Bug 436018 - huge number of wakeups
Summary: huge number of wakeups
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 9
Hardware: x86_64
OS: Linux
Target Milestone: ---
Assignee: Peter Zijlstra
QA Contact: Fedora Extras Quality Assurance
Depends On:
TreeView+ depends on / blocked
Reported: 2008-03-04 21:19 UTC by Ulrich Drepper
Modified: 2014-08-11 05:40 UTC (History)
5 users (show)

Clone Of:
Last Closed: 2009-07-14 16:12:41 UTC

Attachments (Terms of Use)

Description Ulrich Drepper 2008-03-04 21:19:08 UTC
Description of problem:
The supposedly tickless rawhide x86-64 kernel is much worse than the F8 kernel.
 I'm now up to around 140 wkaeups per second on an idle machine.  Powertop shows:

~50%  <kernel API> : Rescheduling interrupts
~13%  <interrupt> : iwl4965
~8%   group_balance : schedule_timeout (process_timedout)
~8%   at-spi-registry : schedule_timeout (process_timedout)
~5%   <interrupt> : extra timer interrupt

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1.start that kernel on X61 laptop
2.run powertop
Actual results:
above numbers

Expected results:
< 20 (< 10 ?) wakeups per second.  Well, maybe the wifi adds more.

Additional info:

Comment 1 Adrien Bustany 2008-03-06 17:20:29 UTC
Same for me, "rescheduling interrupts" is 50% of wakeups on a sony sz61mn/b,

Comment 2 Stephen So 2008-03-15 14:32:04 UTC
This problem of "rescheduling interrupts" is also occurring in

Comment 3 Dave Jones 2008-04-14 17:23:21 UTC
I spoke with Arjan about this a few days ago. His hypothesis was that something
changed in the scheduler which is causing us to rebalance tasks too often.
Peter, any ideas ?

Comment 4 Andrew Hecox 2008-05-12 17:03:57 UTC
did this get anywhere? 

observing under 25-14.fc9.x86_64, on an T61, playing audio but nothing else,
rescheduling interrupts range cause 170-200 (50-65%) wakeups.

Comment 5 Andrew Hecox 2008-05-12 17:40:23 UTC
fwiw, the case is the same if I boot with noirqbalance and acpi_irq_nobalance.
Before rhythbox is loaded, the IRQ rebalancing is happening, but very
infrequently (<20/s) but once loaded, that moves to ~200/s. rhythmbox itself is
causing <40/s while music is playing.

happy to test if needed.

Comment 6 Bug Zapper 2008-05-14 05:46:40 UTC
Changing version to '9' as part of upcoming Fedora 9 GA.
More information and reason for this action is here:

Comment 7 Bug Zapper 2009-06-09 23:40:52 UTC
This message is a reminder that Fedora 9 is nearing its end of life.
Approximately 30 (thirty) days from now Fedora will stop maintaining
and issuing updates for Fedora 9.  It is Fedora's policy to close all
bug reports from releases that are no longer maintained.  At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '9'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version prior to Fedora 9's end of life.

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Comment 8 Bug Zapper 2009-07-14 16:12:41 UTC
Fedora 9 changed to end-of-life (EOL) status on 2009-07-10. Fedora 9 is 
no longer maintained, which means that it will not receive any further 
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of 
Fedora please feel free to reopen this bug against that version.

Thank you for reporting this bug and we are sorry it could not be fixed.

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