Quoting Tvrtko Ursulin (2018-07-03 13:54:01) > > On 03/07/2018 12:07, Chris Wilson wrote: > > Quoting Tvrtko Ursulin (2018-07-03 12:00:13) > >> > >> On 03/07/2018 11:25, Chris Wilson wrote: > >>> We want to do a complete pass before checking the timeout, but just in > >>> case the pass is quite slow, touch the NMI watchdog to prevent a > >>> false positive. > >>> > >>> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > >>> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > >>> --- > >>> drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 8 ++++++++ > >>> 1 file changed, 8 insertions(+) > >>> > >>> diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c > >>> index eefcf7b84054..71c0654b4b4d 100644 > >>> --- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c > >>> +++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c > >>> @@ -23,6 +23,7 @@ > >>> */ > >>> > >>> #include <linux/list_sort.h> > >>> +#include <linux/nmi.h> > >>> #include <linux/prime_numbers.h> > >>> > >>> #include "../i915_selftest.h" > >>> @@ -686,6 +687,13 @@ static int pot_hole(struct drm_i915_private *i915, > >>> i915_vma_unpin(vma); > >>> err = i915_vma_unbind(vma); > >>> GEM_BUG_ON(err); > >>> + > >>> + /* > >>> + * Do a complete pass before timing out, but just > >>> + * in case we are running too slow, ping the NMI > >>> + * watchdog. > >>> + */ > >>> + touch_nmi_watchdog(); > >>> } > >>> > >>> if (igt_timeout(end_time, > >>> > >> > >> Why only in pot_hole, is this the slowest test? > > > > It's the only test of this style where we don't have the igt_timeout > > (cond_resched) inside the innermost loop. > > So.. the obvious question.. :) Why not move igt_timeout to the innermost > loop and avoid low-level hackery? In looking at it, I felt this case it was more interesting^W important to test each boundary before checking the timeout. I was concerned about declaring the pass a success too early. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
