Re: [Intel-gfx] [PATCH] drm/i915/gem: Flush TLBs for all the tiles

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

On 10/05/2022 21:33, Andi Shyti wrote:
> During object cleanup we invalidate the TLBs but we do it only
> for gt0. Invalidate the caches for all the tiles.
> 
> Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
> ---
>   drivers/gpu/drm/i915/gem/i915_gem_pages.c | 11 ++++++++---
>   1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> index 97c820eee115a..444b9f96ba77c 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> @@ -217,10 +217,15 @@ __i915_gem_object_unset_pages(struct drm_i915_gem_object *obj)
>   
>   	if (test_and_clear_bit(I915_BO_WAS_BOUND_BIT, &obj->flags)) {
>   		struct drm_i915_private *i915 = to_i915(obj->base.dev);
> -		intel_wakeref_t wakeref;
> +		struct intel_gt *gt;
> +		int i;
>   
> -		with_intel_runtime_pm_if_active(&i915->runtime_pm, wakeref)
> -			intel_gt_invalidate_tlbs(to_gt(i915));
> +		for_each_gt(gt, i915, i) {
> +			intel_wakeref_t w;
> +
> +			with_intel_runtime_pm_if_active(gt->uncore->rpm, w)
> +				intel_gt_invalidate_tlbs(gt);
> +		}

LGTM.

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

How about an improvement, either immediately or as followup, to define per tile bound flags and so be able to avoid trashing innocent tiles?

Like:

i915_vma_bind:

   set_bit(I915_BO_WAS_BOUND_BIT(vma->vm->gt->info.id), &vma->obj->flags);


__i915_gem_object_unset_pages:

   for_each_gt(gt, i915, i) {
	if (!test_and_clear_bit(I915_BO_WAS_BOUND_BIT(i), &obj->flags))
		continue;

	...
   }

Regards,

Tvrtko

>   	}
>   
>   	return pages;