Hello everyone, When trying the demo program copytex for the first time recently, I noticed pathological behavior: after running for a long time it asserted out and locked up X. Investigation showed this to be due to the glFinish function acting like glFlush and not waiting as it is supposed to for completion of whatever commands had been issued. I took up the task of remedying this. There are, as usual, a variety of different ways of doing so. Influenced by the current gallium code, I planned a separate call to the kernel to wait for the fence created by the pushbuf flush ioctl to complete. After completing the implementation in this way, it occurred to me that it would be more economical to modify the pushbuf flush ioctl call with a flag to indicate whether it should wait for completion or not. This would require modifying the FIRE_RING inline which appears in numerous places. Perhaps my original plan is adequate. The code changes required for the original plan involve mesa, drm, and the kernel. This forum seems like the best starting point to solicit feedback, since the whole thing is motivated by mesa. The Xorg nouveau driver does not seem to need anything of this nature. I have tested on my current hardware, x86-64 dual opteron and 7300 GT card.
The assert out noted in the beginning was due to timeout in the __nouveau_fence_wait function in the kernel. Unfortunately, it does not exit gracefully. The patches that I came up with eliminate the timeout in the case of copytex, but this is clearly a flaw that someday should have a more complete fix. Please let me know if I should send the kernel and drm patches to another forum (like dri-devel). For now I will post them here. Best Wishes, Bob _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
