Thanks all and I replaced with lockdep_assert_held() which seems less overhead.
Regards Sanjeev Sharma On Tue, Aug 12, 2014 at 5:08 AM, David Rientjes <rientjes at google.com> wrote: > On Mon, 11 Aug 2014, Rob Clark wrote: > > > > I'm suggesting that if you don't want to incur the cost of the > conditional > > > everytime you call a certain function with assert_spin_locked() that > you > > > could covert these to lockdep_assert_held() so the check is only done > when > > > lockdep is enabled for debugging. > > > > not sure about the nouveau parts, but for the omap and msm hunks, this > > code getting called at potentially vblank rate (so maybe once or twice > > per ~16ms).. and lockdep has considerable overhead (for a gpu driver) > > so I don't always have it enabled. So it sounds like for those two at > > least assert_spin_locked() is a better option. > > > > Unless there's a bug, assert_spin_locked() is just going to incur an > unnecessary cost every time it is called at runtime. My suggestion was to > limit that check only to debugging kernels that include enabling lockdep > when tracking down problems rather than needlessly evaluating the > conditional every time when there are no bugs. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20140812/cd0a591f/attachment.html>
