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slab, slub, slob: Unify alignment definition

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Every slab has its on alignment definition in include/linux/sl?b_def.h. Extract those
and define a common set in include/linux/slab.h.

SLOB: As notes sometimes we need double word alignment on 32 bit. This gives all
structures allocated by SLOB a unsigned long long alignment like the others do.

SLAB: If ARCH_SLAB_MINALIGN is not set SLAB would set ARCH_SLAB_MINALIGN to
zero meaning no alignment at all. Give it the default unsigned long long alignment.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This commit is contained in:
Christoph Lameter
2011-06-14 16:16:36 -05:00
committed by Pekka Enberg
parent bd50cfa891
commit 3192b920bf
4 changed files with 10 additions and 46 deletions
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10
include/linux/slab.h
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@@ -133,6 +133,16 @@ unsigned int kmem_cache_size(struct kmem_cache *);
#define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH) #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH)
#define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT) #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT)
#ifdef ARCH_DMA_MINALIGN
#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
#else
#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
#endif
#ifndef ARCH_SLAB_MINALIGN
#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
#endif
/* /*
* Common kmalloc functions provided by all allocators * Common kmalloc functions provided by all allocators
*/ */

26
include/linux/slab_def.h
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@@ -17,32 +17,6 @@
#include <trace/events/kmem.h> #include <trace/events/kmem.h>
/*
* Enforce a minimum alignment for the kmalloc caches.
* Usually, the kmalloc caches are cache_line_size() aligned, except when
* DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
* Some archs want to perform DMA into kmalloc caches and need a guaranteed
* alignment larger than the alignment of a 64-bit integer.
* ARCH_KMALLOC_MINALIGN allows that.
* Note that increasing this value may disable some debug features.
*/
#ifdef ARCH_DMA_MINALIGN
#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
#else
#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
#endif
#ifndef ARCH_SLAB_MINALIGN
/*
* Enforce a minimum alignment for all caches.
* Intended for archs that get misalignment faults even for BYTES_PER_WORD
* aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
* If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
* some debug features.
*/
#define ARCH_SLAB_MINALIGN 0
#endif
/* /*
* struct kmem_cache * struct kmem_cache
* *

10
include/linux/slob_def.h
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@@ -1,16 +1,6 @@
#ifndef __LINUX_SLOB_DEF_H #ifndef __LINUX_SLOB_DEF_H
#define __LINUX_SLOB_DEF_H #define __LINUX_SLOB_DEF_H
#ifdef ARCH_DMA_MINALIGN
#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
#else
#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long)
#endif
#ifndef ARCH_SLAB_MINALIGN
#define ARCH_SLAB_MINALIGN __alignof__(unsigned long)
#endif
void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node); void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
static __always_inline void *kmem_cache_alloc(struct kmem_cache *cachep, static __always_inline void *kmem_cache_alloc(struct kmem_cache *cachep,

10
include/linux/slub_def.h
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@@ -113,16 +113,6 @@ struct kmem_cache {
#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
#ifdef ARCH_DMA_MINALIGN
#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
#else
#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
#endif
#ifndef ARCH_SLAB_MINALIGN
#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
#endif
/* /*
* Maximum kmalloc object size handled by SLUB. Larger object allocations * Maximum kmalloc object size handled by SLUB. Larger object allocations
* are passed through to the page allocator. The page allocator "fastpath" * are passed through to the page allocator. The page allocator "fastpath"