Hello I want to use cgroups to control my heavy cpuload consuming applications. All apps are running in the realtime domain and I'm using kernel 4.9 and cgroup v1. I created a small application that monitors the CPU load (by reading the /proc filesystem) and when it enters a full load condition, I dynamically start to put the high consuming processes into a cgroup (which were created during system start-up). Each process will have it's own cgroup created under the root-cgroup. The budget I assign to the process is equal to the budget it has consumed in the previous measurement interval (for example 5s). As long as the load continues to be high, I start to gradually reduce the budget of the cgroup until the system is idle enough. This works reasonably well, but in some cases I see that a very high load consuming application is stopped completely at the moment it is put in a cgroup, although the budget allocated to it is correctly calculated based on the load it consumed in my previous interval. An example: - cpu.rt_period_us = 1000000 - cpu.rt_runtime_us = 400000 I would assume that an application put in a cgroup with this configuration can consume 40% of the CPU and it actually does. But sometimes, immediately after the process assignment, it stops for a short period (something like 1 or 2s) and then starts to consume 40% again. Is that expected behavior? It looks like the "budget" it has consumed in the root-cgroup is taken into account when it is moved to its own group and this results in the stall. Best regards, Ronny
