CGroups

This page describes how CRIU manages CGroups.

Overview

When talking about C/R of CGroups info, we mean three things:

1. The groups tasks live in
2. The groups that exist and are visible by tasks
3. Mountpoints of "cgroup" file system

Here's how CRIU manages them.

CGroups tasks live in

Starting from version 1.3-rc1 CRIU saves the information about CGroups each task lives in in the core image's tc.cg_set field. This is an ID of a "set" found in the cgroup.img's sets section.

Set contains per-controller paths to groups. If a task changes at least one controller's path it is considered to live in different set.

While dumping CRIU gets the set in which the root task lives. Any new set found later should contain only subdirs of the root's set.