This test hung the kernel without triggering oom.
# mount -t cgroup -o memory none /cgroup/memory/
# mkdir /cgroup/memory/A
# echo $$ >/cgroup/memory/A/tasks
# echo 4096M >/cgroup/memory/A/memory.limit_in_bytes
# echo 4096M >/cgroup/memory/A/memory.memsw.limit_in_bytes
# use malloc to allocate more than 4G memory.
Sometimes, this had been thrown out of console,
localhost.localdomain login: INFO: task sm1:5065 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
sm1 D 00000000fffca130 0 5065 5051 0x00000080
ffff880c5f419c38 0000000000000086 ffff880c5f419bc8 ffffffff81034ca8
ffff880100000000 0000000000015440 ffff880c608ab4e0 0000000000015440
ffff880c608aba40 ffff880c5f419fd8 ffff880c608aba48 ffff880c5f419fd8
Call Trace:
[<ffffffff81034ca8>] ? pvclock_clocksource_read+0x58/0xd0
[<ffffffff810f2c60>] ? sync_page+0x0/0x50
[<ffffffff81492553>] io_schedule+0x73/0xc0
[<ffffffff810f2c9d>] sync_page+0x3d/0x50
[<ffffffff81492cba>] __wait_on_bit_lock+0x5a/0xc0
[<ffffffff810f2c37>] __lock_page+0x67/0x70
[<ffffffff8107cf90>] ? wake_bit_function+0x0/0x50
[<ffffffff810f2a6e>] ? find_get_page+0x1e/0xa0
[<ffffffff810f4a5c>] filemap_fault+0x33c/0x450
[<ffffffff81110524>] __do_fault+0x54/0x550
[<ffffffff8113f30a>] ? __mem_cgroup_commit_charge+0x5a/0xa0
[<ffffffff811132a2>] handle_mm_fault+0x1c2/0xc70
[<ffffffff8149809c>] do_page_fault+0x11c/0x320
[<ffffffff81494cd5>] page_fault+0x25/0x30
Reverted the following commit from mmotm tree made the problem go away.
commit 6a5ce1b94e1e5979f8db579f77d6e08a5f44c13b
Author: Minchan Kim <minchan.kim@xxxxxxxxx>
Date: Thu Sep 16 01:17:26 2010 +0200
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 bisected
the regression to
commit bb21c7ce18eff8e6e7877ca1d06c6db719376e3c
Author: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
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 freozen, 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.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx>
Reported-by: M. Vefa Bicakci <bicave@xxxxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rjw@xxxxxxx>
Reviewed-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 225a759..f56a8c3 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1804,12 +1804,11 @@ 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) {
@@ -1827,8 +1826,36 @@ static bool shrink_zones(int priority, struct zonelist *zonelist,
}
shrink_zone(priority, zone, sc);
- all_unreclaimable = false;
}
+}
+
+static inline bool zone_reclaimable(struct zone *zone)
+{
+ return zone->pages_scanned < zone_reclaimable_pages(zone) * 6;
+}
+
+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_reclaimable(zone)) {
+ all_unreclaimable = false;
+ break;
+ }
+ }
+
return all_unreclaimable;
}
@@ -1852,7 +1879,6 @@ 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;
@@ -1869,7 +1895,7 @@ 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
@@ -1931,7 +1957,7 @@ 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;
@@ -2197,8 +2223,7 @@ 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
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