LXR linux/include/linux/slub

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_SLUB_DEF_H
   3#define _LINUX_SLUB_DEF_H
   4
   5/*
   6 * SLUB : A Slab allocator without object queues.
   7 *
   8 * (C) 2007 SGI, Christoph Lameter
   9 */
  10#include <linux/kobject.h>
  11
  12enum stat_item {
  13        ALLOC_FASTPATH,         /* Allocation from cpu slab */
  14        ALLOC_SLOWPATH,         /* Allocation by getting a new cpu slab */
  15        FREE_FASTPATH,          /* Free to cpu slab */
  16        FREE_SLOWPATH,          /* Freeing not to cpu slab */
  17        FREE_FROZEN,            /* Freeing to frozen slab */
  18        FREE_ADD_PARTIAL,       /* Freeing moves slab to partial list */
  19        FREE_REMOVE_PARTIAL,    /* Freeing removes last object */
  20        ALLOC_FROM_PARTIAL,     /* Cpu slab acquired from node partial list */
  21        ALLOC_SLAB,             /* Cpu slab acquired from page allocator */
  22        ALLOC_REFILL,           /* Refill cpu slab from slab freelist */
  23        ALLOC_NODE_MISMATCH,    /* Switching cpu slab */
  24        FREE_SLAB,              /* Slab freed to the page allocator */
  25        CPUSLAB_FLUSH,          /* Abandoning of the cpu slab */
  26        DEACTIVATE_FULL,        /* Cpu slab was full when deactivated */
  27        DEACTIVATE_EMPTY,       /* Cpu slab was empty when deactivated */
  28        DEACTIVATE_TO_HEAD,     /* Cpu slab was moved to the head of partials */
  29        DEACTIVATE_TO_TAIL,     /* Cpu slab was moved to the tail of partials */
  30        DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
  31        DEACTIVATE_BYPASS,      /* Implicit deactivation */
  32        ORDER_FALLBACK,         /* Number of times fallback was necessary */
  33        CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
  34        CMPXCHG_DOUBLE_FAIL,    /* Number of times that cmpxchg double did not match */
  35        CPU_PARTIAL_ALLOC,      /* Used cpu partial on alloc */
  36        CPU_PARTIAL_FREE,       /* Refill cpu partial on free */
  37        CPU_PARTIAL_NODE,       /* Refill cpu partial from node partial */
  38        CPU_PARTIAL_DRAIN,      /* Drain cpu partial to node partial */
  39        NR_SLUB_STAT_ITEMS };
  40
  41struct kmem_cache_cpu {
  42        void **freelist;        /* Pointer to next available object */
  43        unsigned long tid;      /* Globally unique transaction id */
  44        struct page *page;      /* The slab from which we are allocating */
  45#ifdef CONFIG_SLUB_CPU_PARTIAL
  46        struct page *partial;   /* Partially allocated frozen slabs */
  47#endif
  48#ifdef CONFIG_SLUB_STATS
  49        unsigned stat[NR_SLUB_STAT_ITEMS];
  50#endif
  51};
  52
  53#ifdef CONFIG_SLUB_CPU_PARTIAL
  54#define slub_percpu_partial(c)          ((c)->partial)
  55
  56#define slub_set_percpu_partial(c, p)           \
  57({                                              \
  58        slub_percpu_partial(c) = (p)->next;     \
  59})
  60
  61#define slub_percpu_partial_read_once(c)     READ_ONCE(slub_percpu_partial(c))
  62#else
  63#define slub_percpu_partial(c)                  NULL
  64
  65#define slub_set_percpu_partial(c, p)
  66
  67#define slub_percpu_partial_read_once(c)        NULL
  68#endif // CONFIG_SLUB_CPU_PARTIAL
  69
  70/*
  71 * Word size structure that can be atomically updated or read and that
  72 * contains both the order and the number of objects that a slab of the
  73 * given order would contain.
  74 */
  75struct kmem_cache_order_objects {
  76        unsigned int x;
  77};
  78
  79/*
  80 * Slab cache management.
  81 */
  82struct kmem_cache {
  83        struct kmem_cache_cpu __percpu *cpu_slab;
  84        /* Used for retriving partial slabs etc */
  85        slab_flags_t flags;
  86        unsigned long min_partial;
  87        unsigned int size;      /* The size of an object including meta data */
  88        unsigned int object_size;/* The size of an object without meta data */
  89        unsigned int offset;    /* Free pointer offset. */
  90#ifdef CONFIG_SLUB_CPU_PARTIAL
  91        /* Number of per cpu partial objects to keep around */
  92        unsigned int cpu_partial;
  93#endif
  94        struct kmem_cache_order_objects oo;
  95
  96        /* Allocation and freeing of slabs */
  97        struct kmem_cache_order_objects max;
  98        struct kmem_cache_order_objects min;
  99        gfp_t allocflags;       /* gfp flags to use on each alloc */
 100        int refcount;           /* Refcount for slab cache destroy */
 101        void (*ctor)(void *);
 102        unsigned int inuse;             /* Offset to metadata */
 103        unsigned int align;             /* Alignment */
 104        unsigned int reserved;          /* Reserved bytes at the end of slabs */
 105        unsigned int red_left_pad;      /* Left redzone padding size */
 106        const char *name;       /* Name (only for display!) */
 107        struct list_head list;  /* List of slab caches */
 108#ifdef CONFIG_SYSFS
 109        struct kobject kobj;    /* For sysfs */
 110        struct work_struct kobj_remove_work;
 111#endif
 112#ifdef CONFIG_MEMCG
 113        struct memcg_cache_params memcg_params;
 114        /* for propagation, maximum size of a stored attr */
 115        unsigned int max_attr_size;
 116#ifdef CONFIG_SYSFS
 117        struct kset *memcg_kset;
 118#endif
 119#endif
 120
 121#ifdef CONFIG_SLAB_FREELIST_HARDENED
 122        unsigned long random;
 123#endif
 124
 125#ifdef CONFIG_NUMA
 126        /*
 127         * Defragmentation by allocating from a remote node.
 128         */
 129        unsigned int remote_node_defrag_ratio;
 130#endif
 131
 132#ifdef CONFIG_SLAB_FREELIST_RANDOM
 133        unsigned int *random_seq;
 134#endif
 135
 136#ifdef CONFIG_KASAN
 137        struct kasan_cache kasan_info;
 138#endif
 139
 140        unsigned int useroffset;        /* Usercopy region offset */
 141        unsigned int usersize;          /* Usercopy region size */
 142
 143        struct kmem_cache_node *node[MAX_NUMNODES];
 144};
 145
 146#ifdef CONFIG_SLUB_CPU_PARTIAL
 147#define slub_cpu_partial(s)             ((s)->cpu_partial)
 148#define slub_set_cpu_partial(s, n)              \
 149({                                              \
 150        slub_cpu_partial(s) = (n);              \
 151})
 152#else
 153#define slub_cpu_partial(s)             (0)
 154#define slub_set_cpu_partial(s, n)
 155#endif // CONFIG_SLUB_CPU_PARTIAL
 156
 157#ifdef CONFIG_SYSFS
 158#define SLAB_SUPPORTS_SYSFS
 159void sysfs_slab_release(struct kmem_cache *);
 160#else
 161static inline void sysfs_slab_release(struct kmem_cache *s)
 162{
 163}
 164#endif
 165
 166void object_err(struct kmem_cache *s, struct page *page,
 167                u8 *object, char *reason);
 168
 169void *fixup_red_left(struct kmem_cache *s, void *p);
 170
 171static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
 172                                void *x) {
 173        void *object = x - (x - page_address(page)) % cache->size;
 174        void *last_object = page_address(page) +
 175                (page->objects - 1) * cache->size;
 176        void *result = (unlikely(object > last_object)) ? last_object : object;
 177
 178        result = fixup_red_left(cache, result);
 179        return result;
 180}
 181
 182#endif /* _LINUX_SLUB_DEF_H */
 183