On Thu, 10 Apr 2014 16:15:59 +0200, Peter Zijlstra said:
> On Thu, Apr 10, 2014 at 11:18:24AM +0200, Peter Zijlstra wrote:
> > So I managed to reproduce, and the below makes it go away. I just don't
> > understand why though. will stare more.
>
> /me kicks himself.. bloody obvious fail there :-)
>
> Not unlocking the lock after a lockdep trigger will make things get
> stuck real fast :-)
>
> ---
>  kernel/locking/mutex-debug.c | 19 +++++++++----------
>  1 file changed, 9 insertions(+), 10 deletions(-)

Confirming that this makes next-20140409 boot without hanging for me.
Feel free to stick a Tested-by: on it. ;)