Bug 747488

Summary:	nice not working
Product:	[Fedora] Fedora	Reporter:	Thawan Kooburat <kthawan>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED DUPLICATE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	15	CC:	gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-12-18 01:53:33 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Thawan Kooburat 2011-10-20 02:57:39 UTC

Description of problem:
Setting nice value via "nice" command or setpriority() systemcall doesn't work. CPU-bound process with nice(+19) still consume CPU equal to user process with default nice value (presumably 0). 

Version-Release number of selected component (if applicable):
2.6.40.6-0.fc15.x86_64

How reproducible:
The same issue also occurred with the mainline kernel 3.0.7 on FC15.  However, the problem do not occur when I run kernel 2.6.32-71.el6.x86_64 on FC15

Steps to Reproduce:
1. Run 2 CPU-bound process but give one process with nice +19
2. 
3.
  
Actual results:
Observe that both of them still get equal amount of CPU time

Expected results:
In 2.6.32-71.el6.x86_64, process with nice +19 should get about 1.5% of CPU time

Additional info:

Comment 1 Thawan Kooburat 2011-12-18 01:53:33 UTC

Nice command is ignored due to "autogroup" feature

Disable autogroup at runtime or use "noautogroup" kernel boot option to disable it.

*** This bug has been marked as a duplicate of bug 721416 ***