Description of problem:

When running cyclictest over a 12h period on a Dell XR5610 server (SPR-EE) running OCP 4.14.36, we get latency spikes above 30 us.

Depending on the run, it can be a single spike or several (4-5), usually on the same CPU.

Version-Release number of selected component (if applicable):
OCP 4.14.36 (seen on earlier .z releases, too)
Intel FEC sriov-fec.v2.9.0 (not relevant)
Dell XR5610 server with
. BIOS 2.0.4
. iDRAC firmware 7.10.50.10

How reproducible: Always

Steps to Reproduce:

1. Deploy XR5610 with DU profile
2. Run cyclictest

Actual results: Max latency is up to 32 us

Expected results:

No latency values above 20 us:

 # Max Latencies: 00010 00012 00010 00010 00010 00011 00011 00009 00011 00007

Additional info:
With the same configuration, we have run an rtla timerlat test and captured a latency spike > 32 us. I'm attaching the timerlat output as well.