Bug 1249125

Summary:	Add a note about irqbalance and isolcpus
Product:	Red Hat Enterprise Linux 7	Reporter:	Daniel Bristot de Oliveira <daolivei>
Component:	doc-Realtime_Tuning_Guide	Assignee:	Maxim Svistunov <msvistun>
Status:	CLOSED CURRENTRELEASE	QA Contact:	ecs-bugs
Severity:	medium	Docs Contact:
Priority:	medium
Version:	7.2	CC:	bhu, daolivei, msvistun, tcapek, williams
Target Milestone:	rc	Keywords:	Documentation
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-01-27 13:34:38 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:

Description Daniel Bristot de Oliveira 2015-07-31 14:43:48 UTC

Document section:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux_for_Real_Time/7/html/Tuning_Guide/Interrupt_and_process_binding.html

Subsection:
Procedure 2.4. Excluding CPUs from IRQ Balancing

Starting on RHEL 7.2, when using the isolcpus= kernel parameter, and
the IRQBALANCE_BANNED_CPUS is not set on /etc/sysconfig/irqbalance config
file, the irqbalance will automatically avoid IRQs on CPUs isolated via
isolcpus=.

Please, add a note about this behavior in the section:
 - Procedure 2.4. Excluding CPUs from IRQ Balancing

For example:

"NOTE: The irqbalance will automatically avoid IRQs on CPUs isolated via
isolcpus= kernel parameter if IRQBALANCE_BANNED_CPUS is not set"

Comment 3 Radek Bíba 2015-08-06 13:37:49 UTC

Done in git, thanks for the heads up!

http://git.app.eng.bos.redhat.com/git/doc-Red_Hat_Enterprise_Linux-7-Realtime_Tuning_Guide.git/commit/?id=9e500b6422bafc10e0e4ce5778ade5131c99e4bd

(The note is outside the procedure block because (apparently) you can't use a note after you've started with steps.)