Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965145AbXHHVKu (ORCPT ); Wed, 8 Aug 2007 17:10:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763071AbXHHVKh (ORCPT ); Wed, 8 Aug 2007 17:10:37 -0400 Received: from gir.skynet.ie ([193.1.99.77]:56473 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763799AbXHHVKg (ORCPT ); Wed, 8 Aug 2007 17:10:36 -0400 Date: Wed, 8 Aug 2007 22:10:32 +0100 To: Christoph Lameter Cc: Lee.Schermerhorn@hp.com, pj@sgi.com, ak@suse.de, kamezawa.hiroyu@jp.fujitsu.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 2/3] Use one zonelist that is filtered instead of multiple zonelists Message-ID: <20070808211032.GB2441@skynet.ie> References: <20070808161504.32320.79576.sendpatchset@skynet.skynet.ie> <20070808161545.32320.41940.sendpatchset@skynet.skynet.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) From: mel@skynet.ie (Mel Gorman) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3340 Lines: 88 On (08/08/07 10:46), Christoph Lameter didst pronounce: > On Wed, 8 Aug 2007, Mel Gorman wrote: > > > for (i = 0; i < npmem_ranges; i++) { > > + zl = &NODE_DATA(i)->node_zonelist; > > The above shows up again and again. Maybe add a new inline function? > > struct zonelist *zonelist_node(int node) > Not a bad plan. There are least 5 instances of calls like this in mm/ alone so might as well. > > > { > > - return NODE_DATA(0)->node_zonelists + gfp_zone(gfp_flags); > > + return &NODE_DATA(0)->node_zonelist; > > How many callers of gfp_zone are left? Do we still need the function? > Well, the iterator needs it because it expects a high_zoneidx parameter which is == gfp_zone(gfp_flags). It also appears quite a bit the code according to grep. I don't think it can be got rid of now anyway. > Note that the memoryless_node patchset modifies gfp_zone and adds some > more zonelists (sigh). > > > diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.23-rc1-mm2-005_freepages_zonelist/mm/oom_kill.c linux-2.6.23-rc1-mm2-010_use_zonelist/mm/oom_kill.c > > --- linux-2.6.23-rc1-mm2-005_freepages_zonelist/mm/oom_kill.c 2007-08-07 14:45:11.000000000 +0100 > > +++ linux-2.6.23-rc1-mm2-010_use_zonelist/mm/oom_kill.c 2007-08-08 11:35:09.000000000 +0100 > > @@ -177,8 +177,10 @@ static inline int constrained_alloc(stru > > { > > #ifdef CONFIG_NUMA > > struct zone **z; > > + struct zone *zone; > > nodemask_t nodes; > > int node; > > + enum zone_type high_zoneidx = gfp_zone(gfp_mask); > > > > nodes_clear(nodes); > > /* node has memory ? */ > > @@ -186,9 +188,9 @@ static inline int constrained_alloc(stru > > if (NODE_DATA(node)->node_present_pages) > > node_set(node, nodes); > > > > - for (z = zonelist->zones; *z; z++) > > - if (cpuset_zone_allowed_softwall(*z, gfp_mask)) > > - node_clear(zone_to_nid(*z), nodes); > > + for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) > > + if (cpuset_zone_allowed_softwall(zone, gfp_mask)) > > + node_clear(zone_to_nid(zone), nodes); > > else > > return CONSTRAINT_CPUSET; > > > > The above portion has already been changed to no longer use a zonelist by > the memoryless_node patchset in mm. > Oh, well that's good. One less thing to worry about even though we'll be colliding a bit. I'll split the patch in two to have the second part that collides with memoryless_node as a standalone patch. > > + zonelist = &NODE_DATA(slab_node(current->mempolicy))->node_zonelist; > > + for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { > > struct kmem_cache_node *n; > > > > - n = get_node(s, zone_to_nid(*z)); > > + n = get_node(s, zone_to_nid(zone)); > > Encoding the node in the zonelist pointer would help these loops but they > are fallback lists and not on the critical path. > The zone_id is the one I'm really interested in. It looks like the most promising optimisation for avoiding zone_idx in the hotpath. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab - 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/