Messages in this thread | | | Date | Sun, 22 Jun 2008 20:02:02 +0400 | From | Cyrill Gorcunov <> | Subject | Re: v2.6.26-rc7/cgroups: circular locking dependency |
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[KOSAKI Motohiro - Mon, Jun 23, 2008 at 12:34:04AM +0900] | 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. |
Thanks Kosaki!
- Cyrill -
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