> What should I read or learn next to be able to reason about things like cache usage of a C program or possible low-level microoptimizations? Learn how to use

> What should I read or learn next to be able to reason about things like cache usage of a C program or possible low-level microoptimizations? Learn how to use a profiler like Linux' perf, VTune or Apple's Instruments. Which means interpreting the results of it to optimise your code.