You cannot have guaranteed response times (those which must be NEVER exceeded) with Raspbian Linux. There will always be jitter, random jitter.
This is inherent to electronic systems (and operating systems !) which are not designed to be "real-time". This is undeniable. The users of microcontrollers and Arduinos have to come to rely on fully predictable real-time behaviour. After some frustrating experimentation with (Raspbian) Linux and damning it to hell they either escape to the bare metal subforum or go back to their ISRs, register poking, uncached and scheduler-free endeavours
Of course, this is also one of the reasons the forum regulars are quite entertained at some other people who want to replace the real-time ECU of their car with a Raspberry or plan on replacing the realtime controllers inside their new Airbus with Raspberry Pis to save costs...
so far nobody has come to harm (that i know of)
• Don't like the board ? Missing features ? Change to the prosilver theme ! You can find it in your settings.
• Don't like to search the forum BEFORE posting 'cos it's useless ? Try googling : yoursearchtermshere site:raspberrypi.org