[Starlingx-discuss] CPU Isolation discrepancy

[Venkata Ramana Veldanda]

Hi

I am running StarlingX 4.0 in Low Latency Mode in AIO-SX. We have isolated CPUs for application as below using the supported way. However, we can see that kubelet treads are scheduled on application isolated vcpus - Ex: 49, 50, 75.



Could someone explain the behavior here?. Full log is attached.


controller-0:/home/sysadmin# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-4.18.0-147.3.1.rt24.96.el8_1.tis.8.x86_64 root=UUID=837a0268-a574-45ea-b560-a6e5afc483dd ro security_profile=standard module_blacklist=integrity,ima audit=0 tboot=false crashkernel=auto biosdevname=0 console=tty0 iommu=pt usbcore.autosuspend=-1 selinux=0 enforcing=0 nmi_watchdog=0 softlockup_panic=0 intel_iommu=on user_namespace.enable=1 skew_tick=1 hugepagesz=1G hugepages=47 hugepagesz=2M hugepages=0 default_hugepagesz=1G irqaffinity=0,24,48,72 rcu_nocbs=1-23,25-47,49-71,73-95 nohz_full=1-23,25-47,49-71,73-95 isolcpus=1-22,25-46,49-70,73-94 kthread_cpus=0,24,48,72 nopti nospectre_v2 nospectre_v1


[root at controller-0 sysadmin(keystone_admin)]# pidstat -t -p 134731
Linux 4.18.0-147.3.1.rt24.96.el8_1.tis.8.x86_64 (controller-0) 03/03/2021 _x86_64_(96 CPU)




01:26:28 AM     0         -    145642    0.00    0.00    0.00    0.00    50  |__kubelet
01:26:28 AM     0         -    145643    0.01    0.01    0.00    0.02    72  |__kubelet
01:26:28 AM     0         -    146196    0.05    0.03    0.00    0.08    24  |__kubelet
01:26:28 AM     0         -    147027    0.00    0.00    0.00    0.00    75  |__kubelet
01:26:28 AM     0         -    147028    0.00    0.00    0.00    0.00    49  |__kubelet





system host-cpu-list controller-0


| 456f11f6-231f-4c6a-b9d9-fa35a6f6bff6 | 49    | 0         | 1     | 1      | Intel(R) Xeon(R) Gold 6248R CPU | Application-isolated |
|                                      |       |           |       |        | @ 3.00GHz                       |                      |
|                                      |       |           |       |        |                                 |                      |
| d491dd29-8603-4bf1-8620-9fbdde5d5d38 | 50    | 0         | 2     | 1      | Intel(R) Xeon(R) Gold 6248R CPU | Application-isolated |



| 94bb8566-e726-418a-ae1f-3264807bfbcd | 75    | 1         | 3     | 1      | Intel(R) Xeon(R) Gold 6248R CPU | Application-isolated |





Venkata Veldanda

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