[Intel-gfx] [PATCH v2 3/3] drm/i915/gt: Only kick the signal worker if there's been an update

[Andi Shyti]

Hi Karolina,

> One impact of commit 047a1b877ed4 ("dma-buf & drm/amdgpu: remove
> dma_resv workaround") is that it stores many, many more fences. Whereas
> adding an exclusive fence used to remove the shared fence list, that
> list is now preserved and the write fences included into the list. Not
> just a single write fence, but now a write/read fence per context. That
> causes us to have to track more fences than before (albeit half of those
> are redundant), and we trigger more interrupts for multi-engine
> workloads.
> 
> As part of reducing the impact from handling more signaling, we observe
> we only need to kick the signal worker after adding a fence iff we have
> good cause to believe that there is work to be done in processing the
> fence i.e. we either need to enable the interrupt or the request is
> already complete but we don't know if we saw the interrupt and so need
> to check signaling.
> 
> References: 047a1b877ed4 ("dma-buf & drm/amdgpu: remove dma_resv workaround")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Karolina Drobnik <karolina.drobnik at intel.com>

sorry, I missed this patch.

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

Thanks,
Andi