[Intel-gfx] [PATCH 3/3] drm/i915: Reduce GPU error capture mutex hold time

[Matthew Auld]

On Wed, 16 Sep 2020 at 10:01, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>
> Shrink the hold time for the error capture mutex to just around the
> acquire/release of the PTE used for reading back the object via the
> Global GTT. For platforms that do not need the GGTT read back, we can
> skip the mutex entirely and allow concurrent error capture. Where we do
> use the GGTT, by restricting the hold time around the slow readback and
> compression, we are more resilient against softlockups (khungtaskd) as
> the heartbeat may well also trigger an error while the first is on
> going, and this allows the heartbeat reset to skip past the capture and
> not be stalled.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>