RadeonSI Lands Big Batch Of Improvements To Lower CPU Overhead

Following portions of the merge request landing, the rest of the RadeonSI CPU-overhead-lowering work was just merged to Mesa 21.3.

Marek Olšák and the open-source AMD Radeon OpenGL driver developers have been working on this big set of 42 patches over the past number of weeks. The focus is ultimately on lowering the CPU overhead of the driver.

As with other recent workstation optimizations for RadeonSI, the workload in focus for this big patch series was SPECViewPerf / Snx. Though given the low-level overhead work carried out in these patches, it will be interesting to see what other workloads are now also seeing lower overhead on this AMD Gallium3D driver.

See this merge request for all of the code that just landed for next quarter's Mesa 21.3 release.