[Intel-gfx] [PATCH] drm/i915/shrinker: Wrap need_resched() inside preempt-disable

[Joonas Lahtinen]

On pe, 2017-08-04 at 11:41 +0100, Chris Wilson wrote:
> In order for us to successfully detect the end of a timeslice,
> preemption must be disabled. Otherwise, inside the loop we may be
> preempted many times without our noticing, and each time our timeslice
> will be reset, invalidating need_resched()
> 
> Reported-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Reported-by: Tomi Sarvela <tomi.p.sarvela at intel.com>
> Fixes: 290271de34f6 ("drm/i915: Spin for struct_mutex inside shrinker")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: <drm-intel-fixes at lists.freedesktop.org> # v4.13-rc1+

Gets rid of the hang for my BDW.

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

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