]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress
authorTetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Fri, 5 Feb 2016 23:36:30 +0000 (15:36 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 6 Feb 2016 02:10:40 +0000 (18:10 -0800)
commit564e81a57f9788b1475127012e0fd44e9049e342
tree6ed99c6e46c2133dc7ca7eb085a3f1a43407763a
parentccde8bd4014eb2f01102f7a64f0fad3df193b758
mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress

Jan Stancek has reported that system occasionally hanging after "oom01"
testcase from LTP triggers OOM.  Guessing from a result that there is a
kworker thread doing memory allocation and the values between "Node 0
Normal free:" and "Node 0 Normal:" differs when hanging, vmstat is not
up-to-date for some reason.

According to commit 373ccbe59270 ("mm, vmstat: allow WQ concurrency to
discover memory reclaim doesn't make any progress"), it meant to force
the kworker thread to take a short sleep, but it by error used
schedule_timeout(1).  We missed that schedule_timeout() in state
TASK_RUNNING doesn't do anything.

Fix it by using schedule_timeout_uninterruptible(1) which forces the
kworker thread to take a short sleep in order to make sure that vmstat
is up-to-date.

Fixes: 373ccbe59270 ("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make any progress")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Cristopher Lameter <clameter@sgi.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Arkadiusz Miskiewicz <arekm@maven.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/backing-dev.c