1 #ifndef _LINUX_SLUB_DEF_H
2 #define _LINUX_SLUB_DEF_H
5 * SLUB : A Slab allocator without object queues.
7 * (C) 2007 SGI, Christoph Lameter
9 #include <linux/types.h>
10 #include <linux/gfp.h>
11 #include <linux/workqueue.h>
12 #include <linux/kobject.h>
14 #include <linux/kmemleak.h>
17 ALLOC_FASTPATH, /* Allocation from cpu slab */
18 ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */
19 FREE_FASTPATH, /* Free to cpu slub */
20 FREE_SLOWPATH, /* Freeing not to cpu slab */
21 FREE_FROZEN, /* Freeing to frozen slab */
22 FREE_ADD_PARTIAL, /* Freeing moves slab to partial list */
23 FREE_REMOVE_PARTIAL, /* Freeing removes last object */
24 ALLOC_FROM_PARTIAL, /* Cpu slab acquired from partial list */
25 ALLOC_SLAB, /* Cpu slab acquired from page allocator */
26 ALLOC_REFILL, /* Refill cpu slab from slab freelist */
27 FREE_SLAB, /* Slab freed to the page allocator */
28 CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
29 DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
30 DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
31 DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
32 DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
33 DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
34 ORDER_FALLBACK, /* Number of times fallback was necessary */
37 struct kmem_cache_cpu {
38 void **freelist; /* Pointer to next available object */
39 #ifdef CONFIG_CMPXCHG_LOCAL
40 unsigned long tid; /* Globally unique transaction id */
42 struct page *page; /* The slab from which we are allocating */
43 int node; /* The node of the page (or -1 for debug) */
44 #ifdef CONFIG_SLUB_STATS
45 unsigned stat[NR_SLUB_STAT_ITEMS];
49 struct kmem_cache_node {
50 spinlock_t list_lock; /* Protect partial list and nr_partial */
51 unsigned long nr_partial;
52 struct list_head partial;
53 #ifdef CONFIG_SLUB_DEBUG
54 atomic_long_t nr_slabs;
55 atomic_long_t total_objects;
56 struct list_head full;
61 * Word size structure that can be atomically updated or read and that
62 * contains both the order and the number of objects that a slab of the
63 * given order would contain.
65 struct kmem_cache_order_objects {
70 * Slab cache management.
73 struct kmem_cache_cpu __percpu *cpu_slab;
74 /* Used for retriving partial slabs etc */
76 unsigned long min_partial;
77 int size; /* The size of an object including meta data */
78 int objsize; /* The size of an object without meta data */
79 int offset; /* Free pointer offset. */
80 struct kmem_cache_order_objects oo;
82 /* Allocation and freeing of slabs */
83 struct kmem_cache_order_objects max;
84 struct kmem_cache_order_objects min;
85 gfp_t allocflags; /* gfp flags to use on each alloc */
86 int refcount; /* Refcount for slab cache destroy */
88 int inuse; /* Offset to metadata */
89 int align; /* Alignment */
90 int reserved; /* Reserved bytes at the end of slabs */
91 const char *name; /* Name (only for display!) */
92 struct list_head list; /* List of slab caches */
94 struct kobject kobj; /* For sysfs */
99 * Defragmentation by allocating from a remote node.
101 int remote_node_defrag_ratio;
103 struct kmem_cache_node *node[MAX_NUMNODES];
109 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
110 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
112 #define KMALLOC_MIN_SIZE 8
115 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
117 #ifdef ARCH_DMA_MINALIGN
118 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
120 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
123 #ifndef ARCH_SLAB_MINALIGN
124 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
128 * Maximum kmalloc object size handled by SLUB. Larger object allocations
129 * are passed through to the page allocator. The page allocator "fastpath"
130 * is relatively slow so we need this value sufficiently high so that
131 * performance critical objects are allocated through the SLUB fastpath.
133 * This should be dropped to PAGE_SIZE / 2 once the page allocator
134 * "fastpath" becomes competitive with the slab allocator fastpaths.
136 #define SLUB_MAX_SIZE (2 * PAGE_SIZE)
138 #define SLUB_PAGE_SHIFT (PAGE_SHIFT + 2)
140 #ifdef CONFIG_ZONE_DMA
141 #define SLUB_DMA __GFP_DMA
143 /* Disable DMA functionality */
144 #define SLUB_DMA (__force gfp_t)0
148 * We keep the general caches in an array of slab caches that are used for
149 * 2^x bytes of allocations.
151 extern struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
154 * Sorry that the following has to be that ugly but some versions of GCC
155 * have trouble with constant propagation and loops.
157 static __always_inline int kmalloc_index(size_t size)
162 if (size <= KMALLOC_MIN_SIZE)
163 return KMALLOC_SHIFT_LOW;
165 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
167 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
169 if (size <= 8) return 3;
170 if (size <= 16) return 4;
171 if (size <= 32) return 5;
172 if (size <= 64) return 6;
173 if (size <= 128) return 7;
174 if (size <= 256) return 8;
175 if (size <= 512) return 9;
176 if (size <= 1024) return 10;
177 if (size <= 2 * 1024) return 11;
178 if (size <= 4 * 1024) return 12;
180 * The following is only needed to support architectures with a larger page
183 if (size <= 8 * 1024) return 13;
184 if (size <= 16 * 1024) return 14;
185 if (size <= 32 * 1024) return 15;
186 if (size <= 64 * 1024) return 16;
187 if (size <= 128 * 1024) return 17;
188 if (size <= 256 * 1024) return 18;
189 if (size <= 512 * 1024) return 19;
190 if (size <= 1024 * 1024) return 20;
191 if (size <= 2 * 1024 * 1024) return 21;
195 * What we really wanted to do and cannot do because of compiler issues is:
197 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
198 * if (size <= (1 << i))
204 * Find the slab cache for a given combination of allocation flags and size.
206 * This ought to end up with a global pointer to the right cache
209 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
211 int index = kmalloc_index(size);
216 return kmalloc_caches[index];
219 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
220 void *__kmalloc(size_t size, gfp_t flags);
222 static __always_inline void *
223 kmalloc_order(size_t size, gfp_t flags, unsigned int order)
225 void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
226 kmemleak_alloc(ret, size, 1, flags);
230 #ifdef CONFIG_TRACING
232 kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size);
233 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
235 static __always_inline void *
236 kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
238 return kmem_cache_alloc(s, gfpflags);
241 static __always_inline void *
242 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
244 return kmalloc_order(size, flags, order);
248 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
250 unsigned int order = get_order(size);
251 return kmalloc_order_trace(size, flags, order);
254 static __always_inline void *kmalloc(size_t size, gfp_t flags)
256 if (__builtin_constant_p(size)) {
257 if (size > SLUB_MAX_SIZE)
258 return kmalloc_large(size, flags);
260 if (!(flags & SLUB_DMA)) {
261 struct kmem_cache *s = kmalloc_slab(size);
264 return ZERO_SIZE_PTR;
266 return kmem_cache_alloc_trace(s, flags, size);
269 return __kmalloc(size, flags);
273 void *__kmalloc_node(size_t size, gfp_t flags, int node);
274 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
276 #ifdef CONFIG_TRACING
277 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
279 int node, size_t size);
281 static __always_inline void *
282 kmem_cache_alloc_node_trace(struct kmem_cache *s,
284 int node, size_t size)
286 return kmem_cache_alloc_node(s, gfpflags, node);
290 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
292 if (__builtin_constant_p(size) &&
293 size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
294 struct kmem_cache *s = kmalloc_slab(size);
297 return ZERO_SIZE_PTR;
299 return kmem_cache_alloc_node_trace(s, flags, node, size);
301 return __kmalloc_node(size, flags, node);
305 #endif /* _LINUX_SLUB_DEF_H */