[Virtual-pkg-base-maintainers] Bug#708158: base: Desktop slows to be unusable when power cord is removed for a while, then plugged in again. kworker

[Charles W Fox]

Package: base
Severity: important

Dear Maintainer,
*** Please consider answering these questions, where appropriate ***

   * What led up to the situation?

New Debian 7 install yesterday, Dell lattitude E5420 laptop, serial number
19640672489.  No nonstandard hardware.

This is a very common/generic laptop, one of the standard models used at
Sheffield University.

Running fine all day, then unplugged power to go to a 2 hour meeting on
battery.   Just got back from meeting and plugged in again, battery level
is 59pc.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?
When I plug the power cord back in (so the computer goes to charging) the
desktop becomes unusably sluggish, the mouse and keyboard take about a
second to respond to each input.   Unplugging the cord makes everything
work again (but then the battery will run down!)


   * What was the outcome of this action?
As well as sluggishness I can see several kworkers hogging the CPU in top.
The sluggishness makes the computer completly unusable when it is plugged
back in.
  (I think it vanishes once the battery has fully recharged though)

   * What outcome did you expect instead?
Thought Wheezy would have fixed this -- it's been a known issue in Ubunu
for several years now and was a major reason for moving to Deibian,
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/998204
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/887793
http://ubuntuforums.org/showthread.php?t=1921292

I have been trying the suggested fix from the Ubuntu forums for two years
with no success.   Some posters have said that the bug involves ACPI power
management but I'm not sure if this is actually where it comes from.

(Sorry for sending via gmail, I did this report in reportbug but our uni
seems to have disabled SMTP since it switched us to corporate gmail.)

-- 
Dr Charles Fox www.5m.org.uk
Researcher, Department of Computer Science
University of Sheffield, UK