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Bug 1775447

Summary:	Need to tune very early in boot process (initramfs) for worker node
Product:	OpenShift Container Platform	Reporter:	Andrew Theurer <atheurer>
Component:	Node Tuning Operator	Assignee:	Jiří Mencák <jmencak>
Status:	CLOSED NOTABUG	QA Contact:	Simon <skordas>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	4.3.0	CC:	fsimonce, mpatel, scuppett, sejug, yquinn, zkosic
Target Milestone:	---
Target Release:	4.6.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-07-14 11:57:01 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:	1812894, 1827621
Bug Blocks:

Description Andrew Theurer 2019-11-22 01:30:52 UTC

Description of problem:

For proper isolation of CPUs, we need to tune both systemd CPUAffinity and /sys/devices/virtual/workqueue/cpumask


These are both features of tuned for RHEL which does not work for OCP/RHCOS.

Since systemd starts from the initramfs, it loads its config file from there, where CPUaffinity is set.  See https://bugzilla.redhat.com/show_bug.cgi?id=1394965

For the kernel workqueue, this must happen before device initalization.  See https://bugzilla.redhat.com/show_bug.cgi?id=1395899

The solution tuned on RHEL uses is a second ramdisk, see https://bugzilla.redhat.com/show_bug.cgi?id=1414098

We need the ability to add a second ramdisk for worker nodes to support this and potentially other early-boot customizations for tuning.

Comment 2 Jiří Mencák 2020-02-06 13:49:16 UTC

Andrew, is this BZ still relevant in the presence of: https://bugzilla.redhat.com/show_bug.cgi?id=1775917 or can this be closed?

Comment 4 Martin Sivák 2020-04-28 06:21:33 UTC

I believe this report should be updated as NTO will likely be able to use the new systemd kernel option systemd.cpu_affinity (https://bugzilla.redhat.com/show_bug.cgi?id=1827621)

Comment 5 Stephen Cuppett 2020-06-10 11:35:10 UTC

This is not a showstopper for OCP 4.5.0. Setting target release to 4.6.0 (active development branch). For fixes (if any) required/requested on earlier versions of OCP, please create clones targeting 4.5.z and earlier z-stream releases when appropriate.

Comment 6 Jiří Mencák 2020-07-14 11:57:01 UTC

This is an RFE that is being tracked internally by a Jira card.  Closing.

Comment 8 Red Hat Bugzilla 2023-09-14 05:47:23 UTC

The needinfo request[s] on this closed bug have been removed as they have been unresolved for 1000 days