~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/slab.h

Version: ~ [ linux-5.2-rc4 ] ~ [ linux-5.1.9 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.50 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.125 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.181 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.181 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.68 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
  3  *
  4  * (C) SGI 2006, Christoph Lameter
  5  *      Cleaned up and restructured to ease the addition of alternative
  6  *      implementations of SLAB allocators.
  7  * (C) Linux Foundation 2008-2013
  8  *      Unified interface for all slab allocators
  9  */
 10 
 11 #ifndef _LINUX_SLAB_H
 12 #define _LINUX_SLAB_H
 13 
 14 #include <linux/gfp.h>
 15 #include <linux/types.h>
 16 #include <linux/workqueue.h>
 17 
 18 
 19 /*
 20  * Flags to pass to kmem_cache_create().
 21  * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
 22  */
 23 #define SLAB_CONSISTENCY_CHECKS 0x00000100UL    /* DEBUG: Perform (expensive) checks on alloc/free */
 24 #define SLAB_RED_ZONE           0x00000400UL    /* DEBUG: Red zone objs in a cache */
 25 #define SLAB_POISON             0x00000800UL    /* DEBUG: Poison objects */
 26 #define SLAB_HWCACHE_ALIGN      0x00002000UL    /* Align objs on cache lines */
 27 #define SLAB_CACHE_DMA          0x00004000UL    /* Use GFP_DMA memory */
 28 #define SLAB_STORE_USER         0x00010000UL    /* DEBUG: Store the last owner for bug hunting */
 29 #define SLAB_PANIC              0x00040000UL    /* Panic if kmem_cache_create() fails */
 30 /*
 31  * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
 32  *
 33  * This delays freeing the SLAB page by a grace period, it does _NOT_
 34  * delay object freeing. This means that if you do kmem_cache_free()
 35  * that memory location is free to be reused at any time. Thus it may
 36  * be possible to see another object there in the same RCU grace period.
 37  *
 38  * This feature only ensures the memory location backing the object
 39  * stays valid, the trick to using this is relying on an independent
 40  * object validation pass. Something like:
 41  *
 42  *  rcu_read_lock()
 43  * again:
 44  *  obj = lockless_lookup(key);
 45  *  if (obj) {
 46  *    if (!try_get_ref(obj)) // might fail for free objects
 47  *      goto again;
 48  *
 49  *    if (obj->key != key) { // not the object we expected
 50  *      put_ref(obj);
 51  *      goto again;
 52  *    }
 53  *  }
 54  *  rcu_read_unlock();
 55  *
 56  * This is useful if we need to approach a kernel structure obliquely,
 57  * from its address obtained without the usual locking. We can lock
 58  * the structure to stabilize it and check it's still at the given address,
 59  * only if we can be sure that the memory has not been meanwhile reused
 60  * for some other kind of object (which our subsystem's lock might corrupt).
 61  *
 62  * rcu_read_lock before reading the address, then rcu_read_unlock after
 63  * taking the spinlock within the structure expected at that address.
 64  *
 65  * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
 66  */
 67 #define SLAB_TYPESAFE_BY_RCU    0x00080000UL    /* Defer freeing slabs to RCU */
 68 #define SLAB_MEM_SPREAD         0x00100000UL    /* Spread some memory over cpuset */
 69 #define SLAB_TRACE              0x00200000UL    /* Trace allocations and frees */
 70 
 71 /* Flag to prevent checks on free */
 72 #ifdef CONFIG_DEBUG_OBJECTS
 73 # define SLAB_DEBUG_OBJECTS     0x00400000UL
 74 #else
 75 # define SLAB_DEBUG_OBJECTS     0x00000000UL
 76 #endif
 77 
 78 #define SLAB_NOLEAKTRACE        0x00800000UL    /* Avoid kmemleak tracing */
 79 
 80 /* Don't track use of uninitialized memory */
 81 #ifdef CONFIG_KMEMCHECK
 82 # define SLAB_NOTRACK           0x01000000UL
 83 #else
 84 # define SLAB_NOTRACK           0x00000000UL
 85 #endif
 86 #ifdef CONFIG_FAILSLAB
 87 # define SLAB_FAILSLAB          0x02000000UL    /* Fault injection mark */
 88 #else
 89 # define SLAB_FAILSLAB          0x00000000UL
 90 #endif
 91 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 92 # define SLAB_ACCOUNT           0x04000000UL    /* Account to memcg */
 93 #else
 94 # define SLAB_ACCOUNT           0x00000000UL
 95 #endif
 96 
 97 #ifdef CONFIG_KASAN
 98 #define SLAB_KASAN              0x08000000UL
 99 #else
100 #define SLAB_KASAN              0x00000000UL
101 #endif
102 
103 /* The following flags affect the page allocator grouping pages by mobility */
104 #define SLAB_RECLAIM_ACCOUNT    0x00020000UL            /* Objects are reclaimable */
105 #define SLAB_TEMPORARY          SLAB_RECLAIM_ACCOUNT    /* Objects are short-lived */
106 /*
107  * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
108  *
109  * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
110  *
111  * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
112  * Both make kfree a no-op.
113  */
114 #define ZERO_SIZE_PTR ((void *)16)
115 
116 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
117                                 (unsigned long)ZERO_SIZE_PTR)
118 
119 #include <linux/kmemleak.h>
120 #include <linux/kasan.h>
121 
122 struct mem_cgroup;
123 /*
124  * struct kmem_cache related prototypes
125  */
126 void __init kmem_cache_init(void);
127 bool slab_is_available(void);
128 
129 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
130                         unsigned long,
131                         void (*)(void *));
132 void kmem_cache_destroy(struct kmem_cache *);
133 int kmem_cache_shrink(struct kmem_cache *);
134 
135 void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
136 void memcg_deactivate_kmem_caches(struct mem_cgroup *);
137 void memcg_destroy_kmem_caches(struct mem_cgroup *);
138 
139 /*
140  * Please use this macro to create slab caches. Simply specify the
141  * name of the structure and maybe some flags that are listed above.
142  *
143  * The alignment of the struct determines object alignment. If you
144  * f.e. add ____cacheline_aligned_in_smp to the struct declaration
145  * then the objects will be properly aligned in SMP configurations.
146  */
147 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
148                 sizeof(struct __struct), __alignof__(struct __struct),\
149                 (__flags), NULL)
150 
151 /*
152  * Common kmalloc functions provided by all allocators
153  */
154 void * __must_check __krealloc(const void *, size_t, gfp_t);
155 void * __must_check krealloc(const void *, size_t, gfp_t);
156 void kfree(const void *);
157 void kzfree(const void *);
158 size_t ksize(const void *);
159 
160 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
161 const char *__check_heap_object(const void *ptr, unsigned long n,
162                                 struct page *page);
163 #else
164 static inline const char *__check_heap_object(const void *ptr,
165                                               unsigned long n,
166                                               struct page *page)
167 {
168         return NULL;
169 }
170 #endif
171 
172 /*
173  * Some archs want to perform DMA into kmalloc caches and need a guaranteed
174  * alignment larger than the alignment of a 64-bit integer.
175  * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
176  */
177 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
178 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
179 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
180 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
181 #else
182 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
183 #endif
184 
185 /*
186  * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
187  * Intended for arches that get misalignment faults even for 64 bit integer
188  * aligned buffers.
189  */
190 #ifndef ARCH_SLAB_MINALIGN
191 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
192 #endif
193 
194 /*
195  * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
196  * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
197  * aligned pointers.
198  */
199 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
200 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
201 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
202 
203 /*
204  * Kmalloc array related definitions
205  */
206 
207 #ifdef CONFIG_SLAB
208 /*
209  * The largest kmalloc size supported by the SLAB allocators is
210  * 32 megabyte (2^25) or the maximum allocatable page order if that is
211  * less than 32 MB.
212  *
213  * WARNING: Its not easy to increase this value since the allocators have
214  * to do various tricks to work around compiler limitations in order to
215  * ensure proper constant folding.
216  */
217 #define KMALLOC_SHIFT_HIGH      ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
218                                 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
219 #define KMALLOC_SHIFT_MAX       KMALLOC_SHIFT_HIGH
220 #ifndef KMALLOC_SHIFT_LOW
221 #define KMALLOC_SHIFT_LOW       5
222 #endif
223 #endif
224 
225 #ifdef CONFIG_SLUB
226 /*
227  * SLUB directly allocates requests fitting in to an order-1 page
228  * (PAGE_SIZE*2).  Larger requests are passed to the page allocator.
229  */
230 #define KMALLOC_SHIFT_HIGH      (PAGE_SHIFT + 1)
231 #define KMALLOC_SHIFT_MAX       (MAX_ORDER + PAGE_SHIFT - 1)
232 #ifndef KMALLOC_SHIFT_LOW
233 #define KMALLOC_SHIFT_LOW       3
234 #endif
235 #endif
236 
237 #ifdef CONFIG_SLOB
238 /*
239  * SLOB passes all requests larger than one page to the page allocator.
240  * No kmalloc array is necessary since objects of different sizes can
241  * be allocated from the same page.
242  */
243 #define KMALLOC_SHIFT_HIGH      PAGE_SHIFT
244 #define KMALLOC_SHIFT_MAX       (MAX_ORDER + PAGE_SHIFT - 1)
245 #ifndef KMALLOC_SHIFT_LOW
246 #define KMALLOC_SHIFT_LOW       3
247 #endif
248 #endif
249 
250 /* Maximum allocatable size */
251 #define KMALLOC_MAX_SIZE        (1UL << KMALLOC_SHIFT_MAX)
252 /* Maximum size for which we actually use a slab cache */
253 #define KMALLOC_MAX_CACHE_SIZE  (1UL << KMALLOC_SHIFT_HIGH)
254 /* Maximum order allocatable via the slab allocagtor */
255 #define KMALLOC_MAX_ORDER       (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
256 
257 /*
258  * Kmalloc subsystem.
259  */
260 #ifndef KMALLOC_MIN_SIZE
261 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
262 #endif
263 
264 /*
265  * This restriction comes from byte sized index implementation.
266  * Page size is normally 2^12 bytes and, in this case, if we want to use
267  * byte sized index which can represent 2^8 entries, the size of the object
268  * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
269  * If minimum size of kmalloc is less than 16, we use it as minimum object
270  * size and give up to use byte sized index.
271  */
272 #define SLAB_OBJ_MIN_SIZE      (KMALLOC_MIN_SIZE < 16 ? \
273                                (KMALLOC_MIN_SIZE) : 16)
274 
275 #ifndef CONFIG_SLOB
276 extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
277 #ifdef CONFIG_ZONE_DMA
278 extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
279 #endif
280 
281 /*
282  * Figure out which kmalloc slab an allocation of a certain size
283  * belongs to.
284  * 0 = zero alloc
285  * 1 =  65 .. 96 bytes
286  * 2 = 129 .. 192 bytes
287  * n = 2^(n-1)+1 .. 2^n
288  */
289 static __always_inline int kmalloc_index(size_t size)
290 {
291         if (!size)
292                 return 0;
293 
294         if (size <= KMALLOC_MIN_SIZE)
295                 return KMALLOC_SHIFT_LOW;
296 
297         if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
298                 return 1;
299         if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
300                 return 2;
301         if (size <=          8) return 3;
302         if (size <=         16) return 4;
303         if (size <=         32) return 5;
304         if (size <=         64) return 6;
305         if (size <=        128) return 7;
306         if (size <=        256) return 8;
307         if (size <=        512) return 9;
308         if (size <=       1024) return 10;
309         if (size <=   2 * 1024) return 11;
310         if (size <=   4 * 1024) return 12;
311         if (size <=   8 * 1024) return 13;
312         if (size <=  16 * 1024) return 14;
313         if (size <=  32 * 1024) return 15;
314         if (size <=  64 * 1024) return 16;
315         if (size <= 128 * 1024) return 17;
316         if (size <= 256 * 1024) return 18;
317         if (size <= 512 * 1024) return 19;
318         if (size <= 1024 * 1024) return 20;
319         if (size <=  2 * 1024 * 1024) return 21;
320         if (size <=  4 * 1024 * 1024) return 22;
321         if (size <=  8 * 1024 * 1024) return 23;
322         if (size <=  16 * 1024 * 1024) return 24;
323         if (size <=  32 * 1024 * 1024) return 25;
324         if (size <=  64 * 1024 * 1024) return 26;
325         BUG();
326 
327         /* Will never be reached. Needed because the compiler may complain */
328         return -1;
329 }
330 #endif /* !CONFIG_SLOB */
331 
332 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
333 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;
334 void kmem_cache_free(struct kmem_cache *, void *);
335 
336 /*
337  * Bulk allocation and freeing operations. These are accelerated in an
338  * allocator specific way to avoid taking locks repeatedly or building
339  * metadata structures unnecessarily.
340  *
341  * Note that interrupts must be enabled when calling these functions.
342  */
343 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
344 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
345 
346 /*
347  * Caller must not use kfree_bulk() on memory not originally allocated
348  * by kmalloc(), because the SLOB allocator cannot handle this.
349  */
350 static __always_inline void kfree_bulk(size_t size, void **p)
351 {
352         kmem_cache_free_bulk(NULL, size, p);
353 }
354 
355 #ifdef CONFIG_NUMA
356 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc;
357 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc;
358 #else
359 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
360 {
361         return __kmalloc(size, flags);
362 }
363 
364 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
365 {
366         return kmem_cache_alloc(s, flags);
367 }
368 #endif
369 
370 #ifdef CONFIG_TRACING
371 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc;
372 
373 #ifdef CONFIG_NUMA
374 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
375                                            gfp_t gfpflags,
376                                            int node, size_t size) __assume_slab_alignment __malloc;
377 #else
378 static __always_inline void *
379 kmem_cache_alloc_node_trace(struct kmem_cache *s,
380                               gfp_t gfpflags,
381                               int node, size_t size)
382 {
383         return kmem_cache_alloc_trace(s, gfpflags, size);
384 }
385 #endif /* CONFIG_NUMA */
386 
387 #else /* CONFIG_TRACING */
388 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
389                 gfp_t flags, size_t size)
390 {
391         void *ret = kmem_cache_alloc(s, flags);
392 
393         kasan_kmalloc(s, ret, size, flags);
394         return ret;
395 }
396 
397 static __always_inline void *
398 kmem_cache_alloc_node_trace(struct kmem_cache *s,
399                               gfp_t gfpflags,
400                               int node, size_t size)
401 {
402         void *ret = kmem_cache_alloc_node(s, gfpflags, node);
403 
404         kasan_kmalloc(s, ret, size, gfpflags);
405         return ret;
406 }
407 #endif /* CONFIG_TRACING */
408 
409 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
410 
411 #ifdef CONFIG_TRACING
412 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
413 #else
414 static __always_inline void *
415 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
416 {
417         return kmalloc_order(size, flags, order);
418 }
419 #endif
420 
421 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
422 {
423         unsigned int order = get_order(size);
424         return kmalloc_order_trace(size, flags, order);
425 }
426 
427 /**
428  * kmalloc - allocate memory
429  * @size: how many bytes of memory are required.
430  * @flags: the type of memory to allocate.
431  *
432  * kmalloc is the normal method of allocating memory
433  * for objects smaller than page size in the kernel.
434  *
435  * The @flags argument may be one of:
436  *
437  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
438  *
439  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
440  *
441  * %GFP_ATOMIC - Allocation will not sleep.  May use emergency pools.
442  *   For example, use this inside interrupt handlers.
443  *
444  * %GFP_HIGHUSER - Allocate pages from high memory.
445  *
446  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
447  *
448  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
449  *
450  * %GFP_NOWAIT - Allocation will not sleep.
451  *
452  * %__GFP_THISNODE - Allocate node-local memory only.
453  *
454  * %GFP_DMA - Allocation suitable for DMA.
455  *   Should only be used for kmalloc() caches. Otherwise, use a
456  *   slab created with SLAB_DMA.
457  *
458  * Also it is possible to set different flags by OR'ing
459  * in one or more of the following additional @flags:
460  *
461  * %__GFP_COLD - Request cache-cold pages instead of
462  *   trying to return cache-warm pages.
463  *
464  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
465  *
466  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
467  *   (think twice before using).
468  *
469  * %__GFP_NORETRY - If memory is not immediately available,
470  *   then give up at once.
471  *
472  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
473  *
474  * %__GFP_RETRY_MAYFAIL - Try really hard to succeed the allocation but fail
475  *   eventually.
476  *
477  * There are other flags available as well, but these are not intended
478  * for general use, and so are not documented here. For a full list of
479  * potential flags, always refer to linux/gfp.h.
480  */
481 static __always_inline void *kmalloc(size_t size, gfp_t flags)
482 {
483         if (__builtin_constant_p(size)) {
484                 if (size > KMALLOC_MAX_CACHE_SIZE)
485                         return kmalloc_large(size, flags);
486 #ifndef CONFIG_SLOB
487                 if (!(flags & GFP_DMA)) {
488                         int index = kmalloc_index(size);
489 
490                         if (!index)
491                                 return ZERO_SIZE_PTR;
492 
493                         return kmem_cache_alloc_trace(kmalloc_caches[index],
494                                         flags, size);
495                 }
496 #endif
497         }
498         return __kmalloc(size, flags);
499 }
500 
501 /*
502  * Determine size used for the nth kmalloc cache.
503  * return size or 0 if a kmalloc cache for that
504  * size does not exist
505  */
506 static __always_inline int kmalloc_size(int n)
507 {
508 #ifndef CONFIG_SLOB
509         if (n > 2)
510                 return 1 << n;
511 
512         if (n == 1 && KMALLOC_MIN_SIZE <= 32)
513                 return 96;
514 
515         if (n == 2 && KMALLOC_MIN_SIZE <= 64)
516                 return 192;
517 #endif
518         return 0;
519 }
520 
521 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
522 {
523 #ifndef CONFIG_SLOB
524         if (__builtin_constant_p(size) &&
525                 size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {
526                 int i = kmalloc_index(size);
527 
528                 if (!i)
529                         return ZERO_SIZE_PTR;
530 
531                 return kmem_cache_alloc_node_trace(kmalloc_caches[i],
532                                                 flags, node, size);
533         }
534 #endif
535         return __kmalloc_node(size, flags, node);
536 }
537 
538 struct memcg_cache_array {
539         struct rcu_head rcu;
540         struct kmem_cache *entries[0];
541 };
542 
543 /*
544  * This is the main placeholder for memcg-related information in kmem caches.
545  * Both the root cache and the child caches will have it. For the root cache,
546  * this will hold a dynamically allocated array large enough to hold
547  * information about the currently limited memcgs in the system. To allow the
548  * array to be accessed without taking any locks, on relocation we free the old
549  * version only after a grace period.
550  *
551  * Root and child caches hold different metadata.
552  *
553  * @root_cache: Common to root and child caches.  NULL for root, pointer to
554  *              the root cache for children.
555  *
556  * The following fields are specific to root caches.
557  *
558  * @memcg_caches: kmemcg ID indexed table of child caches.  This table is
559  *              used to index child cachces during allocation and cleared
560  *              early during shutdown.
561  *
562  * @root_caches_node: List node for slab_root_caches list.
563  *
564  * @children:   List of all child caches.  While the child caches are also
565  *              reachable through @memcg_caches, a child cache remains on
566  *              this list until it is actually destroyed.
567  *
568  * The following fields are specific to child caches.
569  *
570  * @memcg:      Pointer to the memcg this cache belongs to.
571  *
572  * @children_node: List node for @root_cache->children list.
573  *
574  * @kmem_caches_node: List node for @memcg->kmem_caches list.
575  */
576 struct memcg_cache_params {
577         struct kmem_cache *root_cache;
578         union {
579                 struct {
580                         struct memcg_cache_array __rcu *memcg_caches;
581                         struct list_head __root_caches_node;
582                         struct list_head children;
583                 };
584                 struct {
585                         struct mem_cgroup *memcg;
586                         struct list_head children_node;
587                         struct list_head kmem_caches_node;
588 
589                         void (*deact_fn)(struct kmem_cache *);
590                         union {
591                                 struct rcu_head deact_rcu_head;
592                                 struct work_struct deact_work;
593                         };
594                 };
595         };
596 };
597 
598 int memcg_update_all_caches(int num_memcgs);
599 
600 /**
601  * kmalloc_array - allocate memory for an array.
602  * @n: number of elements.
603  * @size: element size.
604  * @flags: the type of memory to allocate (see kmalloc).
605  */
606 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
607 {
608         if (size != 0 && n > SIZE_MAX / size)
609                 return NULL;
610         if (__builtin_constant_p(n) && __builtin_constant_p(size))
611                 return kmalloc(n * size, flags);
612         return __kmalloc(n * size, flags);
613 }
614 
615 /**
616  * kcalloc - allocate memory for an array. The memory is set to zero.
617  * @n: number of elements.
618  * @size: element size.
619  * @flags: the type of memory to allocate (see kmalloc).
620  */
621 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
622 {
623         return kmalloc_array(n, size, flags | __GFP_ZERO);
624 }
625 
626 /*
627  * kmalloc_track_caller is a special version of kmalloc that records the
628  * calling function of the routine calling it for slab leak tracking instead
629  * of just the calling function (confusing, eh?).
630  * It's useful when the call to kmalloc comes from a widely-used standard
631  * allocator where we care about the real place the memory allocation
632  * request comes from.
633  */
634 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
635 #define kmalloc_track_caller(size, flags) \
636         __kmalloc_track_caller(size, flags, _RET_IP_)
637 
638 #ifdef CONFIG_NUMA
639 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
640 #define kmalloc_node_track_caller(size, flags, node) \
641         __kmalloc_node_track_caller(size, flags, node, \
642                         _RET_IP_)
643 
644 #else /* CONFIG_NUMA */
645 
646 #define kmalloc_node_track_caller(size, flags, node) \
647         kmalloc_track_caller(size, flags)
648 
649 #endif /* CONFIG_NUMA */
650 
651 /*
652  * Shortcuts
653  */
654 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
655 {
656         return kmem_cache_alloc(k, flags | __GFP_ZERO);
657 }
658 
659 /**
660  * kzalloc - allocate memory. The memory is set to zero.
661  * @size: how many bytes of memory are required.
662  * @flags: the type of memory to allocate (see kmalloc).
663  */
664 static inline void *kzalloc(size_t size, gfp_t flags)
665 {
666         return kmalloc(size, flags | __GFP_ZERO);
667 }
668 
669 /**
670  * kzalloc_node - allocate zeroed memory from a particular memory node.
671  * @size: how many bytes of memory are required.
672  * @flags: the type of memory to allocate (see kmalloc).
673  * @node: memory node from which to allocate
674  */
675 static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
676 {
677         return kmalloc_node(size, flags | __GFP_ZERO, node);
678 }
679 
680 unsigned int kmem_cache_size(struct kmem_cache *s);
681 void __init kmem_cache_init_late(void);
682 
683 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
684 int slab_prepare_cpu(unsigned int cpu);
685 int slab_dead_cpu(unsigned int cpu);
686 #else
687 #define slab_prepare_cpu        NULL
688 #define slab_dead_cpu           NULL
689 #endif
690 
691 #endif  /* _LINUX_SLAB_H */
692 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp