From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Christoph Mathys <eraserix@gmail.com>
Cc: Linux RT Users <linux-rt-users@vger.kernel.org>
Subject: Re: Hung task for proc_cgroup_show
Date: Tue, 14 Jul 2015 17:00:16 +0200 [thread overview]
Message-ID: <20150714150016.GC21820@linutronix.de> (raw)
In-Reply-To: <CALqGcGoMqJuvzQpGb84LzyxQCJADB73YEreND0HgOFK5DOQ6ig@mail.gmail.com>
* Christoph Mathys | 2015-07-14 16:40:16 [+0200]:
>Hi there!
Hi,
>I just tried out lxc (Linux Containers) with 3.18.17-rt14. After some
>time (~20min) the lxc-commands stop working. I got the following trace
>from dmesg. Any ideas whats causing it and how to fix it besides a
>reboot? I used the same version of lxc with 3.12-rt with no (I think)
>rt-specific problems.
>
>[ 1200.764167] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
…
>[ 1200.764172] Call Trace:
>[ 1200.764173] [<ffffffff816face4>] schedule+0x34/0xa0
>[ 1200.764174] [<ffffffff816fc2d6>] __rt_mutex_slowlock+0xe6/0x180
>[ 1200.764175] [<ffffffff816fc99a>] rt_mutex_slowlock+0x12a/0x310
>[ 1200.764176] [<ffffffff8115f1b4>] ? vma_merge+0xf4/0x330
>[ 1200.764177] [<ffffffff8115f7ef>] ? vma_set_page_prot+0x3f/0x60
>[ 1200.764178] [<ffffffff816fcc31>] rt_mutex_lock+0x31/0x40
>[ 1200.764179] [<ffffffff816fdfce>] _mutex_lock+0xe/0x10
>[ 1200.764180] [<ffffffff810de2e2>] proc_cgroup_show+0x52/0x200
>[ 1200.764180] [<ffffffff81200941>] proc_single_show+0x51/0xa0
>[ 1200.764182] [<ffffffff811bcdfa>] seq_read+0xea/0x370
>[ 1200.764182] [<ffffffff811980dc>] vfs_read+0x9c/0x180
>[ 1200.764183] [<ffffffff81198c59>] SyS_read+0x49/0xb0
>[ 1200.764184] [<ffffffff81197d91>] ? SyS_lseek+0x91/0xb0
>[ 1200.764185] [<ffffffff816fe676>] system_call_fastpath+0x16/0x1b
This seems to be always cgroup_mutex mutex it blocks on. SysRq d (show
all locks) should be able to show you who has the lock.
>Thanks.
>Christoph
Sebastian
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next prev parent reply other threads:[~2015-07-14 15:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-14 14:40 Hung task for proc_cgroup_show Christoph Mathys
2015-07-14 14:45 ` Christoph Mathys
2015-07-14 15:00 ` Sebastian Andrzej Siewior [this message]
2015-08-03 6:19 ` Christoph Mathys
2015-12-11 16:14 ` Sebastian Andrzej Siewior
2015-12-21 8:58 ` Christoph Mathys
2015-12-21 9:49 ` Christoph Mathys
2015-12-21 17:59 ` Sebastian Andrzej Siewior
2015-12-21 18:11 ` Sebastian Andrzej Siewior
2015-12-22 12:36 ` Christoph Mathys
2015-12-22 13:51 ` Sebastian Andrzej Siewior
2015-12-23 6:53 ` Christoph Mathys
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