From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 6EB416B033F for ; Fri, 20 Aug 2010 13:37:43 -0400 (EDT) Message-Id: <20100820173740.449355843@linux.com> Date: Fri, 20 Aug 2010 12:37:17 -0500 From: Christoph Lameter Subject: [S+Q Cleanup4 6/6] slub: Move gfpflag masking out of the hotpath References: <20100820173711.136529149@linux.com> Content-Disposition: inline; filename=slub_move_gfpflags Sender: owner-linux-mm@kvack.org To: Pekka Enberg Cc: linux-mm@kvack.org, David Rientjes List-ID: Move the gfpflags masking into the hooks for checkers and into the slowpaths. gfpflag masking requires access to a global variable and thus adds an additional cacheline reference to the hotpaths. If no hooks are active then the gfpflag masking will result in code that the compiler can toss out. Acked-by: David Rientjes Signed-off-by: Christoph Lameter --- mm/slub.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) Index: linux-2.6/mm/slub.c =================================================================== --- linux-2.6.orig/mm/slub.c 2010-08-20 11:43:50.000000000 -0500 +++ linux-2.6/mm/slub.c 2010-08-20 11:43:50.000000000 -0500 @@ -796,6 +796,7 @@ static void trace(struct kmem_cache *s, */ static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) { + flags &= gfp_allowed_mask; lockdep_trace_alloc(flags); might_sleep_if(flags & __GFP_WAIT); @@ -804,6 +805,7 @@ static inline int slab_pre_alloc_hook(st static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object) { + flags &= gfp_allowed_mask; kmemcheck_slab_alloc(s, flags, object, s->objsize); kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags); } @@ -1677,6 +1679,7 @@ new_slab: goto load_freelist; } + gfpflags &= gfp_allowed_mask; if (gfpflags & __GFP_WAIT) local_irq_enable(); @@ -1725,8 +1728,6 @@ static __always_inline void *slab_alloc( struct kmem_cache_cpu *c; unsigned long flags; - gfpflags &= gfp_allowed_mask; - if (slab_pre_alloc_hook(s, gfpflags)) return NULL; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org