From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753598AbXIDJhz (ORCPT ); Tue, 4 Sep 2007 05:37:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750874AbXIDJhs (ORCPT ); Tue, 4 Sep 2007 05:37:48 -0400 Received: from main.gmane.org ([80.91.229.2]:52194 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750725AbXIDJhr (ORCPT ); Tue, 4 Sep 2007 05:37:47 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Leroy van Logchem Subject: Re: huge improvement with per-device dirty throttling Date: Tue, 04 Sep 2007 11:37:36 +0200 Message-ID: <46DD2760.3040505@wldelft.nl> References: <1187764638.6869.17.camel@hannibal> <20070822124736.GQ13915@v2.random> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: wl10583.wldelft.nl User-Agent: Thunderbird 2.0.0.6 (X11/20070728) In-Reply-To: <20070822124736.GQ13915@v2.random> Cc: linux-mm@kvack.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrea Arcangeli wrote: > On Wed, Aug 22, 2007 at 01:05:13PM +0200, Andi Kleen wrote: >> Ok perhaps the new adaptive dirty limits helps your single disk >> a lot too. But your improvements seem to be more "collateral damage" @) >> >> But if that was true it might be enough to just change the dirty limits >> to get the same effect on your system. You might want to play with >> /proc/sys/vm/dirty_* > > The adaptive dirty limit is per task so it can't be reproduced with > global sysctl. It made quite some difference when I researched into it > in function of time. This isn't in function of time but it certainly > makes a lot of difference too, actually it's the most important part > of the patchset for most people, the rest is for the corner cases that > aren't handled right currently (writing to a slow device with > writeback cache has always been hanging the whole thing). Self-tuning > static sysctl's. The last years we needed to use very small values for dirty_ratio and dirty_background_ratio to soften the latency problems we have during sustained writes. Imo these patches really help in many cases, please commit to mainline. -- Leroy From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <46DD2760.3040505@wldelft.nl> Date: Tue, 04 Sep 2007 11:37:36 +0200 From: Leroy van Logchem MIME-Version: 1.0 Subject: Re: huge improvement with per-device dirty throttling References: <1187764638.6869.17.camel@hannibal> <20070822124736.GQ13915@v2.random> In-Reply-To: <20070822124736.GQ13915@v2.random> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Andi Kleen , "Jeffrey W. Baker" , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Andrea Arcangeli wrote: > On Wed, Aug 22, 2007 at 01:05:13PM +0200, Andi Kleen wrote: >> Ok perhaps the new adaptive dirty limits helps your single disk >> a lot too. But your improvements seem to be more "collateral damage" @) >> >> But if that was true it might be enough to just change the dirty limits >> to get the same effect on your system. You might want to play with >> /proc/sys/vm/dirty_* > > The adaptive dirty limit is per task so it can't be reproduced with > global sysctl. It made quite some difference when I researched into it > in function of time. This isn't in function of time but it certainly > makes a lot of difference too, actually it's the most important part > of the patchset for most people, the rest is for the corner cases that > aren't handled right currently (writing to a slow device with > writeback cache has always been hanging the whole thing). Self-tuning > static sysctl's. The last years we needed to use very small values for dirty_ratio and dirty_background_ratio to soften the latency problems we have during sustained writes. Imo these patches really help in many cases, please commit to mainline. -- Leroy -- 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