diff options
Diffstat (limited to 'include/linux/slub_def.h')
| -rw-r--r-- | include/linux/slub_def.h | 61 |
1 files changed, 36 insertions, 25 deletions
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index ea27065e80e6..6207a3d8da71 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -28,7 +28,7 @@ struct kmem_cache { 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; + int order; /* * Avoid an extra cache line for UP, SMP and for the node local to @@ -40,7 +40,6 @@ struct kmem_cache { int objects; /* Number of objects in slab */ int refcount; /* Refcount for slab cache destroy */ void (*ctor)(void *, struct kmem_cache *, unsigned long); - void (*dtor)(void *, struct kmem_cache *, unsigned long); int inuse; /* Offset to metadata */ int align; /* Alignment */ const char *name; /* Name (only for display!) */ @@ -57,18 +56,14 @@ struct kmem_cache { /* * Kmalloc subsystem. */ -#define KMALLOC_SHIFT_LOW 3 - -#ifdef CONFIG_LARGE_ALLOCS -#define KMALLOC_SHIFT_HIGH 25 -#else -#if !defined(CONFIG_MMU) || NR_CPUS > 512 || MAX_NUMNODES > 256 -#define KMALLOC_SHIFT_HIGH 20 +#if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8 +#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN #else -#define KMALLOC_SHIFT_HIGH 18 -#endif +#define KMALLOC_MIN_SIZE 8 #endif +#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) + /* * We keep the general caches in an array of slab caches that are used for * 2^x bytes of allocations. @@ -79,13 +74,16 @@ 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(int size) +static inline int kmalloc_index(size_t size) { - /* - * We should return 0 if size == 0 but we use the smallest object - * here for SLAB legacy reasons. - */ - WARN_ON_ONCE(size == 0); + if (!size) + return 0; + + if (size > KMALLOC_MAX_SIZE) + return -1; + + if (size <= KMALLOC_MIN_SIZE) + return KMALLOC_SHIFT_LOW; if (size > 64 && size <= 96) return 1; @@ -107,17 +105,13 @@ static inline int kmalloc_index(int size) if (size <= 64 * 1024) return 16; if (size <= 128 * 1024) return 17; if (size <= 256 * 1024) return 18; -#if KMALLOC_SHIFT_HIGH > 18 if (size <= 512 * 1024) return 19; if (size <= 1024 * 1024) return 20; -#endif -#if KMALLOC_SHIFT_HIGH > 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; -#endif return -1; /* @@ -142,7 +136,12 @@ static inline struct kmem_cache *kmalloc_slab(size_t size) if (index == 0) return NULL; - if (index < 0) { + /* + * 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. @@ -160,13 +159,25 @@ static inline struct kmem_cache *kmalloc_slab(size_t size) #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 NULL; + return ZERO_SIZE_PTR; return kmem_cache_alloc(s, flags); } else @@ -179,7 +190,7 @@ static inline void *kzalloc(size_t size, gfp_t flags) struct kmem_cache *s = kmalloc_slab(size); if (!s) - return NULL; + return ZERO_SIZE_PTR; return kmem_cache_zalloc(s, flags); } else @@ -195,7 +206,7 @@ static inline void *kmalloc_node(size_t size, gfp_t flags, int node) struct kmem_cache *s = kmalloc_slab(size); if (!s) - return NULL; + return ZERO_SIZE_PTR; return kmem_cache_alloc_node(s, flags, node); } else |