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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 | /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_SLAB_DEF_H #define _LINUX_SLAB_DEF_H #include <linux/reciprocal_div.h> /* * Definitions unique to the original Linux SLAB allocator. */ struct kmem_cache { struct array_cache __percpu *cpu_cache; /* 1) Cache tunables. Protected by slab_mutex */ unsigned int batchcount; unsigned int limit; unsigned int shared; unsigned int size; struct reciprocal_value reciprocal_buffer_size; /* 2) touched by every alloc & free from the backend */ slab_flags_t flags; /* constant flags */ unsigned int num; /* # of objs per slab */ /* 3) cache_grow/shrink */ /* order of pgs per slab (2^n) */ unsigned int gfporder; /* force GFP flags, e.g. GFP_DMA */ gfp_t allocflags; size_t colour; /* cache colouring range */ unsigned int colour_off; /* colour offset */ struct kmem_cache *freelist_cache; unsigned int freelist_size; /* constructor func */ void (*ctor)(void *obj); /* 4) cache creation/removal */ const char *name; struct list_head list; int refcount; int object_size; int align; /* 5) statistics */ #ifdef CONFIG_DEBUG_SLAB unsigned long num_active; unsigned long num_allocations; unsigned long high_mark; unsigned long grown; unsigned long reaped; unsigned long errors; unsigned long max_freeable; unsigned long node_allocs; unsigned long node_frees; unsigned long node_overflow; atomic_t allochit; atomic_t allocmiss; atomic_t freehit; atomic_t freemiss; /* * If debugging is enabled, then the allocator can add additional * fields and/or padding to every object. 'size' contains the total * object size including these internal fields, while 'obj_offset' * and 'object_size' contain the offset to the user object and its * size. */ int obj_offset; #endif /* CONFIG_DEBUG_SLAB */ #ifdef CONFIG_MEMCG struct memcg_cache_params memcg_params; #endif #ifdef CONFIG_KASAN struct kasan_cache kasan_info; #endif #ifdef CONFIG_SLAB_FREELIST_RANDOM unsigned int *random_seq; #endif unsigned int useroffset; /* Usercopy region offset */ unsigned int usersize; /* Usercopy region size */ struct kmem_cache_node *node[MAX_NUMNODES]; }; static inline void *nearest_obj(struct kmem_cache *cache, struct page *page, void *x) { void *object = x - (x - page->s_mem) % cache->size; void *last_object = page->s_mem + (cache->num - 1) * cache->size; if (unlikely(object > last_object)) return last_object; else return object; } /* * We want to avoid an expensive divide : (offset / cache->size) * Using the fact that size is a constant for a particular cache, * we can replace (offset / cache->size) by * reciprocal_divide(offset, cache->reciprocal_buffer_size) */ static inline unsigned int obj_to_index(const struct kmem_cache *cache, const struct page *page, void *obj) { u32 offset = (obj - page->s_mem); return reciprocal_divide(offset, cache->reciprocal_buffer_size); } #endif /* _LINUX_SLAB_DEF_H */ |