On Fri, Nov 1, 2013 at 7:06 PM, Bloomfield, Jon <jon.bloomfield@xxxxxxxxx> wrote: > Thanks Daniel, sermon noted. > > I hadn't twigged that we were pinning buffers to the mapable GTT region which didn't really need to be there. Do we definitely never need to modify or interrogate the hw contexts from the CPU ? What about for debug ? We can always use direct cpu mappings to the backing storage as long as we remember to do the coherency dances. Originally we've started to pin all scanout buffers into the mappable part because that's what our old userspace expects to be possible. So by default we kinda need to keep that working. But even for scanout buffers we could add a new flag somewhere so that userspace can promise to the kernel to never ever to a gtt mmap (and then the kernel could also reject any such attempts outright). But that'd be an extension on top if we notice that the 128M of mappable for pinned buffers isn't enough. I expect this to happen once 4k screens get too common ;-) -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
