Bug 471181

Summary: After suspend/resume, processor spends more time in C0 state, C3 hardly used.
Product: [Fedora] Fedora Reporter: James <james>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED WONTFIX QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: 11CC: kernel-maint
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Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2010-06-28 10:48:36 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
dmesg from session none

Description James 2008-11-12 09:04:43 UTC
Created attachment 323309 [details]
dmesg from session

Description of problem:
Before suspend, CPU time is well-portioned between mostly C0 and C3. After resume, according to powertop, the processor spends comparatively much more time in C0 (hardly ever in the low-power states). Wakeups due to ACPI interrupts also seem to be up threefold afterwards. This all results in rise in CPU idle temperature.

Version-Release number of selected component (if applicable):
kernel-2.6.27.5-32.fc9.x86_64 (and a few earlier ones).

How reproducible:
Always.

Steps to Reproduce:
1. Suspend and resume.
  
Actual results:
3 times as many ACPI interrupts, hotter idle temperature.

Expected results:
Same as before suspend/resume.

Additional info:
dmesg attached.
For info on the hardware, see attachments to bug 448150.

Comment 1 James 2008-11-28 20:56:13 UTC
Still seems to be in kernel-2.6.27.7-53.fc9.x86_64.

Comment 2 James 2009-02-27 20:38:57 UTC
Also present in kernel 2.6.29-0.43.rc6.fc10.x86_64. Before a suspend/resume cycle, with an idle desktop, powertop reports the processor switching between C0 and C3 states, with respective residencies 3% and 97%. After suspending and resuming, it doesn't use C3 as much but uses C2, with residencies of around 55%, 43% and 2% for C0, C2 and C3, respectively. The ACPI interrupts have have been a red herring, but there appear to be more rescheduling interrupts after resume.

Comment 3 James 2009-09-07 21:03:34 UTC
Reported upstream, cause is ~40kwups of unknown origin.

Comment 4 Bug Zapper 2010-04-27 12:19:58 UTC
This message is a reminder that Fedora 11 is nearing its end of life.
Approximately 30 (thirty) days from now Fedora will stop maintaining
and issuing updates for Fedora 11.  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 '11'.

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Comment 5 Bug Zapper 2010-06-28 10:48:36 UTC
Fedora 11 changed to end-of-life (EOL) status on 2010-06-25. Fedora 11 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.