In audio threads, I've been told it's good style to not use syscalls like e.g.
printf() because they give control back to the kernel, which can then decide to continue with another thread, which means your audio thread can lose a lot of time. I found the idiom strange because modern Linux kernels could still interrupt the audio thread (preemption). Maybe, however, there's no (or very limited) preemption if the audio thread has RT prio...
Does Linux prempt a thread if all other running threads have lower priority?
Is the behaviour different between realtime and non-realtime kernels?