Performing verification for Jammy. I started a n2-highcpu-32 instance on GCP due to bare metal systems being unavailable due to the certification lab move.
I edited /etc/default/grub.d/50-cloudimg-settings.cfg and set: GRUB_CMDLINE_LINUX_DEFAULT="console=ttyS0,115200 isolcpus=4-7,16-20 rcu_nocb_poll rcu_nocbs=4-7,16-20 systemd.unified_cgroup_hierarchy=1" ran sudo update-grub and rebooted. Due to 5.15.0-121-generic still being in -proposed due to 2024.08.05 releasing slightly later than expected, I enabled -proposed and installed 5.15.0-121-generic to get a baseline. I rebooted again. I then set up htop, s-tui and the while loop to check for processes on 4-7,16-20. I started s-tui, and there were processes placed on the other cores within 3 minutes. By 10 minutes, all cores had stress running on them, and isolation was completely ignored. I then enabled -proposed2 and installed 5.15.0-122-generic: $ uname -rv 5.15.0-122-generic #132-Ubuntu SMP Thu Aug 29 13:45:52 UTC 2024 I re-ran s-tui and started stress. After 1 hour and 20 minutes, the isolcated cpus were still completely isolated, with no processes running on them. Stress was only confined to regular cpus. The kernel in -proposed fixes the issue. Happy to mark verified for jammy. ** Tags removed: verification-needed-jammy-linux ** Tags added: verification-done-jammy-linux -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2076957 Title: isolcpus are ignored when using cgroups V2, causing processes to have wrong affinity To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2076957/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
