The RT scheduler works in a similar way to the ceiling enforcement control of the CFS (for more information, refer to Section 3.2.1, “CFS Tunable Parameters”
) but limits CPU access to real-time tasks only. The amount of time for which real-time task can access the CPU is decided by allocating a run time and a period for each cgroup. All tasks in a cgroup are then allowed to access the CPU for the defined period of time for one run time (for example, tasks in a cgroup can be allowed to run 0.1 seconds in every 1 second). Please note that the following parameters take into account all available logical CPUs, therefore the access times specified with these parameters are in fact multiplied by the number of CPUs.