System information

Tuning the Task Scheduler 165
Tuning the Task Scheduler
14
Modern operating systems, such as SUSE® Linux Enterprise Server, normally run
many different tasks at the same time. For example, you can be searching in a text
file while receiving an e-mail and copying a big file to an external hard drive. These
simple tasks require many additional processes to be run by the system. To provide
each task with its required system resources, the Linux kernel needs a tool to distrib-
ute available system resources to individual tasks. And this is exactly what the task
scheduler does.
The following sections explain the most important terms related to a process schedul-
ing. They also introduce information about the task scheduler policy, scheduling algo-
rithm, description of the task scheduler used by SUSE Linux Enterprise Server, and
references to other sources of relevant information.
14.1 Introduction
The Linux kernel controls the way tasks (or processes) are managed in the running
system. The task scheduler, sometimes called process scheduler, is the part of the ker-
nel that decides which task to run next. It is one of the core components of a multi-
tasking operating system (such as Linux), being responsible for best utilizing system
resources to guarantee that multiple tasks are being executed simultaneously.