From: "Doug Smythies" <dsmythies@telus.net>
To: 'Arto Jantunen' <viiru@iki.fi>,
"'Rafael J. Wysocki'" <rjw@rjwysocki.net>
Cc: 'Srinivas Pandruvada' <srinivas.pandruvada@linux.intel.com>,
"'Chen, Yu C'" <yu.c.chen@intel.com>,
linux-pm@vger.kernel.org, 'Rik van Riel' <riel@redhat.com>,
'Viresh Kumar' <viresh.kumar@linaro.org>,
'Doug Smythies' <dsmythies@telus.net>
Subject: RE: PROBLEM: Cpufreq constantly keeps frequency at maximum on 4.5-rc4
Date: Tue, 1 Mar 2016 11:28:39 -0800 [thread overview]
Message-ID: <001601d173f0$8ff83a10$afe8ae30$@net> (raw)
In-Reply-To: <002801d172b9$845cde50$8d169af0$@net>
Note: Just following up with some energy numbers, that perhaps
should have been included to begin with.
> On 2016.02.28 22:22 Doug Smythies wrote:
>> On 2016.02.28 07:44 Arto Jantunen wrote:
>> Bisect comes up with this commit:
>>
>> commit a9ceb78bc75ca47972096372ff3d48648b16317a
>>
>> I verified the result by reverting
>> 9c4b2867ed7c8c8784dd417ffd16e705e81eb145 and
>> a9ceb78bc75ca47972096372ff3d48648b16317a from 4.5-rc5, the resulting
>> kernel does not have the bug.
...[cut]...
> So what does this have to do with these commits?
>
> Reverting the commits dramatically reduces, but does not eliminate,
> the frequency of the high CPU load long durations situation.
>
> Test results: Each test was 33 minutes, involving 9 incremental
> kernel compiles.
>
> Why an incremental kernel compile? Because it just so happens
> to demonstrate the issue well.
Why 9? Just to have a longer test time for better averaging.
>
> Kernel 1 = 4.5-rc5 + rjw v10 3 patch set. Called "rjwv10".
> Kernel 2 = kernel 1 + above 2 commits reverted. Called "reverted".
>
> Test 1: rjwv10 4056 occurrences
> Test 2: reverted 293 occurrences
> Test 3: rjwv10 7878 occurrences
> Test 4: reverted 259 occurrences
> Test 5: rjwv10 3708 occurrences
> Test 6: reverted 54 occurrences
>
> Average issue reduction ratio: 26 times better.
Turbostat was used for the following:
Test 7: reverted: Package Joules: 47830
Test 8: rjwv10: Package Joules: 54419 (revert saves 12.1% energy)
Test 9: reverted: Package Joules: 49326
Test 10: rjwv10: Package Joules: 55442 (revert saves 11% energy)
Test 11: reverted: acpi-cpufreq ondemand: Package Joules: 49146
Test 12: rjwv10: acpi-cpufreq ondemand: Package Joules: 56302 (revert saves 12.7% energy)
... Doug
next prev parent reply other threads:[~2016-03-01 19:28 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-20 8:49 PROBLEM: Cpufreq constantly keeps frequency at maximum on 4.5-rc4 Arto Jantunen
2016-02-20 16:31 ` Doug Smythies
2016-02-20 17:10 ` Arto Jantunen
2016-02-20 18:03 ` Chen, Yu C
2016-02-21 8:45 ` Arto Jantunen
2016-02-21 8:52 ` Chen, Yu C
2016-02-21 20:02 ` Srinivas Pandruvada
2016-02-21 20:33 ` Arto Jantunen
2016-02-22 6:16 ` Viresh Kumar
2016-02-22 16:39 ` Arto Jantunen
2016-02-22 16:41 ` Viresh Kumar
2016-02-22 16:48 ` Viresh Kumar
2016-02-22 19:25 ` Srinivas Pandruvada
2016-02-28 15:43 ` Arto Jantunen
2016-02-29 6:22 ` Doug Smythies
2016-03-01 19:28 ` Doug Smythies [this message]
2016-02-29 16:49 ` Srinivas Pandruvada
2016-03-01 0:37 ` Rafael J. Wysocki
[not found] ` <20160229201946.0bdcc48e@annuminas.surriel.com>
2016-03-01 7:06 ` Arto Jantunen
2016-03-01 16:59 ` Arto Jantunen
2016-03-01 19:22 ` Rik van Riel
2016-03-01 19:47 ` Arto Jantunen
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