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| author | Alexey Dobriyan <adobriyan@gmail.com> | 2018-04-05 16:20:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-05 21:36:23 -0700 |
| commit | d5f866550df237861f9d59ca0206434b0dea9701 (patch) | |
| tree | 5a410c065c5b77affe3cc98b7e103cc675a15c1b /mm | |
| parent | f4957d5bd09165b165df851fbf8c658f7fcd9922 (diff) | |
| download | linux-d5f866550df237861f9d59ca0206434b0dea9701.tar.bz2 | |
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')
| -rw-r--r-- | mm/slab_common.c | 4 |
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)); |