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/bug.h>
12 #include <linux/workqueue.h>
13 #include <linux/kobject.h>
15 #include <linux/kmemleak.h>
18 ALLOC_FASTPATH, /* Allocation from cpu slab */
19 ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */
20 FREE_FASTPATH, /* Free to cpu slub */
21 FREE_SLOWPATH, /* Freeing not to cpu slab */
22 FREE_FROZEN, /* Freeing to frozen slab */
23 FREE_ADD_PARTIAL, /* Freeing moves slab to partial list */
24 FREE_REMOVE_PARTIAL, /* Freeing removes last object */
25 ALLOC_FROM_PARTIAL, /* Cpu slab acquired from partial list */
26 ALLOC_SLAB, /* Cpu slab acquired from page allocator */
27 ALLOC_REFILL, /* Refill cpu slab from slab freelist */
28 ALLOC_NODE_MISMATCH, /* Switching cpu slab */
29 FREE_SLAB, /* Slab freed to the page allocator */
30 CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
31 DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
32 DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
33 DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
34 DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
35 DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
36 DEACTIVATE_BYPASS, /* Implicit deactivation */
37 ORDER_FALLBACK, /* Number of times fallback was necessary */
38 CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
39 CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */
40 CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
41 CPU_PARTIAL_FREE, /* USed cpu partial on free */
44 struct kmem_cache_cpu {
45 void **freelist; /* Pointer to next available object */
46 unsigned long tid; /* Globally unique transaction id */
47 struct page *page; /* The slab from which we are allocating */
48 struct page *partial; /* Partially allocated frozen slabs */
49 int node; /* The node of the page (or -1 for debug) */
50 #ifdef CONFIG_SLUB_STATS
51 unsigned stat[NR_SLUB_STAT_ITEMS];
55 struct kmem_cache_node {
56 spinlock_t list_lock; /* Protect partial list and nr_partial */
57 unsigned long nr_partial;
58 struct list_head partial;
59 #ifdef CONFIG_SLUB_DEBUG
60 atomic_long_t nr_slabs;
61 atomic_long_t total_objects;
62 struct list_head full;
67 * Word size structure that can be atomically updated or read and that
68 * contains both the order and the number of objects that a slab of the
69 * given order would contain.
71 struct kmem_cache_order_objects {
76 * Slab cache management.
79 struct kmem_cache_cpu __percpu *cpu_slab;
80 /* Used for retriving partial slabs etc */
82 unsigned long min_partial;
83 int size; /* The size of an object including meta data */
84 int objsize; /* The size of an object without meta data */
85 int offset; /* Free pointer offset. */
86 int cpu_partial; /* Number of per cpu partial objects to keep around */
87 struct kmem_cache_order_objects oo;
89 /* Allocation and freeing of slabs */
90 struct kmem_cache_order_objects max;
91 struct kmem_cache_order_objects min;
92 gfp_t allocflags; /* gfp flags to use on each alloc */
93 int refcount; /* Refcount for slab cache destroy */
95 int inuse; /* Offset to metadata */
96 int align; /* Alignment */
97 int reserved; /* Reserved bytes at the end of slabs */
98 const char *name; /* Name (only for display!) */
99 struct list_head list; /* List of slab caches */
101 struct kobject kobj; /* For sysfs */
106 * Defragmentation by allocating from a remote node.
108 int remote_node_defrag_ratio;
110 struct kmem_cache_node *node[MAX_NUMNODES];
116 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
117 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
119 #define KMALLOC_MIN_SIZE 8
122 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
125 * Maximum kmalloc object size handled by SLUB. Larger object allocations
126 * are passed through to the page allocator. The page allocator "fastpath"
127 * is relatively slow so we need this value sufficiently high so that
128 * performance critical objects are allocated through the SLUB fastpath.
130 * This should be dropped to PAGE_SIZE / 2 once the page allocator
131 * "fastpath" becomes competitive with the slab allocator fastpaths.
133 #define SLUB_MAX_SIZE (2 * PAGE_SIZE)
135 #define SLUB_PAGE_SHIFT (PAGE_SHIFT + 2)
137 #ifdef CONFIG_ZONE_DMA
138 #define SLUB_DMA __GFP_DMA
140 /* Disable DMA functionality */
141 #define SLUB_DMA (__force gfp_t)0
145 * We keep the general caches in an array of slab caches that are used for
146 * 2^x bytes of allocations.
148 extern struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
151 * Sorry that the following has to be that ugly but some versions of GCC
152 * have trouble with constant propagation and loops.
154 static __always_inline int kmalloc_index(size_t size)
159 if (size <= KMALLOC_MIN_SIZE)
160 return KMALLOC_SHIFT_LOW;
162 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
164 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
166 if (size <= 8) return 3;
167 if (size <= 16) return 4;
168 if (size <= 32) return 5;
169 if (size <= 64) return 6;
170 if (size <= 128) return 7;
171 if (size <= 256) return 8;
172 if (size <= 512) return 9;
173 if (size <= 1024) return 10;
174 if (size <= 2 * 1024) return 11;
175 if (size <= 4 * 1024) return 12;
177 * The following is only needed to support architectures with a larger page
178 * size than 4k. We need to support 2 * PAGE_SIZE here. So for a 64k page
179 * size we would have to go up to 128k.
181 if (size <= 8 * 1024) return 13;
182 if (size <= 16 * 1024) return 14;
183 if (size <= 32 * 1024) return 15;
184 if (size <= 64 * 1024) return 16;
185 if (size <= 128 * 1024) return 17;
186 if (size <= 256 * 1024) return 18;
187 if (size <= 512 * 1024) return 19;
188 if (size <= 1024 * 1024) return 20;
189 if (size <= 2 * 1024 * 1024) return 21;
191 return -1; /* Will never be reached */
194 * What we really wanted to do and cannot do because of compiler issues is:
196 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
197 * if (size <= (1 << i))
203 * Find the slab cache for a given combination of allocation flags and size.
205 * This ought to end up with a global pointer to the right cache
208 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
210 int index = kmalloc_index(size);
215 return kmalloc_caches[index];
218 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
219 void *__kmalloc(size_t size, gfp_t flags);
221 static __always_inline void *
222 kmalloc_order(size_t size, gfp_t flags, unsigned int order)
224 void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
225 kmemleak_alloc(ret, size, 1, flags);
230 * Calling this on allocated memory will check that the memory
231 * is expected to be in use, and print warnings if not.
233 #ifdef CONFIG_SLUB_DEBUG
234 extern bool verify_mem_not_deleted(const void *x);
236 static inline bool verify_mem_not_deleted(const void *x)
242 #ifdef CONFIG_TRACING
244 kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size);
245 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
247 static __always_inline void *
248 kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
250 return kmem_cache_alloc(s, gfpflags);
253 static __always_inline void *
254 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
256 return kmalloc_order(size, flags, order);
260 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
262 unsigned int order = get_order(size);
263 return kmalloc_order_trace(size, flags, order);
266 static __always_inline void *kmalloc(size_t size, gfp_t flags)
268 if (__builtin_constant_p(size)) {
269 if (size > SLUB_MAX_SIZE)
270 return kmalloc_large(size, flags);
272 if (!(flags & SLUB_DMA)) {
273 struct kmem_cache *s = kmalloc_slab(size);
276 return ZERO_SIZE_PTR;
278 return kmem_cache_alloc_trace(s, flags, size);
281 return __kmalloc(size, flags);
285 void *__kmalloc_node(size_t size, gfp_t flags, int node);
286 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
288 #ifdef CONFIG_TRACING
289 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
291 int node, size_t size);
293 static __always_inline void *
294 kmem_cache_alloc_node_trace(struct kmem_cache *s,
296 int node, size_t size)
298 return kmem_cache_alloc_node(s, gfpflags, node);
302 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
304 if (__builtin_constant_p(size) &&
305 size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
306 struct kmem_cache *s = kmalloc_slab(size);
309 return ZERO_SIZE_PTR;
311 return kmem_cache_alloc_node_trace(s, flags, node, size);
313 return __kmalloc_node(size, flags, node);
317 #endif /* _LINUX_SLUB_DEF_H */