Greetings,

I got the below dmesg and the first bad commit is

git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git

commit 84604340d034a074036e86e85c4055a1c7ea5529
Author:     Peter Zijlstra <peterz@infradead.org>
AuthorDate: Tue Feb 11 12:00:36 2014 +0100
Commit:     Tejun Heo <tj@kernel.org>
CommitDate: Tue Feb 11 10:25:17 2014 -0500

    workqueue: Fix workqueue lockdep name
    
    Tommi noticed a 'funny' lock class name: "%s#5" from a lock acquired
    in process_one_work(). It turns out that commit b196be89cdc14 forgot
    to change the lockdep_init_map() when it changed the @lock_name
    argument from a string to a format.
    
    Fixes: b196be89cdc14 ("workqueue: make alloc_workqueue() take printf
    fmt and args for name")
    
    Reported-by: Tommi Rantala <tt.rantala@gmail.com>
    Signed-off-by: Peter Zijlstra <peterz@infradead.org>
    Signed-off-by: Tejun Heo <tj@kernel.org>
    Cc: stable@vger.kernel.org

[   21.989145] rds_page_remainder_cpu_notify(): cpu 0 action 0x7
[   21.990793] rds_page_remainder_cpu_notify(): cpu 1 action 0x7
[   21.990793] rds_page_remainder_cpu_notify(): cpu 1 action 0x7
[   21.995278] BUG: unable to handle kernel 

git bisect start 84604340d034a074036e86e85c4055a1c7ea5529 38dbfb59d1175ef458d006556061adeaa8751b72 --
# first bad commit: [84604340d034a074036e86e85c4055a1c7ea5529] workqueue: Fix workqueue lockdep name
git bisect good 38dbfb59d1175ef458d006556061adeaa8751b72  # 11:55    285+    148  Linus 3.14-rc1
git bisect  bad 84604340d034a074036e86e85c4055a1c7ea5529  # 11:55      0-     19  workqueue: Fix workqueue lockdep name

Thanks,
Fengguang