On Tue, 14 Jun 2011 16:43:09 -0700, Eric Anholt <e...@anholt.net> wrote: > This reverts commit 4a684a4117abd756291969336af454e8a958802f. > Userland has always been required to set the object's domain to GTT > before using it through a GTT mapping, it's not something that the > kernel is supposed to enforce. (The pagefault support is so that we > can handle multiple mappings without userland having to pin across > them, not so that userland can use GTT after GPU domains without > telling the kernel).
The only place that can do accurate per-page tracking of domains is the kernel. (And avoid clflushes for GTT eviction. Ok, so we're not quite there yet.) Relying on userspace to get it right, and for co-operating processes to coordinate their access to buffers is a misfeature. > Fixes 19.2% +/- 0.8% (n=6) performance regression in cairo-gl > firefox-talos-gfx on my T420 latop. Since GTT mappings are fundamentally slow, don't you think this suggests that mesa is doing something wrong? Or a bug in cairo-gl to make mesa act this way? For the record, on my SugarBay, this patch on top of drm-intel-fixes and mesa.git + your instruction streaming, regresses cairo-xlib 4.5s to 4.7s (4%, with a claim of .1% stddev) and improves cairo-gl from 21.5s to 20.1s (6.5%, with a claim of .5% stddev) for the firefox-talos-gfx. [This is a system that can do under 2s for cairo-xlib using vmap and the perf patches I posted before.] -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
