Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756375Ab1EKVKx (ORCPT ); Wed, 11 May 2011 17:10:53 -0400 Received: from cantor2.suse.de ([195.135.220.15]:42538 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755914Ab1EKVKt (ORCPT ); Wed, 11 May 2011 17:10:49 -0400 Date: Wed, 11 May 2011 22:10:43 +0100 From: Mel Gorman To: David Rientjes Cc: Andrew Morton , James Bottomley , Colin King , Raghavendra D Prabhu , Jan Kara , Chris Mason , Christoph Lameter , Pekka Enberg , Rik van Riel , Johannes Weiner , linux-fsdevel , linux-mm , linux-kernel , linux-ext4 Subject: Re: [PATCH 2/3] mm: slub: Do not take expensive steps for SLUBs speculative high-order allocations Message-ID: <20110511211043.GB17898@suse.de> References: <1305127773-10570-1-git-send-email-mgorman@suse.de> <1305127773-10570-3-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1980 Lines: 53 On Wed, May 11, 2011 at 01:38:44PM -0700, David Rientjes wrote: > On Wed, 11 May 2011, Mel Gorman wrote: > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 9f8a97b..057f1e2 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -1972,6 +1972,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask) > > { > > int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; > > const gfp_t wait = gfp_mask & __GFP_WAIT; > > + const gfp_t can_wake_kswapd = !(gfp_mask & __GFP_NO_KSWAPD); > > > > /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ > > BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); > > @@ -1984,7 +1985,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask) > > */ > > alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); > > > > - if (!wait) { > > + if (!wait && can_wake_kswapd) { > > /* > > * Not worth trying to allocate harder for > > * __GFP_NOMEMALLOC even if it can't schedule. > > diff --git a/mm/slub.c b/mm/slub.c > > index 98c358d..1071723 100644 > > --- a/mm/slub.c > > +++ b/mm/slub.c > > @@ -1170,7 +1170,8 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) > > * Let the initial higher-order allocation fail under memory pressure > > * so we fall-back to the minimum order allocation. > > */ > > - alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY | __GFP_NO_KSWAPD) & ~__GFP_NOFAIL; > > + alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY | __GFP_NO_KSWAPD) & > > + ~(__GFP_NOFAIL | __GFP_WAIT); > > __GFP_NORETRY is a no-op without __GFP_WAIT. > True. I'll remove it in a V2 but I won't respin just yet. > > > > page = alloc_slab_page(alloc_gfp, node, oo); > > if (unlikely(!page)) { -- Mel Gorman SUSE Labs -- 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/