Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161196AbWI2AW3 (ORCPT ); Thu, 28 Sep 2006 20:22:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161198AbWI2AW3 (ORCPT ); Thu, 28 Sep 2006 20:22:29 -0400 Received: from mx1.redhat.com ([66.187.233.31]:62701 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1161196AbWI2AW2 (ORCPT ); Thu, 28 Sep 2006 20:22:28 -0400 Date: Thu, 28 Sep 2006 20:22:12 -0400 From: Dave Jones To: Andrew Morton Cc: Roman Zippel , Linux Kernel Subject: Re: oom kill oddness. Message-ID: <20060929002212.GB19176@redhat.com> Mail-Followup-To: Dave Jones , Andrew Morton , Roman Zippel , Linux Kernel References: <20060927205435.GF1319@redhat.com> <20060928171706.bee0c50b.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060928171706.bee0c50b.akpm@osdl.org> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2315 Lines: 48 On Thu, Sep 28, 2006 at 05:17:06PM -0700, Andrew Morton wrote: > On Fri, 29 Sep 2006 01:03:16 +0200 (CEST) > Roman Zippel wrote: > > > Hi, > > > > On Wed, 27 Sep 2006, Dave Jones wrote: > > > > > So I have two boxes that are very similar. > > > Both have 2GB of RAM & 1GB of swap space. > > > One has a 2.8GHz CPU, the other a 2.93GHz CPU, both dualcore. > > > > > > The slower box survives a 'make -j bzImage' of a 2.6.18 kernel tree > > > without incident. (Although it takes ~4 minutes longer than a -j2) > > > > > > The faster box goes absolutely nuts, oomkilling everything in sight, > > > until eventually after about 10 minutes, the box locks up dead, > > > and won't even respond to pings. > > > > > > Oh, the only other difference - the slower box has 1 disk, whereas the > > > faster box has two in RAID0. I'm not surprised that stuff is getting > > > oom-killed given the pathological scenario, but the fact that the > > > box never recovered at all is a little odd. Does md lack some means > > > of dealing with low memory scenarios ? > > > > I think I see the same thing on the other end on slow machines, here it > > only takes a single compile job, which doesn't quite fit into memory and > > another task (like top) which occasionally wakes up and tries to allocate > > memory and then kills the compile job - that's very annoying. > > > > AFAICT the basic problem is that "did_some_progress" in __alloc_pages() is > > rather local information, other processes can still make progress and keep > > this process from making progress, which gets grumpy and starts killing. > > What's happing here is that most memory is either mapped or in the swap > > cache, so we have a race between processes trying to free memory from the > > cache and processes mapping memory back into their address space. > > Kernel versions please, guys. There have been a lot of oom-killer changes > post-2.6.18. Sorry, I've been stuck on 2.6.18 as that's what we're shipping in FC6 soon. Dave - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/