RADV Gets More Improvements For Mesa 17.1-dev, Lower Dota 2 CPU Usage

While Mesa 17.0 was just released, new feature development continues building up for Mesa 17.1.

David Airlie landed a few more RADV patches into mainline Mesa Git. One of the changes is for detecting command buffers that don't do any work and then discard them. Airlie mentioned, "If a buffer is just full of flushes we flush things on command buffer submission, so don't bother submitting these. This will reduce some CPU overhead on dota2, which submits a fair few command streams that don't end up drawing anything."

Good to hear it will at least benefit Dota 2 and any improvements to the CPU utilization are always appreciated. I've been meaning to run some OpenGL vs. Vulkan CPU utilization benchmarks, so maybe now is a good time for that comparison.

The other work landing was was about mirroring RadeonSI behavior for using an indirect buffer for the initial graphics state.