Due to a series of bugs (essentially, a GPU-side use-after-free caused by a race condition, and a hardware limitation requiring 64-byte alignment of vertex buffer addresses), we previously copied all vertex data to a staging buffer and passed that staging buffer to the hardware instead. Although correct, this was a performance disaster (deploying the workaround to glmark's refract, a scene unaffected by the bug but affected by the costly workaround, dropped performance from 19fps to 6fps).
This series fixes each of these bugs, by introducing BO reference counting, stubs for future work for flushing BOs (thought to be necessary to fix this bug -- it turned out not to be, but is left in the series as it will be necessary in the short-term future), and an offset fixup. In total, this patch removes the staging copy in all cases visible to us (although Gallium has to do a staging copy for user pointers). Performance is helped dramatically :) Alyssa Rosenzweig (2): panfrost: Track BO lifetime with jobs and reference counts panfrost: Fixup vertex offsets to prevent shadow copy src/gallium/drivers/panfrost/pan_context.c | 137 +++++++++++--------- src/gallium/drivers/panfrost/pan_context.h | 12 +- src/gallium/drivers/panfrost/pan_drm.c | 6 + src/gallium/drivers/panfrost/pan_job.c | 82 ++++++++++++ src/gallium/drivers/panfrost/pan_job.h | 16 +++ src/gallium/drivers/panfrost/pan_resource.c | 70 +++++++++- src/gallium/drivers/panfrost/pan_resource.h | 13 ++ src/gallium/drivers/panfrost/pan_screen.c | 2 +- src/gallium/drivers/panfrost/pan_screen.h | 5 +- 9 files changed, 273 insertions(+), 70 deletions(-) -- 2.20.1 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
