Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753023Ab0GITPK (ORCPT ); Fri, 9 Jul 2010 15:15:10 -0400 Received: from nlpi157.sbcis.sbc.com ([207.115.36.171]:34333 "EHLO nlpi157.prodigy.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754627Ab0GITMV (ORCPT ); Fri, 9 Jul 2010 15:12:21 -0400 Message-Id: <20100709190857.912752982@quilx.com> User-Agent: quilt/0.48-1 Date: Fri, 09 Jul 2010 14:07:20 -0500 From: Christoph Lameter To: Pekka Enberg Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Cc: Nick Piggin Cc: David Rientjes Subject: [S+Q2 14/19] slub: Move gfpflag masking out of the hotpath References: <20100709190706.938177313@quilx.com> Content-Disposition: inline; filename=slub_move_gfpflags Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1866 Lines: 56 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. 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 2010-07-07 10:38:17.000000000 -0500 +++ linux-2.6/mm/slub.c 2010-07-07 10:38:22.000000000 -0500 @@ -798,6 +798,7 @@ 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); @@ -806,6 +807,7 @@ 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); } @@ -1648,6 +1650,7 @@ static void *__slab_alloc(struct kmem_ca /* We handle __GFP_ZERO in the caller */ gfpflags &= ~__GFP_ZERO; + gfpflags &= gfp_allowed_mask; if (!c->page) goto new_slab; @@ -1733,8 +1736,6 @@ 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/