From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761232AbZD1IL6 (ORCPT ); Tue, 28 Apr 2009 04:11:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759794AbZD1ILl (ORCPT ); Tue, 28 Apr 2009 04:11:41 -0400 Received: from casper.infradead.org ([85.118.1.10]:40758 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760149AbZD1ILk (ORCPT ); Tue, 28 Apr 2009 04:11:40 -0400 Subject: Re: Swappiness vs. mmap() and interactive response From: Peter Zijlstra To: Balbir Singh Cc: KOSAKI Motohiro , Elladan , linux-kernel@vger.kernel.org, linux-mm , Rik van Riel In-Reply-To: <661de9470904280058ub16c66bi6a52d36ca4c2d52c@mail.gmail.com> References: <20090428044426.GA5035@eskimo.com> <20090428143019.EBBF.A69D9226@jp.fujitsu.com> <1240904919.7620.73.camel@twins> <661de9470904280058ub16c66bi6a52d36ca4c2d52c@mail.gmail.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Tue, 28 Apr 2009 10:11:32 +0200 Message-Id: <1240906292.7620.79.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2009-04-28 at 13:28 +0530, Balbir Singh wrote: > On Tue, Apr 28, 2009 at 1:18 PM, Peter Zijlstra wrote: > > On Tue, 2009-04-28 at 14:35 +0900, KOSAKI Motohiro wrote: > >> (cc to linux-mm and Rik) > >> > >> > >> > Hi, > >> > > >> > So, I just set up Ubuntu Jaunty (using Linux 2.6.28) on a quad core phenom box, > >> > and then I did the following (with XFS over LVM): > >> > > >> > mv /500gig/of/data/on/disk/one /disk/two > >> > > >> > This quickly caused the system to. grind.. to... a.... complete..... halt. > >> > Basically every UI operation, including the mouse in Xorg, started experiencing > >> > multiple second lag and delays. This made the system essentially unusable -- > >> > for example, just flipping to the window where the "mv" command was running > >> > took 10 seconds on more than one occasion. Basically a "click and get coffee" > >> > interface. > >> > >> I have some question and request. > >> > >> 1. please post your /proc/meminfo > >> 2. Do above copy make tons swap-out? IOW your disk read much faster than write? > >> 3. cache limitation of memcgroup solve this problem? > >> 4. Which disk have your /bin and /usr/bin? > >> > > > > FWIW I fundamentally object to 3 as being a solution. > > > > memcgroup were not created to solve latency problems, but they do > isolate memory and if that helps latency, I don't see why that is a > problem. I don't think isolating applications that we think are not > important and interfere or consume more resources than desired is a > bad solution. So being able to isolate is a good excuse for poor replacement these days? Also, exactly because its isolated/limited its sub-optimal. > > I still think the idea of read-ahead driven drop-behind is a good one, > > alas last time we brought that up people thought differently. > > I vaguely remember the patches, but can't recollect the details. A quick google gave me this: http://lkml.org/lkml/2007/7/21/219 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 2BDBE6B003D for ; Tue, 28 Apr 2009 04:11:28 -0400 (EDT) Subject: Re: Swappiness vs. mmap() and interactive response From: Peter Zijlstra In-Reply-To: <661de9470904280058ub16c66bi6a52d36ca4c2d52c@mail.gmail.com> References: <20090428044426.GA5035@eskimo.com> <20090428143019.EBBF.A69D9226@jp.fujitsu.com> <1240904919.7620.73.camel@twins> <661de9470904280058ub16c66bi6a52d36ca4c2d52c@mail.gmail.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Tue, 28 Apr 2009 10:11:32 +0200 Message-Id: <1240906292.7620.79.camel@twins> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org To: Balbir Singh Cc: KOSAKI Motohiro , Elladan , linux-kernel@vger.kernel.org, linux-mm , Rik van Riel List-ID: On Tue, 2009-04-28 at 13:28 +0530, Balbir Singh wrote: > On Tue, Apr 28, 2009 at 1:18 PM, Peter Zijlstra wrote: > > On Tue, 2009-04-28 at 14:35 +0900, KOSAKI Motohiro wrote: > >> (cc to linux-mm and Rik) > >> > >> > >> > Hi, > >> > > >> > So, I just set up Ubuntu Jaunty (using Linux 2.6.28) on a quad core phenom box, > >> > and then I did the following (with XFS over LVM): > >> > > >> > mv /500gig/of/data/on/disk/one /disk/two > >> > > >> > This quickly caused the system to. grind.. to... a.... complete..... halt. > >> > Basically every UI operation, including the mouse in Xorg, started experiencing > >> > multiple second lag and delays. This made the system essentially unusable -- > >> > for example, just flipping to the window where the "mv" command was running > >> > took 10 seconds on more than one occasion. Basically a "click and get coffee" > >> > interface. > >> > >> I have some question and request. > >> > >> 1. please post your /proc/meminfo > >> 2. Do above copy make tons swap-out? IOW your disk read much faster than write? > >> 3. cache limitation of memcgroup solve this problem? > >> 4. Which disk have your /bin and /usr/bin? > >> > > > > FWIW I fundamentally object to 3 as being a solution. > > > > memcgroup were not created to solve latency problems, but they do > isolate memory and if that helps latency, I don't see why that is a > problem. I don't think isolating applications that we think are not > important and interfere or consume more resources than desired is a > bad solution. So being able to isolate is a good excuse for poor replacement these days? Also, exactly because its isolated/limited its sub-optimal. > > I still think the idea of read-ahead driven drop-behind is a good one, > > alas last time we brought that up people thought differently. > > I vaguely remember the patches, but can't recollect the details. A quick google gave me this: http://lkml.org/lkml/2007/7/21/219 -- 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