From: Oleg Nesterov <oleg@redhat.com>
To: Florian Mickler <florian@mickler.org>
Cc: "Ingo Molnar" <mingo@elte.hu>,
"Américo Wang" <xiyou.wangcong@gmail.com>,
"Dave Chinner" <david@fromorbit.com>,
"Eric Dumazet" <eric.dumazet@gmail.com>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [regression, 2.6.37-rc1] 'ip link tap0 up' stuck in do_exit()
Date: Wed, 8 Dec 2010 15:08:22 +0100 [thread overview]
Message-ID: <20101208140822.GA18681@redhat.com> (raw)
In-Reply-To: <20101208134712.GB16923@redhat.com>
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] <defunct>
> >
> > 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.
next prev parent reply other threads:[~2010-12-08 14:08 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-03 6:26 [regression, 2.6.37-rc1] 'ip link tap0 up' stuck in do_exit() Dave Chinner
2010-11-03 7:13 ` Eric Dumazet
2010-11-03 10:34 ` Dave Chinner
2010-11-03 11:29 ` Dave Chinner
2010-11-04 0:21 ` Dave Chinner
2010-11-04 5:47 ` Américo Wang
2010-12-08 9:02 ` Florian Mickler
2010-12-08 13:41 ` Oleg Nesterov
2010-12-08 13:47 ` Oleg Nesterov
2010-12-08 14:08 ` Oleg Nesterov [this message]
2010-12-09 16:47 ` Américo Wang
2010-12-09 17:07 ` Eric Dumazet
2010-12-09 17:09 ` Eric Dumazet
2010-12-09 17:59 ` Jim Bos
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