Current File : //usr/src/kernels/3.10.0-957.21.3.el7.centos.plus.x86_64/include/linux/slab_def.h
#ifndef _LINUX_SLAB_DEF_H
#define _LINUX_SLAB_DEF_H
#include <linux/reciprocal_div.h>
/*
* Definitions unique to the original Linux SLAB allocator.
*
* What we provide here is a way to optimize the frequent kmalloc
* calls in the kernel by selecting the appropriate general cache
* if kmalloc was called with a size that can be established at
* compile time.
*/
#include <linux/init.h>
#include <linux/compiler.h>
/*
* struct kmem_cache
*
* manages a cache.
*/
struct kmem_cache {
/* 1) Cache tunables. Protected by cache_chain_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 */
unsigned int 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 *slabp_cache;
unsigned int slab_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, the following two
* variables contain the offset to the user object and its size.
*/
int obj_offset;
#endif /* CONFIG_DEBUG_SLAB */
#ifdef CONFIG_MEMCG_KMEM
struct memcg_cache_params *memcg_params;
#endif
/* 6) per-cpu/per-node data, touched during every alloc/free */
/*
* We put array[] at the end of kmem_cache, because we want to size
* this array to nr_cpu_ids slots instead of NR_CPUS
* (see kmem_cache_init())
* We still use [NR_CPUS] and not [1] or [0] because cache_cache
* is statically defined, so we reserve the max number of cpus.
*
* We also need to guarantee that the list is able to accomodate a
* pointer for each node since "nodelists" uses the remainder of
* available pointers.
*/
struct kmem_cache_node **node;
struct array_cache *array[NR_CPUS + MAX_NUMNODES];
/*
* Do not add fields after array[]
*/
};
void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
void *__kmalloc(size_t size, gfp_t flags);
#ifdef CONFIG_TRACING
extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t);
#else
static __always_inline void *
kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size)
{
return kmem_cache_alloc(cachep, flags);
}
#endif
static __always_inline void *kmalloc(size_t size, gfp_t flags)
{
struct kmem_cache *cachep;
void *ret;
if (__builtin_constant_p(size)) {
int i;
if (!size)
return ZERO_SIZE_PTR;
if (WARN_ON_ONCE(size > KMALLOC_MAX_SIZE))
return NULL;
i = kmalloc_index(size);
#ifdef CONFIG_ZONE_DMA
if (flags & GFP_DMA)
cachep = kmalloc_dma_caches[i];
else
#endif
cachep = kmalloc_caches[i];
ret = kmem_cache_alloc_trace(cachep, flags, size);
return ret;
}
return __kmalloc(size, flags);
}
#ifdef CONFIG_NUMA
extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
#ifdef CONFIG_TRACING
extern void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
gfp_t flags,
int nodeid,
size_t size);
#else
static __always_inline void *
kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
gfp_t flags,
int nodeid,
size_t size)
{
return kmem_cache_alloc_node(cachep, flags, nodeid);
}
#endif
static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
struct kmem_cache *cachep;
if (__builtin_constant_p(size)) {
int i;
if (!size)
return ZERO_SIZE_PTR;
if (WARN_ON_ONCE(size > KMALLOC_MAX_SIZE))
return NULL;
i = kmalloc_index(size);
#ifdef CONFIG_ZONE_DMA
if (flags & GFP_DMA)
cachep = kmalloc_dma_caches[i];
else
#endif
cachep = kmalloc_caches[i];
return kmem_cache_alloc_node_trace(cachep, flags, node, size);
}
return __kmalloc_node(size, flags, node);
}
#endif /* CONFIG_NUMA */
#endif /* _LINUX_SLAB_DEF_H */
Mini Shell