HP Process Resource Manager User's Guide

Understanding how PRM manages resources
How PRM controls resources
Chapter 240
You specify resource shares for each group in a hierarchy. If a group has
child groups, the parent group’s resource shares are distributed to the
children based on the shares they are assigned. If a group has no
children, it uses the shares. More explicitly, the percentage that a group’s
shares equate to is determined as follows:
1. Start at the top level in the hierarchy. Consider these groups as
sibling groups with an implied parent. This implied parent has 100%
of the CPU resource to distribute. (Shares work the same way for
CPU, private memory, and disk bandwidth resources.)
2. Add all the CPU shares of the first level of sibling groups together
into a variable, TOTAL.
3. Each sibling group receives a percentage of CPU resources equal to
its number of shares divided by TOTAL.
4. If the sibling group has no child groups, it uses the CPU resources
itself.
5. If the sibling group does have child groups, the CPU resource are
distributed further based on the shares assigned to the child groups.
Calculate the percentages of the resource they receive by repeating
items 2 through 5.
Consider the example in Table 2-4, which shows the PRM groups at the
top-level.
Table 2-4 Hierarchical PRM groups—top level
Group CPU shares
Percent of system’s
available CPU resources
Finance 3 30.00%
Development 5 50.00%
OTHERS 2 20.00%