[Mesa-dev] very strange intermittent frame-dropping

[Chris Wilson]

On Wed, Apr 05, 2017 at 10:36:14PM +0100, Luke Kenneth Casson Leighton wrote:
> eero, apologies, the mesa-dev list's traffic is very high, i'll switch
> over to digest, so please do cc me each time, to mitigate that.
> ---
> crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
> 
> 
> On Wed, Apr 5, 2017 at 1:31 PM, Eero Tamminen <eero.t.tamminen at intel.com> wrote:
> > Hi,
> >
> > On 04.04.2017 14:10, Luke Kenneth Casson Leighton wrote:
> >>
> >> On Tue, Apr 4, 2017 at 11:04 AM, Eero Tamminen
> >> <eero.t.tamminen at intel.com> wrote:
> >>>>
> >>>> anyway, apologies: nobody whose applications are affected by this
> >>>> really has a clue where the *actual* bug is so i am escalating it down
> >>>> the chain of library dependencies, making people aware.  it could be
> >>>> X11, it could be mesa, we just don't know.
> >>>
> >>>
> >>>
> >>> Does it happen only with the old, non-compositing window managers like
> >>> FVWM2, or also with something newer?
> >>
> >>
> >>  there's a whole stack of people reporting this occurring, running the
> >> full range of window managers.
> >>
> >>> Does DRI2 vs. DRI3 have any effect on it?
> >>
> >>
> >>  hmm, good question.  i'm running with "DRI" "true"
> >
> >
> > Valid values for "DRI" setting are "2" or "3".
> >
> >
> >> (so don't know if it's 2 or 3),
> >
> > This tells you which version apps get:
> >         LIBGL_DEBUG=verbose glxgears
> >
> 
>  LIBGL_DEBUG=verbose glxgears
> libGL: OpenDriver: trying /usr/lib/x86_64-linux-gnu/dri/tls/i965_dri.so
> libGL: OpenDriver: trying /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
> libGL: Can't open configuration file /home/lkcl/.drirc: No such file
> or directory.
> libGL: Using DRI2 for screen 0
> libGL: Can't open configuration file /home/lkcl/.drirc: No such file
> or directory.
> Running synchronized to the vertical refresh.  The framerate should be
> approximately the same as the monitor refresh rate.
> 303 frames in 5.0 seconds = 60.424 FPS
> 212 frames in 11.7 seconds = 18.079 FPS

Overshoots by 6s. Check dmesg for a GPU hang. Attach
/sys/class/drm/card0/error.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre