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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Christoph Lameter2e892f42006-12-13 00:34:23 -08002 * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
3 *
4 * (C) SGI 2006, Christoph Lameter <clameter@sgi.com>
5 * Cleaned up and restructured to ease the addition of alternative
6 * implementations of SLAB allocators.
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 */
8
9#ifndef _LINUX_SLAB_H
10#define _LINUX_SLAB_H
11
Andrew Morton1b1cec42006-12-06 20:33:22 -080012#include <linux/gfp.h>
Andrew Morton1b1cec42006-12-06 20:33:22 -080013#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014
Christoph Lameter2e892f42006-12-13 00:34:23 -080015/*
16 * Flags to pass to kmem_cache_create().
17 * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set.
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 */
Christoph Lameter55935a32006-12-13 00:34:24 -080019#define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */
Christoph Lameter55935a32006-12-13 00:34:24 -080020#define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */
21#define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */
22#define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */
Christoph Lameter2e892f42006-12-13 00:34:23 -080023#define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */
Christoph Lameter2e892f42006-12-13 00:34:23 -080024#define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */
Christoph Lameter2e892f42006-12-13 00:34:23 -080025#define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */
26#define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
Paul Jackson101a5002006-03-24 03:16:07 -080027#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
Christoph Lameter81819f02007-05-06 14:49:36 -070028#define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
Thomas Gleixner30327ac2008-04-30 00:54:59 -070030/* Flag to prevent checks on free */
31#ifdef CONFIG_DEBUG_OBJECTS
32# define SLAB_DEBUG_OBJECTS 0x00400000UL
33#else
34# define SLAB_DEBUG_OBJECTS 0x00000000UL
35#endif
36
Mel Gormane12ba742007-10-16 01:25:52 -070037/* The following flags affect the page allocator grouping pages by mobility */
38#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
39#define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
Christoph Lameter2e892f42006-12-13 00:34:23 -080040/*
Christoph Lameter6cb8f912007-07-17 04:03:22 -070041 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
42 *
43 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
44 *
45 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
46 * Both make kfree a no-op.
47 */
48#define ZERO_SIZE_PTR ((void *)16)
49
Roland Dreier1d4ec7b2007-07-20 12:13:20 -070050#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
Christoph Lameter6cb8f912007-07-17 04:03:22 -070051 (unsigned long)ZERO_SIZE_PTR)
52
53/*
Christoph Lameter2e892f42006-12-13 00:34:23 -080054 * struct kmem_cache related prototypes
55 */
56void __init kmem_cache_init(void);
Christoph Lameter81819f02007-05-06 14:49:36 -070057int slab_is_available(void);
Matt Mackall10cef602006-01-08 01:01:45 -080058
Christoph Lameter2e892f42006-12-13 00:34:23 -080059struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
Christoph Lameterebe29732006-12-06 20:32:59 -080060 unsigned long,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -070061 void (*)(struct kmem_cache *, void *));
Christoph Lameter2e892f42006-12-13 00:34:23 -080062void kmem_cache_destroy(struct kmem_cache *);
63int kmem_cache_shrink(struct kmem_cache *);
Christoph Lameter2e892f42006-12-13 00:34:23 -080064void kmem_cache_free(struct kmem_cache *, void *);
65unsigned int kmem_cache_size(struct kmem_cache *);
66const char *kmem_cache_name(struct kmem_cache *);
Christoph Lameter55935a32006-12-13 00:34:24 -080067int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Christoph Lameter0a31bd52007-05-06 14:49:57 -070069/*
70 * Please use this macro to create slab caches. Simply specify the
71 * name of the structure and maybe some flags that are listed above.
72 *
73 * The alignment of the struct determines object alignment. If you
74 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
75 * then the objects will be properly aligned in SMP configurations.
76 */
77#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
78 sizeof(struct __struct), __alignof__(struct __struct),\
Paul Mundt20c2df82007-07-20 10:11:58 +090079 (__flags), NULL)
Christoph Lameter0a31bd52007-05-06 14:49:57 -070080
Christoph Lameter2e892f42006-12-13 00:34:23 -080081/*
Christoph Lameter0aa817f2007-05-16 22:11:01 -070082 * The largest kmalloc size supported by the slab allocators is
83 * 32 megabyte (2^25) or the maximum allocatable page order if that is
84 * less than 32 MB.
85 *
86 * WARNING: Its not easy to increase this value since the allocators have
87 * to do various tricks to work around compiler limitations in order to
88 * ensure proper constant folding.
89 */
Christoph Lameterdebee072007-06-23 17:16:43 -070090#define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
91 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
Christoph Lameter0aa817f2007-05-16 22:11:01 -070092
93#define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH)
94#define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT)
95
96/*
Christoph Lameter2e892f42006-12-13 00:34:23 -080097 * Common kmalloc functions provided by all allocators
98 */
Pekka Enbergfd76bab2007-05-06 14:48:40 -070099void * __must_check krealloc(const void *, size_t, gfp_t);
Christoph Lameter2e892f42006-12-13 00:34:23 -0800100void kfree(const void *);
Pekka Enbergfd76bab2007-05-06 14:48:40 -0700101size_t ksize(const void *);
Christoph Lameter2e892f42006-12-13 00:34:23 -0800102
Christoph Lameter81cda662007-07-17 04:03:29 -0700103/*
104 * Allocator specific definitions. These are mainly used to establish optimized
105 * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by
106 * selecting the appropriate general cache at compile time.
107 *
108 * Allocators must define at least:
109 *
110 * kmem_cache_alloc()
111 * __kmalloc()
112 * kmalloc()
113 *
114 * Those wishing to support NUMA must also define:
115 *
116 * kmem_cache_alloc_node()
117 * kmalloc_node()
118 *
119 * See each allocator definition file for additional comments and
120 * implementation notes.
121 */
122#ifdef CONFIG_SLUB
123#include <linux/slub_def.h>
124#elif defined(CONFIG_SLOB)
125#include <linux/slob_def.h>
126#else
127#include <linux/slab_def.h>
128#endif
129
Christoph Lameter2e892f42006-12-13 00:34:23 -0800130/**
131 * kcalloc - allocate memory for an array. The memory is set to zero.
132 * @n: number of elements.
133 * @size: element size.
134 * @flags: the type of memory to allocate.
Paul Drynoff800590f2006-06-23 02:03:48 -0700135 *
136 * The @flags argument may be one of:
137 *
138 * %GFP_USER - Allocate memory on behalf of user. May sleep.
139 *
140 * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
141 *
Paul Mundt6193a2f2007-07-15 23:38:22 -0700142 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
Paul Drynoff800590f2006-06-23 02:03:48 -0700143 * For example, use this inside interrupt handlers.
144 *
145 * %GFP_HIGHUSER - Allocate pages from high memory.
146 *
147 * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
148 *
149 * %GFP_NOFS - Do not make any fs calls while trying to get memory.
150 *
Paul Mundt6193a2f2007-07-15 23:38:22 -0700151 * %GFP_NOWAIT - Allocation will not sleep.
152 *
153 * %GFP_THISNODE - Allocate node-local memory only.
154 *
155 * %GFP_DMA - Allocation suitable for DMA.
156 * Should only be used for kmalloc() caches. Otherwise, use a
157 * slab created with SLAB_DMA.
158 *
Paul Drynoff800590f2006-06-23 02:03:48 -0700159 * Also it is possible to set different flags by OR'ing
160 * in one or more of the following additional @flags:
161 *
162 * %__GFP_COLD - Request cache-cold pages instead of
163 * trying to return cache-warm pages.
164 *
Paul Drynoff800590f2006-06-23 02:03:48 -0700165 * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
166 *
Paul Drynoff800590f2006-06-23 02:03:48 -0700167 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
168 * (think twice before using).
169 *
170 * %__GFP_NORETRY - If memory is not immediately available,
171 * then give up at once.
172 *
173 * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
174 *
175 * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
Paul Mundt6193a2f2007-07-15 23:38:22 -0700176 *
177 * There are other flags available as well, but these are not intended
178 * for general use, and so are not documented here. For a full list of
179 * potential flags, always refer to linux/gfp.h.
Paul Drynoff800590f2006-06-23 02:03:48 -0700180 */
Paul Mundt6193a2f2007-07-15 23:38:22 -0700181static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
Paul Mundt6193a2f2007-07-15 23:38:22 -0700183 if (n != 0 && size > ULONG_MAX / n)
184 return NULL;
Christoph Lameter81cda662007-07-17 04:03:29 -0700185 return __kmalloc(n * size, flags | __GFP_ZERO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186}
187
Paul Mundt6193a2f2007-07-15 23:38:22 -0700188#if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB)
189/**
190 * kmalloc_node - allocate memory from a specific node
191 * @size: how many bytes of memory are required.
192 * @flags: the type of memory to allocate (see kcalloc).
193 * @node: node to allocate from.
194 *
195 * kmalloc() for non-local nodes, used to allocate from a specific node
196 * if available. Equivalent to kmalloc() in the non-NUMA single-node
197 * case.
198 */
Christoph Lameter55935a32006-12-13 00:34:24 -0800199static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
200{
201 return kmalloc(size, flags);
202}
203
204static inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
205{
206 return __kmalloc(size, flags);
207}
Paul Mundt6193a2f2007-07-15 23:38:22 -0700208
209void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
210
211static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
212 gfp_t flags, int node)
213{
214 return kmem_cache_alloc(cachep, flags);
215}
216#endif /* !CONFIG_NUMA && !CONFIG_SLOB */
Christoph Lameter55935a32006-12-13 00:34:24 -0800217
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -0700218/*
219 * kmalloc_track_caller is a special version of kmalloc that records the
220 * calling function of the routine calling it for slab leak tracking instead
221 * of just the calling function (confusing, eh?).
222 * It's useful when the call to kmalloc comes from a widely-used standard
223 * allocator where we care about the real place the memory allocation
224 * request comes from.
225 */
Christoph Lameter81819f02007-05-06 14:49:36 -0700226#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -0700227extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
228#define kmalloc_track_caller(size, flags) \
229 __kmalloc_track_caller(size, flags, __builtin_return_address(0))
Christoph Lameter2e892f42006-12-13 00:34:23 -0800230#else
231#define kmalloc_track_caller(size, flags) \
232 __kmalloc(size, flags)
233#endif /* DEBUG_SLAB */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700235#ifdef CONFIG_NUMA
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800236/*
237 * kmalloc_node_track_caller is a special version of kmalloc_node that
238 * records the calling function of the routine calling it for slab leak
239 * tracking instead of just the calling function (confusing, eh?).
240 * It's useful when the call to kmalloc_node comes from a widely-used
241 * standard allocator where we care about the real place the memory
242 * allocation request comes from.
243 */
Christoph Lameter81819f02007-05-06 14:49:36 -0700244#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800245extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
246#define kmalloc_node_track_caller(size, flags, node) \
247 __kmalloc_node_track_caller(size, flags, node, \
248 __builtin_return_address(0))
Christoph Lameter2e892f42006-12-13 00:34:23 -0800249#else
250#define kmalloc_node_track_caller(size, flags, node) \
251 __kmalloc_node(size, flags, node)
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800252#endif
Christoph Lameter2e892f42006-12-13 00:34:23 -0800253
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800254#else /* CONFIG_NUMA */
Christoph Lameter2e892f42006-12-13 00:34:23 -0800255
256#define kmalloc_node_track_caller(size, flags, node) \
257 kmalloc_track_caller(size, flags)
258
Christoph Lameter55935a32006-12-13 00:34:24 -0800259#endif /* DEBUG_SLAB */
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800260
Christoph Lameter81cda662007-07-17 04:03:29 -0700261/*
262 * Shortcuts
263 */
264static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
265{
266 return kmem_cache_alloc(k, flags | __GFP_ZERO);
267}
268
269/**
270 * kzalloc - allocate memory. The memory is set to zero.
271 * @size: how many bytes of memory are required.
272 * @flags: the type of memory to allocate (see kmalloc).
273 */
274static inline void *kzalloc(size_t size, gfp_t flags)
275{
276 return kmalloc(size, flags | __GFP_ZERO);
277}
278
Linus Torvalds158a9622008-01-02 13:04:48 -0800279#ifdef CONFIG_SLABINFO
280extern const struct seq_operations slabinfo_op;
281ssize_t slabinfo_write(struct file *, const char __user *, size_t, loff_t *);
282#endif
283
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284#endif /* _LINUX_SLAB_H */