[Intel-gfx] [PATCH] drm/i915: Add a tracepoint for using a semaphore

[Daniel Vetter]

On Wed, Sep 25, 2013 at 02:29:34PM +0300, Ville Syrjälä wrote:
> On Wed, Sep 25, 2013 at 11:43:28AM +0100, Chris Wilson wrote:
> > So that we can find the callers who introduce a ring stall. A single
> > ring stall is not too unwelcome, the right issue becomes when they start
> > to interlock and prevent any concurrent work. That, however, is a little
> > tricker to detect with a mere tracepoint!
> > 
> > v2: Rebrand it as a ring event, rather than an object event.
> > v3: Include the seqno in the tracepoint for posterity or something.
> > 
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> >  drivers/gpu/drm/i915/i915_gem.c   |  1 +
> >  drivers/gpu/drm/i915/i915_trace.h | 26 ++++++++++++++++++++++++++
> >  2 files changed, 27 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> > index 82bc029..fa3b373 100644
> > --- a/drivers/gpu/drm/i915/i915_gem.c
> > +++ b/drivers/gpu/drm/i915/i915_gem.c
> > @@ -2625,6 +2625,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
> >  	if (ret)
> >  		return ret;
> >  
> > +	trace_i915_gem_ring_sync_to(from, to, seqno);
> >  	ret = to->sync_to(to, from, seqno);
> 
> Passing the rings in the same order to both might avoid some confusion,
> but I don't care enough to withhold my r-b so:
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Queued for -next, thanks for the patch.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch