Bug 454270 – SCHED_FIFO spec violation

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Bug 454270 - SCHED_FIFO spec violation

Summary:	SCHED_FIFO spec violation

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise MRG
Classification:	Red Hat
Component:	realtime-kernel (Show other bugs)
Sub Component:
Version:	beta
Hardware:	All All

Priority	low Severity high
Target Milestone:	1.0.3
Target Release:	---
Assigned To:	Peter Zijlstra
QA Contact:
Docs Contact:

URL:
Whiteboard:
Keywords:

Depends On:
Blocks:
	Show dependency tree / graph

Reported:	2008-07-07 08:08 EDT by IBM Bug Proxy
Modified:	2014-08-11 01:40 EDT (History)
CC List:	4 users (show)

See Also:
Fixed In Version:
Doc Type:	Bug Fix
Doc Text:
Story Points:	---
Clone Of:
Environment:
Last Closed:	2008-10-07 15:21:34 EDT
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
[PATCH] Enqueue deprioritized RT tasks to head of prio array (7.83 KB, text/plain) 2008-07-07 08:08 EDT, IBM Bug Proxy	no flags	Details
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
IBM Linux Technology Center	46078	None	None	None	Never
Red Hat Product Errata	RHSA-2008:0857	normal	SHIPPED_LIVE	Important: kernel security and bug fix update	2008-10-07 15:18:59 EDT

Groups: None (edit)

Description IBM Bug Proxy 2008-07-07 08:08:21 EDT

=Comment: #0=================================================
Darren V. Hart <dvhltc@us.ibm.com> - 2008-07-03 13:10 EDT
According to the SUS, when a SCHED_FIFO task's priority is lowered, it should be
added to the head of the corresponding priority array:

http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_08.html#tag_02_08_04_01

Peter Z. noticed this and wrote a patch to address it:

http://lkml.org/lkml/2008/6/16/344

The dequeue_rt_stack() apparently still needs some work according to peterz
comments.

=Comment: #2=================================================
Darren V. Hart <dvhltc@us.ibm.com> - 2008-07-03 13:22 EDT
The enqueue_task changed in 2.6.25, so a backport will be required.  It's a
simple patch, so that shouldn't pose a problem.

=Comment: #3=================================================
Darren V. Hart <dvhltc@us.ibm.com> - 2008-07-03 15:01 EDT
I've backported the patch and have an R2 patch ready.  Currently under test on
elm3b172 running release-testing.sh.
=Comment: #4=================================================
Darren V. Hart <dvhltc@us.ibm.com> - 2008-07-03 18:27 EDT

[PATCH] Enqueue deprioritized RT tasks to head of prio array

The attached patch is currently undergoing release-testing.

Comment 1 IBM Bug Proxy 2008-07-07 08:08:24 EDT

Created attachment 311140 [details]
[PATCH] Enqueue deprioritized RT tasks to head of prio array

Comment 2 Clark Williams 2008-08-20 09:46:33 EDT

Are we good with this one?

Comment 3 IBM Bug Proxy 2008-08-20 13:00:53 EDT

(In reply to comment #11)
> ------- Comment From williams@redhat.com 2008-08-20 09:46:33 EDT-------
> Are we good with this one?

Yup.

Comment 5 David Sommerseth 2008-10-06 12:38:27 EDT

Verified by code review

Comment 7 errata-xmlrpc 2008-10-07 15:21:34 EDT

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2008-0857.html

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