Re: [PATCH 4/6] drm/i915/gt: Only invalidate TLBs exposed to user manipulation

From: Andi Shyti
Date: Thu Jun 23 2022 - 07:14:08 EST


Hi Mauro,

On Wed, Jun 15, 2022 at 04:27:38PM +0100, Mauro Carvalho Chehab wrote:
> From: Chris Wilson <chris.p.wilson@xxxxxxxxx>
>
> Don't flush TLBs when the buffer is only used in the GGTT under full
> control of the kernel, as there's no risk of of concurrent access
> and stale access from prefetch.
>
> We only need to invalidate the TLB if they are accessible by the user.
>
> Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")
>
> Signed-off-by: Chris Wilson <chris.p.wilson@xxxxxxxxx>
> Cc: Fei Yang <fei.yang@xxxxxxxxx>
> Cc: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Acked-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>

Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>

Thanks,
Andi