Commit 2e892f43 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[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 <linux/slab_def.h>.  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: default avatarChristoph Lameter <clameter@sgi.com&gt;?>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 872225ca

include/linux/slab.h

+110 −196
Original line number Diff line number Diff line 
/*

 * 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 <clameter@sgi.com>

 * 	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 <linux/gfp.h>

#include <linux/init.h>

#include <linux/types.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>



/* 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 */



#ifndef CONFIG_SLOB

/* 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 */



/* 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 <linux/slab_def.h>

#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)

{

	if (__builtin_constant_p(size)) {

		int i = 0;

#define CACHE(x) \

		if (size <= x) \

			goto found; \

		else \

			i++;

#include "kmalloc_sizes.h"

#undef CACHE

void *kmalloc(size_t size, gfp_t flags)

{

			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 */

include/linux/slab_def.h

0 → 100644
+100 −0
Original line number Diff line number Diff line 
#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;

	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 */

mm/slob.c

+13 −3
Original line number Diff line number Diff line
@@ -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);

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