On Sun, Aug 7, 2011 at 5:25 PM, Marek Olšák <mar...@gmail.com> wrote: > Hi, > > I have been recently trying to get thread offloading of the CS ioctl > into r600g in order to reduce the impact of kernel overhead on fps. > That, unfortunately, requires whole winsys/radeon to be used, because > even the buffer management (bo_map, bo_wait, bo_busy) must take into > account that a CS ioctl may be in progress. Besides that, there are > several possible race conditions in r600g, so instead of rewriting > r600g and trying to do what winsys/radeon is doing, I decided to > simply use winsys/radeon. > > What's new in r600g: > - Thread offloading of the DRM CS ioctl. I expect 0-15% increase in > performance from that in CPU-bound apps. > - The new GEM_WAIT ioctl is used to avoid waiting for a buffer when > possible. (e.g. Mesa may map an index buffer to compute index bounds, > which shouldn't cause unnecessary waiting now) I have sent the DRM > patches which add the ioctl to dri-devel. > - Thread-safety: There are several possible races in r600g. I > especially don't like radeon_bo::reloc, which may cause pretty ugly > races if a resource is shared and relocated in multiple contexts. > winsys/radeon doesn't have that race and also fixes a couple more. > Hopefully this thread-safeness won't cause performance regressions. > > winsys/radeon can do space checking as well, but we don't use that in r600g > yet. > > Performance improvements - I have been able to find a difference with > these apps: > > Unigine Heaven > Before: 7.3 fps > After: 7.6 fps > > Torcs > Before: 29 fps > After: 34 fps > > Note that every commit in the r600winsys2 branch has been committed > without piglit regressions, so that we can bisect through it if > needed. The net loss is a little over 900 lines of code in r600g. The > fenced cache buffer manager in r600g has turned out not to be superior > to pb_cache_bufmgr with the is_buffer_busy hook set, so I removed the > former too, as the latter is way simpler. > > This new work has been pushed into a new branch r600winsys2 in the > main Mesa repository, please review/test. >
Looks good. I'll try and run some tests on various hw later this week. Reviewed-by: Alex Deucher <alexander.deuc...@amd.com> > Marek > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
