remarkable-linux/include/linux/slab_def.h
Christoph Lameter 6cb8f91320 Slab allocators: consistent ZERO_SIZE_PTR support and NULL result semantics
Define ZERO_OR_NULL_PTR macro to be able to remove the checks from the
allocators.  Move ZERO_SIZE_PTR related stuff into slab.h.

Make ZERO_SIZE_PTR work for all slab allocators and get rid of the
WARN_ON_ONCE(size == 0) that is still remaining in SLAB.

Make slub return NULL like the other allocators if a too large memory segment
is requested via __kmalloc.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00

132 lines
2.9 KiB
C

#ifndef _LINUX_SLAB_DEF_H
#define _LINUX_SLAB_DEF_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 <asm/page.h> /* kmalloc_sizes.h needs PAGE_SIZE */
#include <asm/cache.h> /* kmalloc_sizes.h needs L1_CACHE_BYTES */
#include <linux/compiler.h>
/* Size description struct for general caches. */
struct cache_sizes {
size_t cs_size;
struct kmem_cache *cs_cachep;
#ifdef CONFIG_ZONE_DMA
struct kmem_cache *cs_dmacachep;
#endif
};
extern struct cache_sizes malloc_sizes[];
void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
void *__kmalloc(size_t size, gfp_t flags);
static inline void *kmalloc(size_t size, gfp_t flags)
{
if (__builtin_constant_p(size)) {
int i = 0;
if (!size)
return ZERO_SIZE_PTR;
#define CACHE(x) \
if (size <= x) \
goto found; \
else \
i++;
#include "kmalloc_sizes.h"
#undef CACHE
{
extern void __you_cannot_kmalloc_that_much(void);
__you_cannot_kmalloc_that_much();
}
found:
#ifdef CONFIG_ZONE_DMA
if (flags & GFP_DMA)
return kmem_cache_alloc(malloc_sizes[i].cs_dmacachep,
flags);
#endif
return kmem_cache_alloc(malloc_sizes[i].cs_cachep, flags);
}
return __kmalloc(size, flags);
}
static inline void *kzalloc(size_t size, gfp_t flags)
{
if (__builtin_constant_p(size)) {
int i = 0;
if (!size)
return ZERO_SIZE_PTR;
#define CACHE(x) \
if (size <= x) \
goto found; \
else \
i++;
#include "kmalloc_sizes.h"
#undef CACHE
{
extern void __you_cannot_kzalloc_that_much(void);
__you_cannot_kzalloc_that_much();
}
found:
#ifdef CONFIG_ZONE_DMA
if (flags & GFP_DMA)
return kmem_cache_zalloc(malloc_sizes[i].cs_dmacachep,
flags);
#endif
return kmem_cache_zalloc(malloc_sizes[i].cs_cachep, flags);
}
return __kzalloc(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);
static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
if (__builtin_constant_p(size)) {
int i = 0;
if (!size)
return ZERO_SIZE_PTR;
#define CACHE(x) \
if (size <= x) \
goto found; \
else \
i++;
#include "kmalloc_sizes.h"
#undef CACHE
{
extern void __you_cannot_kmalloc_that_much(void);
__you_cannot_kmalloc_that_much();
}
found:
#ifdef CONFIG_ZONE_DMA
if (flags & GFP_DMA)
return kmem_cache_alloc_node(malloc_sizes[i].cs_dmacachep,
flags, node);
#endif
return kmem_cache_alloc_node(malloc_sizes[i].cs_cachep,
flags, node);
}
return __kmalloc_node(size, flags, node);
}
#endif /* CONFIG_NUMA */
extern const struct seq_operations slabinfo_op;
ssize_t slabinfo_write(struct file *, const char __user *, size_t, loff_t *);
#endif /* _LINUX_SLAB_DEF_H */