Re: [Intel-gfx] [PATCH 1/4] drm/i915: Add request cancel low level trace point

[Matthew Brost <matthew.brost@intel.com>]

On Tue, Jan 25, 2022 at 12:27:43PM +0000, Tvrtko Ursulin wrote:
> 
> On 24/01/2022 15:01, Matthew Brost wrote:
> > Add request cancel trace point guarded by
> > CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINT.
> 
> Okay-ish I guess (There is pr_notice with the only real caller, but I
> suppose you want it for selftests? Oh yes, why is missing from the commit
> message.), but I'd emit it from i915_request_cancel since that's what the
> tracepoint is called so it fits.
> 

I had this tracepoint at one point but somehow during the upstreaming it
got lost. Noticed when debugging the below issue this tracepoint wasn't
present, so I brought it back in.

I generally use low level tracepoints for debug, so a pr_notice doesn't
really help there.

Link: https://gitlab.freedesktop.org/drm/intel/-/issues/4960

Matt

> Regards,
> 
> Tvrtko
> 
> > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> > ---
> >   drivers/gpu/drm/i915/gt/intel_context.h |  1 +
> >   drivers/gpu/drm/i915/i915_trace.h       | 10 ++++++++++
> >   2 files changed, 11 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
> > index d8c74bbf9aae2..3aed4d77f116c 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_context.h
> > +++ b/drivers/gpu/drm/i915/gt/intel_context.h
> > @@ -124,6 +124,7 @@ intel_context_is_pinned(struct intel_context *ce)
> >   static inline void intel_context_cancel_request(struct intel_context *ce,
> >   						struct i915_request *rq)
> >   {
> > +	trace_i915_request_cancel(rq);
> >   	GEM_BUG_ON(!ce->ops->cancel_request);
> >   	return ce->ops->cancel_request(ce, rq);
> >   }
> > diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
> > index 37b5c9e9d260e..d0a11a8bb0ca3 100644
> > --- a/drivers/gpu/drm/i915/i915_trace.h
> > +++ b/drivers/gpu/drm/i915/i915_trace.h
> > @@ -324,6 +324,11 @@ DEFINE_EVENT(i915_request, i915_request_add,
> >   );
> >   #if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS)
> > +DEFINE_EVENT(i915_request, i915_request_cancel,
> > +	     TP_PROTO(struct i915_request *rq),
> > +	     TP_ARGS(rq)
> > +);
> > +
> >   DEFINE_EVENT(i915_request, i915_request_guc_submit,
> >   	     TP_PROTO(struct i915_request *rq),
> >   	     TP_ARGS(rq)
> > @@ -497,6 +502,11 @@ DEFINE_EVENT(intel_context, intel_context_do_unpin,
> >   #else
> >   #if !defined(TRACE_HEADER_MULTI_READ)
> > +static inline void
> > +trace_i915_request_cancel(struct i915_request *rq)
> > +{
> > +}
> > +
> >   static inline void
> >   trace_i915_request_guc_submit(struct i915_request *rq)
> >   {
> >