Accrue Attributes

An lnode's accrue attributes are used to store information about the accrual of resource usage. For example, an lnode's cpu.accrue attribute contains the accrued CPU usage for all lnodes within the group as well as that of the current lnode. When any of an lnode's accrue attributes are updated, the change is also applied to the lnode's parent (as with changes to the usage attribute) and so on up to the root lnode, so that the accrued usage at each level in the scheduling tree is the sum of the accrued usage for the lnode and the accrued usage of its children, if any.

For example, a system with two workloads, A and B, might have an lnode hierarchy with lnodes A and B reporting to the root node, and individual users reporting into nodes A and B. The CPU usage of each user can be observed through the usage fields in the lnode of each user, but the sum total of CPU used for workload A is available by looking at the accrued CPU usage in the lnode for workload A.

Figure 9-1 Accounting Based on the Workload Hierarchy