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 ALLOC_NODE_MISMATCH, /* Switching cpu slab */
28 FREE_SLAB, /* Slab freed to the page allocator */
29 CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
30 DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
31 DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
32 DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
33 DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
34 DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
35 DEACTIVATE_BYPASS, /* Implicit deactivation */
36 ORDER_FALLBACK, /* Number of times fallback was necessary */
37 CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
38 CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */
39 CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
40 CPU_PARTIAL_FREE, /* USed cpu partial on free */
43 struct kmem_cache_cpu {
44 void **freelist; /* Pointer to next available object */
45 unsigned long tid; /* Globally unique transaction id */
46 struct page *page; /* The slab from which we are allocating */
47 struct page *partial; /* Partially allocated frozen slabs */
48 #ifdef CONFIG_SLUB_STATS
49 unsigned stat[NR_SLUB_STAT_ITEMS];
53 struct kmem_cache_node {
54 spinlock_t list_lock; /* Protect partial list and nr_partial */
55 unsigned long nr_partial;
56 struct list_head partial;
57 #ifdef CONFIG_SLUB_DEBUG
58 atomic_long_t nr_slabs;
59 atomic_long_t total_objects;
60 struct list_head full;
65 * Word size structure that can be atomically updated or read and that
66 * contains both the order and the number of objects that a slab of the
67 * given order would contain.
69 struct kmem_cache_order_objects {
74 * Slab cache management.
77 struct kmem_cache_cpu __percpu *cpu_slab;
78 /* Used for retriving partial slabs etc */
80 unsigned long min_partial;
81 int size; /* The size of an object including meta data */
82 int objsize; /* The size of an object without meta data */
83 int offset; /* Free pointer offset. */
84 int cpu_partial; /* Number of per cpu partial objects to keep around */
85 struct kmem_cache_order_objects oo;
87 /* Allocation and freeing of slabs */
88 struct kmem_cache_order_objects max;
89 struct kmem_cache_order_objects min;
90 gfp_t allocflags; /* gfp flags to use on each alloc */
91 int refcount; /* Refcount for slab cache destroy */
93 int inuse; /* Offset to metadata */
94 int align; /* Alignment */
95 int reserved; /* Reserved bytes at the end of slabs */
96 const char *name; /* Name (only for display!) */
97 struct list_head list; /* List of slab caches */
99 struct kobject kobj; /* For sysfs */
104 * Defragmentation by allocating from a remote node.
106 int remote_node_defrag_ratio;
108 struct kmem_cache_node *node[MAX_NUMNODES];
114 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
115 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
117 #define KMALLOC_MIN_SIZE 8
120 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
123 * Maximum kmalloc object size handled by SLUB. Larger object allocations
124 * are passed through to the page allocator. The page allocator "fastpath"
125 * is relatively slow so we need this value sufficiently high so that
126 * performance critical objects are allocated through the SLUB fastpath.
128 * This should be dropped to PAGE_SIZE / 2 once the page allocator
129 * "fastpath" becomes competitive with the slab allocator fastpaths.
131 #define SLUB_MAX_SIZE (2 * PAGE_SIZE)
133 #define SLUB_PAGE_SHIFT (PAGE_SHIFT + 2)
135 #ifdef CONFIG_ZONE_DMA
136 #define SLUB_DMA __GFP_DMA
138 /* Disable DMA functionality */
139 #define SLUB_DMA (__force gfp_t)0
143 * We keep the general caches in an array of slab caches that are used for
144 * 2^x bytes of allocations.
146 extern struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
149 * Sorry that the following has to be that ugly but some versions of GCC
150 * have trouble with constant propagation and loops.
152 static __always_inline int kmalloc_index(size_t size)
157 if (size <= KMALLOC_MIN_SIZE)
158 return KMALLOC_SHIFT_LOW;
160 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
162 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
164 if (size <= 8) return 3;
165 if (size <= 16) return 4;
166 if (size <= 32) return 5;
167 if (size <= 64) return 6;
168 if (size <= 128) return 7;
169 if (size <= 256) return 8;
170 if (size <= 512) return 9;
171 if (size <= 1024) return 10;
172 if (size <= 2 * 1024) return 11;
173 if (size <= 4 * 1024) return 12;
175 * The following is only needed to support architectures with a larger page
176 * size than 4k. We need to support 2 * PAGE_SIZE here. So for a 64k page
177 * size we would have to go up to 128k.
179 if (size <= 8 * 1024) return 13;
180 if (size <= 16 * 1024) return 14;
181 if (size <= 32 * 1024) return 15;
182 if (size <= 64 * 1024) return 16;
183 if (size <= 128 * 1024) return 17;
184 if (size <= 256 * 1024) return 18;
185 if (size <= 512 * 1024) return 19;
186 if (size <= 1024 * 1024) return 20;
187 if (size <= 2 * 1024 * 1024) return 21;
189 return -1; /* Will never be reached */
192 * What we really wanted to do and cannot do because of compiler issues is:
194 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
195 * if (size <= (1 << i))
201 * Find the slab cache for a given combination of allocation flags and size.
203 * This ought to end up with a global pointer to the right cache
206 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
208 int index = kmalloc_index(size);
213 return kmalloc_caches[index];
216 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
217 void *__kmalloc(size_t size, gfp_t flags);
219 static __always_inline void *
220 kmalloc_order(size_t size, gfp_t flags, unsigned int order)
222 void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
223 kmemleak_alloc(ret, size, 1, flags);
228 * Calling this on allocated memory will check that the memory
229 * is expected to be in use, and print warnings if not.
231 #ifdef CONFIG_SLUB_DEBUG
232 extern bool verify_mem_not_deleted(const void *x);
234 static inline bool verify_mem_not_deleted(const void *x)
240 #ifdef CONFIG_TRACING
242 kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size);
243 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
245 static __always_inline void *
246 kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
248 return kmem_cache_alloc(s, gfpflags);
251 static __always_inline void *
252 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
254 return kmalloc_order(size, flags, order);
258 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
260 unsigned int order = get_order(size);
261 return kmalloc_order_trace(size, flags, order);
264 static __always_inline void *kmalloc(size_t size, gfp_t flags)
266 if (__builtin_constant_p(size)) {
267 if (size > SLUB_MAX_SIZE)
268 return kmalloc_large(size, flags);
270 if (!(flags & SLUB_DMA)) {
271 struct kmem_cache *s = kmalloc_slab(size);
274 return ZERO_SIZE_PTR;
276 return kmem_cache_alloc_trace(s, flags, size);
279 return __kmalloc(size, flags);
283 void *__kmalloc_node(size_t size, gfp_t flags, int node);
284 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
286 #ifdef CONFIG_TRACING
287 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
289 int node, size_t size);
291 static __always_inline void *
292 kmem_cache_alloc_node_trace(struct kmem_cache *s,
294 int node, size_t size)
296 return kmem_cache_alloc_node(s, gfpflags, node);
300 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
302 if (__builtin_constant_p(size) &&
303 size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
304 struct kmem_cache *s = kmalloc_slab(size);
307 return ZERO_SIZE_PTR;
309 return kmem_cache_alloc_node_trace(s, flags, node, size);
311 return __kmalloc_node(size, flags, node);
315 #endif /* _LINUX_SLUB_DEF_H */