From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: avagin@gmail.com
Cc: kosaki.motohiro@jp.fujitsu.com,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Andrew Morton <akpm@linux-foundation.org>,
Minchan Kim <minchan.kim@gmail.com>,
Andrey Vagin <avagin@openvz.org>, Mel Gorman <mel@csn.ul.ie>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: check zone->all_unreclaimable in all_unreclaimable()
Date: Wed, 9 Mar 2011 15:17:01 +0900 (JST) [thread overview]
Message-ID: <20110309145457.0400.A69D9226@jp.fujitsu.com> (raw)
In-Reply-To: <4D767D43.5020802@gmail.com>
> On 03/08/2011 06:06 AM, KOSAKI Motohiro wrote:
> >>>> Hmm.. Although it solves the problem, I think it's not a good idea that
> >>>> depends on false alram and give up the retry.
> >>>
> >>> Any alternative proposals? We should get the livelock fixed if possible..
> >>
> >> I agree with Minchan and can't think this is a real fix....
> >> Andrey, I'm now trying your fix and it seems your fix for oom-killer,
> >> 'skip-zombie-process' works enough good for my environ.
> >>
> >> What is your enviroment ? number of cpus ? architecture ? size of memory ?
> >
> > me too. 'skip-zombie-process V1' work fine. and I didn't seen this patch
> > improve oom situation.
> >
> > And, The test program is purely fork bomb. Our oom-killer is not silver
> > bullet for fork bomb from very long time ago. That said, oom-killer send
> > SIGKILL and start to kill the victim process. But, it doesn't prevent
> > to be created new memory hogging tasks. Therefore we have no gurantee
> > to win process exiting and creating race.
>
> I think a live-lock is a bug, even if it's provoked by fork bomds.
>
> And now I want say some words about zone->all_unreclaimable. I think
> this flag is "conservative". It is set when situation is bad and it's
> unset when situation get better. If we have a small number of
> reclaimable pages, the situation is still bad. What do you mean, when
> say that kernel is alive? If we have one reclaimable page, is the kernel
> alive? Yes, it can work, it will generate many page faults and do
> something, but anyone say that it is more dead than alive.
>
> Try to look at it from my point of view. The patch will be correct and
> the kernel will be more alive.
>
> Excuse me, If I'm mistaken...
Hi,
Hmmm...
If I could observed your patch, I did support your opinion. but I didn't. so, now I'm
curious why we got the different conclusion. tommorow, I'll try to construct a test
environment to reproduce your system.
Unfortunatelly, zone->all_unreclamable is unreliable value while hibernation processing.
Then I doubt current your patch is enough acceptable. but I'm not against to make alternative
if we can observe the same phenomenon.
At minimum, I also dislike kernel hang up issue.
Thanks.
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next prev parent reply other threads:[~2011-03-09 6:17 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-05 11:44 Andrey Vagin
2011-03-05 15:20 ` Minchan Kim
2011-03-05 15:34 ` Andrew Vagin
2011-03-05 15:53 ` Minchan Kim
2011-03-05 16:41 ` Andrew Vagin
2011-03-05 17:07 ` Minchan Kim
2011-03-07 21:58 ` Andrew Morton
2011-03-07 23:45 ` Minchan Kim
2011-03-09 5:37 ` KAMEZAWA Hiroyuki
2011-03-09 5:43 ` KAMEZAWA Hiroyuki
2011-03-10 6:58 ` Minchan Kim
2011-03-10 23:58 ` KAMEZAWA Hiroyuki
2011-03-11 0:18 ` Minchan Kim
2011-03-11 6:08 ` avagin
2011-03-14 1:03 ` Minchan Kim
2011-03-08 0:44 ` KAMEZAWA Hiroyuki
2011-03-08 3:06 ` KOSAKI Motohiro
2011-03-08 19:02 ` avagin
2011-03-09 5:52 ` KAMEZAWA Hiroyuki
2011-03-09 6:17 ` KOSAKI Motohiro [this message]
2011-03-10 14:08 ` KOSAKI Motohiro
2011-03-08 8:12 ` Andrew Vagin
2011-03-09 6:06 ` KAMEZAWA Hiroyuki
2011-05-04 1:38 ` CAI Qian
2011-05-09 6:54 ` KOSAKI Motohiro
2011-05-09 8:47 ` CAI Qian
2011-05-09 9:19 ` KOSAKI Motohiro
2011-05-10 8:11 ` OOM Killer don't works at all if the system have >gigabytes memory (was Re: [PATCH] mm: check zone->all_unreclaimable in all_unreclaimable()) KOSAKI Motohiro
2011-05-10 8:14 ` [PATCH 1/4] oom: improve dump_tasks() show items KOSAKI Motohiro
2011-05-10 23:29 ` David Rientjes
2011-05-13 10:14 ` KOSAKI Motohiro
2011-05-10 8:15 ` [PATCH 2/4] oom: kill younger process first KOSAKI Motohiro
2011-05-10 23:31 ` David Rientjes
2011-05-13 10:15 ` KOSAKI Motohiro
2011-05-11 23:33 ` Minchan Kim
2011-05-12 0:52 ` KAMEZAWA Hiroyuki
2011-05-12 1:30 ` Minchan Kim
2011-05-12 1:53 ` KAMEZAWA Hiroyuki
2011-05-12 2:23 ` Minchan Kim
2011-05-12 3:39 ` KAMEZAWA Hiroyuki
2011-05-12 4:17 ` Minchan Kim
2011-05-12 14:38 ` Paul E. McKenney
2011-05-13 10:18 ` KOSAKI Motohiro
2011-05-10 8:15 ` [PATCH 3/4] oom: oom-killer don't use permillage of system-ram internally KOSAKI Motohiro
2011-05-10 23:40 ` David Rientjes
2011-05-13 10:30 ` KOSAKI Motohiro
2011-05-10 8:16 ` [PATCH 4/4] oom: don't kill random process KOSAKI Motohiro
2011-05-10 23:41 ` David Rientjes
2011-05-10 23:22 ` OOM Killer don't works at all if the system have >gigabytes memory (was Re: [PATCH] mm: check zone->all_unreclaimable in all_unreclaimable()) David Rientjes
2011-05-11 2:30 ` CAI Qian
2011-05-11 20:34 ` David Rientjes
2011-05-12 0:13 ` Minchan Kim
2011-05-12 19:38 ` David Rientjes
2011-05-13 4:16 ` Minchan Kim
2011-05-13 11:04 ` KOSAKI Motohiro
2011-05-16 20:42 ` David Rientjes
2011-05-13 6:53 ` CAI Qian
2011-05-16 20:46 ` David Rientjes
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