kernel-packages team mailing list archive

[Luis Henriques <luis.henriques@xxxxxxxxxxxxx>]

This bug is awaiting verification that the kernel in -proposed solves
the problem. Please test the kernel and update this bug with the
results. If the problem is solved, change the tag 'verification-needed-
vivid' to 'verification-done-vivid'.

If verification is not done by 5 working days from today, this fix will
be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how
to enable and use -proposed. Thank you!


** Tags added: verification-needed-vivid

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https://bugs.launchpad.net/bugs/1452547

Title:
  Report cpu frequency throttling

Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Vivid:
  Fix Committed

Bug description:
  [Impact]

  == Comment: #0 - Shilpasri G. Bhat <shigbhat@xxxxxxxxxx> - 2015-05-06 07:24:11 ==
  The user can see a drop in performance when frequency is throttled and
  is unaware of throttling. So detect and report such a condition, so
  the user can check the OCC status to reboot the system or check for
  power supply or fan failures.

  The cpu frequency can be throttled by OCC for the following reasons:
  1)If a processor crosses its power and temperature limit then OCC will
  lower its Pmax to reduce the frequency and voltage.
  2)If OCC crashes then the system is forced to Psafe frequency.
  3)If OCC fails to recover then the kernel is not allowed to do any
   further frequency changes and the chip will remain in Psafe.

  
  [Test Case]
  Get into a state where hardware OCC throttles CPU frequency.
  Ensure kernel log shows cpufreq throttling messages.

  
  [Fix]

  This bug is fixed upstream 09a972d1620934142d30cfda455ffe429af751c4

  ---uname output---
  3.19.0-15

  Machine Type = llmtul02b.in.ibm.com

  Contact Information = Shilpasri G Bhat /
  shilpa.bhat@xxxxxxxxxxxxxxxxxx

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