tree d319573849af86fa405b93e5b93add0d34305db7
parent 4c93c355d5d563f300df7e61ef753d7a064411e9
author Christoph Lameter <clameter@sgi.com> 1192523169 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1192552981 -0700

SLUB: Optimize cacheline use for zeroing

We touch a cacheline in the kmem_cache structure for zeroing to get the
size. However, the hot paths in slab_alloc and slab_free do not reference
any other fields in kmem_cache, so we may have to just bring in the
cacheline for this one access.

Add a new field to kmem_cache_cpu that contains the object size. That
cacheline must already be used in the hotpaths. So we save one cacheline
on every slab_alloc if we zero.

We need to update the kmem_cache_cpu object size if an aliasing operation
changes the objsize of an non debug slab.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>