From 2e892f43ccb602e8ffad73396a1000f2040c9e0b Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 13 Dec 2006 00:34:23 -0800 Subject: [PATCH] [PATCH] Cleanup slab headers / API to allow easy addition of new slab allocators This is a response to an earlier discussion on linux-mm about splitting slab.h components per allocator. Patch is against 2.6.19-git11. See http://marc.theaimsgroup.com/?l=linux-mm&m=116469577431008&w=2 This patch cleans up the slab header definitions. We define the common functions of slob and slab in slab.h and put the extra definitions needed for slab's kmalloc implementations in . In order to get a greater set of common functions we add several empty functions to slob.c and also rename slob's kmalloc to __kmalloc. Slob does not need any special definitions since we introduce a fallback case. If there is no need for a slab implementation to provide its own kmalloc mess^H^H^Hacros then we simply fall back to __kmalloc functions. That is sufficient for SLOB. Sort the function in slab.h according to their functionality. First the functions operating on struct kmem_cache * then the kmalloc related functions followed by special debug and fallback definitions. Also redo a lot of comments. Signed-off-by: Christoph Lameter ? Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/slab.h | 306 ++++++++++++++------------------------- include/linux/slab_def.h | 100 +++++++++++++ mm/slob.c | 16 +- 3 files changed, 223 insertions(+), 199 deletions(-) create mode 100644 include/linux/slab_def.h diff --git a/include/linux/slab.h b/include/linux/slab.h index 2271886744f8..e7a9c6b42412 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -1,7 +1,9 @@ /* - * linux/include/linux/slab.h - * Written by Mark Hemment, 1996. - * (markhe@nextd.demon.co.uk) + * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk). + * + * (C) SGI 2006, Christoph Lameter + * Cleaned up and restructured to ease the addition of alternative + * implementations of SLAB allocators. */ #ifndef _LINUX_SLAB_H @@ -10,64 +12,99 @@ #ifdef __KERNEL__ #include -#include #include -#include /* kmalloc_sizes.h needs PAGE_SIZE */ -#include /* kmalloc_sizes.h needs L1_CACHE_BYTES */ -#include -/* kmem_cache_t exists for legacy reasons and is not used by code in mm */ typedef struct kmem_cache kmem_cache_t __deprecated; -/* flags to pass to kmem_cache_create(). - * The first 3 are only valid when the allocator as been build - * SLAB_DEBUG_SUPPORT. +/* + * Flags to pass to kmem_cache_create(). + * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set. */ -#define SLAB_DEBUG_FREE 0x00000100UL /* Peform (expensive) checks on free */ -#define SLAB_DEBUG_INITIAL 0x00000200UL /* Call constructor (as verifier) */ -#define SLAB_RED_ZONE 0x00000400UL /* Red zone objs in a cache */ -#define SLAB_POISON 0x00000800UL /* Poison objects */ -#define SLAB_HWCACHE_ALIGN 0x00002000UL /* align objs on a h/w cache lines */ -#define SLAB_CACHE_DMA 0x00004000UL /* use GFP_DMA memory */ -#define SLAB_MUST_HWCACHE_ALIGN 0x00008000UL /* force alignment */ -#define SLAB_STORE_USER 0x00010000UL /* store the last owner for bug hunting */ -#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* track pages allocated to indicate - what is reclaimable later*/ -#define SLAB_PANIC 0x00040000UL /* panic if kmem_cache_create() fails */ -#define SLAB_DESTROY_BY_RCU 0x00080000UL /* defer freeing pages to RCU */ +#define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */ +#define SLAB_DEBUG_INITIAL 0x00000200UL /* DEBUG: Call constructor (as verifier) */ +#define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */ +#define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */ +#define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */ +#define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */ +#define SLAB_MUST_HWCACHE_ALIGN 0x00008000UL /* Force alignment even if debuggin is active */ +#define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */ +#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */ +#define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */ +#define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */ #define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */ -/* flags passed to a constructor func */ -#define SLAB_CTOR_CONSTRUCTOR 0x001UL /* if not set, then deconstructor */ -#define SLAB_CTOR_ATOMIC 0x002UL /* tell constructor it can't sleep */ -#define SLAB_CTOR_VERIFY 0x004UL /* tell constructor it's a verify call */ +/* Flags passed to a constructor functions */ +#define SLAB_CTOR_CONSTRUCTOR 0x001UL /* If not set, then deconstructor */ +#define SLAB_CTOR_ATOMIC 0x002UL /* Tell constructor it can't sleep */ +#define SLAB_CTOR_VERIFY 0x004UL /* Tell constructor it's a verify call */ -#ifndef CONFIG_SLOB - -/* prototypes */ -extern void __init kmem_cache_init(void); +/* + * struct kmem_cache related prototypes + */ +void __init kmem_cache_init(void); +extern int slab_is_available(void); -extern struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, +struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, unsigned long, void (*)(void *, struct kmem_cache *, unsigned long), void (*)(void *, struct kmem_cache *, unsigned long)); -extern void kmem_cache_destroy(struct kmem_cache *); -extern int kmem_cache_shrink(struct kmem_cache *); -extern void *kmem_cache_alloc(struct kmem_cache *, gfp_t); -extern void *kmem_cache_zalloc(struct kmem_cache *, gfp_t); -extern void kmem_cache_free(struct kmem_cache *, void *); -extern unsigned int kmem_cache_size(struct kmem_cache *); -extern const char *kmem_cache_name(struct kmem_cache *); +void kmem_cache_destroy(struct kmem_cache *); +int kmem_cache_shrink(struct kmem_cache *); +void *kmem_cache_alloc(struct kmem_cache *, gfp_t); +void *kmem_cache_zalloc(struct kmem_cache *, gfp_t); +void kmem_cache_free(struct kmem_cache *, void *); +unsigned int kmem_cache_size(struct kmem_cache *); +const char *kmem_cache_name(struct kmem_cache *); +int kmem_ptr_validate(struct kmem_cache *cachep, void *ptr); + +#ifdef CONFIG_NUMA +extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node); +#else +static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep, + gfp_t flags, int node) +{ + return kmem_cache_alloc(cachep, flags); +} +#endif + +/* + * Common kmalloc functions provided by all allocators + */ +void *__kmalloc(size_t, gfp_t); +void *__kzalloc(size_t, gfp_t); +void kfree(const void *); +unsigned int ksize(const void *); + +/** + * kcalloc - allocate memory for an array. The memory is set to zero. + * @n: number of elements. + * @size: element size. + * @flags: the type of memory to allocate. + */ +static inline void *kcalloc(size_t n, size_t size, gfp_t flags) +{ + if (n != 0 && size > ULONG_MAX / n) + return NULL; + return __kzalloc(n * size, flags); +} -/* Size description struct for general caches. */ -struct cache_sizes { - size_t cs_size; - struct kmem_cache *cs_cachep; - struct kmem_cache *cs_dmacachep; -}; -extern struct cache_sizes malloc_sizes[]; +/* + * Allocator specific definitions. These are mainly used to establish optimized + * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by selecting + * the appropriate general cache at compile time. + */ +#ifdef CONFIG_SLAB +#include +#else -extern void *__kmalloc(size_t, gfp_t); +/* + * Fallback definitions for an allocator not wanting to provide + * its own optimized kmalloc definitions (like SLOB). + */ + +#if defined(CONFIG_NUMA) || defined(CONFIG_DEBUG_SLAB) +#error "SLAB fallback definitions not usable for NUMA or Slab debug" +#endif /** * kmalloc - allocate memory @@ -114,29 +151,22 @@ extern void *__kmalloc(size_t, gfp_t); * * %__GFP_REPEAT - If allocation fails initially, try once more before failing. */ -static inline void *kmalloc(size_t size, gfp_t flags) +void *kmalloc(size_t size, gfp_t flags) { - if (__builtin_constant_p(size)) { - int i = 0; -#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: - return kmem_cache_alloc((flags & GFP_DMA) ? - malloc_sizes[i].cs_dmacachep : - malloc_sizes[i].cs_cachep, flags); - } return __kmalloc(size, flags); } +/** + * kzalloc - allocate memory. The memory is set to zero. + * @size: how many bytes of memory are required. + * @flags: the type of memory to allocate (see kmalloc). + */ +void *kzalloc(size_t size, gfp_t flags) +{ + return __kzalloc(size, flags); +} +#endif + /* * kmalloc_track_caller is a special version of kmalloc that records the * calling function of the routine calling it for slab leak tracking instead @@ -145,89 +175,16 @@ found: * allocator where we care about the real place the memory allocation * request comes from. */ -#ifndef CONFIG_DEBUG_SLAB -#define kmalloc_track_caller(size, flags) \ - __kmalloc(size, flags) -#else +#ifdef CONFIG_DEBUG_SLAB extern void *__kmalloc_track_caller(size_t, gfp_t, void*); #define kmalloc_track_caller(size, flags) \ __kmalloc_track_caller(size, flags, __builtin_return_address(0)) -#endif - -extern void *__kzalloc(size_t, gfp_t); - -/** - * kzalloc - allocate memory. The memory is set to zero. - * @size: how many bytes of memory are required. - * @flags: the type of memory to allocate (see kmalloc). - */ -static inline void *kzalloc(size_t size, gfp_t flags) -{ - if (__builtin_constant_p(size)) { - int i = 0; -#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: - return kmem_cache_zalloc((flags & GFP_DMA) ? - malloc_sizes[i].cs_dmacachep : - malloc_sizes[i].cs_cachep, flags); - } - return __kzalloc(size, flags); -} - -/** - * kcalloc - allocate memory for an array. The memory is set to zero. - * @n: number of elements. - * @size: element size. - * @flags: the type of memory to allocate. - */ -static inline void *kcalloc(size_t n, size_t size, gfp_t flags) -{ - if (n != 0 && size > ULONG_MAX / n) - return NULL; - return kzalloc(n * size, flags); -} - -extern void kfree(const void *); -extern unsigned int ksize(const void *); -extern int slab_is_available(void); +#else +#define kmalloc_track_caller(size, flags) \ + __kmalloc(size, flags) +#endif /* DEBUG_SLAB */ #ifdef CONFIG_NUMA -extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node); -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)) { - int i = 0; -#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: - return kmem_cache_alloc_node((flags & GFP_DMA) ? - malloc_sizes[i].cs_dmacachep : - malloc_sizes[i].cs_cachep, flags, node); - } - return __kmalloc_node(size, flags, node); -} - /* * kmalloc_node_track_caller is a special version of kmalloc_node that * records the calling function of the routine calling it for slab leak @@ -236,70 +193,27 @@ found: * standard allocator where we care about the real place the memory * allocation request comes from. */ -#ifndef CONFIG_DEBUG_SLAB -#define kmalloc_node_track_caller(size, flags, node) \ - __kmalloc_node(size, flags, node) -#else +#ifdef CONFIG_DEBUG_SLAB extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *); #define kmalloc_node_track_caller(size, flags, node) \ __kmalloc_node_track_caller(size, flags, node, \ __builtin_return_address(0)) +#else +#define kmalloc_node_track_caller(size, flags, node) \ + __kmalloc_node(size, flags, node) #endif + #else /* CONFIG_NUMA */ -static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep, - gfp_t flags, int node) -{ - return kmem_cache_alloc(cachep, flags); -} -static inline void *kmalloc_node(size_t size, gfp_t flags, int node) -{ - return kmalloc(size, flags); -} #define kmalloc_node_track_caller(size, flags, node) \ kmalloc_track_caller(size, flags) -#endif -extern int FASTCALL(kmem_cache_reap(int)); -extern int FASTCALL(kmem_ptr_validate(struct kmem_cache *cachep, void *ptr)); - -#else /* CONFIG_SLOB */ - -/* SLOB allocator routines */ - -void kmem_cache_init(void); -struct kmem_cache *kmem_cache_create(const char *c, size_t, size_t, - unsigned long, - void (*)(void *, struct kmem_cache *, unsigned long), - void (*)(void *, struct kmem_cache *, unsigned long)); -void kmem_cache_destroy(struct kmem_cache *c); -void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags); -void *kmem_cache_zalloc(struct kmem_cache *, gfp_t); -void kmem_cache_free(struct kmem_cache *c, void *b); -const char *kmem_cache_name(struct kmem_cache *); -void *kmalloc(size_t size, gfp_t flags); -void *__kzalloc(size_t size, gfp_t flags); -void kfree(const void *m); -unsigned int ksize(const void *m); -unsigned int kmem_cache_size(struct kmem_cache *c); - -static inline void *kcalloc(size_t n, size_t size, gfp_t flags) +static inline void *kmalloc_node(size_t size, gfp_t flags, int node) { - return __kzalloc(n * size, flags); + return kmalloc(size, flags); } -#define kmem_cache_shrink(d) (0) -#define kmem_cache_reap(a) -#define kmem_ptr_validate(a, b) (0) -#define kmem_cache_alloc_node(c, f, n) kmem_cache_alloc(c, f) -#define kmalloc_node(s, f, n) kmalloc(s, f) -#define kzalloc(s, f) __kzalloc(s, f) -#define kmalloc_track_caller kmalloc - -#define kmalloc_node_track_caller kmalloc_node - -#endif /* CONFIG_SLOB */ - +#endif /* !CONFIG_NUMA */ #endif /* __KERNEL__ */ - #endif /* _LINUX_SLAB_H */ + diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h new file mode 100644 index 000000000000..4b463e66ddea --- /dev/null +++ b/include/linux/slab_def.h @@ -0,0 +1,100 @@ +#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 +#include /* kmalloc_sizes.h needs PAGE_SIZE */ +#include /* kmalloc_sizes.h needs L1_CACHE_BYTES */ +#include + +/* Size description struct for general caches. */ +struct cache_sizes { + size_t cs_size; + struct kmem_cache *cs_cachep; + struct kmem_cache *cs_dmacachep; +}; +extern struct cache_sizes malloc_sizes[]; + +static inline void *kmalloc(size_t size, gfp_t flags) +{ + if (__builtin_constant_p(size)) { + int i = 0; +#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: + return kmem_cache_alloc((flags & GFP_DMA) ? + malloc_sizes[i].cs_dmacachep : + 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; +#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: + return kmem_cache_zalloc((flags & GFP_DMA) ? + malloc_sizes[i].cs_dmacachep : + 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); + +static inline void *kmalloc_node(size_t size, gfp_t flags, int node) +{ + if (__builtin_constant_p(size)) { + int i = 0; +#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: + return kmem_cache_alloc_node((flags & GFP_DMA) ? + malloc_sizes[i].cs_dmacachep : + malloc_sizes[i].cs_cachep, flags, node); + } + return __kmalloc_node(size, flags, node); +} + +#endif /* CONFIG_NUMA */ + +#endif /* _LINUX_SLAB_DEF_H */ diff --git a/mm/slob.c b/mm/slob.c index 542394184a58..b90091c4b08c 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -157,7 +157,7 @@ static int fastcall find_order(int size) return order; } -void *kmalloc(size_t size, gfp_t gfp) +void *__kmalloc(size_t size, gfp_t gfp) { slob_t *m; bigblock_t *bb; @@ -186,8 +186,7 @@ void *kmalloc(size_t size, gfp_t gfp) slob_free(bb, sizeof(bigblock_t)); return 0; } - -EXPORT_SYMBOL(kmalloc); +EXPORT_SYMBOL(__kmalloc); void kfree(const void *block) { @@ -329,6 +328,17 @@ EXPORT_SYMBOL(kmem_cache_name); static struct timer_list slob_timer = TIMER_INITIALIZER( (void (*)(unsigned long))kmem_cache_init, 0, 0); +int kmem_cache_shrink(struct kmem_cache *d) +{ + return 0; +} +EXPORT_SYMBOL(kmem_cache_shrink); + +int kmem_ptr_validate(struct kmem_cache *a, void *b) +{ + return 0; +} + void kmem_cache_init(void) { void *p = slob_alloc(PAGE_SIZE, 0, PAGE_SIZE-1); -- 2.20.1