On Thu, 2 Jun 2011 19:42:03 +0100, Alan Cox <alan at lxorguk.ukuu.org.uk> wrote: > On Sat, 28 May 2011 09:54:01 +0100 > Chris Wilson <chris at chris-wilson.co.uk> wrote: > > > On Fri, 27 May 2011 14:37:45 -0700, "Segovia, Benjamin" <benjamin.segovia > > at intel.com> wrote: > > > Hello gurus, > > > > > > I have two question mostly regarding libdrm_intel > > > > > > 1/ What is the difference between drm_intel_bo_map and > > > drm_intel_gem_bo_map_gtt ? > > bo_map uses the CPU domain, and so is CPU linear (needs sw detiling). > > bo_gtt_map uses the uncached [WC] GTT domain, and so is GPU linear > > (detiling is performed by the hardware using a fence). > > > > > 2/ Will it be possible (or is it already possible) to directly share a > > > regularly allocated piece of physical memory? Typical use case is the > > > following one using OpenCL API: > > > > Yes. I've proposed a vmap interface to bind user-pages into the GTT, > > similar to a completely unused bit of TTM functionality. > > It seems to me that stolen memory and other things could all be sorted > out somewhat if the GEM layer and GEM as shmemfs backing were split apart > a bit. A 'privately backed' GEM object wouldn't be able to support > flink() but I can't find much else that would break ? > > Wondering about this for things like the GMA500, and also to get back all > that memory the i9xx driver burns on a PC.
I'd much rather be able to just hand that memory off to the kernel to use along with everything else and have there be nothing magic about it. But as I recall, the mtrr mappings of that memory was often goofy, so it may take some work to clean it up. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 197 bytes Desc: not available URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20110603/c296ad8e/attachment.pgp>
