Peter Steele
2016-Oct-28 17:01 UTC
[libvirt-users] How do you set real time bandwidth for a container?
When I create a VM using libvirt, the VM comes up the path /sys/fs/cgroup/cpu/cpu.rt_runtime_us set to something like 1000000. When I create a container however, the path /sys/fs/cgroup/cpu/cpu.rt_runtime_us is 0. This prevents my containers from being able to run any real time applications. I have to explicitly echo a value into this field in order to give the container some real time bandwidth and allow it to run real time processes. Is it possible to define this in a container's XML config? Or is there another method I should be using to enable real time capability in a container? Peter
Michal Privoznik
2016-Oct-30 21:28 UTC
Re: [libvirt-users] How do you set real time bandwidth for a container?
On 29.10.2016 01:01, Peter Steele wrote:> When I create a VM using libvirt, the VM comes up the path > /sys/fs/cgroup/cpu/cpu.rt_runtime_us set to something like 1000000. When > I create a container however, the path > /sys/fs/cgroup/cpu/cpu.rt_runtime_us is 0. This prevents my containers > from being able to run any real time applications. I have to explicitly > echo a value into this field in order to give the container some real > time bandwidth and allow it to run real time processes.This is some weird kernel default. I mean libvirt does not set that value anywhere.> > Is it possible to define this in a container's XML config? Or is there > another method I should be using to enable real time capability in a > container?No, currently there's no way to provide that in XML config. However, you can create a hook script that is executed whenever domain is being started and that script can set the proper value for you. Michal