Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262709AbVAFDmm (ORCPT ); Wed, 5 Jan 2005 22:42:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262710AbVAFDmm (ORCPT ); Wed, 5 Jan 2005 22:42:42 -0500 Received: from mx1.redhat.com ([66.187.233.31]:48349 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S262709AbVAFDmj (ORCPT ); Wed, 5 Jan 2005 22:42:39 -0500 Date: Wed, 5 Jan 2005 22:42:11 -0500 (EST) From: Rik van Riel X-X-Sender: riel@chimarrao.boston.redhat.com To: Andrew Morton cc: nickpiggin@yahoo.com.au, marcelo.tosatti@cyclades.com, andrea@suse.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH][5/?] count writeback pages in nr_scanned In-Reply-To: <20050105173624.5c3189b9.akpm@osdl.org> Message-ID: References: <20050105020859.3192a298.akpm@osdl.org> <20050105180651.GD4597@dualathlon.random> <20050105174934.GC15739@logos.cnet> <20050105134457.03aca488.akpm@osdl.org> <20050105203217.GB17265@logos.cnet> <41DC7D86.8050609@yahoo.com.au> <20050105173624.5c3189b9.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1499 Lines: 37 On Wed, 5 Jan 2005, Andrew Morton wrote: > Rik van Riel wrote: >> The recent OOM kill problem has been happening: >> 1) with cache pressure on lowmem only, due to a block device write >> 2) with no block congestion at all >> 3) with pretty much all pageable lowmme pages in writeback state > > You must have a wild number of requests configured in the queue. Is > this CFQ? Yes, it is with CFQ. Around 650MB of lowmem is in writeback stage, which is over 99% of the active and inactive lowmem pages... > I've done testing with "all of memory under writeback" before and it > went OK. It's certainly a design objective to handle this well. But > that testing was before we broke it. I suspect something might still be broken. It may take a few days of continuous testing to trigger the bug, though ... > The bug which you fixed would cause the VM to scan itself to death > without throttling. Did the fix fix things? Mostly fixed. Things are down to the point where it often takes over a day to bring out the bug. -- "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." - Brian W. Kernighan - 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/