[Intel-gfx] [PATCH 15/16] drm/i915: Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset

[Daniel Vetter]

On Tue, May 26, 2015 at 09:16:11PM +0100, Chris Wilson wrote:
> On Tue, May 26, 2015 at 05:25:48PM +0200, Daniel Vetter wrote:
> > On Tue, May 26, 2015 at 03:21:22PM +0100, Michel Thierry wrote:
> > > There are some allocations that must be only referenced by 32bit
> > > offsets.
> 
> > > To limit the chances of having the first 4GB already full,
> > > objects not requiring this workaround don't use the first 2 PDPs.
> 
> This is complete tosh. Please have a later patch that uses SEARCH_BELOW
> for 48bit objects, and cite eviction rates and improvements.

Yeah didn't spot that at first, I agree that trying to segregate objects
upfront is premature optimization. There's very few state objects
(compard to textures), usually of differen size classes and different
lifetimes. And they should all be reused anyway for efficient, so after a
few rounds of execbuf things should settle in nicely.

Let's avoid a bit of complexity here when not yet proven to be required.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch