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From: Kevin Fenzi <kevin@scrye•com>
To: netdev@vger•kernel.org, linux-kernel@vger•kernel.org
Subject: Re: localed stuck in recent 3.18 git in copy_net_ns?
Date: Tue, 21 Oct 2014 15:12:25 -0600	[thread overview]
Message-ID: <20141021151225.5df96645@voldemort.scrye.com> (raw)
In-Reply-To: <20141020145359.565fe5e6@voldemort.scrye.com>

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On Mon, 20 Oct 2014 14:53:59 -0600
Kevin Fenzi <kevin@scrye•com> wrote:

> On Mon, 20 Oct 2014 16:43:26 -0400
> Dave Jones <davej@redhat•com> wrote:
> 
> > I've seen similar soft lockup traces from the sys_unshare path when
> > running my fuzz tester.  It seems that if you create enough network
> > namespaces, it can take a huge amount of time for them to be
> > iterated. (Running trinity with '-c unshare' you can see the slow
> > down happen. In some cases, it takes so long that the watchdog
> > process kills it -- though the SIGKILL won't get delivered until
> > the unshare() completes)
> > 
> > Any idea what this machine had been doing prior to this that may
> > have involved creating lots of namespaces ?
> 
> That was right after boot. ;) 
> 
> This is my main rawhide running laptop.
> 
> A 'ip netns list' shows nothing.

Some more information: 

The problem started between: 

v3.17-7872-g5ff0b9e1a1da and v3.17-8307-gf1d0d14120a8

(I can try and do a bisect, but have to head out on a trip tomorrow)

In all the kernels with the problem, there is a kworker process in D. 

sysrq-t says: 
                                            Showing all locks held in the system:
Oct 21 15:06:31 voldemort.scrye.com kernel: 4 locks held by kworker/u16:0/6:
Oct 21 15:06:31 voldemort.scrye.com kernel:  #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff810ccbff>] process_one_work+0x17f/0x850
Oct 21 15:06:31 voldemort.scrye.com kernel:  #1:  (net_cleanup_work){+.+.+.}, at: [<ffffffff810ccbff>] process_one_work+0x17f/0x850
Oct 21 15:06:31 voldemort.scrye.com kernel:  #2:  (net_mutex){+.+.+.}, at: [<ffffffff817069fc>] cleanup_net+0x8c/0x1f0
Oct 21 15:06:31 voldemort.scrye.com kernel:  #3:
(rcu_sched_state.barrier_mutex){+.+...}, at: [<ffffffff8112a395>]
_rcu_barrier+0x35/0x200

On first running any of the systemd units that use PrivateNetwork, then
run ok, but they are also set to timeout after a minute. On sucessive
runs they hang in D also.

kevin

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  reply	other threads:[~2014-10-21 21:12 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-20 20:15 localed stuck in recent 3.18 git in copy_net_ns? Kevin Fenzi
2014-10-20 20:43 ` Dave Jones
2014-10-20 20:53   ` Kevin Fenzi
2014-10-21 21:12     ` Kevin Fenzi [this message]
2014-10-22 17:12       ` Josh Boyer
2014-10-22 17:37         ` Cong Wang
2014-10-22 17:49           ` Josh Boyer
2014-10-22 17:53           ` Eric W. Biederman
2014-10-22 18:11             ` Paul E. McKenney
2014-10-22 18:25               ` Eric W. Biederman
2014-10-22 18:55                 ` Paul E. McKenney
2014-10-22 19:33                   ` Josh Boyer
2014-10-22 22:40                     ` Yanko Kaneti
2014-10-22 23:24                       ` Paul E. McKenney
2014-10-23  6:09                         ` Yanko Kaneti
2014-10-23 12:27                           ` Paul E. McKenney
2014-10-23 15:33                             ` Paul E. McKenney
     [not found]                               ` <CA+5PVA4H6EAf6cBc4a_8W8x4Mgppjc5GsskKaCRry2jq+LP+FA@mail.gmail.com>
2014-10-23 16:28                                 ` Paul E. McKenney
2014-10-23 19:51                               ` Yanko Kaneti
2014-10-23 20:05                                 ` Paul E. McKenney
2014-10-23 21:45                                   ` Yanko Kaneti
2014-10-23 22:04                                     ` Paul E. McKenney
2014-10-24  4:48                                       ` Jay Vosburgh
2014-10-24 14:50                                         ` Paul E. McKenney
2014-10-24 18:20                                           ` Jay Vosburgh
2014-10-24 18:33                                             ` Paul E. McKenney
2014-10-24  9:08                                       ` Yanko Kaneti
2014-10-24 15:40                                         ` Paul E. McKenney
2014-10-24 16:29                                           ` Yanko Kaneti
2014-10-24 16:54                                             ` Paul E. McKenney
2014-10-24 17:09                                               ` Yanko Kaneti
2014-10-24 17:20                                                 ` Paul E. McKenney
2014-10-24 17:35                                                   ` Yanko Kaneti
2014-10-24 18:32                                                     ` Paul E. McKenney
2014-10-24 18:49                                                       ` Jay Vosburgh
2014-10-24 18:57                                                         ` Paul E. McKenney
2014-10-24 20:15                                                           ` Paul E. McKenney
2014-10-24 21:25                                                       ` Yanko Kaneti
2014-10-24 21:49                                                         ` Paul E. McKenney
2014-10-24 22:02                                                           ` Jay Vosburgh
2014-10-24 22:16                                                             ` Paul E. McKenney
2014-10-24 22:41                                                               ` Jay Vosburgh
2014-10-24 22:34                                                           ` Jay Vosburgh
2014-10-24 22:59                                                             ` Paul E. McKenney
2014-10-24 23:05                                                               ` Paul E. McKenney
2014-10-25  0:20                                                                 ` Jay Vosburgh
2014-10-25  2:03                                                                   ` Paul E. McKenney
2014-10-25  4:33                                                                     ` Jay Vosburgh
2014-10-25  5:16                                                                       ` Paul E. McKenney
2014-10-25 16:38                                                                         ` Jay Vosburgh
2014-10-25 18:18                                                                           ` Paul E. McKenney
2014-10-27 17:45                                                                             ` Paul E. McKenney
2014-10-27 20:43                                                                               ` Jay Vosburgh
2014-10-27 21:07                                                                                 ` Paul E. McKenney
2014-10-28  8:12                                                                               ` Yanko Kaneti
2014-10-28 12:50                                                                                 ` Paul E. McKenney
2014-10-28 13:00                                                                                   ` Yanko Kaneti
2014-10-28 15:54                                                                                     ` Kevin Fenzi
2014-10-28 16:15                                                                                       ` Paul E. McKenney
2014-10-25 12:09                                                           ` Yanko Kaneti
2014-10-25 13:38                                                             ` Paul E. McKenney
2014-10-22 17:59           ` Paul E. McKenney
2014-10-22 18:03             ` Josh Boyer

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