第 26 章 Setting system resource limits for applications by using control groups

Using the control groups Linux kernel feature, you can organize processes into hierarchically ordered groups - cgroups. You define the hierarchy (control groups tree) by providing structure to cgroups virtual file system, mounted by default on the /sys/fs/cgroup/ directory.

The systemd service manager uses cgroups to organize all units and services that it governs. Manually, you can manage the hierarchies of cgroups by creating and removing sub-directories in the /sys/fs/cgroup/ directory.

The resource controllers in the kernel then modify the behavior of processes in cgroups by limiting, prioritizing or allocating system resources, of those processes. These resources include the following:

The primary use case of cgroups is aggregating system processes and dividing hardware resources among applications and users. This makes it possible to increase the efficiency, stability, and security of your environment.

For more details about cgroups-v1 and cgroups-v2, install the kernel-doc RPM package. After installation, the documentation is in the /usr/share/doc/kernel-doc-<version>/Documentation directory on the local system. The cgroups-v1 documentation files are in the Documentation/admin-guide/cgroup-v1/ directory. This directory has multiple files for different controllers. The cgroups-v2 documentation is in the Documentation/admin-guide/cgroup-v2.rst file.