[Intel-gfx] [PATCH] drm/i915: Improve lockdep tracking for obj->mm.lock

[Joonas Lahtinen]

On ti, 2016-11-01 at 12:11 +0000, Chris Wilson wrote:
> The shrinker may appear to recurse into obj->mm.lock as the shrinker may
> be called from a direct reclaim path whilst handling get_pages. We
> filter out recursing on the same obj->mm.lock by inspecting
> obj->mm.pages, but we do want to take the lock on a second object in
> order to reap their pages. lockdep spots the recursion on the same
> lockclass and needs annotation to avoid a false positive. To keep the
> two paths distinct, create an enum to indicate which subclass of
> obj->mm.lock. This removes the false positive and avoids masking real
> bugs.
> 
> Suggested-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: 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