Project Attribute Mechanisms

Resource controls can also serve as a simple attribute mechanism for resource management facilities. For example, the number of CPU shares made available to a project in the fair share scheduler (FSS) scheduling class is defined by the project.cpu-shares resource control. Because the project is assigned a fixed number of shares by the control, the various actions associated with exceeding a control are not relevant. In this context, the current value for the project.cpu-shares control is considered an attribute on the specified project.

Another type of project attribute is used to regulate the resource consumption of physical memory by collections of processes attached to a project. These attributes have the prefix rcap, for example, rcap.max-rss. Like a resource control, this type of attribute is configured in the project database. However, while resource controls are synchronously enforced by the kernel, resource caps are asynchronously enforced at the user level by the resource cap enforcement daemon, rcapd. For information on rcapd, see Chapter 10, Physical Memory Control Using the Resource Capping Daemon (Overview) and rcapd(1M).

The project.pool attribute is used to specify a pool binding for a project. For more information on resource pools, see Chapter 12, Resource Pools (Overview).