tuned fails to add realtime grub parameters when using alternate grub config on realtime kernel

[cement-cloud]

OS: Ubuntu 22.04.2 LTS - 5.15.0-1037-realtime

Setup: Specify the cores to be isolated in the realtime-variables.conf profile, apply the profile with sudo tuned-adm profile realtime, confirm that the profile is the current active. Reboot, then run sudo cat /proc/cmdline which returns:

BOOT_IMAGE=/vmlinuz-5.15.0-1037-realtime root=/dev/mapper/ubuntu--vg-ubuntu--lv ro with none of the params from the realtime profile applied.

Based on the output it seems like this is related to grub version and the filepath for grub.cfg.

'2023-05-03 16:27:37,733 INFO     tuned.daemon.daemon: static tuning from profile 'realtime' applied
^C2023-05-03 16:28:32,819 INFO     tuned.daemon.controller: terminating controller
2023-05-03 16:28:32,819 INFO     tuned.daemon.daemon: stopping tuning
2023-05-03 16:28:32,825 INFO     tuned.daemon.daemon: terminating Tuned, rolling back all changes
2023-05-03 16:28:32,825 INFO     tuned.plugins.plugin_script: calling script '/usr/lib/tuned/realtime/script.sh' with arguments '['stop', 'full_rollback']'
2023-05-03 16:28:32,833 INFO     tuned.plugins.plugin_bootloader: removing grub2 tuning previously added by Tuned
2023-05-03 16:28:32,834 INFO     tuned.plugins.plugin_bootloader: cannot find grub.cfg to patch
2023-05-03 16:28:32,834 ERROR    tuned.utils.commands: Executing grub2-editenv error: [Errno 2] No such file or directory: 'grub2-editenv'
2023-05-03 16:28:32,834 WARNING  tuned.plugins.plugin_bootloader: cannot update grubenv: '

I know Ubuntu is using Grub2 but the directory is at /boot/grub, not grub2. I think tuned is using grub2-mkconfig -o /boot/grub2/grub.cfg which would require a different grub command AND a different path. Is there a known workaround for this?

[adriaan42]

Similar things happen on Debian. There already is a proposed patch to find the correct config: #387

And then also the executable (grub-editenv instead of grub2-editenv): https://salsa.debian.org/debian/tuned/-/blob/debian/unstable/debian/patches/find-alternative-executable-for-grub2-editenv.patch