[Intel-gfx] [PATCH v5 3/4] drm/i915/bdw: Pin the context backing objects to GGTT on-demand

[Daniel, Thomas]

> -----Original Message-----
> From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel
> Vetter
> Sent: Monday, November 17, 2014 6:09 PM
> To: Daniel, Thomas
> Cc: intel-gfx at lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH v5 3/4] drm/i915/bdw: Pin the context
> backing objects to GGTT on-demand
> 
> On Thu, Nov 13, 2014 at 10:28:10AM +0000, Thomas Daniel wrote:
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h index 059330c..3c7299d 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -655,6 +655,7 @@ struct intel_context {
> >  	struct {
> >  		struct drm_i915_gem_object *state;
> >  		struct intel_ringbuffer *ringbuf;
> > +		int unpin_count;
> 
> Pinning is already refcounted. Why this additional refcount?

The vma.pin_count is only allocated 4 bits of storage.  If this restriction can be lifted then I can use that.

> And yes I've only realized this now that you've supplied the review
> comments from Akash. I really rely upon the review discussions to spot such
> low-level implementation details.

I know, and I explicitly asked the guys to post comments to the mailing list.

Cheers,
Thomas.

> -Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch