Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755191Ab0LHOPV (ORCPT ); Wed, 8 Dec 2010 09:15:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49615 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751588Ab0LHOPU (ORCPT ); Wed, 8 Dec 2010 09:15:20 -0500 Date: Wed, 8 Dec 2010 15:08:22 +0100 From: Oleg Nesterov To: Florian Mickler Cc: Ingo Molnar , =?iso-8859-1?Q?Am=E9rico?= Wang , Dave Chinner , Eric Dumazet , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [regression, 2.6.37-rc1] 'ip link tap0 up' stuck in do_exit() Message-ID: <20101208140822.GA18681@redhat.com> References: <20101103062609.GB31163@dastard> <1288768402.2467.665.camel@edumazet-laptop> <20101103103448.GA9169@dastard> <20101103112936.GB9169@dastard> <20101104002140.GA13830@dastard> <20101104054718.GC5210@cr0.nay.redhat.com> <20101208100245.01cf23c5@schatten.dmk.lab> <20101208134116.GA16923@redhat.com> <20101208134712.GB16923@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101208134712.GB16923@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1620 Lines: 46 On 12/08, Oleg Nesterov wrote: > > On 12/08, Oleg Nesterov wrote: > > > > On 12/08, Florian Mickler wrote: > > > > > > [ ccing Ingo and Oleg ] as suggested > > > > Well. Of course I can't explain this bug. But, looking at this email > > I do not see amything strange in exit/schedule/etc. > > > > > > >> > > > This is resulting in the command 'ip link set tap0 up' hanging as a zombie: > > > > >> > > > > > > > >> > > > root 3005 1 0 16:53 pts/3 00:00:00 /bin/sh /vm-images/qemu-ifup tap0 > > > > >> > > > root 3011 3005 0 16:53 pts/3 00:00:00 /usr/bin/sudo /sbin/ip link set tap0 up > > > > >> > > > root 3012 3011 0 16:53 pts/3 00:00:00 [ip] > > > > That is. ip is a zombie. > > And. I do not know if this matters or not, but "the command 'ip link > set tap0 up' hanging as a zombie" does not look right. > > This was spawned by > > > >> > > > if [ -n "$1" ];then > > >> > > > /usr/bin/sudo /sbin/ip link set $1 up > > >> > > > sleep 0.5s > > >> > > > /usr/bin/sudo /usr/sbin/brctl addif $switch $1 > > >> > > > exit 0 > > >> > > > fi > > The command does not hang. But it forks the child with pid == 3012, > this child exits. Damn, sorry for noise, forgot to mention... The parent's trace (pid == 3011) can be more useful. Say, if it hangs in do_wait(), then the kernel is obviously wrong. Oleg. -- 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/