| Message ID | 20180703102531.20554-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@chris-wilson.co.uk> > Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > --- > 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? Regards, Tvrtko
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@chris-wilson.co.uk> > > Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > > --- > > 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. -Chris
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@chris-wilson.co.uk> >>> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> >>> --- >>> 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? Regards, Tvrtko
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@chris-wilson.co.uk> > >>> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > >>> --- > >>> 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
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,
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@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> --- drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 8 ++++++++ 1 file changed, 8 insertions(+)