Ben Widawsky <benjamin.widawsky at intel.com> writes: > FWD'd from our internal list now that we have more insight. > ----- Forwarded message from Ben Widawsky <benjamin.widawsky at intel.com> ----- > > Date: Thu, 11 Jul 2013 10:32:03 -0700 > From: Ben Widawsky <benjamin.widawsky at intel.com> > To: linux-gfx at linux.intel.com > Subject: intel_gpu_top broken for HSW. Ideas needed > Message-ID: <20130711173202.GB8802 at intel.com> > > Hi everybody. > > While investigating a hard hang on Haswell. Eero noticed that > intel_gpu_top helped to invoke the hang faster. I used this in my test > case to validation, and they are suspecting it is a known issue which we > have not yet worked around (and cannot reasonably workaround). > > [internal bug sighting redacted] > > To sum up, we cannot concurrently access registers within the same > cacheline. It has the potential to hit a known bug. > > I see some choices: > 1. Don't do anything. > 2. Try to eliminate shared registers as much as possible. Instdone is > used by the hangcheck, and we can eliminate hangcheck with a > module parameter. Eero, can you try this as a workaround, btw? Commit: 92cab7345131db7af18f630a799ce6b2e8e624c5 gets rid of instdone on hangcheck. -Mika > 3. Somehow make the kernel collect the top data and serialize access > there. > > Anyone else have input? I personally do not use top very much, so I > won't be volunteering to do any of these. > > ----- End forwarded message ----- > > -- > Ben Widawsky, Intel Open Source Technology Center > _______________________________________________ > Intel-gfx mailing list > Intel-gfx at lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
