What were you trying to do that didn't work?

Basically, isolating cores with the isolated_cores= config is not working with the realtime profiles. There are two cases that have been tried:

ARM bare-metal system with 80 cores, running the real-time kernel:

1. Configure isolated cores in /etc/tuned/realtime-variables.conf to isolated_cores=1,2,3,4,5
2. Activate the profile "# tuned-adm profile realtime"
3. Check TUNED_BOOT_CMDLINE in /etc/tuned/bootcmdline, all cores except core0 are passed to isolcpus= (ie. cores 1 to 79 are passed)

RHEL9 RT KVM guest with 4 vCPUs:

1. Configure isolated cores in /etc/tuned/realtime-variables.conf to isolated_cores=1-3
2. Activate the profile "# tuned-adm profile realtime"
3. Check TUNED_BOOT_CMDLINE in /etc/tuned/bootcmdline, no CPUs are passed to the isolcpus= kernel command-line. It only contains "isolcpus=managed_irq,domain,"

Please provide the package NVR for which bug is seen:

ARM versions:

kernel-rt-5.14.0-388.el9.aarch64
kernel-rt-core-5.14.0-388.el9.aarch64
kernel-rt-modules-5.14.0-388.el9.aarch64
kernel-rt-modules-core-5.14.0-388.el9.aarch64
kernel-rt-modules-extra-5.14.0-388.el9.aarch64
tuned-2.21.0-1.el9_3.noarch
tuned-profiles-cpu-partitioning-2.21.0-1.el9_3.noarch
tuned-profiles-nfv-2.21.0-1.el9_3.noarch
tuned-profiles-nfv-guest-2.21.0-1.el9_3.noarch
tuned-profiles-nfv-host-2.21.0-1.el9_3.noarch
tuned-profiles-realtime-2.21.0-1.el9_3.noarch

x86 guest versions:

kernel-rt-5.14.0-388.el9.x86_64
kernel-rt-core-5.14.0-388.el9.x86_64
kernel-rt-modules-5.14.0-388.el9.x86_64
kernel-rt-modules-core-5.14.0-388.el9.x86_64
tuned-2.21.0-1.el9_3.noarch
tuned-profiles-nfv-host-2.21.0-1.el9_3.noarch
tuned-profiles-realtime-2.21.0-1.el9_3.noarch

How reproducible:

Described above.

Expected results

The isolcpus kernel command-line should contain the same CPUs as passed to isolated_cores=

Actual results

Described above.