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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
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
112 for (i = 0; i < nr; i++)
113 kmem_cache_free(s, p[i]);
114}
115
Jesper Dangaard Brouer865762a2015-11-20 15:57:58 -0800116int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
Christoph Lameter484748f2015-09-04 15:45:34 -0700117 void **p)
118{
119 size_t i;
120
121 for (i = 0; i < nr; i++) {
122 void *x = p[i] = kmem_cache_alloc(s, flags);
123 if (!x) {
124 __kmem_cache_free_bulk(s, i, p);
Jesper Dangaard Brouer865762a2015-11-20 15:57:58 -0800125 return 0;
Christoph Lameter484748f2015-09-04 15:45:34 -0700126 }
127 }
Jesper Dangaard Brouer865762a2015-11-20 15:57:58 -0800128 return i;
Christoph Lameter484748f2015-09-04 15:45:34 -0700129}
130
Johannes Weiner127424c2016-01-20 15:02:32 -0800131#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800132void slab_init_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700133{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800134 s->memcg_params.is_root_cache = true;
Vladimir Davydov426589f2015-02-12 14:59:23 -0800135 INIT_LIST_HEAD(&s->memcg_params.list);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800136 RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
137}
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700138
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800139static int init_memcg_params(struct kmem_cache *s,
140 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
141{
142 struct memcg_cache_array *arr;
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700143
144 if (memcg) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800145 s->memcg_params.is_root_cache = false;
146 s->memcg_params.memcg = memcg;
147 s->memcg_params.root_cache = root_cache;
148 return 0;
149 }
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700150
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800151 slab_init_memcg_params(s);
152
153 if (!memcg_nr_cache_ids)
154 return 0;
155
156 arr = kzalloc(sizeof(struct memcg_cache_array) +
157 memcg_nr_cache_ids * sizeof(void *),
158 GFP_KERNEL);
159 if (!arr)
160 return -ENOMEM;
161
162 RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700163 return 0;
164}
165
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800166static void destroy_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700167{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800168 if (is_root_cache(s))
169 kfree(rcu_access_pointer(s->memcg_params.memcg_caches));
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700170}
171
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800172static int update_memcg_params(struct kmem_cache *s, int new_array_size)
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700173{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800174 struct memcg_cache_array *old, *new;
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700175
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800176 if (!is_root_cache(s))
177 return 0;
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700178
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800179 new = kzalloc(sizeof(struct memcg_cache_array) +
180 new_array_size * sizeof(void *), GFP_KERNEL);
181 if (!new)
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700182 return -ENOMEM;
183
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800184 old = rcu_dereference_protected(s->memcg_params.memcg_caches,
185 lockdep_is_held(&slab_mutex));
186 if (old)
187 memcpy(new->entries, old->entries,
188 memcg_nr_cache_ids * sizeof(void *));
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700189
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800190 rcu_assign_pointer(s->memcg_params.memcg_caches, new);
191 if (old)
192 kfree_rcu(old, rcu);
Vladimir Davydov6f817f42014-10-09 15:28:47 -0700193 return 0;
194}
195
Glauber Costa55007d82012-12-18 14:22:38 -0800196int memcg_update_all_caches(int num_memcgs)
197{
198 struct kmem_cache *s;
199 int ret = 0;
Glauber Costa55007d82012-12-18 14:22:38 -0800200
Vladimir Davydov05257a12015-02-12 14:59:01 -0800201 mutex_lock(&slab_mutex);
Glauber Costa55007d82012-12-18 14:22:38 -0800202 list_for_each_entry(s, &slab_caches, list) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800203 ret = update_memcg_params(s, num_memcgs);
Glauber Costa55007d82012-12-18 14:22:38 -0800204 /*
Glauber Costa55007d82012-12-18 14:22:38 -0800205 * Instead of freeing the memory, we'll just leave the caches
206 * up to this point in an updated state.
207 */
208 if (ret)
Vladimir Davydov05257a12015-02-12 14:59:01 -0800209 break;
Glauber Costa55007d82012-12-18 14:22:38 -0800210 }
Glauber Costa55007d82012-12-18 14:22:38 -0800211 mutex_unlock(&slab_mutex);
212 return ret;
213}
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700214#else
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800215static inline int init_memcg_params(struct kmem_cache *s,
216 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700217{
218 return 0;
219}
220
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800221static inline void destroy_memcg_params(struct kmem_cache *s)
Vladimir Davydov33a690c2014-10-09 15:28:43 -0700222{
223}
Johannes Weiner127424c2016-01-20 15:02:32 -0800224#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
Glauber Costa55007d82012-12-18 14:22:38 -0800225
Christoph Lameter039363f2012-07-06 15:25:10 -0500226/*
Joonsoo Kim423c9292014-10-09 15:26:22 -0700227 * Find a mergeable slab cache
228 */
229int slab_unmergeable(struct kmem_cache *s)
230{
231 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
232 return 1;
233
234 if (!is_root_cache(s))
235 return 1;
236
237 if (s->ctor)
238 return 1;
239
240 /*
241 * We may have set a slab to be unmergeable during bootstrap.
242 */
243 if (s->refcount < 0)
244 return 1;
245
246 return 0;
247}
248
249struct kmem_cache *find_mergeable(size_t size, size_t align,
250 unsigned long flags, const char *name, void (*ctor)(void *))
251{
252 struct kmem_cache *s;
253
254 if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
255 return NULL;
256
257 if (ctor)
258 return NULL;
259
260 size = ALIGN(size, sizeof(void *));
261 align = calculate_alignment(flags, align, size);
262 size = ALIGN(size, align);
263 flags = kmem_cache_flags(size, flags, name, NULL);
264
Joonsoo Kim54362052014-12-10 15:42:18 -0800265 list_for_each_entry_reverse(s, &slab_caches, list) {
Joonsoo Kim423c9292014-10-09 15:26:22 -0700266 if (slab_unmergeable(s))
267 continue;
268
269 if (size > s->size)
270 continue;
271
272 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
273 continue;
274 /*
275 * Check if alignment is compatible.
276 * Courtesy of Adrian Drzewiecki
277 */
278 if ((s->size & ~(align - 1)) != s->size)
279 continue;
280
281 if (s->size - size >= sizeof(void *))
282 continue;
283
Joonsoo Kim95069ac82014-11-13 15:19:25 -0800284 if (IS_ENABLED(CONFIG_SLAB) && align &&
285 (align > s->align || s->align % align))
286 continue;
287
Joonsoo Kim423c9292014-10-09 15:26:22 -0700288 return s;
289 }
290 return NULL;
291}
292
293/*
Christoph Lameter45906852012-11-28 16:23:16 +0000294 * Figure out what the alignment of the objects will be given a set of
295 * flags, a user specified alignment and the size of the objects.
296 */
297unsigned long calculate_alignment(unsigned long flags,
298 unsigned long align, unsigned long size)
299{
300 /*
301 * If the user wants hardware cache aligned objects then follow that
302 * suggestion if the object is sufficiently large.
303 *
304 * The hardware cache alignment cannot override the specified
305 * alignment though. If that is greater then use it.
306 */
307 if (flags & SLAB_HWCACHE_ALIGN) {
308 unsigned long ralign = cache_line_size();
309 while (size <= ralign / 2)
310 ralign /= 2;
311 align = max(align, ralign);
312 }
313
314 if (align < ARCH_SLAB_MINALIGN)
315 align = ARCH_SLAB_MINALIGN;
316
317 return ALIGN(align, sizeof(void *));
318}
319
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800320static struct kmem_cache *create_cache(const char *name,
321 size_t object_size, size_t size, size_t align,
322 unsigned long flags, void (*ctor)(void *),
323 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700324{
325 struct kmem_cache *s;
326 int err;
327
328 err = -ENOMEM;
329 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
330 if (!s)
331 goto out;
332
333 s->name = name;
334 s->object_size = object_size;
335 s->size = size;
336 s->align = align;
337 s->ctor = ctor;
338
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800339 err = init_memcg_params(s, memcg, root_cache);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700340 if (err)
341 goto out_free_cache;
342
343 err = __kmem_cache_create(s, flags);
344 if (err)
345 goto out_free_cache;
346
347 s->refcount = 1;
348 list_add(&s->list, &slab_caches);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700349out:
350 if (err)
351 return ERR_PTR(err);
352 return s;
353
354out_free_cache:
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800355 destroy_memcg_params(s);
Vaishali Thakkar7c4da062015-02-10 14:09:40 -0800356 kmem_cache_free(kmem_cache, s);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700357 goto out;
358}
Christoph Lameter45906852012-11-28 16:23:16 +0000359
360/*
Christoph Lameter039363f2012-07-06 15:25:10 -0500361 * kmem_cache_create - Create a cache.
362 * @name: A string which is used in /proc/slabinfo to identify this cache.
363 * @size: The size of objects to be created in this cache.
364 * @align: The required alignment for the objects.
365 * @flags: SLAB flags
366 * @ctor: A constructor for the objects.
367 *
368 * Returns a ptr to the cache on success, NULL on failure.
369 * Cannot be called within a interrupt, but can be interrupted.
370 * The @ctor is run when new pages are allocated by the cache.
371 *
372 * The flags are
373 *
374 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
375 * to catch references to uninitialised memory.
376 *
377 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
378 * for buffer overruns.
379 *
380 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
381 * cacheline. This can be beneficial if you're counting cycles as closely
382 * as davem.
383 */
Glauber Costa2633d7a2012-12-18 14:22:34 -0800384struct kmem_cache *
Vladimir Davydov794b1242014-04-07 15:39:26 -0700385kmem_cache_create(const char *name, size_t size, size_t align,
386 unsigned long flags, void (*ctor)(void *))
Christoph Lameter039363f2012-07-06 15:25:10 -0500387{
Alexandru Moise40911a72015-11-05 18:45:43 -0800388 struct kmem_cache *s = NULL;
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800389 const char *cache_name;
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800390 int err;
Christoph Lameter039363f2012-07-06 15:25:10 -0500391
Pekka Enbergb9205362012-08-16 10:12:18 +0300392 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700393 get_online_mems();
Vladimir Davydov05257a12015-02-12 14:59:01 -0800394 memcg_get_cache_ids();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700395
Pekka Enbergb9205362012-08-16 10:12:18 +0300396 mutex_lock(&slab_mutex);
Christoph Lameter686d5502012-09-05 00:20:33 +0000397
Vladimir Davydov794b1242014-04-07 15:39:26 -0700398 err = kmem_cache_sanity_check(name, size);
Andrew Morton3aa24f52014-10-09 15:25:58 -0700399 if (err) {
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800400 goto out_unlock;
Andrew Morton3aa24f52014-10-09 15:25:58 -0700401 }
Christoph Lameter686d5502012-09-05 00:20:33 +0000402
Glauber Costad8843922012-10-17 15:36:51 +0400403 /*
404 * Some allocators will constraint the set of valid flags to a subset
405 * of all flags. We expect them to define CACHE_CREATE_MASK in this
406 * case, and we'll just provide them with a sanitized version of the
407 * passed flags.
408 */
409 flags &= CACHE_CREATE_MASK;
Christoph Lameter686d5502012-09-05 00:20:33 +0000410
Vladimir Davydov794b1242014-04-07 15:39:26 -0700411 s = __kmem_cache_alias(name, size, align, flags, ctor);
412 if (s)
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800413 goto out_unlock;
Glauber Costa2633d7a2012-12-18 14:22:34 -0800414
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800415 cache_name = kstrdup_const(name, GFP_KERNEL);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700416 if (!cache_name) {
417 err = -ENOMEM;
418 goto out_unlock;
419 }
Glauber Costa2633d7a2012-12-18 14:22:34 -0800420
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800421 s = create_cache(cache_name, size, size,
422 calculate_alignment(flags, align, size),
423 flags, ctor, NULL, NULL);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700424 if (IS_ERR(s)) {
425 err = PTR_ERR(s);
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800426 kfree_const(cache_name);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700427 }
Vladimir Davydov3965fc32014-01-23 15:52:55 -0800428
429out_unlock:
Christoph Lameter20cea962012-07-06 15:25:13 -0500430 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700431
Vladimir Davydov05257a12015-02-12 14:59:01 -0800432 memcg_put_cache_ids();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700433 put_online_mems();
Christoph Lameter20cea962012-07-06 15:25:13 -0500434 put_online_cpus();
435
Dave Jonesba3253c72014-01-29 14:05:48 -0800436 if (err) {
Christoph Lameter686d5502012-09-05 00:20:33 +0000437 if (flags & SLAB_PANIC)
438 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
439 name, err);
440 else {
441 printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
442 name, err);
443 dump_stack();
444 }
Christoph Lameter686d5502012-09-05 00:20:33 +0000445 return NULL;
446 }
Christoph Lameter039363f2012-07-06 15:25:10 -0500447 return s;
Glauber Costa2633d7a2012-12-18 14:22:34 -0800448}
Christoph Lameter039363f2012-07-06 15:25:10 -0500449EXPORT_SYMBOL(kmem_cache_create);
Christoph Lameter97d06602012-07-06 15:25:11 -0500450
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800451static int shutdown_cache(struct kmem_cache *s,
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800452 struct list_head *release, bool *need_rcu_barrier)
453{
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800454 if (__kmem_cache_shutdown(s) != 0)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800455 return -EBUSY;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800456
457 if (s->flags & SLAB_DESTROY_BY_RCU)
458 *need_rcu_barrier = true;
459
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800460 list_move(&s->list, release);
461 return 0;
462}
463
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800464static void release_caches(struct list_head *release, bool need_rcu_barrier)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800465{
466 struct kmem_cache *s, *s2;
467
468 if (need_rcu_barrier)
469 rcu_barrier();
470
471 list_for_each_entry_safe(s, s2, release, list) {
472#ifdef SLAB_SUPPORTS_SYSFS
473 sysfs_slab_remove(s);
474#else
475 slab_kmem_cache_release(s);
476#endif
477 }
478}
479
Johannes Weiner127424c2016-01-20 15:02:32 -0800480#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700481/*
Vladimir Davydov776ed0f2014-06-04 16:10:02 -0700482 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
Vladimir Davydov794b1242014-04-07 15:39:26 -0700483 * @memcg: The memory cgroup the new cache is for.
484 * @root_cache: The parent of the new cache.
485 *
486 * This function attempts to create a kmem cache that will serve allocation
487 * requests going from @memcg to @root_cache. The new cache inherits properties
488 * from its parent.
489 */
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800490void memcg_create_kmem_cache(struct mem_cgroup *memcg,
491 struct kmem_cache *root_cache)
Vladimir Davydov794b1242014-04-07 15:39:26 -0700492{
Vladimir Davydov3e0350a2015-02-10 14:11:44 -0800493 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
Michal Hocko33398cf2015-09-08 15:01:02 -0700494 struct cgroup_subsys_state *css = &memcg->css;
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800495 struct memcg_cache_array *arr;
Vladimir Davydovbd673142014-06-04 16:07:40 -0700496 struct kmem_cache *s = NULL;
Vladimir Davydov794b1242014-04-07 15:39:26 -0700497 char *cache_name;
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800498 int idx;
Vladimir Davydov794b1242014-04-07 15:39:26 -0700499
500 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700501 get_online_mems();
502
Vladimir Davydov794b1242014-04-07 15:39:26 -0700503 mutex_lock(&slab_mutex);
504
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800505 /*
Johannes Weiner567e9ab2016-01-20 15:02:24 -0800506 * The memory cgroup could have been offlined while the cache
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800507 * creation work was pending.
508 */
Johannes Weiner567e9ab2016-01-20 15:02:24 -0800509 if (!memcg_kmem_online(memcg))
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800510 goto out_unlock;
511
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800512 idx = memcg_cache_id(memcg);
513 arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
514 lockdep_is_held(&slab_mutex));
515
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800516 /*
517 * Since per-memcg caches are created asynchronously on first
518 * allocation (see memcg_kmem_get_cache()), several threads can try to
519 * create the same cache, but only one of them may succeed.
520 */
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800521 if (arr->entries[idx])
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800522 goto out_unlock;
523
Vladimir Davydovf1008362015-02-12 14:59:29 -0800524 cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
Vladimir Davydov073ee1c2014-06-04 16:08:23 -0700525 cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
Vladimir Davydovf1008362015-02-12 14:59:29 -0800526 css->id, memcg_name_buf);
Vladimir Davydov794b1242014-04-07 15:39:26 -0700527 if (!cache_name)
528 goto out_unlock;
529
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800530 s = create_cache(cache_name, root_cache->object_size,
531 root_cache->size, root_cache->align,
532 root_cache->flags, root_cache->ctor,
533 memcg, root_cache);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800534 /*
535 * If we could not create a memcg cache, do not complain, because
536 * that's not critical at all as we can always proceed with the root
537 * cache.
538 */
Vladimir Davydovbd673142014-06-04 16:07:40 -0700539 if (IS_ERR(s)) {
Vladimir Davydov794b1242014-04-07 15:39:26 -0700540 kfree(cache_name);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800541 goto out_unlock;
Vladimir Davydovbd673142014-06-04 16:07:40 -0700542 }
Vladimir Davydov794b1242014-04-07 15:39:26 -0700543
Vladimir Davydov426589f2015-02-12 14:59:23 -0800544 list_add(&s->memcg_params.list, &root_cache->memcg_params.list);
545
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800546 /*
547 * Since readers won't lock (see cache_from_memcg_idx()), we need a
548 * barrier here to ensure nobody will see the kmem_cache partially
549 * initialized.
550 */
551 smp_wmb();
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800552 arr->entries[idx] = s;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800553
Vladimir Davydov794b1242014-04-07 15:39:26 -0700554out_unlock:
555 mutex_unlock(&slab_mutex);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700556
557 put_online_mems();
Vladimir Davydov794b1242014-04-07 15:39:26 -0700558 put_online_cpus();
559}
Vladimir Davydovb8529902014-04-07 15:39:28 -0700560
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800561void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
562{
563 int idx;
564 struct memcg_cache_array *arr;
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800565 struct kmem_cache *s, *c;
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800566
567 idx = memcg_cache_id(memcg);
568
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800569 get_online_cpus();
570 get_online_mems();
571
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800572 mutex_lock(&slab_mutex);
573 list_for_each_entry(s, &slab_caches, list) {
574 if (!is_root_cache(s))
575 continue;
576
577 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
578 lockdep_is_held(&slab_mutex));
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800579 c = arr->entries[idx];
580 if (!c)
581 continue;
582
583 __kmem_cache_shrink(c, true);
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800584 arr->entries[idx] = NULL;
585 }
586 mutex_unlock(&slab_mutex);
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800587
588 put_online_mems();
589 put_online_cpus();
Vladimir Davydov2a4db7e2015-02-12 14:59:32 -0800590}
591
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800592static int __shutdown_memcg_cache(struct kmem_cache *s,
593 struct list_head *release, bool *need_rcu_barrier)
594{
595 BUG_ON(is_root_cache(s));
596
597 if (shutdown_cache(s, release, need_rcu_barrier))
598 return -EBUSY;
599
600 list_del(&s->memcg_params.list);
601 return 0;
602}
603
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800604void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
Vladimir Davydovb8529902014-04-07 15:39:28 -0700605{
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800606 LIST_HEAD(release);
607 bool need_rcu_barrier = false;
608 struct kmem_cache *s, *s2;
Vladimir Davydovb8529902014-04-07 15:39:28 -0700609
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800610 get_online_cpus();
611 get_online_mems();
Vladimir Davydovb8529902014-04-07 15:39:28 -0700612
Vladimir Davydovb8529902014-04-07 15:39:28 -0700613 mutex_lock(&slab_mutex);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800614 list_for_each_entry_safe(s, s2, &slab_caches, list) {
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800615 if (is_root_cache(s) || s->memcg_params.memcg != memcg)
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800616 continue;
617 /*
618 * The cgroup is about to be freed and therefore has no charges
619 * left. Hence, all its caches must be empty by now.
620 */
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800621 BUG_ON(__shutdown_memcg_cache(s, &release, &need_rcu_barrier));
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800622 }
623 mutex_unlock(&slab_mutex);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700624
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800625 put_online_mems();
626 put_online_cpus();
627
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800628 release_caches(&release, need_rcu_barrier);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700629}
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800630
631static int shutdown_memcg_caches(struct kmem_cache *s,
632 struct list_head *release, bool *need_rcu_barrier)
633{
634 struct memcg_cache_array *arr;
635 struct kmem_cache *c, *c2;
636 LIST_HEAD(busy);
637 int i;
638
639 BUG_ON(!is_root_cache(s));
640
641 /*
642 * First, shutdown active caches, i.e. caches that belong to online
643 * memory cgroups.
644 */
645 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
646 lockdep_is_held(&slab_mutex));
647 for_each_memcg_cache_index(i) {
648 c = arr->entries[i];
649 if (!c)
650 continue;
651 if (__shutdown_memcg_cache(c, release, need_rcu_barrier))
652 /*
653 * The cache still has objects. Move it to a temporary
654 * list so as not to try to destroy it for a second
655 * time while iterating over inactive caches below.
656 */
657 list_move(&c->memcg_params.list, &busy);
658 else
659 /*
660 * The cache is empty and will be destroyed soon. Clear
661 * the pointer to it in the memcg_caches array so that
662 * it will never be accessed even if the root cache
663 * stays alive.
664 */
665 arr->entries[i] = NULL;
666 }
667
668 /*
669 * Second, shutdown all caches left from memory cgroups that are now
670 * offline.
671 */
672 list_for_each_entry_safe(c, c2, &s->memcg_params.list,
673 memcg_params.list)
674 __shutdown_memcg_cache(c, release, need_rcu_barrier);
675
676 list_splice(&busy, &s->memcg_params.list);
677
678 /*
679 * A cache being destroyed must be empty. In particular, this means
680 * that all per memcg caches attached to it must be empty too.
681 */
682 if (!list_empty(&s->memcg_params.list))
683 return -EBUSY;
684 return 0;
685}
686#else
687static inline int shutdown_memcg_caches(struct kmem_cache *s,
688 struct list_head *release, bool *need_rcu_barrier)
689{
690 return 0;
691}
Johannes Weiner127424c2016-01-20 15:02:32 -0800692#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
Vladimir Davydov794b1242014-04-07 15:39:26 -0700693
Christoph Lameter41a21282014-05-06 12:50:08 -0700694void slab_kmem_cache_release(struct kmem_cache *s)
695{
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800696 destroy_memcg_params(s);
Andrzej Hajda3dec16e2015-02-13 14:36:38 -0800697 kfree_const(s->name);
Christoph Lameter41a21282014-05-06 12:50:08 -0700698 kmem_cache_free(kmem_cache, s);
699}
700
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000701void kmem_cache_destroy(struct kmem_cache *s)
702{
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800703 LIST_HEAD(release);
704 bool need_rcu_barrier = false;
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800705 int err;
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800706
Sergey Senozhatsky3942d292015-09-08 15:00:50 -0700707 if (unlikely(!s))
708 return;
709
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000710 get_online_cpus();
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700711 get_online_mems();
712
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000713 mutex_lock(&slab_mutex);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700714
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000715 s->refcount--;
Vladimir Davydovb8529902014-04-07 15:39:28 -0700716 if (s->refcount)
717 goto out_unlock;
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000718
Vladimir Davydovd60fdcc2015-11-05 18:45:11 -0800719 err = shutdown_memcg_caches(s, &release, &need_rcu_barrier);
720 if (!err)
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800721 err = shutdown_cache(s, &release, &need_rcu_barrier);
Vladimir Davydovb8529902014-04-07 15:39:28 -0700722
Vladimir Davydovcd918c52015-11-05 18:45:14 -0800723 if (err) {
724 pr_err("kmem_cache_destroy %s: "
725 "Slab cache still has objects\n", s->name);
726 dump_stack();
727 }
Vladimir Davydovb8529902014-04-07 15:39:28 -0700728out_unlock:
729 mutex_unlock(&slab_mutex);
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800730
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700731 put_online_mems();
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000732 put_online_cpus();
Vladimir Davydovd5b3cf72015-02-10 14:11:47 -0800733
Vladimir Davydovc9a77a72015-11-05 18:45:08 -0800734 release_caches(&release, need_rcu_barrier);
Christoph Lameter945cf2b2012-09-04 23:18:33 +0000735}
736EXPORT_SYMBOL(kmem_cache_destroy);
737
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700738/**
739 * kmem_cache_shrink - Shrink a cache.
740 * @cachep: The cache to shrink.
741 *
742 * Releases as many slabs as possible for a cache.
743 * To help debugging, a zero exit status indicates all slabs were released.
744 */
745int kmem_cache_shrink(struct kmem_cache *cachep)
746{
747 int ret;
748
749 get_online_cpus();
750 get_online_mems();
Vladimir Davydovd6e0b7f2015-02-12 14:59:47 -0800751 ret = __kmem_cache_shrink(cachep, false);
Vladimir Davydov03afc0e2014-06-04 16:07:20 -0700752 put_online_mems();
753 put_online_cpus();
754 return ret;
755}
756EXPORT_SYMBOL(kmem_cache_shrink);
757
Denis Kirjanovfda90122015-11-05 18:44:59 -0800758bool slab_is_available(void)
Christoph Lameter97d06602012-07-06 15:25:11 -0500759{
760 return slab_state >= UP;
761}
Glauber Costab7454ad2012-10-19 18:20:25 +0400762
Christoph Lameter45530c42012-11-28 16:23:07 +0000763#ifndef CONFIG_SLOB
764/* Create a cache during boot when no slab services are available yet */
765void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
766 unsigned long flags)
767{
768 int err;
769
770 s->name = name;
771 s->size = s->object_size = size;
Christoph Lameter45906852012-11-28 16:23:16 +0000772 s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -0800773
774 slab_init_memcg_params(s);
775
Christoph Lameter45530c42012-11-28 16:23:07 +0000776 err = __kmem_cache_create(s, flags);
777
778 if (err)
Christoph Lameter31ba7342013-01-10 19:00:53 +0000779 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
Christoph Lameter45530c42012-11-28 16:23:07 +0000780 name, size, err);
781
782 s->refcount = -1; /* Exempt from merging for now */
783}
784
785struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
786 unsigned long flags)
787{
788 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
789
790 if (!s)
791 panic("Out of memory when creating slab %s\n", name);
792
793 create_boot_cache(s, name, size, flags);
794 list_add(&s->list, &slab_caches);
795 s->refcount = 1;
796 return s;
797}
798
Christoph Lameter9425c582013-01-10 19:12:17 +0000799struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
800EXPORT_SYMBOL(kmalloc_caches);
801
802#ifdef CONFIG_ZONE_DMA
803struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
804EXPORT_SYMBOL(kmalloc_dma_caches);
805#endif
806
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000807/*
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000808 * Conversion table for small slabs sizes / 8 to the index in the
809 * kmalloc array. This is necessary for slabs < 192 since we have non power
810 * of two cache sizes there. The size of larger slabs can be determined using
811 * fls.
812 */
813static s8 size_index[24] = {
814 3, /* 8 */
815 4, /* 16 */
816 5, /* 24 */
817 5, /* 32 */
818 6, /* 40 */
819 6, /* 48 */
820 6, /* 56 */
821 6, /* 64 */
822 1, /* 72 */
823 1, /* 80 */
824 1, /* 88 */
825 1, /* 96 */
826 7, /* 104 */
827 7, /* 112 */
828 7, /* 120 */
829 7, /* 128 */
830 2, /* 136 */
831 2, /* 144 */
832 2, /* 152 */
833 2, /* 160 */
834 2, /* 168 */
835 2, /* 176 */
836 2, /* 184 */
837 2 /* 192 */
838};
839
840static inline int size_index_elem(size_t bytes)
841{
842 return (bytes - 1) / 8;
843}
844
845/*
846 * Find the kmem_cache structure that serves a given size of
847 * allocation
848 */
849struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
850{
851 int index;
852
Joonsoo Kim9de1bc82013-08-02 11:02:42 +0900853 if (unlikely(size > KMALLOC_MAX_SIZE)) {
Sasha Levin907985f2013-06-10 15:18:00 -0400854 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
Christoph Lameter6286ae92013-05-03 15:43:18 +0000855 return NULL;
Sasha Levin907985f2013-06-10 15:18:00 -0400856 }
Christoph Lameter6286ae92013-05-03 15:43:18 +0000857
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000858 if (size <= 192) {
859 if (!size)
860 return ZERO_SIZE_PTR;
861
862 index = size_index[size_index_elem(size)];
863 } else
864 index = fls(size - 1);
865
866#ifdef CONFIG_ZONE_DMA
Joonsoo Kimb1e05412013-02-04 23:46:46 +0900867 if (unlikely((flags & GFP_DMA)))
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000868 return kmalloc_dma_caches[index];
869
870#endif
871 return kmalloc_caches[index];
872}
873
874/*
Gavin Guo4066c332015-06-24 16:55:54 -0700875 * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
876 * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
877 * kmalloc-67108864.
878 */
879static struct {
880 const char *name;
881 unsigned long size;
882} const kmalloc_info[] __initconst = {
883 {NULL, 0}, {"kmalloc-96", 96},
884 {"kmalloc-192", 192}, {"kmalloc-8", 8},
885 {"kmalloc-16", 16}, {"kmalloc-32", 32},
886 {"kmalloc-64", 64}, {"kmalloc-128", 128},
887 {"kmalloc-256", 256}, {"kmalloc-512", 512},
888 {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048},
889 {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192},
890 {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768},
891 {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072},
892 {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288},
893 {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152},
894 {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608},
895 {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432},
896 {"kmalloc-67108864", 67108864}
897};
898
899/*
Daniel Sanders34cc6992015-06-24 16:55:57 -0700900 * Patch up the size_index table if we have strange large alignment
901 * requirements for the kmalloc array. This is only the case for
902 * MIPS it seems. The standard arches will not generate any code here.
903 *
904 * Largest permitted alignment is 256 bytes due to the way we
905 * handle the index determination for the smaller caches.
906 *
907 * Make sure that nothing crazy happens if someone starts tinkering
908 * around with ARCH_KMALLOC_MINALIGN
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000909 */
Daniel Sanders34cc6992015-06-24 16:55:57 -0700910void __init setup_kmalloc_cache_index_table(void)
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000911{
912 int i;
913
Christoph Lameter2c59dd62013-01-10 19:14:19 +0000914 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
915 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
916
917 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
918 int elem = size_index_elem(i);
919
920 if (elem >= ARRAY_SIZE(size_index))
921 break;
922 size_index[elem] = KMALLOC_SHIFT_LOW;
923 }
924
925 if (KMALLOC_MIN_SIZE >= 64) {
926 /*
927 * The 96 byte size cache is not used if the alignment
928 * is 64 byte.
929 */
930 for (i = 64 + 8; i <= 96; i += 8)
931 size_index[size_index_elem(i)] = 7;
932
933 }
934
935 if (KMALLOC_MIN_SIZE >= 128) {
936 /*
937 * The 192 byte sized cache is not used if the alignment
938 * is 128 byte. Redirect kmalloc to use the 256 byte cache
939 * instead.
940 */
941 for (i = 128 + 8; i <= 192; i += 8)
942 size_index[size_index_elem(i)] = 8;
943 }
Daniel Sanders34cc6992015-06-24 16:55:57 -0700944}
945
Christoph Lameterae6f2462015-06-30 09:01:11 -0500946static void __init new_kmalloc_cache(int idx, unsigned long flags)
Christoph Lametera9730fc2015-06-29 09:28:08 -0500947{
948 kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name,
949 kmalloc_info[idx].size, flags);
950}
951
Daniel Sanders34cc6992015-06-24 16:55:57 -0700952/*
953 * Create the kmalloc array. Some of the regular kmalloc arrays
954 * may already have been created because they were needed to
955 * enable allocations for slab creation.
956 */
957void __init create_kmalloc_caches(unsigned long flags)
958{
959 int i;
960
Christoph Lametera9730fc2015-06-29 09:28:08 -0500961 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
962 if (!kmalloc_caches[i])
963 new_kmalloc_cache(i, flags);
Chris Mason956e46e2013-05-08 15:56:28 -0400964
965 /*
Christoph Lametera9730fc2015-06-29 09:28:08 -0500966 * Caches that are not of the two-to-the-power-of size.
967 * These have to be created immediately after the
968 * earlier power of two caches
Chris Mason956e46e2013-05-08 15:56:28 -0400969 */
Christoph Lametera9730fc2015-06-29 09:28:08 -0500970 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
971 new_kmalloc_cache(1, flags);
972 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
973 new_kmalloc_cache(2, flags);
Christoph Lameter8a965b32013-05-03 18:04:18 +0000974 }
975
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000976 /* Kmalloc array is now usable */
977 slab_state = UP;
978
Christoph Lameterf97d5f62013-01-10 19:12:17 +0000979#ifdef CONFIG_ZONE_DMA
980 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
981 struct kmem_cache *s = kmalloc_caches[i];
982
983 if (s) {
984 int size = kmalloc_size(i);
985 char *n = kasprintf(GFP_NOWAIT,
986 "dma-kmalloc-%d", size);
987
988 BUG_ON(!n);
989 kmalloc_dma_caches[i] = create_kmalloc_cache(n,
990 size, SLAB_CACHE_DMA | flags);
991 }
992 }
993#endif
994}
Christoph Lameter45530c42012-11-28 16:23:07 +0000995#endif /* !CONFIG_SLOB */
996
Vladimir Davydovcea371f2014-06-04 16:07:04 -0700997/*
998 * To avoid unnecessary overhead, we pass through large allocation requests
999 * directly to the page allocator. We use __GFP_COMP, because we will need to
1000 * know the allocation order to free the pages properly in kfree.
1001 */
Vladimir Davydov52383432014-06-04 16:06:39 -07001002void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
1003{
1004 void *ret;
1005 struct page *page;
1006
1007 flags |= __GFP_COMP;
1008 page = alloc_kmem_pages(flags, order);
1009 ret = page ? page_address(page) : NULL;
1010 kmemleak_alloc(ret, size, 1, flags);
Andrey Ryabinin0316bec2015-02-13 14:39:42 -08001011 kasan_kmalloc_large(ret, size);
Vladimir Davydov52383432014-06-04 16:06:39 -07001012 return ret;
1013}
1014EXPORT_SYMBOL(kmalloc_order);
1015
Christoph Lameterf1b6eb62013-09-04 16:35:34 +00001016#ifdef CONFIG_TRACING
1017void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
1018{
1019 void *ret = kmalloc_order(size, flags, order);
1020 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
1021 return ret;
1022}
1023EXPORT_SYMBOL(kmalloc_order_trace);
1024#endif
Christoph Lameter45530c42012-11-28 16:23:07 +00001025
Glauber Costab7454ad2012-10-19 18:20:25 +04001026#ifdef CONFIG_SLABINFO
Wanpeng Lie9b4db22013-07-04 08:33:24 +08001027
1028#ifdef CONFIG_SLAB
1029#define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
1030#else
1031#define SLABINFO_RIGHTS S_IRUSR
1032#endif
1033
Vladimir Davydovb0475012014-12-10 15:44:19 -08001034static void print_slabinfo_header(struct seq_file *m)
Glauber Costabcee6e22012-10-19 18:20:26 +04001035{
1036 /*
1037 * Output format version, so at least we can change it
1038 * without _too_ many complaints.
1039 */
1040#ifdef CONFIG_DEBUG_SLAB
1041 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
1042#else
1043 seq_puts(m, "slabinfo - version: 2.1\n");
1044#endif
1045 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
1046 "<objperslab> <pagesperslab>");
1047 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
1048 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
1049#ifdef CONFIG_DEBUG_SLAB
1050 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
1051 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
1052 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
1053#endif
1054 seq_putc(m, '\n');
1055}
1056
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001057void *slab_start(struct seq_file *m, loff_t *pos)
Glauber Costab7454ad2012-10-19 18:20:25 +04001058{
Glauber Costab7454ad2012-10-19 18:20:25 +04001059 mutex_lock(&slab_mutex);
Glauber Costab7454ad2012-10-19 18:20:25 +04001060 return seq_list_start(&slab_caches, *pos);
1061}
1062
Wanpeng Li276a2432013-07-08 08:08:28 +08001063void *slab_next(struct seq_file *m, void *p, loff_t *pos)
Glauber Costab7454ad2012-10-19 18:20:25 +04001064{
1065 return seq_list_next(p, &slab_caches, pos);
1066}
1067
Wanpeng Li276a2432013-07-08 08:08:28 +08001068void slab_stop(struct seq_file *m, void *p)
Glauber Costab7454ad2012-10-19 18:20:25 +04001069{
1070 mutex_unlock(&slab_mutex);
1071}
1072
Glauber Costa749c5412012-12-18 14:23:01 -08001073static void
1074memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
Glauber Costab7454ad2012-10-19 18:20:25 +04001075{
Glauber Costa749c5412012-12-18 14:23:01 -08001076 struct kmem_cache *c;
1077 struct slabinfo sinfo;
Glauber Costa749c5412012-12-18 14:23:01 -08001078
1079 if (!is_root_cache(s))
1080 return;
1081
Vladimir Davydov426589f2015-02-12 14:59:23 -08001082 for_each_memcg_cache(c, s) {
Glauber Costa749c5412012-12-18 14:23:01 -08001083 memset(&sinfo, 0, sizeof(sinfo));
1084 get_slabinfo(c, &sinfo);
1085
1086 info->active_slabs += sinfo.active_slabs;
1087 info->num_slabs += sinfo.num_slabs;
1088 info->shared_avail += sinfo.shared_avail;
1089 info->active_objs += sinfo.active_objs;
1090 info->num_objs += sinfo.num_objs;
1091 }
1092}
1093
Vladimir Davydovb0475012014-12-10 15:44:19 -08001094static void cache_show(struct kmem_cache *s, struct seq_file *m)
Glauber Costa749c5412012-12-18 14:23:01 -08001095{
Glauber Costa0d7561c2012-10-19 18:20:27 +04001096 struct slabinfo sinfo;
1097
1098 memset(&sinfo, 0, sizeof(sinfo));
1099 get_slabinfo(s, &sinfo);
1100
Glauber Costa749c5412012-12-18 14:23:01 -08001101 memcg_accumulate_slabinfo(s, &sinfo);
1102
Glauber Costa0d7561c2012-10-19 18:20:27 +04001103 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
Glauber Costa749c5412012-12-18 14:23:01 -08001104 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
Glauber Costa0d7561c2012-10-19 18:20:27 +04001105 sinfo.objects_per_slab, (1 << sinfo.cache_order));
1106
1107 seq_printf(m, " : tunables %4u %4u %4u",
1108 sinfo.limit, sinfo.batchcount, sinfo.shared);
1109 seq_printf(m, " : slabdata %6lu %6lu %6lu",
1110 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1111 slabinfo_show_stats(m, s);
1112 seq_putc(m, '\n');
Glauber Costab7454ad2012-10-19 18:20:25 +04001113}
1114
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001115static int slab_show(struct seq_file *m, void *p)
Glauber Costa749c5412012-12-18 14:23:01 -08001116{
1117 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1118
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001119 if (p == slab_caches.next)
1120 print_slabinfo_header(m);
Vladimir Davydovb0475012014-12-10 15:44:19 -08001121 if (is_root_cache(s))
1122 cache_show(s, m);
1123 return 0;
Glauber Costa749c5412012-12-18 14:23:01 -08001124}
1125
Johannes Weiner127424c2016-01-20 15:02:32 -08001126#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
Vladimir Davydovb0475012014-12-10 15:44:19 -08001127int memcg_slab_show(struct seq_file *m, void *p)
1128{
1129 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1130 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
1131
1132 if (p == slab_caches.next)
1133 print_slabinfo_header(m);
Vladimir Davydovf7ce3192015-02-12 14:59:20 -08001134 if (!is_root_cache(s) && s->memcg_params.memcg == memcg)
Vladimir Davydovb0475012014-12-10 15:44:19 -08001135 cache_show(s, m);
1136 return 0;
1137}
1138#endif
1139
Glauber Costab7454ad2012-10-19 18:20:25 +04001140/*
1141 * slabinfo_op - iterator that generates /proc/slabinfo
1142 *
1143 * Output layout:
1144 * cache-name
1145 * num-active-objs
1146 * total-objs
1147 * object size
1148 * num-active-slabs
1149 * total-slabs
1150 * num-pages-per-slab
1151 * + further values on SMP and with statistics enabled
1152 */
1153static const struct seq_operations slabinfo_op = {
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001154 .start = slab_start,
Wanpeng Li276a2432013-07-08 08:08:28 +08001155 .next = slab_next,
1156 .stop = slab_stop,
Vladimir Davydov1df3b262014-12-10 15:42:16 -08001157 .show = slab_show,
Glauber Costab7454ad2012-10-19 18:20:25 +04001158};
1159
1160static int slabinfo_open(struct inode *inode, struct file *file)
1161{
1162 return seq_open(file, &slabinfo_op);
1163}
1164
1165static const struct file_operations proc_slabinfo_operations = {
1166 .open = slabinfo_open,
1167 .read = seq_read,
1168 .write = slabinfo_write,
1169 .llseek = seq_lseek,
1170 .release = seq_release,
1171};
1172
1173static int __init slab_proc_init(void)
1174{
Wanpeng Lie9b4db22013-07-04 08:33:24 +08001175 proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
1176 &proc_slabinfo_operations);
Glauber Costab7454ad2012-10-19 18:20:25 +04001177 return 0;
1178}
1179module_init(slab_proc_init);
1180#endif /* CONFIG_SLABINFO */
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001181
1182static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1183 gfp_t flags)
1184{
1185 void *ret;
1186 size_t ks = 0;
1187
1188 if (p)
1189 ks = ksize(p);
1190
Andrey Ryabinin0316bec2015-02-13 14:39:42 -08001191 if (ks >= new_size) {
1192 kasan_krealloc((void *)p, new_size);
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001193 return (void *)p;
Andrey Ryabinin0316bec2015-02-13 14:39:42 -08001194 }
Andrey Ryabinin928cec92014-08-06 16:04:44 -07001195
1196 ret = kmalloc_track_caller(new_size, flags);
1197 if (ret && p)
1198 memcpy(ret, p, ks);
1199
1200 return ret;
1201}
1202
1203/**
1204 * __krealloc - like krealloc() but don't free @p.
1205 * @p: object to reallocate memory for.
1206 * @new_size: how many bytes of memory are required.
1207 * @flags: the type of memory to allocate.
1208 *
1209 * This function is like krealloc() except it never frees the originally
1210 * allocated buffer. Use this if you don't want to free the buffer immediately
1211 * like, for example, with RCU.
1212 */
1213void *__krealloc(const void *p, size_t new_size, gfp_t flags)
1214{
1215 if (unlikely(!new_size))
1216 return ZERO_SIZE_PTR;
1217
1218 return __do_krealloc(p, new_size, flags);
1219
1220}
1221EXPORT_SYMBOL(__krealloc);
1222
1223/**
1224 * krealloc - reallocate memory. The contents will remain unchanged.
1225 * @p: object to reallocate memory for.
1226 * @new_size: how many bytes of memory are required.
1227 * @flags: the type of memory to allocate.
1228 *
1229 * The contents of the object pointed to are preserved up to the
1230 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1231 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1232 * %NULL pointer, the object pointed to is freed.
1233 */
1234void *krealloc(const void *p, size_t new_size, gfp_t flags)
1235{
1236 void *ret;
1237
1238 if (unlikely(!new_size)) {
1239 kfree(p);
1240 return ZERO_SIZE_PTR;
1241 }
1242
1243 ret = __do_krealloc(p, new_size, flags);
1244 if (ret && p != ret)
1245 kfree(p);
1246
1247 return ret;
1248}
1249EXPORT_SYMBOL(krealloc);
1250
1251/**
1252 * kzfree - like kfree but zero memory
1253 * @p: object to free memory of
1254 *
1255 * The memory of the object @p points to is zeroed before freed.
1256 * If @p is %NULL, kzfree() does nothing.
1257 *
1258 * Note: this function zeroes the whole allocated buffer which can be a good
1259 * deal bigger than the requested buffer size passed to kmalloc(). So be
1260 * careful when using this function in performance sensitive code.
1261 */
1262void kzfree(const void *p)
1263{
1264 size_t ks;
1265 void *mem = (void *)p;
1266
1267 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1268 return;
1269 ks = ksize(mem);
1270 memset(mem, 0, ks);
1271 kfree(mem);
1272}
1273EXPORT_SYMBOL(kzfree);
1274
1275/* Tracepoints definitions. */
1276EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1277EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1278EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1279EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1280EXPORT_TRACEPOINT_SYMBOL(kfree);
1281EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);