[Intel-gfx] [PATCH 3/3] drm/i915: use might_lock_nested in get_pages annotation

[Joonas Lahtinen]

Quoting Daniel Vetter (2019-11-04 19:37:20)
> So strictly speaking the existing annotation is also ok, because we
> have a chain of
> 
> obj->mm.lock#I915_MM_GET_PAGES -> fs_reclaim -> obj->mm.lock
> 
> (the shrinker cannot get at an object while we're in get_pages, hence
> this is safe). But it's confusing, so try to take the right subclass
> of the lock.
> 
> This does a bit reduce our lockdep based checking, but then it's also
> less fragile, in case we ever change the nesting around.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Peter Zijlstra <peterz at infradead.org>
> Cc: Ingo Molnar <mingo at redhat.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: linux-kernel at vger.kernel.org

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

Regards, Joonas