|
|
#ifndef _LINUX_SLUB_DEF_H
#define _LINUX_SLUB_DEF_H
/*
* SLUB : A Slab allocator without object queues.
*
* (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
*/
#include <linux/types.h>
#include <linux/gfp.h>
#include <linux/workqueue.h>
#include <linux/kobject.h>
struct kmem_cache_node {
spinlock_t list_lock; /* Protect partial list and nr_partial */
unsigned long nr_partial;
atomic_long_t nr_slabs;
struct list_head partial;
struct list_head full;
};
/*
* Slab cache management.
*/
struct kmem_cache {
/* Used for retriving partial slabs etc */
unsigned long flags;
int size; /* The size of an object including meta data */
int objsize; /* The size of an object without meta data */
int offset; /* Free pointer offset. */
unsigned int order;
/*
* Avoid an extra cache line for UP, SMP and for the node local to
* struct kmem_cache.
*/
struct kmem_cache_node local_node;
/* Allocation and freeing of slabs */
int objects; /* Number of objects in slab */
int refcount; /* Refcount for slab cache destroy */
void (*ctor)(void *, struct kmem_cache *, unsigned long);
int inuse; /* Offset to metadata */
int align; /* Alignment */
const char *name; /* Name (only for display!) */
struct list_head list; /* List of slab caches */
struct kobject kobj; /* For sysfs */
#ifdef CONFIG_NUMA
int defrag_ratio;
struct kmem_cache_node *node[MAX_NUMNODES];
#endif
struct page *cpu_slab[NR_CPUS];
};
/*
* Kmalloc subsystem.
*/
#define KMALLOC_SHIFT_LOW 3
/*
* We keep the general caches in an array of slab caches that are used for
* 2^x bytes of allocations.
*/
extern struct kmem_cache kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
/*
* Sorry that the following has to be that ugly but some versions of GCC
* have trouble with constant propagation and loops.
*/
static inline int kmalloc_index(size_t size)
{
if (!size)
return 0;
if (size > KMALLOC_MAX_SIZE)
return -1;
if (size > 64 && size <= 96)
return 1;
if (size > 128 && size <= 192)
return 2;
if (size <= 8) return 3;
if (size <= 16) return 4;
if (size <= 32) return 5;
if (size <= 64) return 6;
if (size <= 128) return 7;
if (size <= 256) return 8;
if (size <= 512) return 9;
if (size <= 1024) return 10;
if (size <= 2 * 1024) return 11;
if (size <= 4 * 1024) return 12;
if (size <= 8 * 1024) return 13;
if (size <= 16 * 1024) return 14;
if (size <= 32 * 1024) return 15;
if (size <= 64 * 1024) return 16;
if (size <= 128 * 1024) return 17;
if (size <= 256 * 1024) return 18;
if (size <= 512 * 1024) return 19;
if (size <= 1024 * 1024) return 20;
if (size <= 2 * 1024 * 1024) return 21;
if (size <= 4 * 1024 * 1024) return 22;
if (size <= 8 * 1024 * 1024) return 23;
if (size <= 16 * 1024 * 1024) return 24;
if (size <= 32 * 1024 * 1024) return 25;
return -1;
/*
* What we really wanted to do and cannot do because of compiler issues is:
* int i;
* for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
* if (size <= (1 << i))
* return i;
*/
}
/*
* Find the slab cache for a given combination of allocation flags and size.
*
* This ought to end up with a global pointer to the right cache
* in kmalloc_caches.
*/
static inline struct kmem_cache *kmalloc_slab(size_t size)
{
int index = kmalloc_index(size);
if (index == 0)
return NULL;
/*
* This function only gets expanded if __builtin_constant_p(size), so
* testing it here shouldn't be needed. But some versions of gcc need
* help.
*/
if (__builtin_constant_p(size) && index < 0) {
/*
* Generate a link failure. Would be great if we could
* do something to stop the compile here.
*/
extern void __kmalloc_size_too_large(void);
__kmalloc_size_too_large();
}
return &kmalloc_caches[index];
}
#ifdef CONFIG_ZONE_DMA
#define SLUB_DMA __GFP_DMA
#else
/* Disable DMA functionality */
#define SLUB_DMA 0
#endif
/*
* ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
*
* Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
*
* ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
* Both make kfree a no-op.
*/
#define ZERO_SIZE_PTR ((void *)16)
static inline void *kmalloc(size_t size, gfp_t flags)
{
if (__builtin_constant_p(size) && !(flags & SLUB_DMA)) {
struct kmem_cache *s = kmalloc_slab(size);
if (!s)
return ZERO_SIZE_PTR;
return kmem_cache_alloc(s, flags);
} else
return __kmalloc(size, flags);
}
static inline void *kzalloc(size_t size, gfp_t flags)
{
if (__builtin_constant_p(size) && !(flags & SLUB_DMA)) {
struct kmem_cache *s = kmalloc_slab(size);
if (!s)
return ZERO_SIZE_PTR;
return kmem_cache_zalloc(s, flags);
} else
return __kzalloc(size, flags);
}
#ifdef CONFIG_NUMA
extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
if (__builtin_constant_p(size) && !(flags & SLUB_DMA)) {
struct kmem_cache *s = kmalloc_slab(size);
if (!s)
return ZERO_SIZE_PTR;
return kmem_cache_alloc_node(s, flags, node);
} else
return __kmalloc_node(size, flags, node);
}
#endif
#endif /* _LINUX_SLUB_DEF_H */
|
