[Intel-gfx] [PATCH i-g-t] tests/initial_state: Add a test to capture the state of the GPU

[Chris Wilson]

On Tue, May 16, 2017 at 09:43:52AM +0000, Lofstedt, Marta wrote:
> 
> 
> > -----Original Message-----
> > From: Chris Wilson [mailto:chris at chris-wilson.co.uk]
> > Sent: Tuesday, May 16, 2017 12:04 PM
> > To: Lofstedt, Marta <marta.lofstedt at intel.com>
> > Cc: Daniel Vetter <daniel at ffwll.ch>; Martin Peres
> > <martin.peres at linux.intel.com>; intel-gfx at lists.freedesktop.org
> > Subject: Re: [Intel-gfx] [PATCH i-g-t] tests/initial_state: Add a test to capture
> > the state of the GPU
> > 
> > On Tue, May 16, 2017 at 08:54:51AM +0000, Lofstedt, Marta wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Chris Wilson [mailto:chris at chris-wilson.co.uk]
> > > > Sent: Tuesday, May 16, 2017 11:21 AM
> > > > To: Lofstedt, Marta <marta.lofstedt at intel.com>
> > > > Cc: Daniel Vetter <daniel at ffwll.ch>; Martin Peres
> > > > <martin.peres at linux.intel.com>; intel-gfx at lists.freedesktop.org
> > > > Subject: Re: [Intel-gfx] [PATCH i-g-t] tests/initial_state: Add a
> > > > test to capture the state of the GPU
> > > >
> > > > On Tue, May 16, 2017 at 07:42:51AM +0000, Lofstedt, Marta wrote:
> > > > > I hereby pull-out this patch.
> > > > > The idea of it was to know if we were already wedged at the
> > > > > beginning of
> > > > testing, that would give us information on how to interpret silly
> > > > results; such that test starting to get skipped and/or we got
> > > > dmesg-warns/incomplete on tests that usually should be skipped.
> > > > > Also, we are planning to soon deploy a piglit.conf solution where
> > > > > testing
> > > > will be terminated on wedged, so I agree that my test isn't really needed.
> > > >
> > > > Not everything is broken by wedged; internally we just use that as
> > > > an indicator that GEM is hosed. KMS should still work, we must still
> > > > be able to drive the displays to show the error and keep the servers
> > > > alive until the data is saved (and hopefully gracefully degrade that
> > > > we don't have to interrupt their immediate session).
> > >
> > > It doesn't matter if it is broken or not, if we are terminally wedged the rest
> > of the result may be silly. Look for example at CI_DRM_2612, the fi-elk-e7500
> > is wedged at igt at gem_busy@basic-hang-default, then all test are skipped
> > until gem_exec_reloc at basic-cpu-gtt-noreloc where the machine hangs, but
> > it is a gem test so it should have been skipped, right. My conclusion from
> > seeing this pattern multiple times is that after terminally wedged, silly things
> > can happen, i.e. we can't trust the results, and since we don't want silly bugs,
> > the CI testing should be stopped.
> > 
> > The machine didn't hang, it was remotely killed because the run timed out.
> How do you know that?

The dmesg is a stream of flip timeouts until we run out of total BAT
runtime (12 minutes + some startup slack).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre