HP-UX Workload Manager User's Guide

Configuring WLM
Defining the PRM components (optional)
Chapter 5180
between their respective weights (in other words, the ratio of group A’s
allocation to group B’s allocation equals the ratio of group A’s weight to
group B’s weight).
NOTE WLM uses this same policy for using weight to determine CPU
allocations across partitions. For more information on how WLM
manages CPU allocations across partitions, see Chapter 7, “Managing
SLOs across partitions,” on page 255.
Consider the following example. The Allocation column represents the
allocations resulting from higher priority levels. The Requested
allocation column represents the allocations the SLOs at the current
priority are requesting.
In this example, 40 CPU shares (or 40% of the total CPU resources) are
allocated to the groups listed in column 1. Thus, WLM has 60% of the
CPU resources to distribute among groups. WLM takes this amount of
CPU resources and begins allocating it according to the weights.
The sum of the weights assigned to the groups is 20. Groups A and C both
have equal weights (5) and allocations (10). Therefore, WLM attempts to
allocate 25% (5/20) of the total CPU resources to these groups. This
translates to 15 additional CPU shares each. Similarly, groups B and
OTHERS, with weights of 2 and 8 respectively, should get 10% (2/20) and
40% (8/20) of the total CPU resources.
However, before distributing the CPU resources, WLM must observe the
policy mentioned previously. Group B already has more shares than it is
entitled to—it has 20% of the CPU allocation while its weight is only 10%
(2/20) of the total weight. Consequently, B gets no more CPU resources.
Table 5-1 weight keyword example (weights take effect)
Group Allocation Weight
Requested
allocation
Final
allocation
A 10 5 15 15
B 20 2 60 20
C 10 5 70 25
OTHERS 0 8 80 40