Bug 664027

Summary: 100% of core usage by load balancing tick
Product: [Fedora] Fedora Reporter: Krzysztof "Uosiu" Hajdamowicz <uosiumen>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED DUPLICATE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: low    
Version: 14CC: dougsland, gansalmon, itamar, jfeeney, jonathan, kernel-maint, kmcmartin, madhu.chinakonda
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-02-28 19:15:25 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:
Attachments:
Description Flags
Powertop console output
none
/boot/grub/menu.lst
none
dmesg
none
powertop with nozh=off none

Description Krzysztof "Uosiu" Hajdamowicz 2010-12-17 18:52:42 UTC 
Created attachment 469426 [details]
Powertop console output

Description of problem:
100% usage of one core during my laptop idle time.

Version-Release number of selected component (if applicable):
kernel-2.6.35.9-64.fc14.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Boot PC
2. check CPU usage
3. use powertop to discover cpu-eater
  
Actual results:
Load balancing tick is consuming 75% of CPU wakeups, 100% of core usage

Expected results:
should be no time+power-consuming additional kernel actions.

Additional info:
smolt hardware profile:
http://www.smolts.org/client/show_all/pub_155ba98d-3576-4e0a-8940-e209a5675506
Comment 1 Kyle McMartin 2010-12-17 18:54:31 UTC 
Do you have a more sensible value if you boot with nohz=off?
Comment 2 Krzysztof "Uosiu" Hajdamowicz 2010-12-17 18:56:41 UTC 
Created attachment 469428 [details]
/boot/grub/menu.lst

this is my /boot/grub/menu.lst
Comment 3 Krzysztof "Uosiu" Hajdamowicz 2010-12-17 18:57:35 UTC 
Created attachment 469429 [details]
dmesg

dmesg
Comment 4 Krzysztof "Uosiu" Hajdamowicz 2010-12-17 22:59:08 UTC 
Created attachment 469466 [details]
powertop with nozh=off

23:58 [ root @ samhain ] /root ROOTMODE> cat /boot/grub/menu.lst|grep nohz
	kernel /vmlinuz-2.6.35.9-64.fc14.x86_64 ro root=UUID=bf375cc8-11ae-4fb4-8c96-6580b5a97268 rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=pl_PL.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=pl2 rhgb quiet nohz=off
Comment 5 Matthew Garrett 2011-02-28 19:15:25 UTC 

*** This bug has been marked as a duplicate of bug 680041 ***