This is a note to let you know that I've just added the patch titled mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress to the 4.3-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-vmstat-fix-wrong-wq-sleep-when-memory-reclaim-doesn-t-make-any-progress.patch and it can be found in the queue-4.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 564e81a57f9788b1475127012e0fd44e9049e342 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Date: Fri, 5 Feb 2016 15:36:30 -0800 Subject: mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> commit 564e81a57f9788b1475127012e0fd44e9049e342 upstream. 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@xxxxxxxxxxxxxxxxxxx> Reported-by: Jan Stancek <jstancek@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Cristopher Lameter <clameter@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Arkadiusz Miskiewicz <arekm@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/backing-dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -989,7 +989,7 @@ long wait_iff_congested(struct zone *zon * here rather than calling cond_resched(). */ if (current->flags & PF_WQ_WORKER) - schedule_timeout(1); + schedule_timeout_uninterruptible(1); else cond_resched(); Patches currently in stable-queue which might be from penguin-kernel@xxxxxxxxxxxxxxxxxxx are queue-4.3/mm-oom_kill.c-reverse-the-order-of-setting-tif_memdie-and-sending-sigkill.patch queue-4.3/mm-vmstat-fix-wrong-wq-sleep-when-memory-reclaim-doesn-t-make-any-progress.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html