Unix жүйелеріндегі процестердің басымдығын реттеу құралы

Computer utility for Unix like operating systems

nice is a program found on Unix and Unix like operating systems such as Linux. It directly maps to a kernel call of the same name. nice is used to invoke a utility or shell script with a particular CPU priority, thus giving the process more or less CPU time than other processes. A niceness of 20 is the lowest niceness, or highest priority. The default niceness for processes is inherited from its parent process and is usually 0. Systems have diverged on what priority is the lowest. Linux systems document a niceness of 19 as the lowest priority, BSD systems document 20 as the lowest priority. In both cases, the "lowest" priority is documented as running only when nothing else wants to.

Niceness value is a number attached to processes in *nix systems, that is used along with other data (such as the amount of I/O done by each process) by the kernel process scheduler to calculate a process' 'true priority'which is used to decide how much CPU time is allocated to it. The program's name, nice, is an allusion to its task of modifying a process' niceness value. The term niceness itself originates from the idea that a process with a higher niceness value is nicer to other processes in the system and to users by virtue of demanding less CPU powerfreeing up processing time and power for the more demanding programs, who would in this case be less nice to the system from a CPU usage perspective.

The related renice program can be used to change the priority of a process that is already running.