Setting absolute limits on CPU for Docker containers

Question

I\'m trying to set absolute limits on Docker container CPU usage. The CPU shares concept (docker run -c ) is relative, but I would like to say som

Answer 1

I believe I've gotten this working. I had to restart my Docker daemon with --exec-driver=lxc as I could not find a way to pass cgroup arguments to libcontainer. This approach worked for me:

# Run with absolute limit
sudo docker run --lxc-conf="lxc.cgroup.cpu.cfs_quota_us=50000" -it ubuntu bash

The necessary CFS docs on bandwidth limiting are here.

I briefly confirmed with sysbench that this does seem to introduce an absolute limit, as shown below:

$ sudo docker run --lxc-conf="lxc.cgroup.cpu.cfs_quota_us=10000" --lxc-conf="lxc.cgroup.cpu.cfs_period_us=50000" -it ubuntu bash
root@302e651c0686:/# sysbench --test=cpu --num-threads=1 run
   <snip> 
   total time:                          90.5450s
$ sudo docker run --lxc-conf="lxc.cgroup.cpu.cfs_quota_us=20000" --lxc-conf="lxc.cgroup.cpu.cfs_period_us=50000" -it ubuntu bash
root@302e651c0686:/# sysbench --test=cpu --num-threads=1 run
   <snip> 
    total time:                          45.0423s