[Intel-gfx] [PATCH] drm/i915/gt: Include a tell-tale for engine parking

[Chris Wilson]

Quoting Mika Kuoppala (2020-01-22 14:39:19)
> Chris Wilson <chris at chris-wilson.co.uk> writes:
> 
> > We have two trace messages that rely on the function name for
> > distinction. However, if gcc inlines the function, the two traces end up
> > with the same function name and are indistinguishable. Add a different
> > message to each to clarify which one we hit, i.e. which phase of engine
> > parking we are processing.
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> >  drivers/gpu/drm/i915/gt/intel_engine_pm.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> > index ea90ab3e396e..b6cf284e3a2d 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> > @@ -112,7 +112,7 @@ __queue_and_release_pm(struct i915_request *rq,
> >  {
> >       struct intel_gt_timelines *timelines = &engine->gt->timelines;
> >  
> > -     ENGINE_TRACE(engine, "\n");
> > +     ENGINE_TRACE(engine, "parking\n");
> >  
> >       /*
> >        * We have to serialise all potential retirement paths with our
> > @@ -249,7 +249,7 @@ static int __engine_park(struct intel_wakeref *wf)
> >       if (!switch_to_kernel_context(engine))
> >               return -EBUSY;
> >  
> > -     ENGINE_TRACE(engine, "\n");
> > +     ENGINE_TRACE(engine, "parked\n");
> 
> Reading the functions, the exact spots are a mystery for me still
> as of why in these exact lines. Like the 'parked' would mean it
> is parked already, which it seems not to.

True, but 'park' was too similar to 'parking', whereas 'parked' at least
conveyed that 'parking' was over, which was the important concept that I
wanted clarity over in the debug traces.

They are mere labels, if you have a better idea, ... :)
-Chris