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authorAlexey Dobriyan <adobriyan@gmail.com>2018-04-06 01:20:40 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-06 06:36:23 +0200
commitd5f866550df237861f9d59ca0206434b0dea9701 (patch)
tree5a410c065c5b77affe3cc98b7e103cc675a15c1b /mm/slab_common.c
parentslab: make kmem_cache_create() work with 32-bit sizes (diff)
downloadlinux-d5f866550df237861f9d59ca0206434b0dea9701.tar.xz
linux-d5f866550df237861f9d59ca0206434b0dea9701.zip
slab: make size_index[] array u8
All those small numbers are reverse indexes into kmalloc caches array and can't be negative. On x86_64 "unsigned int = fls()" can drop CDQE instruction: add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-2 (-2) Function old new delta kmalloc_slab 101 99 -2 Link: http://lkml.kernel.org/r/20180305200730.15812-7-adobriyan@gmail.com Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slab_common.c')
-rw-r--r--mm/slab_common.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c
index a4545a61a7c8..dda966e6bc58 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -971,7 +971,7 @@ EXPORT_SYMBOL(kmalloc_dma_caches);
* of two cache sizes there. The size of larger slabs can be determined using
* fls.
*/
-static s8 size_index[24] __ro_after_init = {
+static u8 size_index[24] __ro_after_init = {
3, /* 8 */
4, /* 16 */
5, /* 24 */
@@ -1009,7 +1009,7 @@ static inline int size_index_elem(size_t bytes)
*/
struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
{
- int index;
+ unsigned int index;
if (unlikely(size > KMALLOC_MAX_SIZE)) {
WARN_ON_ONCE(!(flags & __GFP_NOWARN));