Squeezing More Performance Out Of The Linux Kernel With Clang + LTO

The Clang-built kernel didn't dominate across all I/O but with Compile Bench for instance the GCC-built version of Linux 5.14-rc1 still performed the best.

The srsRAN LTE/5G software radio suite was showing slight performance benefits when running on the Clang-built kernel with LTO.

In some cases the Clang-built kernel was faster than when using GCC for building the kernel but at times the LTO-optimized build was lagging behind.

Showing the greatest change in performance when using Clang for compiling the Linux kernel was Stress-NG's context switching benchmark. However, this may be an artifact of Stress-NG as when using ctx-clock to measure the context switching performance there wasn't a measurable difference between the GCC and Clang built kernels.