Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932115Ab0LISBs (ORCPT ); Thu, 9 Dec 2010 13:01:48 -0500 Received: from smtp-vbr11.xs4all.nl ([194.109.24.31]:1969 "EHLO smtp-vbr11.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932097Ab0LISBr (ORCPT ); Thu, 9 Dec 2010 13:01:47 -0500 Message-ID: <4D011914.3000301@xs4all.nl> Date: Thu, 09 Dec 2010 18:59:48 +0100 From: Jim Bos User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.12) Gecko/20101106 Thunderbird/3.1.6 MIME-Version: 1.0 To: =?ISO-8859-1?Q?Am=E9rico_Wang?= CC: Oleg Nesterov , Florian Mickler , Ingo Molnar , 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() 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> <20101208140822.GA18681@redhat.com> <20101209164748.GA3218@hack> In-Reply-To: <20101209164748.GA3218@hack> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2296 Lines: 66 On 12/09/2010 05:47 PM, Am?rico Wang wrote: > On Wed, Dec 08, 2010 at 03:08:22PM +0100, Oleg Nesterov wrote: >> 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. >> > > Yeah, there is no point that a zombie can trigger a BUG_ON in kenrel. > But it is still interesting to know why it becomes a zombie... > > -- > 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/ ip link tap0 up not working might be this issue: http://marc.info/?l=linux-netdev&m=128783852132311&w=2 ( Latest Virtualbox 3.2.12 works around this issue ) Jim -- 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/