Commit 90810645 authored by Christoph Lameter's avatar Christoph Lameter Committed by Pekka Enberg
Browse files

slab allocators: Provide generic description of alignment defines 



Provide description for alignment defines.

Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent 3192b920

include/linux/slab.h

+10 −0
Original line number Diff line number Diff line
@@ -133,12 +133,22 @@ unsigned int kmem_cache_size(struct kmem_cache *); 
#define KMALLOC_MAX_SIZE	(1UL << KMALLOC_SHIFT_HIGH)

#define KMALLOC_MAX_ORDER	(KMALLOC_SHIFT_HIGH - PAGE_SHIFT)



/*

 * Some archs want to perform DMA into kmalloc caches and need a guaranteed

 * alignment larger than the alignment of a 64-bit integer.

 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.

 */

#ifdef ARCH_DMA_MINALIGN

#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN

#else

#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)

#endif



/*

 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.

 * Intended for arches that get misalignment faults even for 64 bit integer

 * aligned buffers.

 */

#ifndef ARCH_SLAB_MINALIGN

#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)

#endif