From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754381Ab0IIKBy (ORCPT ); Thu, 9 Sep 2010 06:01:54 -0400 Received: from mx.ij.cx ([212.13.201.15]:53346 "EHLO wes.ijneb.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754321Ab0IIKBw (ORCPT ); Thu, 9 Sep 2010 06:01:52 -0400 Date: Thu, 9 Sep 2010 11:01:45 +0100 (BST) From: Mark Hills To: KAMEZAWA Hiroyuki cc: Daisuke Nishimura , linux-kernel@vger.kernel.org, balbir@linux.vnet.ibm.com Subject: Re: cgroup: rmdir() does not complete In-Reply-To: <20100902084200.e9b773cf.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <20100827095639.6e7297de.nishimura@mxp.nes.nec.co.jp> <20100827113506.2bbbb7b9.kamezawa.hiroyu@jp.fujitsu.com> <20100827123948.b4427a15.nishimura@mxp.nes.nec.co.jp> <20100827144225.3190167a.kamezawa.hiroyu@jp.fujitsu.com> <20100902084200.e9b773cf.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mark@pogo.org.uk Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2 Sep 2010, KAMEZAWA Hiroyuki wrote: [...] > But hmm...it's curious who holds mutex and what happens. I have a system showing the failure case (but still do not have a way to reliably repeat it) Here are the two processes: 23586 pts/0 RL+ 5059:18 /net/homes/mhills/tmp/soaked-cgroup 23685 pts/6 DL+ 0:00 /net/homes/mhills/tmp/soaked-cgroup 23586 spends almost all of its time in 'RL+' status, occasionally it is seen in 'DL+' status. >>From my analysis before, both are blocked on rmdir(), but one is spinning, holding the lock on the /cgroup, and the other is waiting for the lock. If I strace 23586 then the rmdir() fails with EINTR. How best to capture information which might show why the process spins? -- Mark