Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.

Bug 2006953

Summary:	Long reboot recovery time for DU node with RT kernel with large number of pods
Product:	OpenShift Container Platform	Reporter:	Ian Miller <imiller>
Component:	Telco Edge	Assignee:	Ian Miller <imiller>
Telco Edge sub component:	RAN	QA Contact:	yliu1
Status:	CLOSED CURRENTRELEASE	Docs Contact:
Severity:	medium
Priority:	unspecified	CC:	vlaad
Version:	4.9
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	2008604 (view as bug list)		Environment:
Last Closed:	2022-08-26 14:31:50 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2008604

Description Ian Miller 2021-09-22 17:48:52 UTC

Reboot recovery time of a DU node with the RT kernel is much longer than without RT kernel. The root cause is BZ 1975356. The DU node profile needs to enable the fix by adding rcupdate.rcu_normal_after_boot=0 to the kernel commandline.

Comment 1 yliu1 2021-09-22 17:59:59 UTC

Soft reboot test on 4.9 load with the additional kernel arg took about 14 minutes with 43 test pods. 
If this kernel arg was not added, it could take more than half an hour to recovery.