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Commit | Line | Data |
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039363f3 CL |
1 | /* |
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> | |
20cea968 CL |
14 | #include <linux/cpu.h> |
15 | #include <linux/uaccess.h> | |
b7454ad3 GC |
16 | #include <linux/seq_file.h> |
17 | #include <linux/proc_fs.h> | |
039363f3 CL |
18 | #include <asm/cacheflush.h> |
19 | #include <asm/tlbflush.h> | |
20 | #include <asm/page.h> | |
2633d7a0 | 21 | #include <linux/memcontrol.h> |
039363f3 | 22 | |
97d06609 CL |
23 | #include "slab.h" |
24 | ||
25 | enum slab_state slab_state; | |
18004c5d CL |
26 | LIST_HEAD(slab_caches); |
27 | DEFINE_MUTEX(slab_mutex); | |
9b030cb8 | 28 | struct kmem_cache *kmem_cache; |
97d06609 | 29 | |
77be4b13 | 30 | #ifdef CONFIG_DEBUG_VM |
2633d7a0 GC |
31 | static int kmem_cache_sanity_check(struct mem_cgroup *memcg, const char *name, |
32 | size_t size) | |
039363f3 CL |
33 | { |
34 | struct kmem_cache *s = NULL; | |
35 | ||
039363f3 CL |
36 | if (!name || in_interrupt() || size < sizeof(void *) || |
37 | size > KMALLOC_MAX_SIZE) { | |
77be4b13 SK |
38 | pr_err("kmem_cache_create(%s) integrity check failed\n", name); |
39 | return -EINVAL; | |
039363f3 | 40 | } |
b920536a | 41 | |
20cea968 CL |
42 | list_for_each_entry(s, &slab_caches, list) { |
43 | char tmp; | |
44 | int res; | |
45 | ||
46 | /* | |
47 | * This happens when the module gets unloaded and doesn't | |
48 | * destroy its slab cache and no-one else reuses the vmalloc | |
49 | * area of the module. Print a warning. | |
50 | */ | |
51 | res = probe_kernel_address(s->name, tmp); | |
52 | if (res) { | |
77be4b13 | 53 | pr_err("Slab cache with size %d has lost its name\n", |
20cea968 CL |
54 | s->object_size); |
55 | continue; | |
56 | } | |
57 | ||
2633d7a0 GC |
58 | /* |
59 | * For simplicity, we won't check this in the list of memcg | |
60 | * caches. We have control over memcg naming, and if there | |
61 | * aren't duplicates in the global list, there won't be any | |
62 | * duplicates in the memcg lists as well. | |
63 | */ | |
64 | if (!memcg && !strcmp(s->name, name)) { | |
77be4b13 SK |
65 | pr_err("%s (%s): Cache name already exists.\n", |
66 | __func__, name); | |
20cea968 CL |
67 | dump_stack(); |
68 | s = NULL; | |
77be4b13 | 69 | return -EINVAL; |
20cea968 CL |
70 | } |
71 | } | |
72 | ||
73 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ | |
77be4b13 SK |
74 | return 0; |
75 | } | |
76 | #else | |
2633d7a0 GC |
77 | static inline int kmem_cache_sanity_check(struct mem_cgroup *memcg, |
78 | const char *name, size_t size) | |
77be4b13 SK |
79 | { |
80 | return 0; | |
81 | } | |
20cea968 CL |
82 | #endif |
83 | ||
45906855 CL |
84 | /* |
85 | * Figure out what the alignment of the objects will be given a set of | |
86 | * flags, a user specified alignment and the size of the objects. | |
87 | */ | |
88 | unsigned long calculate_alignment(unsigned long flags, | |
89 | unsigned long align, unsigned long size) | |
90 | { | |
91 | /* | |
92 | * If the user wants hardware cache aligned objects then follow that | |
93 | * suggestion if the object is sufficiently large. | |
94 | * | |
95 | * The hardware cache alignment cannot override the specified | |
96 | * alignment though. If that is greater then use it. | |
97 | */ | |
98 | if (flags & SLAB_HWCACHE_ALIGN) { | |
99 | unsigned long ralign = cache_line_size(); | |
100 | while (size <= ralign / 2) | |
101 | ralign /= 2; | |
102 | align = max(align, ralign); | |
103 | } | |
104 | ||
105 | if (align < ARCH_SLAB_MINALIGN) | |
106 | align = ARCH_SLAB_MINALIGN; | |
107 | ||
108 | return ALIGN(align, sizeof(void *)); | |
109 | } | |
110 | ||
111 | ||
77be4b13 SK |
112 | /* |
113 | * kmem_cache_create - Create a cache. | |
114 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
115 | * @size: The size of objects to be created in this cache. | |
116 | * @align: The required alignment for the objects. | |
117 | * @flags: SLAB flags | |
118 | * @ctor: A constructor for the objects. | |
119 | * | |
120 | * Returns a ptr to the cache on success, NULL on failure. | |
121 | * Cannot be called within a interrupt, but can be interrupted. | |
122 | * The @ctor is run when new pages are allocated by the cache. | |
123 | * | |
124 | * The flags are | |
125 | * | |
126 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
127 | * to catch references to uninitialised memory. | |
128 | * | |
129 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
130 | * for buffer overruns. | |
131 | * | |
132 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
133 | * cacheline. This can be beneficial if you're counting cycles as closely | |
134 | * as davem. | |
135 | */ | |
136 | ||
2633d7a0 GC |
137 | struct kmem_cache * |
138 | kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size, | |
139 | size_t align, unsigned long flags, void (*ctor)(void *)) | |
77be4b13 SK |
140 | { |
141 | struct kmem_cache *s = NULL; | |
686d550d | 142 | int err = 0; |
039363f3 | 143 | |
77be4b13 SK |
144 | get_online_cpus(); |
145 | mutex_lock(&slab_mutex); | |
686d550d | 146 | |
2633d7a0 | 147 | if (!kmem_cache_sanity_check(memcg, name, size) == 0) |
686d550d CL |
148 | goto out_locked; |
149 | ||
d8843922 GC |
150 | /* |
151 | * Some allocators will constraint the set of valid flags to a subset | |
152 | * of all flags. We expect them to define CACHE_CREATE_MASK in this | |
153 | * case, and we'll just provide them with a sanitized version of the | |
154 | * passed flags. | |
155 | */ | |
156 | flags &= CACHE_CREATE_MASK; | |
686d550d | 157 | |
2633d7a0 | 158 | s = __kmem_cache_alias(memcg, name, size, align, flags, ctor); |
cbb79694 CL |
159 | if (s) |
160 | goto out_locked; | |
161 | ||
278b1bb1 | 162 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); |
db265eca | 163 | if (s) { |
8a13a4cc | 164 | s->object_size = s->size = size; |
45906855 | 165 | s->align = calculate_alignment(flags, align, size); |
8a13a4cc | 166 | s->ctor = ctor; |
2633d7a0 GC |
167 | |
168 | if (memcg_register_cache(memcg, s)) { | |
169 | kmem_cache_free(kmem_cache, s); | |
170 | err = -ENOMEM; | |
171 | goto out_locked; | |
172 | } | |
173 | ||
8a13a4cc CL |
174 | s->name = kstrdup(name, GFP_KERNEL); |
175 | if (!s->name) { | |
176 | kmem_cache_free(kmem_cache, s); | |
177 | err = -ENOMEM; | |
178 | goto out_locked; | |
179 | } | |
180 | ||
181 | err = __kmem_cache_create(s, flags); | |
cce89f4f | 182 | if (!err) { |
cce89f4f | 183 | s->refcount = 1; |
db265eca | 184 | list_add(&s->list, &slab_caches); |
2633d7a0 | 185 | memcg_cache_list_add(memcg, s); |
cce89f4f | 186 | } else { |
8a13a4cc | 187 | kfree(s->name); |
278b1bb1 CL |
188 | kmem_cache_free(kmem_cache, s); |
189 | } | |
8a13a4cc | 190 | } else |
278b1bb1 | 191 | err = -ENOMEM; |
7c9adf5a | 192 | |
686d550d | 193 | out_locked: |
20cea968 CL |
194 | mutex_unlock(&slab_mutex); |
195 | put_online_cpus(); | |
196 | ||
686d550d CL |
197 | if (err) { |
198 | ||
199 | if (flags & SLAB_PANIC) | |
200 | panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", | |
201 | name, err); | |
202 | else { | |
203 | printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d", | |
204 | name, err); | |
205 | dump_stack(); | |
206 | } | |
207 | ||
208 | return NULL; | |
209 | } | |
039363f3 CL |
210 | |
211 | return s; | |
212 | } | |
2633d7a0 GC |
213 | |
214 | struct kmem_cache * | |
215 | kmem_cache_create(const char *name, size_t size, size_t align, | |
216 | unsigned long flags, void (*ctor)(void *)) | |
217 | { | |
218 | return kmem_cache_create_memcg(NULL, name, size, align, flags, ctor); | |
219 | } | |
039363f3 | 220 | EXPORT_SYMBOL(kmem_cache_create); |
97d06609 | 221 | |
945cf2b6 CL |
222 | void kmem_cache_destroy(struct kmem_cache *s) |
223 | { | |
224 | get_online_cpus(); | |
225 | mutex_lock(&slab_mutex); | |
226 | s->refcount--; | |
227 | if (!s->refcount) { | |
228 | list_del(&s->list); | |
229 | ||
230 | if (!__kmem_cache_shutdown(s)) { | |
210ed9de | 231 | mutex_unlock(&slab_mutex); |
945cf2b6 CL |
232 | if (s->flags & SLAB_DESTROY_BY_RCU) |
233 | rcu_barrier(); | |
234 | ||
2633d7a0 | 235 | memcg_release_cache(s); |
db265eca | 236 | kfree(s->name); |
8f4c765c | 237 | kmem_cache_free(kmem_cache, s); |
945cf2b6 CL |
238 | } else { |
239 | list_add(&s->list, &slab_caches); | |
210ed9de | 240 | mutex_unlock(&slab_mutex); |
945cf2b6 CL |
241 | printk(KERN_ERR "kmem_cache_destroy %s: Slab cache still has objects\n", |
242 | s->name); | |
243 | dump_stack(); | |
244 | } | |
210ed9de JK |
245 | } else { |
246 | mutex_unlock(&slab_mutex); | |
945cf2b6 | 247 | } |
945cf2b6 CL |
248 | put_online_cpus(); |
249 | } | |
250 | EXPORT_SYMBOL(kmem_cache_destroy); | |
251 | ||
97d06609 CL |
252 | int slab_is_available(void) |
253 | { | |
254 | return slab_state >= UP; | |
255 | } | |
b7454ad3 | 256 | |
45530c44 CL |
257 | #ifndef CONFIG_SLOB |
258 | /* Create a cache during boot when no slab services are available yet */ | |
259 | void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size, | |
260 | unsigned long flags) | |
261 | { | |
262 | int err; | |
263 | ||
264 | s->name = name; | |
265 | s->size = s->object_size = size; | |
45906855 | 266 | s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size); |
45530c44 CL |
267 | err = __kmem_cache_create(s, flags); |
268 | ||
269 | if (err) | |
270 | panic("Creation of kmalloc slab %s size=%zd failed. Reason %d\n", | |
271 | name, size, err); | |
272 | ||
273 | s->refcount = -1; /* Exempt from merging for now */ | |
274 | } | |
275 | ||
276 | struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size, | |
277 | unsigned long flags) | |
278 | { | |
279 | struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); | |
280 | ||
281 | if (!s) | |
282 | panic("Out of memory when creating slab %s\n", name); | |
283 | ||
284 | create_boot_cache(s, name, size, flags); | |
285 | list_add(&s->list, &slab_caches); | |
286 | s->refcount = 1; | |
287 | return s; | |
288 | } | |
289 | ||
290 | #endif /* !CONFIG_SLOB */ | |
291 | ||
292 | ||
b7454ad3 | 293 | #ifdef CONFIG_SLABINFO |
bcee6e2a GC |
294 | static void print_slabinfo_header(struct seq_file *m) |
295 | { | |
296 | /* | |
297 | * Output format version, so at least we can change it | |
298 | * without _too_ many complaints. | |
299 | */ | |
300 | #ifdef CONFIG_DEBUG_SLAB | |
301 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
302 | #else | |
303 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
304 | #endif | |
305 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " | |
306 | "<objperslab> <pagesperslab>"); | |
307 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); | |
308 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
309 | #ifdef CONFIG_DEBUG_SLAB | |
310 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " | |
311 | "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); | |
312 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); | |
313 | #endif | |
314 | seq_putc(m, '\n'); | |
315 | } | |
316 | ||
b7454ad3 GC |
317 | static void *s_start(struct seq_file *m, loff_t *pos) |
318 | { | |
319 | loff_t n = *pos; | |
320 | ||
321 | mutex_lock(&slab_mutex); | |
322 | if (!n) | |
323 | print_slabinfo_header(m); | |
324 | ||
325 | return seq_list_start(&slab_caches, *pos); | |
326 | } | |
327 | ||
328 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) | |
329 | { | |
330 | return seq_list_next(p, &slab_caches, pos); | |
331 | } | |
332 | ||
333 | static void s_stop(struct seq_file *m, void *p) | |
334 | { | |
335 | mutex_unlock(&slab_mutex); | |
336 | } | |
337 | ||
338 | static int s_show(struct seq_file *m, void *p) | |
339 | { | |
0d7561c6 GC |
340 | struct kmem_cache *s = list_entry(p, struct kmem_cache, list); |
341 | struct slabinfo sinfo; | |
342 | ||
343 | memset(&sinfo, 0, sizeof(sinfo)); | |
344 | get_slabinfo(s, &sinfo); | |
345 | ||
346 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", | |
347 | s->name, sinfo.active_objs, sinfo.num_objs, s->size, | |
348 | sinfo.objects_per_slab, (1 << sinfo.cache_order)); | |
349 | ||
350 | seq_printf(m, " : tunables %4u %4u %4u", | |
351 | sinfo.limit, sinfo.batchcount, sinfo.shared); | |
352 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
353 | sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); | |
354 | slabinfo_show_stats(m, s); | |
355 | seq_putc(m, '\n'); | |
356 | return 0; | |
b7454ad3 GC |
357 | } |
358 | ||
359 | /* | |
360 | * slabinfo_op - iterator that generates /proc/slabinfo | |
361 | * | |
362 | * Output layout: | |
363 | * cache-name | |
364 | * num-active-objs | |
365 | * total-objs | |
366 | * object size | |
367 | * num-active-slabs | |
368 | * total-slabs | |
369 | * num-pages-per-slab | |
370 | * + further values on SMP and with statistics enabled | |
371 | */ | |
372 | static const struct seq_operations slabinfo_op = { | |
373 | .start = s_start, | |
374 | .next = s_next, | |
375 | .stop = s_stop, | |
376 | .show = s_show, | |
377 | }; | |
378 | ||
379 | static int slabinfo_open(struct inode *inode, struct file *file) | |
380 | { | |
381 | return seq_open(file, &slabinfo_op); | |
382 | } | |
383 | ||
384 | static const struct file_operations proc_slabinfo_operations = { | |
385 | .open = slabinfo_open, | |
386 | .read = seq_read, | |
387 | .write = slabinfo_write, | |
388 | .llseek = seq_lseek, | |
389 | .release = seq_release, | |
390 | }; | |
391 | ||
392 | static int __init slab_proc_init(void) | |
393 | { | |
394 | proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations); | |
395 | return 0; | |
396 | } | |
397 | module_init(slab_proc_init); | |
398 | #endif /* CONFIG_SLABINFO */ |