[Intel-gfx] [PATCH] drm/i915/selftests: Touch the NMI watchdog inside a GTT pass

[Tvrtko Ursulin]

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 at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at 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