[Intel-gfx] [PATCH 5/5] drm/i915/gt: Disable arbitration on no-preempt requests

[Andi Shyti]

Hi Chris,

On Thu, Jan 07, 2021 at 10:17:24PM +0000, Chris Wilson wrote:
> If a request is submitted and known to require no preemption, disable
> arbitration around the batch which prevents the HW from handling a
> preemption request during the payload.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: Matthew Brost <matthew.brost at intel.com>
> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 6 +++---
>  drivers/gpu/drm/i915/gt/gen8_engine_cs.c       | 3 +++
>  2 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index cf9a6b4eb913..b91b32195dcf 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -2534,6 +2534,9 @@ static int eb_submit(struct i915_execbuffer *eb, struct i915_vma *batch)
>  {
>  	int err;
>  
> +	if (intel_context_nopreempt(eb->context))
> +		__set_bit(I915_FENCE_FLAG_NOPREEMPT, &eb->request->fence.flags);
> +
>  	err = eb_move_to_gpu(eb);
>  	if (err)
>  		return err;
> @@ -2574,9 +2577,6 @@ static int eb_submit(struct i915_execbuffer *eb, struct i915_vma *batch)
>  			return err;
>  	}
>  
> -	if (intel_context_nopreempt(eb->context))
> -		__set_bit(I915_FENCE_FLAG_NOPREEMPT, &eb->request->fence.flags);
> -

makes sense to me...

Reviewed-by: Andi Shyti <andi.shyti at intel.com>

Thanks,
Andi