Ubuntu
linux package

  1. Bug #2016186
  2. Comment #1

Comment 1 for bug 2016186

Revision history for this message
Jared Ledvina (Datadog) (jaredledvina-dd) wrote :

A few clarifications from IRC:
1. We run all of our Ubuntu 22.04 LTS nodes with the kernel args 'systemd.unified_cgroup_hierarchy=0 systemd.legacy_systemd_cgroup_controller=true' to force cgroups v1 as, unfortunately, we cannot safely turn on cgroups v2 yet (that's another pile of work I want to do!).
2. If you install 'linux-modules-extra-aws', 'modprobe bfq', and then 'echo bfq > /sys/block/nvme0n1/queue/scheduler' you will see stats in the '/sys/fs/cgroup/blkio/blkio.bfq.io_service*' files.
3. However, we continue to only see 0's in the '/sys/fs/cgroup/blkio/blkio.throttle.io_service*' files.

Potentially an upstream change but, definitely something that breaks with the '5.19.0.1022.23~22.04.6' Jammy package update. For me, this likely means I need to pin everything to the older 5.15 package pending cgroups v2 working or a fix to this. Obviously I'd prefer having this fixed so that we can get to 5.19 and stick w/ cgroups v1. I'd also offer a note that pushing 5.19 to Jammy without this support feels like a breaking change. I'm more worried that _other_ cgroups v1 controllers aren't working in a way I haven't noticed yet. Anyway, thanks so much for the help so far and gimme a holler if I can test/confirm anything else!