blob: f3a8eecd99f3c4b5eb68d10389e3b96546699f4d [file] [log] [blame]
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#ifdef __KERNEL__
13
14#include <linux/gfp.h>
Andrew Morton1b1cec42006-12-06 20:33:22 -080015#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
Christoph Lameter2e892f42006-12-13 00:34:23 -080017/*
18 * Flags to pass to kmem_cache_create().
19 * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set.
Linus Torvalds1da177e2005-04-16 15:20:36 -070020 */
Christoph Lameter55935a32006-12-13 00:34:24 -080021#define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */
Christoph Lameter55935a32006-12-13 00:34:24 -080022#define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */
23#define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */
24#define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */
Christoph Lameter2e892f42006-12-13 00:34:23 -080025#define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */
Christoph Lameter2e892f42006-12-13 00:34:23 -080026#define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */
Christoph Lameter2e892f42006-12-13 00:34:23 -080027#define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */
28#define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
Paul Jackson101a5002006-03-24 03:16:07 -080029#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
Christoph Lameter81819f02007-05-06 14:49:36 -070030#define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
Mel Gormane12ba742007-10-16 01:25:52 -070032/* The following flags affect the page allocator grouping pages by mobility */
33#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
34#define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
Christoph Lameter2e892f42006-12-13 00:34:23 -080035/*
Christoph Lameter6cb8f912007-07-17 04:03:22 -070036 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
37 *
38 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
39 *
40 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
41 * Both make kfree a no-op.
42 */
43#define ZERO_SIZE_PTR ((void *)16)
44
Roland Dreier1d4ec7b2007-07-20 12:13:20 -070045#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
Christoph Lameter6cb8f912007-07-17 04:03:22 -070046 (unsigned long)ZERO_SIZE_PTR)
47
48/*
Christoph Lameter2e892f42006-12-13 00:34:23 -080049 * struct kmem_cache related prototypes
50 */
51void __init kmem_cache_init(void);
Christoph Lameter81819f02007-05-06 14:49:36 -070052int slab_is_available(void);
Matt Mackall10cef602006-01-08 01:01:45 -080053
Christoph Lameter2e892f42006-12-13 00:34:23 -080054struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
Christoph Lameterebe29732006-12-06 20:32:59 -080055 unsigned long,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -070056 void (*)(struct kmem_cache *, void *));
Christoph Lameter2e892f42006-12-13 00:34:23 -080057void kmem_cache_destroy(struct kmem_cache *);
58int kmem_cache_shrink(struct kmem_cache *);
Christoph Lameter2e892f42006-12-13 00:34:23 -080059void kmem_cache_free(struct kmem_cache *, void *);
60unsigned int kmem_cache_size(struct kmem_cache *);
61const char *kmem_cache_name(struct kmem_cache *);
Christoph Lameter55935a32006-12-13 00:34:24 -080062int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Christoph Lameter0a31bd52007-05-06 14:49:57 -070064/*
65 * Please use this macro to create slab caches. Simply specify the
66 * name of the structure and maybe some flags that are listed above.
67 *
68 * The alignment of the struct determines object alignment. If you
69 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
70 * then the objects will be properly aligned in SMP configurations.
71 */
72#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
73 sizeof(struct __struct), __alignof__(struct __struct),\
Paul Mundt20c2df82007-07-20 10:11:58 +090074 (__flags), NULL)
Christoph Lameter0a31bd52007-05-06 14:49:57 -070075
Christoph Lameter2e892f42006-12-13 00:34:23 -080076/*
Christoph Lameter0aa817f2007-05-16 22:11:01 -070077 * The largest kmalloc size supported by the slab allocators is
78 * 32 megabyte (2^25) or the maximum allocatable page order if that is
79 * less than 32 MB.
80 *
81 * WARNING: Its not easy to increase this value since the allocators have
82 * to do various tricks to work around compiler limitations in order to
83 * ensure proper constant folding.
84 */
Christoph Lameterdebee072007-06-23 17:16:43 -070085#define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
86 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
Christoph Lameter0aa817f2007-05-16 22:11:01 -070087
88#define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH)
89#define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT)
90
91/*
Christoph Lameter2e892f42006-12-13 00:34:23 -080092 * Common kmalloc functions provided by all allocators
93 */
Pekka Enbergfd76bab2007-05-06 14:48:40 -070094void * __must_check krealloc(const void *, size_t, gfp_t);
Christoph Lameter2e892f42006-12-13 00:34:23 -080095void kfree(const void *);
Pekka Enbergfd76bab2007-05-06 14:48:40 -070096size_t ksize(const void *);
Christoph Lameter2e892f42006-12-13 00:34:23 -080097
Christoph Lameter81cda662007-07-17 04:03:29 -070098/*
99 * Allocator specific definitions. These are mainly used to establish optimized
100 * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by
101 * selecting the appropriate general cache at compile time.
102 *
103 * Allocators must define at least:
104 *
105 * kmem_cache_alloc()
106 * __kmalloc()
107 * kmalloc()
108 *
109 * Those wishing to support NUMA must also define:
110 *
111 * kmem_cache_alloc_node()
112 * kmalloc_node()
113 *
114 * See each allocator definition file for additional comments and
115 * implementation notes.
116 */
117#ifdef CONFIG_SLUB
118#include <linux/slub_def.h>
119#elif defined(CONFIG_SLOB)
120#include <linux/slob_def.h>
121#else
122#include <linux/slab_def.h>
123#endif
124
Christoph Lameter2e892f42006-12-13 00:34:23 -0800125/**
126 * kcalloc - allocate memory for an array. The memory is set to zero.
127 * @n: number of elements.
128 * @size: element size.
129 * @flags: the type of memory to allocate.
Paul Drynoff800590f2006-06-23 02:03:48 -0700130 *
131 * The @flags argument may be one of:
132 *
133 * %GFP_USER - Allocate memory on behalf of user. May sleep.
134 *
135 * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
136 *
Paul Mundt6193a2f2007-07-15 23:38:22 -0700137 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
Paul Drynoff800590f2006-06-23 02:03:48 -0700138 * For example, use this inside interrupt handlers.
139 *
140 * %GFP_HIGHUSER - Allocate pages from high memory.
141 *
142 * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
143 *
144 * %GFP_NOFS - Do not make any fs calls while trying to get memory.
145 *
Paul Mundt6193a2f2007-07-15 23:38:22 -0700146 * %GFP_NOWAIT - Allocation will not sleep.
147 *
148 * %GFP_THISNODE - Allocate node-local memory only.
149 *
150 * %GFP_DMA - Allocation suitable for DMA.
151 * Should only be used for kmalloc() caches. Otherwise, use a
152 * slab created with SLAB_DMA.
153 *
Paul Drynoff800590f2006-06-23 02:03:48 -0700154 * Also it is possible to set different flags by OR'ing
155 * in one or more of the following additional @flags:
156 *
157 * %__GFP_COLD - Request cache-cold pages instead of
158 * trying to return cache-warm pages.
159 *
Paul Drynoff800590f2006-06-23 02:03:48 -0700160 * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
161 *
Paul Drynoff800590f2006-06-23 02:03:48 -0700162 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
163 * (think twice before using).
164 *
165 * %__GFP_NORETRY - If memory is not immediately available,
166 * then give up at once.
167 *
168 * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
169 *
170 * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
Paul Mundt6193a2f2007-07-15 23:38:22 -0700171 *
172 * There are other flags available as well, but these are not intended
173 * for general use, and so are not documented here. For a full list of
174 * potential flags, always refer to linux/gfp.h.
Paul Drynoff800590f2006-06-23 02:03:48 -0700175 */
Paul Mundt6193a2f2007-07-15 23:38:22 -0700176static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177{
Paul Mundt6193a2f2007-07-15 23:38:22 -0700178 if (n != 0 && size > ULONG_MAX / n)
179 return NULL;
Christoph Lameter81cda662007-07-17 04:03:29 -0700180 return __kmalloc(n * size, flags | __GFP_ZERO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181}
182
Paul Mundt6193a2f2007-07-15 23:38:22 -0700183#if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB)
184/**
185 * kmalloc_node - allocate memory from a specific node
186 * @size: how many bytes of memory are required.
187 * @flags: the type of memory to allocate (see kcalloc).
188 * @node: node to allocate from.
189 *
190 * kmalloc() for non-local nodes, used to allocate from a specific node
191 * if available. Equivalent to kmalloc() in the non-NUMA single-node
192 * case.
193 */
Christoph Lameter55935a32006-12-13 00:34:24 -0800194static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
195{
196 return kmalloc(size, flags);
197}
198
199static inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
200{
201 return __kmalloc(size, flags);
202}
Paul Mundt6193a2f2007-07-15 23:38:22 -0700203
204void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
205
206static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
207 gfp_t flags, int node)
208{
209 return kmem_cache_alloc(cachep, flags);
210}
211#endif /* !CONFIG_NUMA && !CONFIG_SLOB */
Christoph Lameter55935a32006-12-13 00:34:24 -0800212
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -0700213/*
214 * kmalloc_track_caller is a special version of kmalloc that records the
215 * calling function of the routine calling it for slab leak tracking instead
216 * of just the calling function (confusing, eh?).
217 * It's useful when the call to kmalloc comes from a widely-used standard
218 * allocator where we care about the real place the memory allocation
219 * request comes from.
220 */
Christoph Lameter81819f02007-05-06 14:49:36 -0700221#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
Christoph Hellwig1d2c8ee2006-10-04 02:15:25 -0700222extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
223#define kmalloc_track_caller(size, flags) \
224 __kmalloc_track_caller(size, flags, __builtin_return_address(0))
Christoph Lameter2e892f42006-12-13 00:34:23 -0800225#else
226#define kmalloc_track_caller(size, flags) \
227 __kmalloc(size, flags)
228#endif /* DEBUG_SLAB */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Manfred Spraul97e2bde2005-05-01 08:58:38 -0700230#ifdef CONFIG_NUMA
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800231/*
232 * kmalloc_node_track_caller is a special version of kmalloc_node that
233 * records the calling function of the routine calling it for slab leak
234 * tracking instead of just the calling function (confusing, eh?).
235 * It's useful when the call to kmalloc_node comes from a widely-used
236 * standard allocator where we care about the real place the memory
237 * allocation request comes from.
238 */
Christoph Lameter81819f02007-05-06 14:49:36 -0700239#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800240extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
241#define kmalloc_node_track_caller(size, flags, node) \
242 __kmalloc_node_track_caller(size, flags, node, \
243 __builtin_return_address(0))
Christoph Lameter2e892f42006-12-13 00:34:23 -0800244#else
245#define kmalloc_node_track_caller(size, flags, node) \
246 __kmalloc_node(size, flags, node)
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800247#endif
Christoph Lameter2e892f42006-12-13 00:34:23 -0800248
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800249#else /* CONFIG_NUMA */
Christoph Lameter2e892f42006-12-13 00:34:23 -0800250
251#define kmalloc_node_track_caller(size, flags, node) \
252 kmalloc_track_caller(size, flags)
253
Christoph Lameter55935a32006-12-13 00:34:24 -0800254#endif /* DEBUG_SLAB */
Christoph Hellwig8b98c162006-12-06 20:32:30 -0800255
Christoph Lameter81cda662007-07-17 04:03:29 -0700256/*
257 * Shortcuts
258 */
259static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
260{
261 return kmem_cache_alloc(k, flags | __GFP_ZERO);
262}
263
264/**
265 * kzalloc - allocate memory. The memory is set to zero.
266 * @size: how many bytes of memory are required.
267 * @flags: the type of memory to allocate (see kmalloc).
268 */
269static inline void *kzalloc(size_t size, gfp_t flags)
270{
271 return kmalloc(size, flags | __GFP_ZERO);
272}
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274#endif /* __KERNEL__ */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275#endif /* _LINUX_SLAB_H */