With 4.13 rc.2 (9.2 and RT kernel), SNO with DU profiles is noticed to have frequent server reboot in steady state when ptp profiles are applied. 

Note that we used to experience server freeze once in a while, but because we were not able to collect crashdump when that happened, we enabled the following configs by default. So instead of seeing freezes, we now see server reboots with coredump generated as the new symptoms.

kernel.sysrq=1
kernel.panic_on_rcu_stall=1
kernel.hung_task_panic=1 

4.13-rc.2

Frequent - more than 10 reboots in 24 hrs. (about 5 of them are from our automated tests, but most reboots happened itself in steady state)

And we have seem multiple "still running" reboots (see end timestamp), they sometimes get cleared on a followup reboot, sometimes they keep piling up. 

[core@helix49 ~]$ last reboot
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 19:00   still running
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 18:07   still running
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 17:33 - 18:04  (00:30)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 17:16 - 18:04  (00:48)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 16:47 - 18:04  (01:17)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 14:57 - 18:04  (03:07)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 14:39 - 18:04  (03:25)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 14:07 - 18:04  (03:56)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 12:20 - 18:04  (05:43)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 11:41 - 18:04  (06:23)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 11:16 - 18:04  (06:48)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 10:43 - 18:04  (07:21)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 10:02 - 18:04  (08:02)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 09:25 - 18:04  (08:38)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 07:17 - 18:04  (10:47)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 06:01 - 18:04  (12:02)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 04:14 - 18:04  (13:50)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 03:45 - 04:11  (00:25)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 02:44 - 04:11  (01:26)
reboot   system boot  5.14.0-284.4.1.r Tue Apr  4 01:08 - 04:11  (03:02)
reboot   system boot  5.14.0-284.4.1.r Mon Apr  3 19:34 - 04:11  (08:36)
reboot   system boot  5.14.0-284.4.1.r Mon Apr  3 19:09 - 19:31  (00:21)
reboot   system boot  5.14.0-284.4.1.e Mon Apr  3 18:23 - 19:06  (00:43)
reboot   system boot  5.14.0-284.4.1.e Mon Apr  3 18:18 - 18:20  (00:02)wtmp begins Mon Apr  3 18:18:47 2023
[core@helix49 ~]$ ls -la /var/crash/
total 8
drwxr-xr-x. 20 root root 4096 Apr  4 18:56 .
drwxr-xr-x. 24 root root 4096 Apr  3 19:34 ..
drwxr-xr-x.  2 root root   67 Apr  4 01:05 127.0.0.1-2023-04-04-01:05:31
drwxr-xr-x.  2 root root   67 Apr  4 02:41 127.0.0.1-2023-04-04-02:40:54
drwxr-xr-x.  2 root root   67 Apr  4 03:43 127.0.0.1-2023-04-04-03:42:35
drwxr-xr-x.  2 root root   67 Apr  4 05:58 127.0.0.1-2023-04-04-05:58:27
drwxr-xr-x.  2 root root   67 Apr  4 07:14 127.0.0.1-2023-04-04-07:13:44
drwxr-xr-x.  2 root root   67 Apr  4 09:22 127.0.0.1-2023-04-04-09:22:26
drwxr-xr-x.  2 root root   67 Apr  4 09:59 127.0.0.1-2023-04-04-09:58:44
drwxr-xr-x.  2 root root   67 Apr  4 10:40 127.0.0.1-2023-04-04-10:39:44
drwxr-xr-x.  2 root root   67 Apr  4 11:13 127.0.0.1-2023-04-04-11:12:47
drwxr-xr-x.  2 root root   67 Apr  4 11:38 127.0.0.1-2023-04-04-11:38:25
drwxr-xr-x.  2 root root   67 Apr  4 12:18 127.0.0.1-2023-04-04-12:17:37
drwxr-xr-x.  2 root root   67 Apr  4 14:04 127.0.0.1-2023-04-04-14:04:27
drwxr-xr-x.  2 root root   67 Apr  4 14:36 127.0.0.1-2023-04-04-14:36:20
drwxr-xr-x.  2 root root   67 Apr  4 14:54 127.0.0.1-2023-04-04-14:54:20
drwxr-xr-x.  2 root root   67 Apr  4 16:44 127.0.0.1-2023-04-04-16:44:00
drwxr-xr-x.  2 root root   67 Apr  4 17:13 127.0.0.1-2023-04-04-17:13:12
drwxr-xr-x.  2 root root   67 Apr  4 17:30 127.0.0.1-2023-04-04-17:30:32
drwxr-xr-x.  2 root root   67 Apr  4 18:57 127.0.0.1-2023-04-04-18:56:41

1. Install 4.13-rc.2 OCP on Single Node Openshift with Du profiles applied, specifically on this server, there are 
- 4 ptp profiles configured - 1 Boundary clock (E810 NIC) and 3 downstream slaves (CX-6 NICs).
- config these via Tuned, so crash dumps are auto generated on rcu stall.
kernel.sysrq=1 
kernel.panic_on_rcu_stall=1 
kernel.hung_task_panic=1 

2. let the system run overnight
3.

system rebooted itself, and coredumps are generated

system is stable