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RE: [intel-pstate driver regression] processor frequency very high even if in idle

From "Doug Smythies" <dsmythies@telus.net>
Newsgroups linux.kernel
Subject RE: [intel-pstate driver regression] processor frequency very high even if in idle
Date 2016-03-30 21:00 +0200
Message-ID <ritvs-1a3-9@gated-at.bofh.it> (permalink)
References (2 earlier) <ri9wJ-3Fl-9@gated-at.bofh.it> <riloe-3NH-23@gated-at.bofh.it> <rimaD-4sj-27@gated-at.bofh.it> <riqnU-7t2-17@gated-at.bofh.it> <riqHh-7AW-43@gated-at.bofh.it>
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On 2016.03.30 08:52 Jörg Otte wrote:
> 2016-03-30 17:33 GMT+02:00 Pandruvada, Srinivas <srinivas.pandruvada@intel.com>:
>> On Wed, 2016-03-30 at 13:05 +0200, Rafael J. Wysocki wrote:
>>> On Wed, Mar 30, 2016 at 12:17 PM, Jörg Otte <jrg.otte@gmail.com>

>>>>>> Now in v4.6-rc1 the characteristic has dramatically changed.
>>>>>> If in idle the processor frequency is more or less a few
>>>>>> MHz around 2500Mhz.
>>>>>> I currently use acpi_cpufreq which works as usual.
>>>>>> Processor: Intel(R) Core(TM) i5-4200M CPU @ 2.50GHz
>>>>>> (family: 0x6, model: 0x3c, stepping: 0x3)

>> I want to reproduce this if I can. Can you give us info about your
>> setup (Linux distribution, laptop model etc.)?

I would like to try to reproduce the issue also.

> Distro: Ubuntu 14.04.4 LTS

Note that with Ubuntu 14.04, I had issues where my CPU
would lock at pstate 24 (not always 24, but usually),
regardless of load.
However, it was always after an S3 suspend, occurred 100%
of the time, and was independent of intel_pstate or
acpi-cpufreq CPU frequency scaling drivers.

Since changing my test server to Ubuntu server edition 16.04
(development version), I have not had those issues. While I have
no proof, I have assumed the issue elimination was somehow related
to the change to systemd.

It might be worth observing both what the intel_pstate is asking for
and what the processor is actually doing.

What is being asked for:
# rdmsr --bitfield 15:8 -d -a 0x199

What is being given:
# rdmsr --bitfield 15:8 -d -a 0x198

An old problematic example from an idle system (mine)
Note, my minimum pstate is 16:

What was being given:
# rdmsr --bitfield 15:8 -d -a 0x198
24
24
24
24
24
24
24
24

What was being asked for:
# rdmsr --bitfield 15:8 -d -a 0x199
16
16
16
16
16
16
16
16

To gain further insight, it might also be worth acquiring
some trace data. On an otherwise idle system, do:

# perf record -a --event=power:pstate_sample sleep 300

If pressed for time, your sleep time can be less than 5 minutes,
but try to get at least 100 seconds.

The resulting perf.data file will be too big to include as an
on-list attachment, but send it (or them) to me off-list for
post processing, and I'll report back.

... Doug

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Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-03-29 19:40 +0200
  Re: [intel-pstate driver regression] processor frequency very high even if in idle "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-29 23:40 +0200
    Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-03-30 12:20 +0200
      Re: [intel-pstate driver regression] processor frequency very high  even if in idle "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-30 13:10 +0200
        Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-03-30 17:30 +0200
          Re: [intel-pstate driver regression] processor frequency very high even if in idle "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-30 20:40 +0200
            Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-03-31 11:10 +0200
              Re: [intel-pstate driver regression] processor frequency very high even if in idle "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-31 13:50 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-03-31 17:30 +0200
                Re: [intel-pstate driver regression] processor frequency very high even if in idle "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-31 17:50 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-03-31 18:20 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-03-31 19:30 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-03-31 20:00 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle "Rafael J. Wysocki" <rafael@kernel.org> - 2016-04-01 02:10 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-04-01 11:50 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-04-01 17:10 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle "Rafael J. Wysocki" <rafael@kernel.org> - 2016-04-01 22:30 +0200
                Re: [intel-pstate driver regression] processor frequency very high even if in idle "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-04-01 14:40 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-04-01 16:10 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-04-01 19:50 +0200
                RE: [intel-pstate driver regression] processor frequency very high even if in idle "Doug Smythies" <dsmythies@telus.net> - 2016-04-01 20:40 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-04-01 20:50 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle "Rafael J. Wysocki" <rafael@kernel.org> - 2016-04-01 22:00 +0200
                RE: [intel-pstate driver regression] processor frequency very high even if in idle "Doug Smythies" <dsmythies@telus.net> - 2016-04-02 01:40 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle "Rafael J. Wysocki" <rafael@kernel.org> - 2016-04-02 02:30 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle "Rafael J. Wysocki" <rafael@kernel.org> - 2016-04-01 22:30 +0200
                RE: [intel-pstate driver regression] processor frequency very high even if in idle "Doug Smythies" <dsmythies@telus.net> - 2016-04-01 17:30 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-04-01 18:50 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-04-01 19:40 +0200
        Re: [intel-pstate driver regression] processor frequency very high  even if in idle "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> - 2016-03-30 17:40 +0200
          Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-03-30 18:00 +0200
            Re: [intel-pstate driver regression] processor frequency very high  even if in idle Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-03-30 21:00 +0200
              Re: [intel-pstate driver regression] processor frequency very high  even if in idle "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-30 22:20 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-03-30 22:30 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Jörg Otte <jrg.otte@gmail.com> - 2016-03-31 11:30 +0200
                RE: [intel-pstate driver regression] processor frequency very high even if in idle "Doug Smythies" <dsmythies@telus.net> - 2016-03-31 16:40 +0200
                RE: [intel-pstate driver regression] processor frequency very high even if in idle "Doug Smythies" <dsmythies@telus.net> - 2016-03-31 17:20 +0200
                Re: [intel-pstate driver regression] processor frequency very high  even if in idle Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-03-31 17:20 +0200
                RE: [intel-pstate driver regression] processor frequency very high even if in idle "Doug Smythies" <dsmythies@telus.net> - 2016-04-01 09:30 +0200
            RE: [intel-pstate driver regression] processor frequency very high even if in idle "Doug Smythies" <dsmythies@telus.net> - 2016-03-30 21:00 +0200

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