From: "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com>
To: "Vegard Nossum" <vegard.nossum@gmail.com>
Cc: "Paul Menage" <menage@google.com>,
containers@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, "Paul Jackson" <pj@sgi.com>
Subject: Re: v2.6.26-rc7/cgroups: circular locking dependency
Date: Mon, 23 Jun 2008 00:34:04 +0900 [thread overview]
Message-ID: <2f11576a0806220834m3572ee80i72229cb9a1613558@mail.gmail.com> (raw)
In-Reply-To: <20080621173859.GA6846@damson.getinternet.no>
CC'ed Paul Jackson
it seems typical ABBA deadlock.
I think cpuset use cgrou_lock() by mistake.
IMHO, cpuset_handle_cpuhp() sholdn't use cgroup_lock() and
shouldn't call rebuild_sched_domains().
-> #1 (cgroup_mutex){--..}:
[<c015a435>] __lock_acquire+0xf45/0x1040
[<c015a5c8>] lock_acquire+0x98/0xd0
[<c05416d1>] mutex_lock_nested+0xb1/0x300
[<c0160e6f>] cgroup_lock+0xf/0x20 cgroup_lock
[<c0164750>] cpuset_handle_cpuhp+0x20/0x180
[<c014ea77>] notifier_call_chain+0x37/0x70
[<c014eae9>] __raw_notifier_call_chain+0x19/0x20
[<c051f8c8>] _cpu_down+0x78/0x240 cpu_hotplug.lock
[<c051fabb>] cpu_down+0x2b/0x40 cpu_add_remove_lock
[<c0520cd9>] store_online+0x39/0x80
[<c02f627b>] sysdev_store+0x2b/0x40
[<c01d3372>] sysfs_write_file+0xa2/0x100
[<c0195486>] vfs_write+0x96/0x130
[<c0195b4d>] sys_write+0x3d/0x70
[<c010831b>] sysenter_past_esp+0x78/0xd1
[<ffffffff>] 0xffffffff
-> #0 (&cpu_hotplug.lock){--..}:
[<c0159fe5>] __lock_acquire+0xaf5/0x1040
[<c015a5c8>] lock_acquire+0x98/0xd0
[<c05416d1>] mutex_lock_nested+0xb1/0x300
[<c015efbc>] get_online_cpus+0x2c/0x40 cpu_hotplug.lock
[<c0163e6d>] rebuild_sched_domains+0x7d/0x3a0
[<c01653a4>] cpuset_common_file_write+0x204/0x440 cgroup_lock
[<c0162bc7>] cgroup_file_write+0x67/0x130
[<c0195486>] vfs_write+0x96/0x130
[<c0195b4d>] sys_write+0x3d/0x70
[<c010831b>] sysenter_past_esp+0x78/0xd1
[<ffffffff>] 0xffffffff
> Hi,
>
> I decided to see what cgroups is all about, and followed the instructions
> in Documentation/cgroups.txt :-) It happened when I did this:
>
> [root@damson /dev/cgroup/Vegard 0]
> # echo 1 > cpuset.cpus
>
> I can also provide the kernel config if necessary.
>
>
> Vegard
>
>
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.26-rc7 #25
> -------------------------------------------------------
> bash/10032 is trying to acquire lock:
> (&cpu_hotplug.lock){--..}, at: [<c015efbc>] get_online_cpus+0x2c/0x40
>
> but task is already holding lock:
> (cgroup_mutex){--..}, at: [<c0160e6f>] cgroup_lock+0xf/0x20
>
> which lock already depends on the new lock.
next prev parent reply other threads:[~2008-06-22 15:34 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-21 17:38 Vegard Nossum
2008-06-22 9:10 ` Cyrill Gorcunov
2008-06-22 9:42 ` Vegard Nossum
2008-06-22 9:50 ` Cyrill Gorcunov
2008-06-22 15:34 ` KOSAKI Motohiro [this message]
2008-06-22 15:50 ` Peter Zijlstra
2008-06-23 12:02 ` Paul Jackson
2008-06-24 6:29 ` Max Krasnyansky
2008-06-26 7:25 ` Paul Menage
2008-06-26 17:45 ` Max Krasnyansky
2008-06-22 16:02 ` Cyrill Gorcunov
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