Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754637AbYFVBiV (ORCPT ); Sat, 21 Jun 2008 21:38:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752685AbYFVBiJ (ORCPT ); Sat, 21 Jun 2008 21:38:09 -0400 Received: from gir.skynet.ie ([193.1.99.77]:47990 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752551AbYFVBiH (ORCPT ); Sat, 21 Jun 2008 21:38:07 -0400 Date: Sun, 22 Jun 2008 02:38:02 +0100 From: Mel Gorman To: Christoph Lameter Cc: Alexander Beregalov , kernel-testers@vger.kernel.org, kernel list , linux-mm@kvack.org, Lee Schermerhorn , KAMEZAWA Hiroyuki , Hugh Dickins , Nick Piggin , Andrew Morton , Linus Torvalds , bfields@fieldses.org, neilb@suse.de, linux-nfs@vger.kernel.org Subject: Re: 2.6.26-rc: nfsd hangs for a few sec Message-ID: <20080622013801.GE4692@csn.ul.ie> References: <20080621224135.GD4692@csn.ul.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) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2908 Lines: 84 On (21/06/08 17:18), Christoph Lameter didst pronounce: > On Sat, 21 Jun 2008, Mel Gorman wrote: > > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -1249,15 +1249,13 @@ static unsigned long shrink_zone(int priority, struct zone *zone, > > static unsigned long shrink_zones(int priority, struct zonelist *zonelist, > > struct scan_control *sc) > > { > > + enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask); > > unsigned long nr_reclaimed = 0; > > - struct zone **zones = zonelist->zones; > > - int i; > > - > > + struct zone **z; > > + struct zone *zone; > > > > sc->all_unreclaimable = 1; > > - for (i = 0; zones[i] != NULL; i++) { > > - struct zone *zone = zones[i]; > > - > > + for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { > > if (!populated_zone(zone)) > > continue; > > /* > > > > Code before - Walk the zonelist for GFP_KERNEL > > Before the change we walk all zones of the zonelist. > Yeah, but the zonelist is for GFP_KERNEL so it should not include the HIGHMEM zones, right? The key change is that after the patch there are fewer zonelists than get filtered. > > Code after - Filter zonelist based on what is allowed for GFP_KERNEL > > After the change we walk only zones for GFP_KERNEL. Meaning no HIGHMEM > and MOVABLE zones. Doesnt that mean that reclaim is limited to ZONE_DMA > and ZONE_NORMAL? Is that really intended? > It is for GFP_KERNEL allocations but that is expected. > If not then the following patch should return us to old behavior: > I think the effect of that patch is that zones get shrunk that have nothing to do with the requestors requirements. Right? > --- > mm/vmscan.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > Index: linux-2.6/mm/vmscan.c > =================================================================== > --- linux-2.6.orig/mm/vmscan.c 2008-06-21 17:15:45.597627317 -0700 > +++ linux-2.6/mm/vmscan.c 2008-06-21 17:17:16.273293260 -0700 > @@ -1249,13 +1249,12 @@ static unsigned long shrink_zone(int pri > static unsigned long shrink_zones(int priority, struct zonelist *zonelist, > struct scan_control *sc) > { > - enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask); > unsigned long nr_reclaimed = 0; > struct zoneref *z; > struct zone *zone; > > sc->all_unreclaimable = 1; > - for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { > + for_each_zone_zonelist(zone, z, zonelist, MAX_NR_ZONES - 1) { > if (!populated_zone(zone)) > continue; > /* > -- 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/