[Intel-gfx] [PATCH] RFC: drm/i915: Switch obj->mm.lock lockdep annotations on its head

[Daniel Vetter]

On Wed, Aug 14, 2019 at 07:57:57PM +0100, Chris Wilson wrote:
> Quoting Daniel Vetter (2019-08-14 19:49:41)
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > index d474c6ac4100..1ea3c3c96a5a 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > @@ -157,7 +157,15 @@ struct drm_i915_gem_object {
> >         unsigned int pin_global;
> >  
> >         struct {
> > -               struct mutex lock; /* protects the pages and their use */
> > +               /*
> > +                * Protects the pages and their use.
> 
> "Their use" is still a misleading suggest of mine. This should be
> "protects the pinning of pages". The couple of other things it is used
> for are tied to the concept of the pages being pinned; further use should
> be discouraged; direct use prohibited.

So something like "Protects the pinning of pages. Do not use directly, but
instead go through the get/put_pages and pin/unpin interfaces." There's a
few too many of those to list them all imo ...
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch