[Intel-gfx] [PATCH 3/3] drm/i915: Skip capturing an error state if we already have one

[Chris Wilson]

On Tue, Jul 05, 2016 at 01:10:29PM +0300, Mika Kuoppala wrote:
> Chris Wilson <chris at chris-wilson.co.uk> writes:
> 
> > As we only ever keep the first error state around, we can avoid some
> > work that can be quite intrusive if we don't record the error the second
> > time around. This does move the race whereby the user could discard one
> > error state as the second is being captured, but that race exists in the
> > current code and we hope that recapturing error state is only done for
> > debugging.
> >
> > Note that as we discard the error state for simulated errors, igt that
> > exercise error capture continue to function.
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> 
> Reading through how the simulated works, we could record rings early and
> as such bail out early if context doesn't want error capture.

Hmm, not really. We do want to do the full error capture even for
simulated hangs so that we do exercise the raciness of the code in igt.

Most of the time we don't want the risk exposure or the overhead,
especially in normal runtime where we only see the first error the user
hits.

Thanks for the review
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre