From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756214Ab0IBPsO (ORCPT ); Thu, 2 Sep 2010 11:48:14 -0400 Received: from mail-vw0-f46.google.com ([209.85.212.46]:42208 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756182Ab0IBPsL (ORCPT ); Thu, 2 Sep 2010 11:48:11 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=d0W9096QnaVzofnJG5GFTIAGKJXi1CjGaMPc292U0J02R4aqVpaLCUmAsL+z4oSufZ +WrL4IAB8TTn4HUVOR9MBGIqZ++3MZ/IX/tzc6p/9n7hQrjVyR4v8v9g6z3NF6UkdIfz 2rYafW/+2AHa0PRM8b9fHwYk/+Q1TdCWHHSw8= From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , Minchan Kim , Johannes Weiner , Rik van Riel , "Rafael J. Wysocki" , "M. Vefa Bicakci" , stable@kernel.org, KOSAKI Motohiro Subject: [PATCH] vmscan: don't use return value trick when oom_killer_disabled Date: Fri, 3 Sep 2010 00:47:41 +0900 Message-Id: <1283442461-16290-1-git-send-email-minchan.kim@gmail.com> X-Mailer: git-send-email 1.7.0.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 two. 1) hibernate_preallocate_memory() call alloc_pages() wrong order 2) vmscan don't care enough OOM case when oom_killer_disabled. This patch only fix (2). Why is oom_killer_disabled so special? because when hibernation case, zone->all_unreclaimable never be turned on. hibernation freeze all tasks at first, then kswapd can't works in this case, and zone->all_unreclaimable is only turned from kswapd. Cc: Johannes Weiner Cc: Rik van Riel Cc: "Rafael J. Wysocki" Cc: M. Vefa Bicakci Cc: stable@kernel.org Signed-off-by: KOSAKI Motohiro Signed-off-by: Minchan Kim --- mm/vmscan.c | 33 +++++++++++++++++++++++++++------ 1 files changed, 27 insertions(+), 6 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index f620ab3..53b23a7 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1893,12 +1893,11 @@ 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) { @@ -1916,8 +1915,31 @@ static bool shrink_zones(int priority, struct zonelist *zonelist, } shrink_zone(priority, zone, sc); - all_unreclaimable = false; } +} + +static inline 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->pages_scanned < (zone_reclaimable_pages(zone) * 6)) { + all_unreclaimable = false; + break; + } + } + return all_unreclaimable; } @@ -1941,7 +1963,6 @@ 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; @@ -1958,7 +1979,7 @@ 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 @@ -2020,7 +2041,7 @@ 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; -- 1.7.0.5