3 ms·
I think most things are trending that direction, even in soft/non real-time. How fast can an interrupt respond these days anyway, a dozen microseconds?
by qppo 6y ago
I think most things are trending that direction, even in soft/non real-time. How fast can an interrupt respond these days anyway, a dozen microseconds?
- ianhowson 6y agoNanoseconds if you can respond inside the interrupt handler ('top half' in Linux.) Microseconds to milliseconds with significant variability if you need to be scheduled ('bottom half'.)
- jacquesm 6y agoAnd that only if your codepath is deterministic. Linux can do pretty funny stuff at times. I've run a plasma cutter under Linux on a run-of-the-mill VIA SBC, it was actually pretty easy: just make a program setuid root, use that to disable interrupts after you've read all your data in and then just go wild on polled and precision timed IO until you're done. Re-enable interrupts and return as if nothing ever happened.