8.2 Subsystems

You control the access that cgroups have to system resources by specifying parameters to various kernel modules known as subsystems (or as resource controllers in some cgroups documentation).

The following table lists the subsystems that are provided with the cgroups package.

Subsystem

Description

blkio

Controls and reports block I/O operations. See Section 8.2.1, “blkio Parameters”.

Note

The blkio subsystem is enabled in the 2.6.39 UEK, but not in the 2.6.32 UEK.

cpu

Controls access to CPU resources. See Section 8.2.2, “cpu Parameters”.

cpuacct

Reports usage of CPU resources. See Section 8.2.3, “cpuacct Parameters”.

cpuset

Controls access to CPU cores and memory nodes (for systems with NUMA architectures). See Section 8.2.4, “cpuset Parameters”.

devices

Controls access to system devices. See Section 8.2.5, “devices Parameters”.

freezer

Suspends or resumes cgroup tasks. See Section 8.2.6, “freezer Parameter”.

memory

Controls access to memory resources, and reports on memory usage. See Section 8.2.7, “memory Parameters”.

net_cls

Tags network packets for use by network traffic control. See Section 8.2.8, “net_cls Parameter”.

The following sections describe the parameters that you can set for each subsystem.