Re: Regression in 4.8 - CPU speed set very low

From	Larry Finger <Larry.Finger@lwfinger.net>
Newsgroups	linux.kernel
Subject	Re: Regression in 4.8 - CPU speed set very low
Date	2016-10-01 00:00 +0200
Message-ID	<sne0x-7A2-9@gated-at.bofh.it> (permalink)
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On 09/29/2016 10:56 AM, Srinivas Pandruvada wrote:
> On Thu, 2016-09-29 at 14:19 +0200, Rafael J. Wysocki wrote:
>
> [...]
>
>>> My laptop was inadvertently put to sleep while I was gone. I forgot
>>> to leave a
>>> note for my wife and she quieted the noisy cpu fan. :)
>> It looks like in 4.8-rc we made a change that caused the "high" trip
>> point to
>> be acted on.
> This high trip point we don't expose in thermal subsystem (the thermal
>  zone dump didn't show this anywhere as a trip). This is exposed by
> core-dts driver only. This is the point BIOS is supposed to act, I
> guess that's why you are seeing 50% clock modulation.
>
>
> Are you running thermald
>
> What is?
> # ps -e | grep thermald
>
>
>>
>> Srinivas, Rui, do you recall what that can be?
>>
>> One more question (I think I asked it previously): In the failing
>> case
>> (4.8-rc1 and later), when the frequency drops down to the 400 MHz,
>> does it
>> ever go back higher or is it stuck at that level forever?
>>
>> In any case, it may help to file a bug at bugzilla.kernel.org against
>> CPU/thermal or similar and let me know the bug number.  We'll need to
>> collect some tracepoint data to debug this and some place to put them
>> into for easy reference.
> Yes, this is good idea.

To complete the record in this thread, the problem also happened with kernel 
4.7, thus it is not a regression in 4.8-rcX. The full discussion is at 
https://bugzilla.kernel.org/show_bug.cgi?id=173361.

Larry

Thread

Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-24 04:50 +0200
  Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-09-26 13:40 +0200
    Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-26 18:20 +0200
      Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-09-26 23:10 +0200
        Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-26 23:30 +0200
          Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rafael@kernel.org> - 2016-09-26 23:40 +0200
            Re: Regression in 4.8 - CPU speed set very low Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-09-26 23:50 +0200
              Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-27 00:20 +0200
            Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-27 00:20 +0200
              Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rafael@kernel.org> - 2016-09-27 00:20 +0200
                Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-27 02:00 +0200
                Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rafael@kernel.org> - 2016-09-27 02:30 +0200
                Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-27 02:50 +0200
                Re: Regression in 4.8 - CPU speed set very low Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-09-27 03:40 +0200
                Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-27 05:00 +0200
                RE: Regression in 4.8 - CPU speed set very low "Doug Smythies" <dsmythies@telus.net> - 2016-09-27 05:20 +0200
                Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-27 10:50 +0200
                Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rafael@kernel.org> - 2016-09-27 13:50 +0200
                Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-29 04:30 +0200
                Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-09-29 14:20 +0200
                Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-29 17:10 +0200
                Re: Regression in 4.8 - CPU speed set very low Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-09-29 18:00 +0200
                Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-29 18:30 +0200
                Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-09-29 22:50 +0200
                Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-10-01 00:00 +0200
          Re: Regression in 4.8 - CPU speed set very low lsorense@csclub.uwaterloo.ca (Lennart Sorensen) - 2016-09-27 17:00 +0200
            Re: Regression in 4.8 - CPU speed set very low Larry Finger <Larry.Finger@lwfinger.net> - 2016-09-29 04:30 +0200
              Re: Regression in 4.8 - CPU speed set very low lsorense@csclub.uwaterloo.ca (Lennart Sorensen) - 2016-09-29 16:20 +0200
        Re: Regression in 4.8 - CPU speed set very low Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-09-26 23:30 +0200
          Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rafael@kernel.org> - 2016-09-26 23:40 +0200
            Re: Regression in 4.8 - CPU speed set very low Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-09-26 23:50 +0200
              Re: Regression in 4.8 - CPU speed set very low "Rafael J. Wysocki" <rafael@kernel.org> - 2016-09-26 23:50 +0200

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