[Intel-gfx] [PATCH 6/8] drm/i915: Pin the pages first in shmem prepare read/write

[Chris Wilson]

On Thu, Jun 09, 2016 at 04:06:59PM +0300, Joonas Lahtinen wrote:
> On to, 2016-06-09 at 12:29 +0100, Chris Wilson wrote:
> > There is an improbable, but not impossible, case that if we leave the
> > pages unpin as we operate on the object, then somebody may steal the
> > lock and change the cache domains after we have already inspected them.
> > 
> 
> Which lock exactly?

The shrinker steals struct_mutex from underneath us. The guard is
pinning pages around operating on the object.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre