 -07001015 page = alloc_pages(flags, order);
Vladimir Davydov52383432014-06-04 16:06:39 -07001016 ret = page ? page_address(page) : NULL;
1017 kmemleak_alloc(ret, size, 1, flags);
Alexander Potapenko505f5dc2016-03-25 14:22:02 -07001018 kasan_kmalloc_large(ret, size, flags);
Vladimir Davydov52383432014-06-04 16:06:39 -07001019 return ret;
1020}
1021EXPORT_SYMBOL(kmalloc_order);
1022
Christoph Lameterf1b6eb62013-09-04 16:35:34 +00001023#ifdef CONFIG_TRACING
1024void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
1025{
1026 void *ret = kmalloc_order(size, flags, order);
1027 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
1028 return ret;
1029}
1030EXPORT_SYMBOL(kmalloc_order_trace);
1031#endif
Christoph Lameter45530c42012-11-28 16:23:07 +00001032
Thomas Garnier7c00fce2016-07-26 15:21:56 -07001033#ifdef CONFIG_SLAB_FREELIST_RANDOM
1034/* Randomize a generic freelist */
1035static void freelist_randomize(struct rnd_state *state, unsigned int *list,
1036 size_t count)
1037{
1038 size_t i;
1039 unsigned int rand;
1040
1041 for (i = 0; i < count; i++)
1042 list[i] = i;
1043
1044 /* Fisher-Yates shuffle */
1045 for (i = count - 1; i > 0; i--) {
1046 rand = prandom_u32_state(state);
1047 rand %= (i + 1);
1048 swap(list[i], list[rand]);
1049 }
1050}
1051
1052/* Create a random sequence per cache */
1053int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
1054 gfp_t gfp)
1055{
1056 struct rnd_state state;
1057
1058 if (count < 2 || cachep->random_seq)
1059 return 0;
1060
1061 cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
1062 if (!cachep->random_seq)
1063 return -ENOMEM;
1064
1065 /* Get best entropy at this stage of boot */
1066 prandom_seed_state(&state, get_random_long());
1067
1068 freelist_randomize(&state, cachep->random_seq, count);
1069 return 0;
1070}
1071
1072/* Destroy the per-cache random freelist sequence */
1073void cache_random_seq_destroy(struct kmem_cache *cachep)
1074{
1075 kfree(cachep->random_seq);
1076 cachep->random_seq = NULL;
1077}
1078#endif /* CONFIG_SLAB_FREELIST_RANDOM */
1079
Glauber Costab7454ad2012-10-19 18:20:25 +04001080#ifdef CONFIG_SLABINFO
Wanpeng Lie9b4db22013-07-04 08:33:24 +08001081
1082#ifdef CONFIG_SLAB
1083#define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
1084#else
1085#define SLABINFO_RIGHTS S_IRUSR
1086#endif
1087
Vladimir Davydovb0475012014-12-10 15:44:19 -08001088static void print_slabinfo_header(struct seq_file *m)
Glauber Costabcee6e22012-10-19 18:20:26 +04001089{
1090 /*
1091 * Output format version, so at least we can change it
1092 * without _too_ many complaints.
1093 */
1094#ifdef CONFIG_DEBUG_SLAB
1095 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
1096#else
1097 seq_puts(m, "slabinfo - version: 2.1\n");
1098#endif
Joe Perches756a0252016-03-17 14:19:47 -07001099 seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
Glauber Costabcee6e22012-10-19 18:20:26 +04001100 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
1101 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
1102#ifdef CONFIG_DEBUG_SLAB
Joe Perches756a0252016-03-17 14:19:47 -07001103 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
Glauber Costabcee6e22012-10-19 18:20:26 +04001104 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
1105#endif
1106 seq_putc(m, '\n');
1107}
1108
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001109void *slab_start(struct seq_file *m, loff_t *pos)
Glauber Costab7454ad2012-10-19 18:20:25 +04001110{
Glauber Costab7454ad2012-10-19 18:20:25 +04001111 mutex_lock(&slab_mutex);
Glauber Costab7454ad2012-10-19 18:20:25 +04001112 return seq_list_start(&slab_caches, *pos);
1113}
1114
Wanpeng Li276a2432013-07-08 08:08:28 +08001115void *slab_next(struct seq_file *m, void *p, loff_t *pos)
Glauber Costab7454ad2012-10-19 18:20:25 +04001116{
1117 return seq_list_next(p, &slab_caches, pos);
1118}
1119
Wanpeng Li276a2432013-07-08 08:08:28 +08001120void slab_stop(struct seq_file *m, void *p)
Glauber Costab7454ad2012-10-19 18:20:25 +04001121{
1122 mutex_unlock(&slab_mutex);
1123}
1124
Glauber Costa749c5412012-12-18 14:23:01 -08001125static void
1126memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
Glauber Costab7454ad2012-10-19 18:20:25 +04001127{
Glauber Costa749c5412012-12-18 14:23:01 -08001128 struct kmem_cache *c;
1129 struct slabinfo sinfo;
Glauber Costa749c5412012-12-18 14:23:01 -08001130
1131 if (!is_root_cache(s))
1132 return;
1133
Vladimir Davydov426589f2015-02-12 14:59:23 -08001134 for_each_memcg_cache(c, s) {
Glauber Costa749c5412012-12-18 14:23:01 -08001135 memset(&sinfo, 0, sizeof(sinfo));
1136 get_slabinfo(c, &sinfo);
1137
1138 info->active_slabs += sinfo.active_slabs;
1139 info->num_slabs += sinfo.num_slabs;
1140 info->shared_avail += sinfo.shared_avail;
1141 info->active_objs += sinfo.active_objs;
1142 info->num_objs += sinfo.num_objs;
1143 }
1144}
1145
Vladimir Davydovb0475012014-12-10 15:44:19 -08001146static void cache_show(struct kmem_cache *s, struct seq_file *m)
Glauber Costa749c5412012-12-18 14:23:01 -08001147{
Glauber Costa0d7561c2012-10-19 18:20:27 +04001148 struct slabinfo sinfo;
1149
1150 memset(&sinfo, 0, sizeof(sinfo));
1151 get_slabinfo(s, &sinfo);
1152
Glauber Costa749c5412012-12-18 14:23:01 -08001153 memcg_accumulate_slabinfo(s, &sinfo);
1154
Glauber Costa0d7561c2012-10-19 18:20:27 +04001155 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
Glauber Costa749c5412012-12-18 14:23:01 -08001156 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
Glauber Costa0d7561c2012-10-19 18:20:27 +04001157 sinfo.objects_per_slab, (1 << sinfo.cache_order));
1158
1159 seq_printf(m, " : tunables %4u %4u %4u",
1160 sinfo.limit, sinfo.batchcount, sinfo.shared);
1161 seq_printf(m, " : slabdata %6lu %6lu %6lu",
1162 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1163 slabinfo_show_stats(m, s);
1164 seq_putc(m, '\n');
Glauber Costab7454ad2012-10-19 18:20:25 +04001165}
1166
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001167static int slab_show(struct seq_file *m, void *p)
Glauber Costa749c5412012-12-18 14:23:01 -08001168{
1169 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1170
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001171 if (p == slab_caches.next)
1172 print_slabinfo_header(m);
Vladimir Davydovb0475012014-12-10 15:44:19 -08001173 if (is_root_cache(s))
1174 cache_show(s, m);
1175 return 0;
Glauber Costa749c5412012-12-18 14:23:01 -08001176}
1177
Johannes Weiner127424c2016-01-20 15:02:32 -08001178#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
Vladimir Davydovb0475012014-12-10 15:44:19 -08001179int memcg_slab_show(struct seq_file *m, void *p)
1180{
1181 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1182 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
1183
1184 if (p == slab_caches.next)
1185 print_slabinfo_header(m);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -08001186 if (!is_root_cache(s) && s->memcg_params.memcg == memcg)
Vladimir Davydovb0475012014-12-10 15:44:19 -08001187 cache_show(s, m);
1188 return 0;
1189}
1190#endif
1191
Glauber Costab7454ad2012-10-19 18:20:25 +04001192/*
1193 * slabinfo_op - iterator that generates /proc/slabinfo
1194 *
1195 * Output layout:
1196 * cache-name
1197 * num-active-objs
1198 * total-objs
1199 * object size
1200 * num-active-slabs
1201 * total-slabs
1202 * num-pages-per-slab
1203 * + further values on SMP and with statistics enabled
1204 */
1205static const struct seq_operations slabinfo_op = {
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001206 .start = slab_start,
Wanpeng Li276a2432013-07-08 08:08:28 +08001207 .next = slab_next,
1208 .stop = slab_stop,
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001209 .show = slab_show,
Glauber Costab7454ad2012-10-19 18:20:25 +04001210};
1211
1212static int slabinfo_open(struct inode *inode, struct file *file)
1213{
1214 return seq_open(file, &slabinfo_op);
1215}
1216
1217static const struct file_operations proc_slabinfo_operations = {
1218 .open = slabinfo_open,
1219 .read = seq_read,
1220 .write = slabinfo_write,
1221 .llseek = seq_lseek,
1222 .release = seq_release,
1223};
1224
1225static int __init slab_proc_init(void)
1226{
Wanpeng Lie9b4db22013-07-04 08:33:24 +08001227 proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
1228 &proc_slabinfo_operations);
Glauber Costab7454ad2012-10-19 18:20:25 +04001229 return 0;
1230}
1231module_init(slab_proc_init);
1232#endif /* CONFIG_SLABINFO */
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001233
1234static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1235 gfp_t flags)
1236{
1237 void *ret;
1238 size_t ks = 0;
1239
1240 if (p)
1241 ks = ksize(p);
1242
Andrey Ryabinin0316bec2015-02-13 14:39:42 -08001243 if (ks >= new_size) {
Alexander Potapenko505f5dc2016-03-25 14:22:02 -07001244 kasan_krealloc((void *)p, new_size, flags);
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001245 return (void *)p;
Andrey Ryabinin0316bec2015-02-13 14:39:42 -08001246 }
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001247
1248 ret = kmalloc_track_caller(new_size, flags);
1249 if (ret && p)
1250 memcpy(ret, p, ks);
1251
1252 return ret;
1253}
1254
1255/**
1256 * __krealloc - like krealloc() but don't free @p.
1257 * @p: object to reallocate memory for.
1258 * @new_size: how many bytes of memory are required.
1259 * @flags: the type of memory to allocate.
1260 *
1261 * This function is like krealloc() except it never frees the originally
1262 * allocated buffer. Use this if you don't want to free the buffer immediately
1263 * like, for example, with RCU.
1264 */
1265void *__krealloc(const void *p, size_t new_size, gfp_t flags)
1266{
1267 if (unlikely(!new_size))
1268 return ZERO_SIZE_PTR;
1269
1270 return __do_krealloc(p, new_size, flags);
1271
1272}
1273EXPORT_SYMBOL(__krealloc);
1274
1275/**
1276 * krealloc - reallocate memory. The contents will remain unchanged.
1277 * @p: object to reallocate memory for.
1278 * @new_size: how many bytes of memory are required.
1279 * @flags: the type of memory to allocate.
1280 *
1281 * The contents of the object pointed to are preserved up to the
1282 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1283 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1284 * %NULL pointer, the object pointed to is freed.
1285 */
1286void *krealloc(const void *p, size_t new_size, gfp_t flags)
1287{
1288 void *ret;
1289
1290 if (unlikely(!new_size)) {
1291 kfree(p);
1292 return ZERO_SIZE_PTR;
1293 }
1294
1295 ret = __do_krealloc(p, new_size, flags);
1296 if (ret && p != ret)
1297 kfree(p);
1298
1299 return ret;
1300}
1301EXPORT_SYMBOL(krealloc);
1302
1303/**
1304 * kzfree - like kfree but zero memory
1305 * @p: object to free memory of
1306 *
1307 * The memory of the object @p points to is zeroed before freed.
1308 * If @p is %NULL, kzfree() does nothing.
1309 *
1310 * Note: this function zeroes the whole allocated buffer which can be a good
1311 * deal bigger than the requested buffer size passed to kmalloc(). So be
1312 * careful when using this function in performance sensitive code.
1313 */
1314void kzfree(const void *p)
1315{
1316 size_t ks;
1317 void *mem = (void *)p;
1318
1319 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1320 return;
1321 ks = ksize(mem);
1322 memset(mem, 0, ks);
1323 kfree(mem);
1324}
1325EXPORT_SYMBOL(kzfree);
1326
1327/* Tracepoints definitions. */
1328EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1329EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1330EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1331EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1332EXPORT_TRACEPOINT_SYMBOL(kfree);
1333EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);