[Intel-gfx] [PATCH v6] igt/gem_trtt: Exercise the TRTT hardware

[Chris Wilson]

On Mon, Mar 21, 2016 at 03:30:33PM +0530, Goel, Akash wrote:
> 
> 
> On 3/18/2016 9:31 PM, Chris Wilson wrote:
> >On Fri, Mar 18, 2016 at 09:19:35PM +0530, Goel, Akash wrote:
> >>On 3/18/2016 4:02 PM, Chris Wilson wrote:
> >>>The point about looping is to try and ensure that every possible code
> >>>path is interrupted (since we only interrupt every 2us and the code paths
> >>>tend to be shorter than than!).
> >>
> >>Thanks, will follow the gem_softpin.c example.
> >>
> >>I hope you meant 2ms here & not 2us, since the signal_helper_process
> >>is sending signals at the ~500 Hz rate.
> >
> >Yeah, failed hopeless. Though I thought it was a 5000Hz rate. Any way
> >the point is that the chance of a signal interrupting a critical path
> >anywhere other than at a wait is small, and so we want to repeat the
> >test a few times to increase our chances.
> 
> Just rebased. Should I use the 'igt_interruptible' now for eviction
> tests in place of
> 
> +       igt_subtest("evict-active-interruptible") {
> +               struct timespec start = {};
> +               while (igt_seconds_elapsed(&start) < 20)
> +                       test_evict_active(fd);
> +       }

Please give it a whirl. It was the outcome of our discussion, trying to
be more accurate as to when repeating an ioctl due to signal interruption
is actually worthwhile. Improvements welcome!
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre