Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758373Ab1EBX6a (ORCPT ); Mon, 2 May 2011 19:58:30 -0400 Received: from cantor.suse.de ([195.135.220.2]:51471 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757552Ab1EBX62 (ORCPT ); Mon, 2 May 2011 19:58:28 -0400 Subject: Re: memcg: fix fatal livelock in kswapd From: James Bottomley To: Ying Han Cc: Johannes Weiner , Chris Mason , linux-fsdevel , linux-mm , linux-kernel , Paul Menage , Li Zefan , containers@lists.linux-foundation.org, Balbir Singh In-Reply-To: References: <1304366849.15370.27.camel@mulgrave.site> <20110502224838.GB10278@cmpxchg.org> Content-Type: text/plain; charset="UTF-8" Date: Mon, 02 May 2011 18:58:18 -0500 Message-ID: <1304380698.15370.36.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1559 Lines: 35 On Mon, 2011-05-02 at 16:14 -0700, Ying Han wrote: > On Mon, May 2, 2011 at 3:48 PM, Johannes Weiner wrote: > > I am very much for removing this hack. There is still more scan > > pressure applied to memcgs in excess of their soft limit even if the > > extra scan is happening at a sane priority level. And the fact that > > global reclaim operates completely unaware of memcgs is a different > > story. > > > > However, this code came into place with v2.6.31-8387-g4e41695. Why is > > it only now showing up? > > > > You also wrote in that thread that this happens on a standard F15 > > installation. On the F15 I am running here, systemd does not > > configure memcgs, however. Did you manually configure memcgs and set > > soft limits? Because I wonder how it ended up in soft limit reclaim > > in the first place. It doesn't ... it's standard FC15 ... the mere fact of having memcg compiled into the kernel is enough to do it (conversely disabling it at compile time fixes the problem). > curious as well. if we have workload to reproduce it, i would like to try Well, the only one I can suggest is the one that produces it (large untar). There seems to be something magical about the memory size (mine is 2G) because adding more also seems to make the problem go away. James -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/