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. Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
