Re: [RFC][PATCH 1/3] rt_mutex: Add lockdep annotations

[Peter Zijlstra]

On Sun, Jun 04, 2017 at 04:26:43PM +0200, Thomas Gleixner wrote:
> On Wed, 31 May 2017, Peter Zijlstra wrote:
> 
> > Now that (PI) futexes have their own private RT-mutex interface and
> > implementation we can easily add lockdep annotations to the existing
> > RT-mutex interface.
> > 
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> > ---
> >  include/linux/rtmutex.h        |   25 +++++++++++++++++++++----
> >  kernel/locking/rtmutex-debug.c |    6 +++++-
> 
> Shouldn't we get rid of all that home brewn rtmutex debug muck?

mutex also still has its mutex-debug.* stuff. It validates a little more
state. Also, and I think this is the main benefit, it has the magic bits
in that detect corruption without the full space/time costs of lockdep.

Maybe we can trim the rtmutex-debug a wee bit, but then futexes don't
get that coverage.

I'll put looking at this on the todo list.