[Intel-gfx] [PATCH 2/3] drm/i915: Priority boost for locked waits

[Joonas Lahtinen]

On la, 2017-01-21 at 09:25 +0000, Chris Wilson wrote:
> We always try to do an unlocked wait before resorting to having a
> blocking wait under the mutex - so we very rarely have to sleep under
> the struct_mutex. However, when we do we want that wait to be as short
> as possible as the struct_mutex is our BKL that will stall the driver and
> all clients.
> 
> There should be no impact for all typical workloads.
> 
> v2: Move down a layer to apply to all waits.
> v3: Make the priority boost explicit. This makes the paths where we want
> boosting under the mutex clear and prevents boosting priority uselessly
> for when we are waiting for idle.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation