From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id BE4936B0055 for ; Tue, 28 Apr 2009 03:57:32 -0400 (EDT) Received: by yx-out-1718.google.com with SMTP id 36so233341yxh.26 for ; Tue, 28 Apr 2009 00:58:26 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1240904919.7620.73.camel@twins> References: <20090428044426.GA5035@eskimo.com> <20090428143019.EBBF.A69D9226@jp.fujitsu.com> <1240904919.7620.73.camel@twins> Date: Tue, 28 Apr 2009 13:28:25 +0530 Message-ID: <661de9470904280058ub16c66bi6a52d36ca4c2d52c@mail.gmail.com> Subject: Re: Swappiness vs. mmap() and interactive response From: Balbir Singh Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Peter Zijlstra Cc: KOSAKI Motohiro , Elladan , linux-kernel@vger.kernel.org, linux-mm , Rik van Riel List-ID: On Tue, Apr 28, 2009 at 1:18 PM, Peter Zijlstra wrot= e: > 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 ph= enom 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..... h= alt. >> > Basically every UI operation, including the mouse in Xorg, started exp= eriencing >> > multiple second lag and delays. =A0This made the system essentially un= usable -- >> > for example, just flipping to the window where the "mv" command was ru= nning >> > took 10 seconds on more than one occasion. =A0Basically a "click and g= et 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. > 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. Balbir -- 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