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/kmemleak.h>
15 #include <trace/events/kmem.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 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 ORDER_FALLBACK, /* Number of times fallback was necessary */
38 struct kmem_cache_cpu {
39 void **freelist; /* Pointer to first free per cpu object */
40 struct page *page; /* The slab from which we are allocating */
41 int node; /* The node of the page (or -1 for debug) */
42 #ifdef CONFIG_SLUB_STATS
43 unsigned stat[NR_SLUB_STAT_ITEMS];
47 struct kmem_cache_node {
48 spinlock_t list_lock; /* Protect partial list and nr_partial */
49 unsigned long nr_partial;
50 struct list_head partial;
51 #ifdef CONFIG_SLUB_DEBUG
52 atomic_long_t nr_slabs;
53 atomic_long_t total_objects;
54 struct list_head full;
59 * Word size structure that can be atomically updated or read and that
60 * contains both the order and the number of objects that a slab of the
61 * given order would contain.
63 struct kmem_cache_order_objects {
68 * Slab cache management.
71 struct kmem_cache_cpu __percpu *cpu_slab;
72 /* Used for retriving partial slabs etc */
74 int size; /* The size of an object including meta data */
75 int objsize; /* The size of an object without meta data */
76 int offset; /* Free pointer offset. */
77 struct kmem_cache_order_objects oo;
79 /* Allocation and freeing of slabs */
80 struct kmem_cache_order_objects max;
81 struct kmem_cache_order_objects min;
82 gfp_t allocflags; /* gfp flags to use on each alloc */
83 int refcount; /* Refcount for slab cache destroy */
85 int inuse; /* Offset to metadata */
86 int align; /* Alignment */
87 unsigned long min_partial;
88 const char *name; /* Name (only for display!) */
89 struct list_head list; /* List of slab caches */
90 #ifdef CONFIG_SLUB_DEBUG
91 struct kobject kobj; /* For sysfs */
96 * Defragmentation by allocating from a remote node.
98 int remote_node_defrag_ratio;
99 struct kmem_cache_node *node[MAX_NUMNODES];
101 /* Avoid an extra cache line for UP */
102 struct kmem_cache_node local_node;
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
142 /* Reserve extra caches for potential DMA use */
143 #define KMALLOC_CACHES (2 * SLUB_PAGE_SHIFT)
145 /* Disable DMA functionality */
146 #define SLUB_DMA (__force gfp_t)0
147 #define KMALLOC_CACHES SLUB_PAGE_SHIFT
151 * We keep the general caches in an array of slab caches that are used for
152 * 2^x bytes of allocations.
154 extern struct kmem_cache kmalloc_caches[KMALLOC_CACHES];
157 * Sorry that the following has to be that ugly but some versions of GCC
158 * have trouble with constant propagation and loops.
160 static __always_inline int kmalloc_index(size_t size)
165 if (size <= KMALLOC_MIN_SIZE)
166 return KMALLOC_SHIFT_LOW;
168 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
170 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
172 if (size <= 8) return 3;
173 if (size <= 16) return 4;
174 if (size <= 32) return 5;
175 if (size <= 64) return 6;
176 if (size <= 128) return 7;
177 if (size <= 256) return 8;
178 if (size <= 512) return 9;
179 if (size <= 1024) return 10;
180 if (size <= 2 * 1024) return 11;
181 if (size <= 4 * 1024) return 12;
183 * The following is only needed to support architectures with a larger page
186 if (size <= 8 * 1024) return 13;
187 if (size <= 16 * 1024) return 14;
188 if (size <= 32 * 1024) return 15;
189 if (size <= 64 * 1024) return 16;
190 if (size <= 128 * 1024) return 17;
191 if (size <= 256 * 1024) return 18;
192 if (size <= 512 * 1024) return 19;
193 if (size <= 1024 * 1024) return 20;
194 if (size <= 2 * 1024 * 1024) return 21;
198 * What we really wanted to do and cannot do because of compiler issues is:
200 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
201 * if (size <= (1 << i))
207 * Find the slab cache for a given combination of allocation flags and size.
209 * This ought to end up with a global pointer to the right cache
212 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
214 int index = kmalloc_index(size);
219 return &kmalloc_caches[index];
222 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
223 void *__kmalloc(size_t size, gfp_t flags);
225 #ifdef CONFIG_TRACING
226 extern void *kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags);
228 static __always_inline void *
229 kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags)
231 return kmem_cache_alloc(s, gfpflags);
235 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
237 unsigned int order = get_order(size);
238 void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
240 kmemleak_alloc(ret, size, 1, flags);
241 trace_kmalloc(_THIS_IP_, ret, size, PAGE_SIZE << order, flags);
246 static __always_inline void *kmalloc(size_t size, gfp_t flags)
250 if (__builtin_constant_p(size)) {
251 if (size > SLUB_MAX_SIZE)
252 return kmalloc_large(size, flags);
254 if (!(flags & SLUB_DMA)) {
255 struct kmem_cache *s = kmalloc_slab(size);
258 return ZERO_SIZE_PTR;
260 ret = kmem_cache_alloc_notrace(s, flags);
262 trace_kmalloc(_THIS_IP_, ret, size, s->size, flags);
267 return __kmalloc(size, flags);
271 void *__kmalloc_node(size_t size, gfp_t flags, int node);
272 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
274 #ifdef CONFIG_TRACING
275 extern void *kmem_cache_alloc_node_notrace(struct kmem_cache *s,
279 static __always_inline void *
280 kmem_cache_alloc_node_notrace(struct kmem_cache *s,
284 return kmem_cache_alloc_node(s, gfpflags, node);
288 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 ret = kmem_cache_alloc_node_notrace(s, flags, node);
301 trace_kmalloc_node(_THIS_IP_, ret,
302 size, s->size, flags, node);
306 return __kmalloc_node(size, flags, node);
310 #endif /* _LINUX_SLUB_DEF_H */