mm/slab_common.c

   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>
  14 #include <linux/cpu.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/proc_fs.h>
  18 #include <asm/cacheflush.h>
  19 #include <asm/tlbflush.h>
  20 #include <asm/page.h>
  21 #include <linux/memcontrol.h>
  22 #include <trace/events/kmem.h>
  23
  24 #include "slab.h"
  25
  26 enum slab_state slab_state;
  27 LIST_HEAD(slab_caches);
  28 DEFINE_MUTEX(slab_mutex);
  29 struct kmem_cache *kmem_cache;
  30
  31 #ifdef CONFIG_DEBUG_VM
  32 static int kmem_cache_sanity_check(const char *name, size_t size)
  33 {
  34         struct kmem_cache *s = NULL;
  35
  36         if (!name || in_interrupt() || size < sizeof(void *) ||
  37                 size > KMALLOC_MAX_SIZE) {
  38                 pr_err("kmem_cache_create(%s) integrity check failed\n", name);
  39                 return -EINVAL;
  40         }
  41
  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) {
  53                         pr_err("Slab cache with size %d has lost its name\n",
  54                                s->object_size);
  55                         continue;
  56                 }
  57
  58 #if !defined(CONFIG_SLUB) || !defined(CONFIG_SLUB_DEBUG_ON)
  59                 if (!strcmp(s->name, name)) {
  60                         pr_err("%s (%s): Cache name already exists.\n",
  61                                __func__, name);
  62                         dump_stack();
  63                         s = NULL;
  64                         return -EINVAL;
  65                 }
  66 #endif
  67         }
  68
  69         WARN_ON(strchr(name, ' '));     /* It confuses parsers */
  70         return 0;
  71 }
  72 #else
  73 static inline int kmem_cache_sanity_check(const char *name, size_t size)
  74 {
  75         return 0;
  76 }
  77 #endif
  78
  79 #ifdef CONFIG_MEMCG_KMEM
  80 int memcg_update_all_caches(int num_memcgs)
  81 {
  82         struct kmem_cache *s;
  83         int ret = 0;
  84         mutex_lock(&slab_mutex);
  85
  86         list_for_each_entry(s, &slab_caches, list) {
  87                 if (!is_root_cache(s))
  88                         continue;
  89
  90                 ret = memcg_update_cache_size(s, num_memcgs);
  91                 /*
  92                  * See comment in memcontrol.c, memcg_update_cache_size:
  93                  * Instead of freeing the memory, we'll just leave the caches
  94                  * up to this point in an updated state.
  95                  */
  96                 if (ret)
  97                         goto out;
  98         }
  99
 100         memcg_update_array_size(num_memcgs);
 101 out:
 102         mutex_unlock(&slab_mutex);
 103         return ret;
 104 }
 105 #endif
 106
 107 /*
 108  * Figure out what the alignment of the objects will be given a set of
 109  * flags, a user specified alignment and the size of the objects.
 110  */
 111 unsigned long calculate_alignment(unsigned long flags,
 112                 unsigned long align, unsigned long size)
 113 {
 114         /*
 115          * If the user wants hardware cache aligned objects then follow that
 116          * suggestion if the object is sufficiently large.
 117          *
 118          * The hardware cache alignment cannot override the specified
 119          * alignment though. If that is greater then use it.
 120          */
 121         if (flags & SLAB_HWCACHE_ALIGN) {
 122                 unsigned long ralign = cache_line_size();
 123                 while (size <= ralign / 2)
 124                         ralign /= 2;
 125                 align = max(align, ralign);
 126         }
 127
 128         if (align < ARCH_SLAB_MINALIGN)
 129                 align = ARCH_SLAB_MINALIGN;
 130
 131         return ALIGN(align, sizeof(void *));
 132 }
 133
 134 static struct kmem_cache *
 135 do_kmem_cache_create(char *name, size_t object_size, size_t size, size_t align,
 136                      unsigned long flags, void (*ctor)(void *),
 137                      struct mem_cgroup *memcg, struct kmem_cache *root_cache)
 138 {
 139         struct kmem_cache *s;
 140         int err;
 141
 142         err = -ENOMEM;
 143         s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
 144         if (!s)
 145                 goto out;
 146
 147         s->name = name;
 148         s->object_size = object_size;
 149         s->size = size;
 150         s->align = align;
 151         s->ctor = ctor;
 152
 153         err = memcg_alloc_cache_params(memcg, s, root_cache);
 154         if (err)
 155                 goto out_free_cache;
 156
 157         err = __kmem_cache_create(s, flags);
 158         if (err)
 159                 goto out_free_cache;
 160
 161         s->refcount = 1;
 162         list_add(&s->list, &slab_caches);
 163 out:
 164         if (err)
 165                 return ERR_PTR(err);
 166         return s;
 167
 168 out_free_cache:
 169         memcg_free_cache_params(s);
 170         kfree(s);
 171         goto out;
 172 }
 173
 174 /*
 175  * kmem_cache_create - Create a cache.
 176  * @name: A string which is used in /proc/slabinfo to identify this cache.
 177  * @size: The size of objects to be created in this cache.
 178  * @align: The required alignment for the objects.
 179  * @flags: SLAB flags
 180  * @ctor: A constructor for the objects.
 181  *
 182  * Returns a ptr to the cache on success, NULL on failure.
 183  * Cannot be called within a interrupt, but can be interrupted.
 184  * The @ctor is run when new pages are allocated by the cache.
 185  *
 186  * The flags are
 187  *
 188  * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
 189  * to catch references to uninitialised memory.
 190  *
 191  * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
 192  * for buffer overruns.
 193  *
 194  * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
 195  * cacheline.  This can be beneficial if you're counting cycles as closely
 196  * as davem.
 197  */
 198 struct kmem_cache *
 199 kmem_cache_create(const char *name, size_t size, size_t align,
 200                   unsigned long flags, void (*ctor)(void *))
 201 {
 202         struct kmem_cache *s;
 203         char *cache_name;
 204         int err;
 205
 206         get_online_cpus();
 207         get_online_mems();
 208
 209         mutex_lock(&slab_mutex);
 210
 211         err = kmem_cache_sanity_check(name, size);
 212         if (err)
 213                 goto out_unlock;
 214
 215         /*
 216          * Some allocators will constraint the set of valid flags to a subset
 217          * of all flags. We expect them to define CACHE_CREATE_MASK in this
 218          * case, and we'll just provide them with a sanitized version of the
 219          * passed flags.
 220          */
 221         flags &= CACHE_CREATE_MASK;
 222
 223         s = __kmem_cache_alias(name, size, align, flags, ctor);
 224         if (s)
 225                 goto out_unlock;
 226
 227         cache_name = kstrdup(name, GFP_KERNEL);
 228         if (!cache_name) {
 229                 err = -ENOMEM;
 230                 goto out_unlock;
 231         }
 232
 233         s = do_kmem_cache_create(cache_name, size, size,
 234                                  calculate_alignment(flags, align, size),
 235                                  flags, ctor, NULL, NULL);
 236         if (IS_ERR(s)) {
 237                 err = PTR_ERR(s);
 238                 kfree(cache_name);
 239         }
 240
 241 out_unlock:
 242         mutex_unlock(&slab_mutex);
 243
 244         put_online_mems();
 245         put_online_cpus();
 246
 247         if (err) {
 248                 if (flags & SLAB_PANIC)
 249                         panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
 250                                 name, err);
 251                 else {
 252                         printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
 253                                 name, err);
 254                         dump_stack();
 255                 }
 256                 return NULL;
 257         }
 258         return s;
 259 }
 260 EXPORT_SYMBOL(kmem_cache_create);
 261
 262 #ifdef CONFIG_MEMCG_KMEM
 263 /*
 264  * memcg_create_kmem_cache - Create a cache for a memory cgroup.
 265  * @memcg: The memory cgroup the new cache is for.
 266  * @root_cache: The parent of the new cache.
 267  * @memcg_name: The name of the memory cgroup (used for naming the new cache).
 268  *
 269  * This function attempts to create a kmem cache that will serve allocation
 270  * requests going from @memcg to @root_cache. The new cache inherits properties
 271  * from its parent.
 272  */
 273 struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
 274                                            struct kmem_cache *root_cache,
 275                                            const char *memcg_name)
 276 {
 277         struct kmem_cache *s = NULL;
 278         char *cache_name;
 279
 280         get_online_cpus();
 281         get_online_mems();
 282
 283         mutex_lock(&slab_mutex);
 284
 285         cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
 286                                memcg_cache_id(memcg), memcg_name);
 287         if (!cache_name)
 288                 goto out_unlock;
 289
 290         s = do_kmem_cache_create(cache_name, root_cache->object_size,
 291                                  root_cache->size, root_cache->align,
 292                                  root_cache->flags, root_cache->ctor,
 293                                  memcg, root_cache);
 294         if (IS_ERR(s)) {
 295                 kfree(cache_name);
 296                 s = NULL;
 297         }
 298
 299 out_unlock:
 300         mutex_unlock(&slab_mutex);
 301
 302         put_online_mems();
 303         put_online_cpus();
 304
 305         return s;
 306 }
 307
 308 static int memcg_cleanup_cache_params(struct kmem_cache *s)
 309 {
 310         int rc;
 311
 312         if (!s->memcg_params ||
 313             !s->memcg_params->is_root_cache)
 314                 return 0;
 315
 316         mutex_unlock(&slab_mutex);
 317         rc = __memcg_cleanup_cache_params(s);
 318         mutex_lock(&slab_mutex);
 319
 320         return rc;
 321 }
 322 #else
 323 static int memcg_cleanup_cache_params(struct kmem_cache *s)
 324 {
 325         return 0;
 326 }
 327 #endif /* CONFIG_MEMCG_KMEM */
 328
 329 void slab_kmem_cache_release(struct kmem_cache *s)
 330 {
 331         kfree(s->name);
 332         kmem_cache_free(kmem_cache, s);
 333 }
 334
 335 void kmem_cache_destroy(struct kmem_cache *s)
 336 {
 337         get_online_cpus();
 338         get_online_mems();
 339
 340         mutex_lock(&slab_mutex);
 341
 342         s->refcount--;
 343         if (s->refcount)
 344                 goto out_unlock;
 345
 346         if (memcg_cleanup_cache_params(s) != 0)
 347                 goto out_unlock;
 348
 349         if (__kmem_cache_shutdown(s) != 0) {
 350                 printk(KERN_ERR "kmem_cache_destroy %s: "
 351                        "Slab cache still has objects\n", s->name);
 352                 dump_stack();
 353                 goto out_unlock;
 354         }
 355
 356         list_del(&s->list);
 357
 358         mutex_unlock(&slab_mutex);
 359         if (s->flags & SLAB_DESTROY_BY_RCU)
 360                 rcu_barrier();
 361
 362         memcg_free_cache_params(s);
 363 #ifdef SLAB_SUPPORTS_SYSFS
 364         sysfs_slab_remove(s);
 365 #else
 366         slab_kmem_cache_release(s);
 367 #endif
 368         goto out;
 369
 370 out_unlock:
 371         mutex_unlock(&slab_mutex);
 372 out:
 373         put_online_mems();
 374         put_online_cpus();
 375 }
 376 EXPORT_SYMBOL(kmem_cache_destroy);
 377
 378 /**
 379  * kmem_cache_shrink - Shrink a cache.
 380  * @cachep: The cache to shrink.
 381  *
 382  * Releases as many slabs as possible for a cache.
 383  * To help debugging, a zero exit status indicates all slabs were released.
 384  */
 385 int kmem_cache_shrink(struct kmem_cache *cachep)
 386 {
 387         int ret;
 388
 389         get_online_cpus();
 390         get_online_mems();
 391         ret = __kmem_cache_shrink(cachep);
 392         put_online_mems();
 393         put_online_cpus();
 394         return ret;
 395 }
 396 EXPORT_SYMBOL(kmem_cache_shrink);
 397
 398 int slab_is_available(void)
 399 {
 400         return slab_state >= UP;
 401 }
 402
 403 #ifndef CONFIG_SLOB
 404 /* Create a cache during boot when no slab services are available yet */
 405 void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
 406                 unsigned long flags)
 407 {
 408         int err;
 409
 410         s->name = name;
 411         s->size = s->object_size = size;
 412         s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
 413         err = __kmem_cache_create(s, flags);
 414
 415         if (err)
 416                 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
 417                                         name, size, err);
 418
 419         s->refcount = -1;       /* Exempt from merging for now */
 420 }
 421
 422 struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
 423                                 unsigned long flags)
 424 {
 425         struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
 426
 427         if (!s)
 428                 panic("Out of memory when creating slab %s\n", name);
 429
 430         create_boot_cache(s, name, size, flags);
 431         list_add(&s->list, &slab_caches);
 432         s->refcount = 1;
 433         return s;
 434 }
 435
 436 struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
 437 EXPORT_SYMBOL(kmalloc_caches);
 438
 439 #ifdef CONFIG_ZONE_DMA
 440 struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
 441 EXPORT_SYMBOL(kmalloc_dma_caches);
 442 #endif
 443
 444 /*
 445  * Conversion table for small slabs sizes / 8 to the index in the
 446  * kmalloc array. This is necessary for slabs < 192 since we have non power
 447  * of two cache sizes there. The size of larger slabs can be determined using
 448  * fls.
 449  */
 450 static s8 size_index[24] = {
 451         3,      /* 8 */
 452         4,      /* 16 */
 453         5,      /* 24 */
 454         5,      /* 32 */
 455         6,      /* 40 */
 456         6,      /* 48 */
 457         6,      /* 56 */
 458         6,      /* 64 */
 459         1,      /* 72 */
 460         1,      /* 80 */
 461         1,      /* 88 */
 462         1,      /* 96 */
 463         7,      /* 104 */
 464         7,      /* 112 */
 465         7,      /* 120 */
 466         7,      /* 128 */
 467         2,      /* 136 */
 468         2,      /* 144 */
 469         2,      /* 152 */
 470         2,      /* 160 */
 471         2,      /* 168 */
 472         2,      /* 176 */
 473         2,      /* 184 */
 474         2       /* 192 */
 475 };
 476
 477 static inline int size_index_elem(size_t bytes)
 478 {
 479         return (bytes - 1) / 8;
 480 }
 481
 482 /*
 483  * Find the kmem_cache structure that serves a given size of
 484  * allocation
 485  */
 486 struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
 487 {
 488         int index;
 489
 490         if (unlikely(size > KMALLOC_MAX_SIZE)) {
 491                 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
 492                 return NULL;
 493         }
 494
 495         if (size <= 192) {
 496                 if (!size)
 497                         return ZERO_SIZE_PTR;
 498
 499                 index = size_index[size_index_elem(size)];
 500         } else
 501                 index = fls(size - 1);
 502
 503 #ifdef CONFIG_ZONE_DMA
 504         if (unlikely((flags & GFP_DMA)))
 505                 return kmalloc_dma_caches[index];
 506
 507 #endif
 508         return kmalloc_caches[index];
 509 }
 510
 511 /*
 512  * Create the kmalloc array. Some of the regular kmalloc arrays
 513  * may already have been created because they were needed to
 514  * enable allocations for slab creation.
 515  */
 516 void __init create_kmalloc_caches(unsigned long flags)
 517 {
 518         int i;
 519
 520         /*
 521          * Patch up the size_index table if we have strange large alignment
 522          * requirements for the kmalloc array. This is only the case for
 523          * MIPS it seems. The standard arches will not generate any code here.
 524          *
 525          * Largest permitted alignment is 256 bytes due to the way we
 526          * handle the index determination for the smaller caches.
 527          *
 528          * Make sure that nothing crazy happens if someone starts tinkering
 529          * around with ARCH_KMALLOC_MINALIGN
 530          */
 531         BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
 532                 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
 533
 534         for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
 535                 int elem = size_index_elem(i);
 536
 537                 if (elem >= ARRAY_SIZE(size_index))
 538                         break;
 539                 size_index[elem] = KMALLOC_SHIFT_LOW;
 540         }
 541
 542         if (KMALLOC_MIN_SIZE >= 64) {
 543                 /*
 544                  * The 96 byte size cache is not used if the alignment
 545                  * is 64 byte.
 546                  */
 547                 for (i = 64 + 8; i <= 96; i += 8)
 548                         size_index[size_index_elem(i)] = 7;
 549
 550         }
 551
 552         if (KMALLOC_MIN_SIZE >= 128) {
 553                 /*
 554                  * The 192 byte sized cache is not used if the alignment
 555                  * is 128 byte. Redirect kmalloc to use the 256 byte cache
 556                  * instead.
 557                  */
 558                 for (i = 128 + 8; i <= 192; i += 8)
 559                         size_index[size_index_elem(i)] = 8;
 560         }
 561         for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
 562                 if (!kmalloc_caches[i]) {
 563                         kmalloc_caches[i] = create_kmalloc_cache(NULL,
 564                                                         1 << i, flags);
 565                 }
 566
 567                 /*
 568                  * Caches that are not of the two-to-the-power-of size.
 569                  * These have to be created immediately after the
 570                  * earlier power of two caches
 571                  */
 572                 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
 573                         kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags);
 574
 575                 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
 576                         kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
 577         }
 578
 579         /* Kmalloc array is now usable */
 580         slab_state = UP;
 581
 582         for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
 583                 struct kmem_cache *s = kmalloc_caches[i];
 584                 char *n;
 585
 586                 if (s) {
 587                         n = kasprintf(GFP_NOWAIT, "kmalloc-%d", kmalloc_size(i));
 588
 589                         BUG_ON(!n);
 590                         s->name = n;
 591                 }
 592         }
 593
 594 #ifdef CONFIG_ZONE_DMA
 595         for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
 596                 struct kmem_cache *s = kmalloc_caches[i];
 597
 598                 if (s) {
 599                         int size = kmalloc_size(i);
 600                         char *n = kasprintf(GFP_NOWAIT,
 601                                  "dma-kmalloc-%d", size);
 602
 603                         BUG_ON(!n);
 604                         kmalloc_dma_caches[i] = create_kmalloc_cache(n,
 605                                 size, SLAB_CACHE_DMA | flags);
 606                 }
 607         }
 608 #endif
 609 }
 610 #endif /* !CONFIG_SLOB */
 611
 612 /*
 613  * To avoid unnecessary overhead, we pass through large allocation requests
 614  * directly to the page allocator. We use __GFP_COMP, because we will need to
 615  * know the allocation order to free the pages properly in kfree.
 616  */
 617 void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
 618 {
 619         void *ret;
 620         struct page *page;
 621
 622         flags |= __GFP_COMP;
 623         page = alloc_kmem_pages(flags, order);
 624         ret = page ? page_address(page) : NULL;
 625         kmemleak_alloc(ret, size, 1, flags);
 626         return ret;
 627 }
 628 EXPORT_SYMBOL(kmalloc_order);
 629
 630 #ifdef CONFIG_TRACING
 631 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
 632 {
 633         void *ret = kmalloc_order(size, flags, order);
 634         trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
 635         return ret;
 636 }
 637 EXPORT_SYMBOL(kmalloc_order_trace);
 638 #endif
 639
 640 #ifdef CONFIG_SLABINFO
 641
 642 #ifdef CONFIG_SLAB
 643 #define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
 644 #else
 645 #define SLABINFO_RIGHTS S_IRUSR
 646 #endif
 647
 648 void print_slabinfo_header(struct seq_file *m)
 649 {
 650         /*
 651          * Output format version, so at least we can change it
 652          * without _too_ many complaints.
 653          */
 654 #ifdef CONFIG_DEBUG_SLAB
 655         seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
 656 #else
 657         seq_puts(m, "slabinfo - version: 2.1\n");
 658 #endif
 659         seq_puts(m, "# name            <active_objs> <num_objs> <objsize> "
 660                  "<objperslab> <pagesperslab>");
 661         seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
 662         seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
 663 #ifdef CONFIG_DEBUG_SLAB
 664         seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
 665                  "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
 666         seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
 667 #endif
 668         seq_putc(m, '\n');
 669 }
 670
 671 static void *s_start(struct seq_file *m, loff_t *pos)
 672 {
 673         loff_t n = *pos;
 674
 675         mutex_lock(&slab_mutex);
 676         if (!n)
 677                 print_slabinfo_header(m);
 678
 679         return seq_list_start(&slab_caches, *pos);
 680 }
 681
 682 void *slab_next(struct seq_file *m, void *p, loff_t *pos)
 683 {
 684         return seq_list_next(p, &slab_caches, pos);
 685 }
 686
 687 void slab_stop(struct seq_file *m, void *p)
 688 {
 689         mutex_unlock(&slab_mutex);
 690 }
 691
 692 static void
 693 memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
 694 {
 695         struct kmem_cache *c;
 696         struct slabinfo sinfo;
 697         int i;
 698
 699         if (!is_root_cache(s))
 700                 return;
 701
 702         for_each_memcg_cache_index(i) {
 703                 c = cache_from_memcg_idx(s, i);
 704                 if (!c)
 705                         continue;
 706
 707                 memset(&sinfo, 0, sizeof(sinfo));
 708                 get_slabinfo(c, &sinfo);
 709
 710                 info->active_slabs += sinfo.active_slabs;
 711                 info->num_slabs += sinfo.num_slabs;
 712                 info->shared_avail += sinfo.shared_avail;
 713                 info->active_objs += sinfo.active_objs;
 714                 info->num_objs += sinfo.num_objs;
 715         }
 716 }
 717
 718 int cache_show(struct kmem_cache *s, struct seq_file *m)
 719 {
 720         struct slabinfo sinfo;
 721
 722         memset(&sinfo, 0, sizeof(sinfo));
 723         get_slabinfo(s, &sinfo);
 724
 725         memcg_accumulate_slabinfo(s, &sinfo);
 726
 727         seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
 728                    cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
 729                    sinfo.objects_per_slab, (1 << sinfo.cache_order));
 730
 731         seq_printf(m, " : tunables %4u %4u %4u",
 732                    sinfo.limit, sinfo.batchcount, sinfo.shared);
 733         seq_printf(m, " : slabdata %6lu %6lu %6lu",
 734                    sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
 735         slabinfo_show_stats(m, s);
 736         seq_putc(m, '\n');
 737         return 0;
 738 }
 739
 740 static int s_show(struct seq_file *m, void *p)
 741 {
 742         struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
 743
 744         if (!is_root_cache(s))
 745                 return 0;
 746         return cache_show(s, m);
 747 }
 748
 749 /*
 750  * slabinfo_op - iterator that generates /proc/slabinfo
 751  *
 752  * Output layout:
 753  * cache-name
 754  * num-active-objs
 755  * total-objs
 756  * object size
 757  * num-active-slabs
 758  * total-slabs
 759  * num-pages-per-slab
 760  * + further values on SMP and with statistics enabled
 761  */
 762 static const struct seq_operations slabinfo_op = {
 763         .start = s_start,
 764         .next = slab_next,
 765         .stop = slab_stop,
 766         .show = s_show,
 767 };
 768
 769 static int slabinfo_open(struct inode *inode, struct file *file)
 770 {
 771         return seq_open(file, &slabinfo_op);
 772 }
 773
 774 static const struct file_operations proc_slabinfo_operations = {
 775         .open           = slabinfo_open,
 776         .read           = seq_read,
 777         .write          = slabinfo_write,
 778         .llseek         = seq_lseek,
 779         .release        = seq_release,
 780 };
 781
 782 static int __init slab_proc_init(void)
 783 {
 784         proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
 785                                                 &proc_slabinfo_operations);
 786         return 0;
 787 }
 788 module_init(slab_proc_init);
 789 #endif /* CONFIG_SLABINFO */