Greetings,

I got this lockdep warning and the first bad commit is
d206e09036d6201f90b2719484c8a59526c46125 ("Merge branch 'for-3.8' of
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup")

[    1.969480] 
[    1.969686] ======================================================
[    1.970200] [ INFO: possible circular locking dependency detected ]
[    1.970200] 3.7.0-05910-g6be35c7 #1 Not tainted
[    1.970200] -------------------------------------------------------
[    1.970200] swapper/0/1 is trying to acquire lock:
[    1.970200]  (cgroup_mutex){+.+...}, at: [<81068053>] cgroup_lock+0xf/0x11
[    1.970200] 
[    1.970200] but task is already holding lock:
[    1.970200]  (cpu_hotplug.lock){+.+.+.}, at: [<8102674b>] cpu_hotplug_begin+0x1d/0x40
[    1.970200] 
[    1.970200] which lock already depends on the new lock.
[    1.970200] 
[    1.970200] 

Thanks,
Fengguang