HP Process Resource Manager User's Guide

Chapter 1 19

1 Overview

This chapter introduces the basic concepts and functions of HP Process

Resource Manager. It covers:

• What is HP Process Resource Manager?

• Why use HP Process Resource Manager?

What is HP Process Resource Manager?

Process Resource Manager (PRM) is a resource management tool used to

control the amount of resources that processes use during peak system

load (at 100% CPU resource, 100% memory resource, or 100% disk

bandwidth utilization). PRM can guarantee a minimum allocation of

system resources available to a group of processes through the use of

PRM groups.

A PRM group is a collection of users and applications that are joined

together and assigned certain amounts of CPU resource, memory

resource, and disk bandwidth. The two types of PRM groups are FSS

PRM groups and PSET PRM groups. An FSS PRM group is the

traditional PRM group, whose CPU entitlement is speciﬁed in shares.

This group uses the Fair Share Scheduler (FSS) in the HP-UX kernel

within the system’s default processor set (PSET). A PSET PRM group is

a PRM group whose CPU entitlement is speciﬁed by assigning it a subset

of the system’s cores (PSET). (A core is the actual data-processing engine

within a processor. A single processor might have multiple cores. A core

might support multiple execution threads, as explained in the section

“Hyper-Threading” on page 49.) Processes in a PSET have equal access

to CPU cycles on their assigned cores through the HP-UX standard

scheduler.