NICE(3C)
NAME
nice − set program priority
USAGE
nice(incr)
DESCRIPTION
This interface has been made obsolete by setpriority(2).
The amount incr increases the scheduling priority of the process. Positive priorities get less service than normal. Priority 10 allows long-running programs to operate without adversely affecting the entire system’s performance.
The priority is limited to the range −20 (most urgent) to 20 (least).
The priority of a process passes to a child process when fork (2) is called. To recall a privileged process to normal priority from an unknown state, call nice with arguments −40 (goes to priority −20 because of truncation), 20 (to get to zero), then zero successively.