From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id 6D4336B0011 for ; Thu, 19 May 2011 11:03:05 -0400 (EDT) Received: by pwi12 with SMTP id 12so1681768pwi.14 for ; Thu, 19 May 2011 08:00:44 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20110519145147.GA14658@localhost> References: <20110514165346.GV6008@one.firstfloor.org> <20110514174333.GW6008@one.firstfloor.org> <20110515152747.GA25905@localhost> <20110517060001.GC24069@localhost> <20110519145147.GA14658@localhost> From: Andrew Lutomirski Date: Thu, 19 May 2011 11:00:24 -0400 Message-ID: Subject: Re: Kernel falls apart under light memory pressure (i.e. linking vmlinux) Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Wu Fengguang Cc: Minchan Kim , Andi Kleen , "linux-mm@kvack.org" , LKML , KOSAKI Motohiro , KAMEZAWA Hiroyuki , Mel Gorman , Johannes Weiner , Rik van Riel On Thu, May 19, 2011 at 10:51 AM, Wu Fengguang wrote: >> > I had 6GB swap available, so there shouldn't have >> > been any OOM. >> >> Yes. It's strange but we have seen such case several times, AFAIR. > > I noticed that the test script mounted a "ramfs" not "tmpfs", hence > the 1.4G pages won't be swapped? That's intentional. I run LVM over dm-crypt on an SSD, and I thought that might be part of the problem. I wanted a script that would see if I could reproduce the problem without stressing that system too much, so I created a second backing store on dm-crypt over ramfs so that no real I/O will happen. The script is quite effective at bringing down my system, so I haven't changed it. (I have 6GB of "real" swap on the LVM, so pinning 1500MB into RAM ought to cause some thrashing but not take the system down. And this script with a larger ramfs does not take down my desktop, which is an 8GB Sandy Bridge box. But whatever the underlying bug is seems to mainly affect Sandy Bridge *laptops*, so maybe that's expected.) --Andy > > 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org