Bug 1250750

Summary:	evaluate realtime performance implications of turning on CONFIG_CGROUP_SCHED in realtime kernel
Product:	Red Hat Enterprise Linux 7	Reporter:	Clark Williams <williams>
Component:	kernel-rt	Assignee:	Steven Rostedt <srostedt>
Status:	CLOSED ERRATA	QA Contact:	Jiri Kastner <jkastner>
Severity:	high	Docs Contact:
Priority:	high
Version:	7.3	CC:	bhu, hhuang, pagupta, williams
Target Milestone:	rc
Target Release:	7.3
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-11-03 19:35:42 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:	1274397, 1282922, 1313485

Description Clark Williams 2015-08-05 21:55:01 UTC

Current RT kernel does not have CGROUP_SCHED config enabled, but may be needed down the road. Anecdotal evidence shows that that there is a 4-8us max latency penalty when testing with rteval. 

We need to determine if there is a consistent increase to max latency with CGROUP_SCHED enabled and if so, are there changes we can make to reduce the effect.

Comment 1 Clark Williams 2015-09-01 15:13:38 UTC

Pushing out to 7.3

Comment 2 Beth Uptagrafft 2015-09-02 17:17:37 UTC

Moving to 7.3

Comment 3 Clark Williams 2016-06-23 21:36:17 UTC

CONFIG_CGROUP_SCHED enabled in kernel-rt-3.10.0-382.rt56.363.el7. No significant performance loss noted in rteval runs.

Comment 7 errata-xmlrpc 2016-11-03 19:35:42 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2016-2584.html