How to use the command cgexec (with examples)

The cgexec command is used to limit, measure, and control the resources used by processes by placing them in cgroups. Cgroups, also known as controllers, are different types of resource controllers such as cpu, memory, etc. The cgexec command allows you to execute a process in a given cgroup with a specified controller.

Use case 1: Execute a process in a given cgroup with a given controller

Code:

cgexec -g controller:cgroup_name process_name

Motivation: The motivation behind using this example is to assign specific resource limits to a process by placing it in a particular cgroup. This allows for better resource management and allocation within a system.

Explanation:

• cgexec: the command used to execute a process in a cgroup
• -g controller:cgroup_name: specifies the controller and the cgroup where the process will be executed
  • controller: the type of controller that determines the resource being controlled (e.g., cpu, memory)
  • cgroup_name: the name of the cgroup where the process will be executed
• process_name: the name of the process that will be executed in the specified cgroup with the given controller

Example output:

$ cgexec -g cpu:my_cgroup_name stress --cpu 1

This will execute the stress command with the --cpu 1 option (which will generate a workload on the CPU) in the my_cgroup_name cgroup using the cpu controller.

Conclusion:

The cgexec command is a powerful tool for managing resource allocation in a system by placing processes in specific control groups. By using the -g option, you can execute processes in a given cgroup with a specific controller, allowing for fine-grained resource control and utilization.