device drivers:

why timing is important, e.g. atomic operations: webcam, etc.. mv of single file on same filesystem and ln versus cp.

timing for sampling (e.g. radar, our sound system, constant sampling rate)

reading from devices, e.g. analog to digital converter example (as in sample and hold)

atomically reading a 64 bit register (e.g. RTC) into two 32 bit variables.

Just In Time hack: jit_hack.c
insmod jit_hack.o
cat /proc/jithack