From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx121.postini.com [74.125.245.121]) by kanga.kvack.org (Postfix) with SMTP id A81296B0033 for ; Mon, 26 Aug 2013 09:52:06 -0400 (EDT) Received: by mail-we0-f177.google.com with SMTP id q55so2717344wes.22 for ; Mon, 26 Aug 2013 06:52:05 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: From: Michal Suchanek Date: Mon, 26 Aug 2013 15:51:24 +0200 Message-ID: Subject: Re: doing lots of disk writes causes oom killer to kill processes Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Hillf Danton Cc: LKML , Linux-MM On 12 March 2013 03:15, Hillf Danton wrote: >>On 11 March 2013 13:15, Michal Suchanek wrote: >>>On 8 February 2013 17:31, Michal Suchanek wrote: >>> Hello, >>> >>> I am dealing with VM disk images and performing something like wiping >>> free space to prepare image for compressing and storing on server or >>> copying it to external USB disk causes >>> >>> 1) system lockup in order of a few tens of seconds when all CPU cores >>> are 100% used by system and the machine is basicaly unusable >>> >>> 2) oom killer killing processes >>> >>> This all on system with 8G ram so there should be plenty space to work with. >>> >>> This happens with kernels 3.6.4 or 3.7.1 >>> >>> With earlier kernel versions (some 3.0 or 3.2 kernels) this was not a >>> problem even with less ram. >>> >>> I have vm.swappiness = 0 set for a long time already. >>> >>> >>I did some testing with 3.7.1 and with swappiness as much as 75 the >>kernel still causes all cores to loop somewhere in system when writing >>lots of data to disk. >> >>With swappiness as much as 90 processes still get killed on large disk writes. >> >>Given that the max is 100 the interval in which mm works at all is >>going to be very narrow, less than 10% of the paramater range. This is >>a severe regression as is the cpu time consumed by the kernel. >> >>The io scheduler is the default cfq. >> >>If you have any idea what to try other than downgrading to an earlier >>unaffected kernel I would like to hear. >> > Can you try commit 3cf23841b4b7(mm/vmscan.c: avoid possible > deadlock caused by too_many_isolated())? > > Or try 3.8 and/or 3.9, additionally? > Hello, with deadline IO scheduler I experience this issue less often but it still happens. I am on 3.9.6 Debian kernel so 3.8 did not fix this problem. Do you have some idea what to log so that useful information about the lockup is gathered? Thanks Michal -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org