I have some machiens on AWS that are running Rocky 8 and I’m trying to do some troubelshooting. I want to use “PSI” (Pressure Stall Information) from the kernel, and I’ve tried multiple ways of editing the kernel command line to add “psi=1” – and it all appears to work, but then when I reboot the grub command line that I have is ignored. I’ve also tried disabling selinux from the kernel command line to see if that would work.
Currently I can see this:
[root@vm-aws-mrms-fus-sr1 log]# grubby --info DEFAULT
index=0
kernel=“/boot/vmlinuz-4.18.0-553.16.1.el8_10.x86_64” args=“ro console=ttyS0,115200n8 no_timer_check net.ifnames=0 nvme_core.io_timeout=4294967295 nvme_core.max_retries=10 crashkernel=auto psi=1 selinux=0 $tuned_params”
root=“UUID=36ec20a7-50b7-4345-92a7-7ae76f1a93a6”
initrd=“/boot/initramfs-4.18.0-553.16.1.el8_10.x86_64.img $tuned_initrd”
title=“Rocky Linux (4.18.0-553.16.1.el8_10.x86_64) 8.10 (Green Obsidian)”
id=“b262527e2ab8431581d1e8f33da9a2a0-4.18.0-553.16.1.el8_10.x86_64”
But when I reboot I get this:
[root@vm-aws-mrms-fus-sr1 log]# cat /proc/cmdline
BOOT_IMAGE=(hd0,gpt2)/vmlinuz-4.18.0-553.16.1.el8_10.x86_64 root=UUID=36ec20a7-50b7-4345-92a7-7ae76f1a93a6 ro console=ttyS0,115200n8 no_timer_check net.ifnames=0 nvme_core.io_timeout=4294967295 nvme_core.max_retries=10 crashkernel=auto
I’m not a kernel guru – but I am really stuck trying to figure out why this is not working.