From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753458Ab0ILQcK (ORCPT ); Sun, 12 Sep 2010 12:32:10 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:36899 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752403Ab0ILQcI (ORCPT ); Sun, 12 Sep 2010 12:32:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=FlnRbOkzQ9y9VV2DUXXmtDJ3a5gPXnd7gLaObcX0tCvigRhCHq59W3WzSGpf8gQQc3 WAmKzdAPcHnUdsCt9dM/ED3KwMowP8Zgg4bCnHNUibEZfO0lpdRdC7RJnDJimOnUiX3w b/OvX5jpe80VTbRUE6mtTSbhXpPgZxO98MooA= Date: Mon, 13 Sep 2010 01:32:00 +0900 From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , KOSAKI Motohiro , Minchan Kim , Johannes Weiner , Rik van Riel , "Rafael J. Wysocki" , "M. Vefa Bicakci" , stable@kernel.org Subject: [PATCH v2] vmscan: check all_unreclaimable in direct reclaim path Message-ID: <20100912163200.GA4098@barrios-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adnrew, Please drop my old version and merge this verstion. (old : vmscan-check-all_unreclaimable-in-direct-reclaim-path.patch) * Changelog from v2 * remove inline - suggested by Andrew * add function desription - suggeseted by Adnrew == CUT HERE == Subject: [PATCH v2] vmscan: check all_unreclaimable in direct reclaim path M. Vefa Bicakci reported 2.6.35 kernel hang up when hibernation on his 32bit 3GB mem machine. (https://bugzilla.kernel.org/show_bug.cgi?id=16771) Also he was bisected first bad commit is below commit bb21c7ce18eff8e6e7877ca1d06c6db719376e3c Author: KOSAKI Motohiro Date: Fri Jun 4 14:15:05 2010 -0700 vmscan: fix do_try_to_free_pages() return value when priority==0 reclaim failure At first impression, this seemed very strange because the above commit only chenged function return value and hibernate_preallocate_memory() ignore return value of shrink_all_memory(). But it's related. Now, page allocation from hibernation code may enter infinite loop if the system has highmem. The reasons are that vmscan don't care enough OOM case when oom_killer_disabled. The problem sequence is following as. 1. hibernation 2. oom_disable 3. alloc_pages 4. do_try_to_free_pages if (scanning_global_lru(sc) && !all_unreclaimable) return 1; If kswapd is not freezed, it would set zone->all_unreclaimable to 1 and then shrink_zones maybe return true(ie, all_unreclaimable is true). so at last, alloc_pages could go to _nopage_. If it is, it should have no problem. This patch adds all_unreclaimable check to protect in direct reclaim path, too. It can care of hibernation OOM case and help bailout all_unreclaimable case slightly. Cc: Rik van Riel Cc: M. Vefa Bicakci Cc: stable@kernel.org Acked-by: Rafael J. Wysocki Reviewed-by: Johannes Weiner Signed-off-by: KOSAKI Motohiro Signed-off-by: Minchan Kim --- mm/vmscan.c | 46 ++++++++++++++++++++++++++++++++++++++-------- 1 files changed, 38 insertions(+), 8 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 7870893..ecae0ef 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1877,12 +1877,11 @@ static void shrink_zone(int priority, struct zone *zone, * If a zone is deemed to be full of pinned pages then just give it a light * scan then give up on it. */ -static bool shrink_zones(int priority, struct zonelist *zonelist, +static void shrink_zones(int priority, struct zonelist *zonelist, struct scan_control *sc) { struct zoneref *z; struct zone *zone; - bool all_unreclaimable = true; for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(sc->gfp_mask), sc->nodemask) { @@ -1900,8 +1899,41 @@ static bool shrink_zones(int priority, struct zonelist *zonelist, } shrink_zone(priority, zone, sc); - all_unreclaimable = false; } +} + +static bool zone_reclaimable(struct zone *zone) +{ + return zone->pages_scanned < zone_reclaimable_pages(zone) * 6; +} + +/* + * As hibernation is going on, kswapd is freezed so that it can't mark + * the zone into all_unreclaimable. It can't handle OOM during hibernation. + * So let's check zone's unreclaimable in direct reclaim as well as kswapd. + */ +static bool all_unreclaimable(struct zonelist *zonelist, + struct scan_control *sc) +{ + struct zoneref *z; + struct zone *zone; + bool all_unreclaimable = true; + + if (!scanning_global_lru(sc)) + return false; + + for_each_zone_zonelist_nodemask(zone, z, zonelist, + gfp_zone(sc->gfp_mask), sc->nodemask) { + if (!populated_zone(zone)) + continue; + if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) + continue; + if (zone_reclaimable(zone)) { + all_unreclaimable = false; + break; + } + } + return all_unreclaimable; } @@ -1925,7 +1957,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, struct scan_control *sc) { int priority; - bool all_unreclaimable; unsigned long total_scanned = 0; struct reclaim_state *reclaim_state = current->reclaim_state; struct zoneref *z; @@ -1942,7 +1973,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, sc->nr_scanned = 0; if (!priority) disable_swap_token(); - all_unreclaimable = shrink_zones(priority, zonelist, sc); + shrink_zones(priority, zonelist, sc); /* * Don't shrink slabs when reclaiming memory from * over limit cgroups @@ -2004,7 +2035,7 @@ out: return sc->nr_reclaimed; /* top priority shrink_zones still had more to do? don't OOM, then */ - if (scanning_global_lru(sc) && !all_unreclaimable) + if (!all_unreclaimable(zonelist, sc)) return 1; return 0; @@ -2270,8 +2301,7 @@ loop_again: total_scanned += sc.nr_scanned; if (zone->all_unreclaimable) continue; - if (nr_slab == 0 && - zone->pages_scanned >= (zone_reclaimable_pages(zone) * 6)) + if (nr_slab == 0 && !zone_reclaimable(zone)) zone->all_unreclaimable = 1; /* * If we've done a decent amount of scanning and -- 1.7.0.5 -- Kind regards, Minchan Kim 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 C51966B00B5 for ; Sun, 12 Sep 2010 12:32:09 -0400 (EDT) Received: by pzk26 with SMTP id 26so1449379pzk.14 for ; Sun, 12 Sep 2010 09:32:08 -0700 (PDT) Date: Mon, 13 Sep 2010 01:32:00 +0900 From: Minchan Kim Subject: [PATCH v2] vmscan: check all_unreclaimable in direct reclaim path Message-ID: <20100912163200.GA4098@barrios-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: linux-mm , LKML , KOSAKI Motohiro , Minchan Kim , Johannes Weiner , Rik van Riel , "Rafael J. Wysocki" , "M. Vefa Bicakci" , stable@kernel.org List-ID: Adnrew, Please drop my old version and merge this verstion. (old : vmscan-check-all_unreclaimable-in-direct-reclaim-path.patch) * Changelog from v2 * remove inline - suggested by Andrew * add function desription - suggeseted by Adnrew == CUT HERE == Subject: [PATCH v2] vmscan: check all_unreclaimable in direct reclaim path M. Vefa Bicakci reported 2.6.35 kernel hang up when hibernation on his 32bit 3GB mem machine. (https://bugzilla.kernel.org/show_bug.cgi?id=16771) Also he was bisected first bad commit is below commit bb21c7ce18eff8e6e7877ca1d06c6db719376e3c Author: KOSAKI Motohiro Date: Fri Jun 4 14:15:05 2010 -0700 vmscan: fix do_try_to_free_pages() return value when priority==0 reclaim failure At first impression, this seemed very strange because the above commit only chenged function return value and hibernate_preallocate_memory() ignore return value of shrink_all_memory(). But it's related. Now, page allocation from hibernation code may enter infinite loop if the system has highmem. The reasons are that vmscan don't care enough OOM case when oom_killer_disabled. The problem sequence is following as. 1. hibernation 2. oom_disable 3. alloc_pages 4. do_try_to_free_pages if (scanning_global_lru(sc) && !all_unreclaimable) return 1; If kswapd is not freezed, it would set zone->all_unreclaimable to 1 and then shrink_zones maybe return true(ie, all_unreclaimable is true). so at last, alloc_pages could go to _nopage_. If it is, it should have no problem. This patch adds all_unreclaimable check to protect in direct reclaim path, too. It can care of hibernation OOM case and help bailout all_unreclaimable case slightly. Cc: Rik van Riel Cc: M. Vefa Bicakci Cc: stable@kernel.org Acked-by: Rafael J. Wysocki Reviewed-by: Johannes Weiner Signed-off-by: KOSAKI Motohiro Signed-off-by: Minchan Kim --- mm/vmscan.c | 46 ++++++++++++++++++++++++++++++++++++++-------- 1 files changed, 38 insertions(+), 8 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 7870893..ecae0ef 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1877,12 +1877,11 @@ static void shrink_zone(int priority, struct zone *zone, * If a zone is deemed to be full of pinned pages then just give it a light * scan then give up on it. */ -static bool shrink_zones(int priority, struct zonelist *zonelist, +static void shrink_zones(int priority, struct zonelist *zonelist, struct scan_control *sc) { struct zoneref *z; struct zone *zone; - bool all_unreclaimable = true; for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(sc->gfp_mask), sc->nodemask) { @@ -1900,8 +1899,41 @@ static bool shrink_zones(int priority, struct zonelist *zonelist, } shrink_zone(priority, zone, sc); - all_unreclaimable = false; } +} + +static bool zone_reclaimable(struct zone *zone) +{ + return zone->pages_scanned < zone_reclaimable_pages(zone) * 6; +} + +/* + * As hibernation is going on, kswapd is freezed so that it can't mark + * the zone into all_unreclaimable. It can't handle OOM during hibernation. + * So let's check zone's unreclaimable in direct reclaim as well as kswapd. + */ +static bool all_unreclaimable(struct zonelist *zonelist, + struct scan_control *sc) +{ + struct zoneref *z; + struct zone *zone; + bool all_unreclaimable = true; + + if (!scanning_global_lru(sc)) + return false; + + for_each_zone_zonelist_nodemask(zone, z, zonelist, + gfp_zone(sc->gfp_mask), sc->nodemask) { + if (!populated_zone(zone)) + continue; + if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) + continue; + if (zone_reclaimable(zone)) { + all_unreclaimable = false; + break; + } + } + return all_unreclaimable; } @@ -1925,7 +1957,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, struct scan_control *sc) { int priority; - bool all_unreclaimable; unsigned long total_scanned = 0; struct reclaim_state *reclaim_state = current->reclaim_state; struct zoneref *z; @@ -1942,7 +1973,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, sc->nr_scanned = 0; if (!priority) disable_swap_token(); - all_unreclaimable = shrink_zones(priority, zonelist, sc); + shrink_zones(priority, zonelist, sc); /* * Don't shrink slabs when reclaiming memory from * over limit cgroups @@ -2004,7 +2035,7 @@ out: return sc->nr_reclaimed; /* top priority shrink_zones still had more to do? don't OOM, then */ - if (scanning_global_lru(sc) && !all_unreclaimable) + if (!all_unreclaimable(zonelist, sc)) return 1; return 0; @@ -2270,8 +2301,7 @@ loop_again: total_scanned += sc.nr_scanned; if (zone->all_unreclaimable) continue; - if (nr_slab == 0 && - zone->pages_scanned >= (zone_reclaimable_pages(zone) * 6)) + if (nr_slab == 0 && !zone_reclaimable(zone)) zone->all_unreclaimable = 1; /* * If we've done a decent amount of scanning and -- 1.7.0.5 -- Kind regards, Minchan Kim -- 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