Developer Mike Blumenkrantz, who is one of many under contract by Valve, has released another blog post highlighting another fun optimization from their ongoing Mesa driver work.
The post as usual is highly technical, so if you want to full info give it a read. The issue is with how Mesa was dealing with the Vulkan Queue system, and what they were doing originally seemed to be a bit of a problem where it was "splitting the batched submits into individual ones, each submit also allocates a struct to contain the submit info so that the drivers can use the same interface. So it’s increasing the kernel overhead by performing multiple submits and also increasing memory allocations" with Blumenkrantz mentioning multiple tests that "showcase some driver pain points".
The result is a pull request (not yet merged) that gives a performance improvement on RADV GFX11 (RDNA3) of 1000% in one case and 50% in another. An impressive win but it continues. On Lavapipe (a CPU-based Software Vulkan driver) it saw a 3000% improvement in one case and a 1000% improvement in another, Intel Arc (Intel DG2) one case saw a 5000% improvement and Turnip A740 had a 4000% improvement and a 3000% improvement for another point.