From: Pavel Machek <pavel@ucw.cz>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>,
David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@suse.de>,
Nick Piggin <npiggin@suse.de>, Mel Gorman <mel@csn.ul.ie>,
Peter Ziljstra <a.p.ziljstra@chello.nl>,
San Mehat <san@android.com>, Arve Hj?nnev?g <arve@android.com>,
linux-kernel@vger.kernel.org
Subject: Re: Misleading OOM messages
Date: Tue, 19 May 2009 22:39:45 +0200 [thread overview]
Message-ID: <20090519203944.GD1362@ucw.cz> (raw)
In-Reply-To: <alpine.DEB.1.10.0905151713230.26489@qirst.com>
On Fri 2009-05-15 17:15:54, Christoph Lameter wrote:
> On Fri, 15 May 2009, Pavel Machek wrote:
>
> > > Nope. If you have too little memory for your app then the kernel pages
> > > portions of the app out to disk. Thats is why you have a VM (VIRTUAL
> > > machine). The app is not running with physical memory.
> >
> > Try running your machine with mem=8M, then tell me how virtual memory
> > works.
>
> Well that is of course not enough memory.
Ok, so in the end, there are two reasons for OOM:
1) Out of virtual memory.
there's simply not enough ram+swap to fit the data. You go OOM.
This seems to be common on small machines. 8M is pushing it, but
64M ram + 64M swap + todays gnome would probably do that.
And maybe the way to hint people would be printing 'out of
_virtual_ memory'.
2) Something goes very wrong with reclaim
this seems to be common on very big machines you have experience
with.
Perhaps 1 and 2 can be told appart by zero swap free in the 1) case?
And perhaps you can invent some better message for 2) case?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2009-05-22 6:13 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-10 22:07 [patch 01/11 -mmotm] lowmemorykiller: Only iterate over process list when needed David Rientjes
2009-05-10 22:07 ` [patch 02/11 -mmotm] lowmemorykiller: Don't count free space unless it meets the specified limit by itself David Rientjes
2009-05-12 9:23 ` Mel Gorman
2009-05-13 0:27 ` Arve Hjønnevåg
2009-05-13 9:42 ` Mel Gorman
2009-05-14 23:25 ` Arve Hjønnevåg
2009-05-15 9:18 ` Mel Gorman
2009-05-10 22:07 ` [patch 03/11 -mmotm] oom: cleanup android low memory killer David Rientjes
2009-05-10 22:07 ` [patch 04/11 -mmotm] oom: fix possible android low memory killer NULL pointer David Rientjes
2009-05-10 22:07 ` [patch 05/11 -mmotm] oom: fix possible oom_dump_tasks " David Rientjes
2009-05-11 21:11 ` Andrew Morton
2009-05-11 21:28 ` David Rientjes
2009-05-11 21:41 ` Greg KH
2009-05-11 22:05 ` David Rientjes
2009-05-12 9:38 ` Mel Gorman
2009-05-10 22:07 ` [patch 06/11 -mmotm] oom: move oom_adj value from task_struct to mm_struct David Rientjes
2009-05-11 0:17 ` KOSAKI Motohiro
2009-05-11 0:26 ` David Rientjes
2009-05-11 1:47 ` KOSAKI Motohiro
2009-05-11 8:43 ` David Rientjes
2009-05-11 21:19 ` Andrew Morton
2009-05-12 9:56 ` Mel Gorman
2009-05-10 22:07 ` [patch 07/11 -mmotm] oom: prevent possible OOM_DISABLE livelock David Rientjes
2009-05-11 21:22 ` Andrew Morton
2009-05-10 22:07 ` [patch 08/11 -mmotm] oom: invoke oom killer for __GFP_NOFAIL David Rientjes
2009-05-10 23:59 ` KOSAKI Motohiro
2009-05-11 0:24 ` David Rientjes
2009-05-11 1:45 ` KOSAKI Motohiro
2009-05-11 7:40 ` Minchan Kim
2009-05-11 8:49 ` David Rientjes
2009-05-11 11:23 ` Minchan Kim
2009-05-11 8:45 ` David Rientjes
2009-05-11 16:03 ` Dave Hansen
2009-05-11 19:09 ` David Rientjes
2009-05-11 19:45 ` Dave Hansen
2009-05-11 20:21 ` David Rientjes
2009-05-11 21:29 ` Andrew Morton
2009-05-11 21:45 ` David Rientjes
2009-05-11 22:11 ` Andrew Morton
2009-05-11 22:31 ` David Rientjes
2009-05-11 22:46 ` Andrew Morton
2009-05-11 23:00 ` David Rientjes
2009-05-11 23:14 ` Andrew Morton
2009-05-11 23:37 ` David Rientjes
2009-05-12 5:39 ` Peter Zijlstra
2009-05-12 11:36 ` KOSAKI Motohiro
2009-05-12 10:05 ` Mel Gorman
2009-05-10 22:07 ` [patch 09/11 -mmotm] oom: return vm size of oom killed task David Rientjes
2009-05-11 21:36 ` Andrew Morton
2009-05-10 22:07 ` [patch 10/11 -mmotm] oom: avoid oom kill if no interruptible tasks David Rientjes
2009-05-11 21:39 ` Andrew Morton
2009-05-11 23:08 ` David Rientjes
2009-05-10 22:07 ` [patch 11/11 -mmotm] oom: fail allocations if oom killer can't free memory David Rientjes
2009-05-12 21:14 ` Misleading OOM messages Christoph Lameter
2009-05-14 9:29 ` Pavel Machek
2009-05-14 19:46 ` Christoph Lameter
2009-05-14 20:38 ` Dave Hansen
2009-05-14 20:49 ` Christoph Lameter
2009-05-14 20:49 ` David Rientjes
2009-05-14 21:05 ` Dave Hansen
2009-05-14 21:12 ` David Rientjes
2009-05-14 21:30 ` Christoph Lameter
2009-05-14 21:34 ` Pavel Machek
2009-05-14 21:41 ` Dave Hansen
2009-05-15 13:05 ` Pavel Machek
2009-05-15 17:59 ` Christoph Lameter
2009-05-15 18:22 ` Dave Hansen
2009-05-15 19:29 ` Christoph Lameter
2009-05-15 20:02 ` Pavel Machek
2009-05-15 21:15 ` Christoph Lameter
2009-05-19 20:39 ` Pavel Machek [this message]
2009-05-22 13:53 ` Christoph Lameter
2009-05-22 14:17 ` Warn when we run out of swap space (was Re: Misleading OOM messages) Christoph Lameter
2009-05-22 14:56 ` Pavel Machek
2009-05-22 19:01 ` Misleading OOM messages Christoph Lameter
2009-05-22 19:40 ` Randy Dunlap
2009-05-22 19:44 ` Christoph Lameter
2009-05-22 21:45 ` Alan Cox
2009-05-22 21:43 ` Alan Cox
2009-05-15 17:57 ` Christoph Lameter
2009-05-15 18:15 ` Dave Hansen
2009-05-15 18:19 ` Balbir Singh
2009-05-15 19:26 ` Christoph Lameter
2009-05-15 20:31 ` Balbir Singh
2009-05-18 14:34 ` Christoph Lameter
2009-05-18 15:45 ` Balbir Singh
2009-05-14 21:37 ` Dave Hansen
2009-05-14 22:00 ` David Rientjes
2009-05-15 17:58 ` Christoph Lameter
2009-05-15 18:23 ` Dave Hansen
2009-05-15 18:57 ` Balbir Singh
2009-05-15 19:37 ` David Rientjes
2009-05-14 20:56 ` Pavel Machek
2009-05-12 9:09 ` [patch 01/11 -mmotm] lowmemorykiller: Only iterate over process list when needed Mel Gorman
2009-05-13 0:43 ` Arve Hjønnevåg
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