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>
13 #include <linux/kmemtrace.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 first free per cpu object */
39 struct page *page; /* The slab from which we are allocating */
40 int node; /* The node of the page (or -1 for debug) */
41 unsigned int offset; /* Freepointer offset (in word units) */
42 unsigned int objsize; /* Size of an object (from kmem_cache) */
43 #ifdef CONFIG_SLUB_STATS
44 unsigned stat[NR_SLUB_STAT_ITEMS];
48 struct kmem_cache_node {
49 spinlock_t list_lock; /* Protect partial list and nr_partial */
50 unsigned long nr_partial;
51 struct list_head partial;
52 #ifdef CONFIG_SLUB_DEBUG
53 atomic_long_t nr_slabs;
54 atomic_long_t total_objects;
55 struct list_head full;
60 * Word size structure that can be atomically updated or read and that
61 * contains both the order and the number of objects that a slab of the
62 * given order would contain.
64 struct kmem_cache_order_objects {
69 * Slab cache management.
72 struct kmem_cache_cpu *cpu_slab;
73 /* Used for retriving partial slabs etc */
75 int size; /* The size of an object including meta data */
76 int objsize; /* The size of an object without meta data */
77 int offset; /* Free pointer offset. */
78 struct kmem_cache_order_objects oo;
81 * Avoid an extra cache line for UP, SMP and for the node local to
84 struct kmem_cache_node local_node;
86 /* Allocation and freeing of slabs */
87 struct kmem_cache_order_objects max;
88 struct kmem_cache_order_objects min;
89 gfp_t allocflags; /* gfp flags to use on each alloc */
90 int refcount; /* Refcount for slab cache destroy */
92 int inuse; /* Offset to metadata */
93 int align; /* Alignment */
94 unsigned long min_partial;
95 const char *name; /* Name (only for display!) */
96 struct list_head list; /* List of slab caches */
97 #ifdef CONFIG_SLUB_DEBUG
98 struct kobject kobj; /* For sysfs */
103 * Defragmentation by allocating from a remote node.
105 int remote_node_defrag_ratio;
106 struct kmem_cache_node *node[MAX_NUMNODES];
113 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
114 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
116 #define KMALLOC_MIN_SIZE 8
119 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
122 * Maximum kmalloc object size handled by SLUB. Larger object allocations
123 * are passed through to the page allocator. The page allocator "fastpath"
124 * is relatively slow so we need this value sufficiently high so that
125 * performance critical objects are allocated through the SLUB fastpath.
127 * This should be dropped to PAGE_SIZE / 2 once the page allocator
128 * "fastpath" becomes competitive with the slab allocator fastpaths.
130 #define SLUB_MAX_SIZE (2 * PAGE_SIZE)
132 #define SLUB_PAGE_SHIFT (PAGE_SHIFT + 2)
134 #ifdef CONFIG_ZONE_DMA
135 #define SLUB_DMA __GFP_DMA
136 /* Reserve extra caches for potential DMA use */
137 #define KMALLOC_CACHES (2 * SLUB_PAGE_SHIFT - 6)
139 /* Disable DMA functionality */
140 #define SLUB_DMA (__force gfp_t)0
141 #define KMALLOC_CACHES SLUB_PAGE_SHIFT
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[KMALLOC_CACHES];
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
180 if (size <= 8 * 1024) return 13;
181 if (size <= 16 * 1024) return 14;
182 if (size <= 32 * 1024) return 15;
183 if (size <= 64 * 1024) return 16;
184 if (size <= 128 * 1024) return 17;
185 if (size <= 256 * 1024) return 18;
186 if (size <= 512 * 1024) return 19;
187 if (size <= 1024 * 1024) return 20;
188 if (size <= 2 * 1024 * 1024) return 21;
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 #ifdef CONFIG_TRACING
220 extern void *kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags);
222 static __always_inline void *
223 kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags)
225 return kmem_cache_alloc(s, gfpflags);
229 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
231 unsigned int order = get_order(size);
232 void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
234 kmemleak_alloc(ret, size, 1, flags);
235 trace_kmalloc(_THIS_IP_, ret, size, PAGE_SIZE << order, flags);
240 static __always_inline void *kmalloc(size_t size, gfp_t flags)
244 if (__builtin_constant_p(size)) {
245 if (size > SLUB_MAX_SIZE)
246 return kmalloc_large(size, flags);
248 if (!(flags & SLUB_DMA)) {
249 struct kmem_cache *s = kmalloc_slab(size);
252 return ZERO_SIZE_PTR;
254 ret = kmem_cache_alloc_notrace(s, flags);
256 trace_kmalloc(_THIS_IP_, ret, size, s->size, flags);
261 return __kmalloc(size, flags);
265 void *__kmalloc_node(size_t size, gfp_t flags, int node);
266 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
268 #ifdef CONFIG_TRACING
269 extern void *kmem_cache_alloc_node_notrace(struct kmem_cache *s,
273 static __always_inline void *
274 kmem_cache_alloc_node_notrace(struct kmem_cache *s,
278 return kmem_cache_alloc_node(s, gfpflags, node);
282 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
286 if (__builtin_constant_p(size) &&
287 size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
288 struct kmem_cache *s = kmalloc_slab(size);
291 return ZERO_SIZE_PTR;
293 ret = kmem_cache_alloc_node_notrace(s, flags, node);
295 trace_kmalloc_node(_THIS_IP_, ret,
296 size, s->size, flags, node);
300 return __kmalloc_node(size, flags, node);
304 #endif /* _LINUX_SLUB_DEF_H */