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Add real-time CPU time allocation support

Open agners opened this issue 1 month ago • 2 comments

With https://github.com/home-assistant/supervisor/pull/2602 and #1236 CPU real-time allocation support got added using cgroupsv1 and CONFIG_RT_GROUP_SCHED.

Unfortunately, cgroupsv2 did not offer a replacement, so it got removed with #1329.

We should check if this is still true in 2025.

agners avatar Nov 25 '25 10:11 agners

The https://github.com/home-assistant/operating-system/issues/1235#issuecomment-782400690 explains how allocation exactly worked with cgroupsv1.

agners avatar Nov 25 '25 10:11 agners

Hm, it seems CGroups v2 still does not have the necessary batteries included:

WARNING: cgroup2 cpu controller doesn’t yet support the (bandwidth) control of realtime processes.

From: https://docs.kernel.org/admin-guide/cgroup-v2.html#cpu

There is also a corresponding Docker issue: https://github.com/moby/moby/issues/48259. I think for now we simply can't do this 😢

agners avatar Nov 25 '25 20:11 agners