cgroup - control group
The control groups, abbreviated as cgroups in this guide, are a Linux kernel feature that allows you to allocate resources — such as CPU time, system memory, network bandwidth, or combinations of these resources — among hierarchically ordered groups of processes running on a system. By using cgroups, system administrators gain fine-grained control over allocating, prioritizing, denying, managing, and monitoring system resources. Hardware resources can be smartly divided up among applications and users, increasing overall efficiency.
Control Groups provide a way to hierarchically group and label processes, and to apply resource limits to them. Traditionally, all processes received similar amounts of system resources that the administrator could modulate with the process niceness value. With this approach, applications that involved a large number of processes received more resources than applications with few processes, regardless of the relative importance of these applications.