|Things I never cared about until recently:
||[Nov. 28th, 2003|04:17 pm]
The current implementation of nanosleep is based on the normal kernel timer mechanism, which has a resolution of 1/HZ s (i.e,
10 ms on Linux/i386 and 1 ms on Linux/Alpha). Therefore, nanosleep pauses always for at least the specified time, however it
can take up to 10 ms longer than specified until the process becomes runnable again. For the same reason, the value returned in
case of a delivered signal in *rem is usually rounded to the next larger multiple of 1/HZ s.
As some applications require much more precise pauses (e.g., in order to control some time-critical hardware), nanosleep is also
capable of short high-precision pauses. If the process is scheduled under a real-time policy like SCHED_FIFO or SCHED_RR, then
pauses of up to 2 ms will be performed as busy waits with microsecond precision.