Testing for kernel performance regressions

Unfortunately simulating VHDL would in most cases be far too slow to perform a realistic test of the kernel.

I actually work on the Linux driver for a particular family of input devices from one manufacturer. Most of the customers are integrating devices which are targeting older kernel versions rather than mainline, so our main focus is there. But we do track patches that are going into mainline and make sure they are sane, and do some occasional testing.