Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755119AbXK0Bal (ORCPT ); Mon, 26 Nov 2007 20:30:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752518AbXK0Bad (ORCPT ); Mon, 26 Nov 2007 20:30:33 -0500 Received: from paragon.brong.net ([74.52.187.94]:45111 "EHLO paragon.brong.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752499AbXK0Bac (ORCPT ); Mon, 26 Nov 2007 20:30:32 -0500 Date: Tue, 27 Nov 2007 12:30:28 +1100 From: Bron Gondwana To: Linus Torvalds Cc: Bron Gondwana , Peter Zijlstra , Christian Kujau , Andrew Morton , Linux Kernel Mailing List , robm@fastmail.fm Subject: Re: [PATCH 1/1] mm: add dirty_highmem option Message-ID: <20071127013028.GA31038@brong.net> References: <20071115115049.GA8297@brong.net> <1195155601.22457.25.camel@lappy> <1195159457.22457.35.camel@lappy> <20071122034204.GA14079@brong.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: brong.net User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1519 Lines: 35 On Mon, Nov 26, 2007 at 09:53:17AM -0800, Linus Torvalds wrote: > > > On Thu, 22 Nov 2007, Bron Gondwana wrote: > > > > This patch includes some code cleanup from Linus and a toggle in > > /proc/sys/vm/dirty_highmem which can be set to 1 to add the highmem > > back to the total available memory count. > > Just to verify - can you confirm that this "just fixes it" for you? > > I think this is the right approach to take, and seems very safe (ie people > who know that their loads are ok can just set the flag), but I do want to > verify that there was nothing else going on, and that you now see the same > performance as you did in 2.6.16? > > The other alternative, of course, would be to simply allow the dirty > percentages to be > 100%, but that's just *odd* ;) Yes, toggling dirty_highmem "just fixes it" in all our tests. I hadn't tested it on the production machine yet - but I'm just installing it there now since it's been running fine on a less important machine for a few days now. I did wonder about allowing the dirty percentage to go way up, but that would have cause "this one goes up to 110%" comments in the sysctl limits code and people would have thought I was childish. Can't have that. Much better to have "int one = 1" instead. Bron. - 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/