From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 2C70D6B004F for ; Mon, 31 Aug 2009 08:59:59 -0400 (EDT) Date: Mon, 31 Aug 2009 20:59:41 +0800 From: Wu Fengguang Subject: Re: [RFC][PATCH 0/4] memcg: add support for hwpoison testing Message-ID: <20090831125941.GA20982@localhost> References: <20090831102640.092092954@intel.com> <20090831124920.GN4770@balbir.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090831124920.GN4770@balbir.in.ibm.com> Sender: owner-linux-mm@kvack.org To: Balbir Singh Cc: Andi Kleen , Andrew Morton , LKML , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Rik van Riel , Mel Gorman , "lizf@cn.fujitsu.com" , "nishimura@mxp.nes.nec.co.jp" , "menage@google.com" , linux-mm List-ID: On Mon, Aug 31, 2009 at 08:49:20PM +0800, Balbir Singh wrote: > * Wu Fengguang [2009-08-31 18:26:40]: > > > Hi all, > > > > In hardware poison testing, we want to inject hwpoison errors to pages > > of a collection of selected tasks, so that random tasks (eg. init) won't > > be killed in stress tests and lead to test failure. > > > > Memory cgroup provides an ideal tool for tracking and testing these target > > process pages. All we have to do is to > > - export the memory cgroup id via cgroupfs > > - export two functions/structs for hwpoison_inject.c > > > > This might be an unexpected usage of memory cgroup. The last patch and this > > script demonstrates how the exported interfaces are to be used to limit the > > scope of hwpoison injection. > > > > test -d /cgroup/hwpoison && rmdir /cgroup/hwpoison > > mkdir /cgroup/hwpoison > > > > usemem -m 100 -s 100 & # eat 100MB and sleep 100s > > echo `pidof usemem` > /cgroup/hwpoison/tasks > > > > ==> memcg_id=$( > ==> echo $memcg_id > /debug/hwpoison/corrupt-filter-memcg > > > > # hwpoison all pfn > > pfn=0 > > while true > > do > > let pfn=pfn+1 > > echo $pfn > /debug/hwpoison/corrupt-pfn > > if [ $? -ne 0 ]; then > > break > > fi > > done > > > > Comments are welcome, thanks! > > > > I took a quick look and the patches seem OKAY to me, but I have > question, can't we do all of this from user space? The bits about > id export and import the ids look like they can be replaced by names > in user space. You mean to match by cgrp->dentry->d_name.name in kernel hwpoison_inject.c and do this in user space? DIR_NAME=hwpoison mkdir /cgroup/$DIR_NAME echo $DIR_NAME > /debug/hwpoison/corrupt-filter-memcg Looks like a good idea! Thanks, Fengguang -- 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