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[REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device correctly") causes performance drop

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  [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device  correctly") causes performance drop Laura Abbott <labbott@redhat.com> - 2016-03-16 23:30 +0100
    Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone  device correctly") causes performance drop Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-16 23:50 +0100
      Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone  device correctly") causes performance drop Laura Abbott <labbott@redhat.com> - 2016-03-17 01:10 +0100
        Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone  device correctly") causes performance drop Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-17 01:20 +0100
        Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone  device correctly") causes performance drop "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> - 2016-03-17 01:30 +0100
    RE: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone  device correctly") causes performance drop "Zhang, Rui" <rui.zhang@intel.com> - 2016-03-17 01:20 +0100

#1359402 — [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device correctly") causes performance drop

Hi,

Fedora received a bug report (https://bugzilla.redhat.com/show_bug.cgi?id=1317190)
of a major performance drop on various bench marks and general system
sluggishness with the 4.4.4 kernel update. The benchmarks were showing
a reduction to about 18% performance (not minor).

Bisection showed the first bad commit was

commit 774ac8b7eff69e0786970157de2157e68b22f456
Author: Zhang Rui <rui.zhang@intel.com>
Date:   Fri Oct 30 16:31:47 2015 +0800

     Thermal: initialize thermal zone device correctly
     
     commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream.
     
     After thermal zone device registered, as we have not read any
     temperature before, thus tz->temperature should not be 0,
     which actually means 0C, and thermal trend is not available.
     In this case, we need specially handling for the first
     thermal_zone_device_update().
     
     Both thermal core framework and step_wise governor is
     enhanced to handle this. And since the step_wise governor
     is the only one that uses trends, so it's the only thermal
     governor that needs to be updated.
     
     Tested-by: Manuel Krause <manuelkrause@netscape.net>
     Tested-by: szegad <szegadlo@poczta.onet.pl>
     Tested-by: prash <prash.n.rao@gmail.com>
     Tested-by: amish <ammdispose-arch@yahoo.com>
     Tested-by: Matthias <morpheusxyz123@yahoo.de>
     Reviewed-by: Javi Merino <javi.merino@arm.com>
     Signed-off-by: Zhang Rui <rui.zhang@intel.com>
     Signed-off-by: Chen Yu <yu.c.chen@intel.com>
     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>



Reverting this plus to other commits in the series (a67208e94d94
"Thermal: handle thermal zone device properly during system sleep"
and 27f356149d59 "Thermal: do thermal zone update after a cooling
device registered") confirmed the performance was back to normal.

Bugzilla has the full discussion but this comment from one of the
reporters sums it up:

"In 4.4.3 and prior, my 2.40 MHz processor would fluctuate between
1000 and 3400 MHz.  In 4.4.4, the processor would fluctuate between
400 and 700 MHz, according to /proc/cpuinfo.

Setting /sys/devices/system/cpu/cpufreq/policy0/scaling_governor to
performance, instead of the default "powersave" forces the CPU to
2400 MHz, and improves performance greatly, but still not to the
same level as in 4.4.3."

Any ideas?

Thanks,
Laura

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#1359430 — Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device correctly") causes performance drop

On Wed, Mar 16, 2016 at 03:27:57PM -0700, Laura Abbott wrote:
> Hi,
> 
> Fedora received a bug report (https://bugzilla.redhat.com/show_bug.cgi?id=1317190)
> of a major performance drop on various bench marks and general system
> sluggishness with the 4.4.4 kernel update. The benchmarks were showing
> a reduction to about 18% performance (not minor).
> 
> Bisection showed the first bad commit was
> 
> commit 774ac8b7eff69e0786970157de2157e68b22f456
> Author: Zhang Rui <rui.zhang@intel.com>
> Date:   Fri Oct 30 16:31:47 2015 +0800
> 
>     Thermal: initialize thermal zone device correctly
>     commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream.
>     After thermal zone device registered, as we have not read any
>     temperature before, thus tz->temperature should not be 0,
>     which actually means 0C, and thermal trend is not available.
>     In this case, we need specially handling for the first
>     thermal_zone_device_update().
>     Both thermal core framework and step_wise governor is
>     enhanced to handle this. And since the step_wise governor
>     is the only one that uses trends, so it's the only thermal
>     governor that needs to be updated.
>     Tested-by: Manuel Krause <manuelkrause@netscape.net>
>     Tested-by: szegad <szegadlo@poczta.onet.pl>
>     Tested-by: prash <prash.n.rao@gmail.com>
>     Tested-by: amish <ammdispose-arch@yahoo.com>
>     Tested-by: Matthias <morpheusxyz123@yahoo.de>
>     Reviewed-by: Javi Merino <javi.merino@arm.com>
>     Signed-off-by: Zhang Rui <rui.zhang@intel.com>
>     Signed-off-by: Chen Yu <yu.c.chen@intel.com>
>     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> 
> 
> Reverting this plus to other commits in the series (a67208e94d94
> "Thermal: handle thermal zone device properly during system sleep"
> and 27f356149d59 "Thermal: do thermal zone update after a cooling
> device registered") confirmed the performance was back to normal.
> 
> Bugzilla has the full discussion but this comment from one of the
> reporters sums it up:
> 
> "In 4.4.3 and prior, my 2.40 MHz processor would fluctuate between
> 1000 and 3400 MHz.  In 4.4.4, the processor would fluctuate between
> 400 and 700 MHz, according to /proc/cpuinfo.
> 
> Setting /sys/devices/system/cpu/cpufreq/policy0/scaling_governor to
> performance, instead of the default "powersave" forces the CPU to
> 2400 MHz, and improves performance greatly, but still not to the
> same level as in 4.4.3."
> 
> Any ideas?

Is this same "slowdown" also seen in 4.5?

thanks,

greg k-h

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#1359478 — Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device correctly") causes performance drop

On 03/16/2016 03:46 PM, Greg Kroah-Hartman wrote:
> On Wed, Mar 16, 2016 at 03:27:57PM -0700, Laura Abbott wrote:
>> Hi,
>>
>> Fedora received a bug report (https://bugzilla.redhat.com/show_bug.cgi?id=1317190)
>> of a major performance drop on various bench marks and general system
>> sluggishness with the 4.4.4 kernel update. The benchmarks were showing
>> a reduction to about 18% performance (not minor).
>>
>> Bisection showed the first bad commit was
>>
>> commit 774ac8b7eff69e0786970157de2157e68b22f456
>> Author: Zhang Rui <rui.zhang@intel.com>
>> Date:   Fri Oct 30 16:31:47 2015 +0800
>>
>>      Thermal: initialize thermal zone device correctly
>>      commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream.
>>      After thermal zone device registered, as we have not read any
>>      temperature before, thus tz->temperature should not be 0,
>>      which actually means 0C, and thermal trend is not available.
>>      In this case, we need specially handling for the first
>>      thermal_zone_device_update().
>>      Both thermal core framework and step_wise governor is
>>      enhanced to handle this. And since the step_wise governor
>>      is the only one that uses trends, so it's the only thermal
>>      governor that needs to be updated.
>>      Tested-by: Manuel Krause <manuelkrause@netscape.net>
>>      Tested-by: szegad <szegadlo@poczta.onet.pl>
>>      Tested-by: prash <prash.n.rao@gmail.com>
>>      Tested-by: amish <ammdispose-arch@yahoo.com>
>>      Tested-by: Matthias <morpheusxyz123@yahoo.de>
>>      Reviewed-by: Javi Merino <javi.merino@arm.com>
>>      Signed-off-by: Zhang Rui <rui.zhang@intel.com>
>>      Signed-off-by: Chen Yu <yu.c.chen@intel.com>
>>      Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>
>>
>>
>> Reverting this plus to other commits in the series (a67208e94d94
>> "Thermal: handle thermal zone device properly during system sleep"
>> and 27f356149d59 "Thermal: do thermal zone update after a cooling
>> device registered") confirmed the performance was back to normal.
>>
>> Bugzilla has the full discussion but this comment from one of the
>> reporters sums it up:
>>
>> "In 4.4.3 and prior, my 2.40 MHz processor would fluctuate between
>> 1000 and 3400 MHz.  In 4.4.4, the processor would fluctuate between
>> 400 and 700 MHz, according to /proc/cpuinfo.
>>
>> Setting /sys/devices/system/cpu/cpufreq/policy0/scaling_governor to
>> performance, instead of the default "powersave" forces the CPU to
>> 2400 MHz, and improves performance greatly, but still not to the
>> same level as in 4.4.3."
>>
>> Any ideas?
>
> Is this same "slowdown" also seen in 4.5?
>
> thanks,
>
> greg k-h
>

Yes, the same issue is seen on 4.5 according to the reporter.

Thanks,
Laura

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#1359482 — Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device correctly") causes performance drop

On Wed, Mar 16, 2016 at 05:00:07PM -0700, Laura Abbott wrote:
> On 03/16/2016 03:46 PM, Greg Kroah-Hartman wrote:
> >On Wed, Mar 16, 2016 at 03:27:57PM -0700, Laura Abbott wrote:
> >>Hi,
> >>
> >>Fedora received a bug report (https://bugzilla.redhat.com/show_bug.cgi?id=1317190)
> >>of a major performance drop on various bench marks and general system
> >>sluggishness with the 4.4.4 kernel update. The benchmarks were showing
> >>a reduction to about 18% performance (not minor).
> >>
> >>Bisection showed the first bad commit was
> >>
> >>commit 774ac8b7eff69e0786970157de2157e68b22f456
> >>Author: Zhang Rui <rui.zhang@intel.com>
> >>Date:   Fri Oct 30 16:31:47 2015 +0800
> >>
> >>     Thermal: initialize thermal zone device correctly
> >>     commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream.
> >>     After thermal zone device registered, as we have not read any
> >>     temperature before, thus tz->temperature should not be 0,
> >>     which actually means 0C, and thermal trend is not available.
> >>     In this case, we need specially handling for the first
> >>     thermal_zone_device_update().
> >>     Both thermal core framework and step_wise governor is
> >>     enhanced to handle this. And since the step_wise governor
> >>     is the only one that uses trends, so it's the only thermal
> >>     governor that needs to be updated.
> >>     Tested-by: Manuel Krause <manuelkrause@netscape.net>
> >>     Tested-by: szegad <szegadlo@poczta.onet.pl>
> >>     Tested-by: prash <prash.n.rao@gmail.com>
> >>     Tested-by: amish <ammdispose-arch@yahoo.com>
> >>     Tested-by: Matthias <morpheusxyz123@yahoo.de>
> >>     Reviewed-by: Javi Merino <javi.merino@arm.com>
> >>     Signed-off-by: Zhang Rui <rui.zhang@intel.com>
> >>     Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> >>     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> >>
> >>
> >>
> >>Reverting this plus to other commits in the series (a67208e94d94
> >>"Thermal: handle thermal zone device properly during system sleep"
> >>and 27f356149d59 "Thermal: do thermal zone update after a cooling
> >>device registered") confirmed the performance was back to normal.
> >>
> >>Bugzilla has the full discussion but this comment from one of the
> >>reporters sums it up:
> >>
> >>"In 4.4.3 and prior, my 2.40 MHz processor would fluctuate between
> >>1000 and 3400 MHz.  In 4.4.4, the processor would fluctuate between
> >>400 and 700 MHz, according to /proc/cpuinfo.
> >>
> >>Setting /sys/devices/system/cpu/cpufreq/policy0/scaling_governor to
> >>performance, instead of the default "powersave" forces the CPU to
> >>2400 MHz, and improves performance greatly, but still not to the
> >>same level as in 4.4.3."
> >>
> >>Any ideas?
> >
> >Is this same "slowdown" also seen in 4.5?
> >
> >thanks,
> >
> >greg k-h
> >
> 
> Yes, the same issue is seen on 4.5 according to the reporter.

Great, we are "bug compatible" :)

Can you please work to get this resolved in Linus's tree and then we can
backport the needed changes into the 4.4-stable release.

Zhang, any ideas here?

thanks,

greg k-h

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#1359486 — Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device correctly") causes performance drop

On Wed, 2016-03-16 at 17:00 -0700, Laura Abbott wrote:
> On 03/16/2016 03:46 PM, Greg Kroah-Hartman wrote:
> > On Wed, Mar 16, 2016 at 03:27:57PM -0700, Laura Abbott wrote:
> > > Hi,
> > > 
> > > Fedora received a bug report (https://bugzilla.redhat.com/show_bu
> > > g.cgi?id=1317190)
> > > of a major performance drop on various bench marks and general
> > > system
> > > sluggishness with the 4.4.4 kernel update. The benchmarks were
> > > showing
> > > a reduction to about 18% performance (not minor).
> > > 
> > > Bisection showed the first bad commit was
> > > 
> > > commit 774ac8b7eff69e0786970157de2157e68b22f456
> > > Author: Zhang Rui <rui.zhang@intel.com>
> > > Date:   Fri Oct 30 16:31:47 2015 +0800
> > > 
> > >      Thermal: initialize thermal zone device correctly
> > >      commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream.
> > >      After thermal zone device registered, as we have not read
> > > any
> > >      temperature before, thus tz->temperature should not be 0,
> > >      which actually means 0C, and thermal trend is not available.
> > >      In this case, we need specially handling for the first
> > >      thermal_zone_device_update().
> > >      Both thermal core framework and step_wise governor is
> > >      enhanced to handle this. And since the step_wise governor
> > >      is the only one that uses trends, so it's the only thermal
> > >      governor that needs to be updated.
> > >      Tested-by: Manuel Krause <manuelkrause@netscape.net>
> > >      Tested-by: szegad <szegadlo@poczta.onet.pl>
> > >      Tested-by: prash <prash.n.rao@gmail.com>
> > >      Tested-by: amish <ammdispose-arch@yahoo.com>
> > >      Tested-by: Matthias <morpheusxyz123@yahoo.de>
> > >      Reviewed-by: Javi Merino <javi.merino@arm.com>
> > >      Signed-off-by: Zhang Rui <rui.zhang@intel.com>
> > >      Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> > >      Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.or
> > > g>
> > > 
> > > 
> > > 
> > > Reverting this plus to other commits in the series (a67208e94d94
> > > "Thermal: handle thermal zone device properly during system
> > > sleep"
> > > and 27f356149d59 "Thermal: do thermal zone update after a cooling
> > > device registered") confirmed the performance was back to normal.
> > > 
> > > Bugzilla has the full discussion but this comment from one of the
> > > reporters sums it up:
> > > 
> > > "In 4.4.3 and prior, my 2.40 MHz processor would fluctuate
> > > between
> > > 1000 and 3400 MHz.  In 4.4.4, the processor would fluctuate
> > > between
> > > 400 and 700 MHz, according to /proc/cpuinfo.
> > > 
> > > Setting /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
> > > to
> > > performance, instead of the default "powersave" forces the CPU to
> > > 2400 MHz, and improves performance greatly, but still not to the
> > > same level as in 4.4.3."
> > > 
> > > Any ideas?
> > 
> > Is this same "slowdown" also seen in 4.5?
> > 
> > thanks,
> > 
> > greg k-h
> > 
> 
> Yes, the same issue is seen on 4.5 according to the reporter.
What does it show here when performance drops?
grep . /sys/devices/system/cpu/intel_pstate/*

Is the problem still occurs if you set 
/sys/class/thermal/thermal_zone*/mode to "disabled" 

Thanks,
Srinivas

> 
> Thanks,
> Laura
> --
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> the body of a message to majordomo@vger.kernel.org
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#1359481 — RE: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device correctly") causes performance drop

Can you send me the output of "grep . /sys/class/thermal/*/*" both w/ and w/o the broken patch series?

Thanks,
rui

> -----Original Message-----
> From: Laura Abbott [mailto:labbott@redhat.com]
> Sent: Thursday, March 17, 2016 6:28 AM
> To: Zhang, Rui <rui.zhang@intel.com>; Javi Merino <javi.merino@arm.com>;
> Chen, Yu C <yu.c.chen@intel.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Manuel Krause
> <manuelkrause@netscape.net>; szegad <szegadlo@poczta.onet.pl>; prash
> <prash.n.rao@gmail.com>; amish <ammdispose-arch@yahoo.com>; Matthias
> <morpheusxyz123@yahoo.de>; linux-pm@vger.kernel.org; Linux Kernel
> Mailing List <linux-kernel@vger.kernel.org>
> Subject: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device
> correctly") causes performance drop
> Importance: High
> 
> Hi,
> 
> Fedora received a bug report
> (https://bugzilla.redhat.com/show_bug.cgi?id=1317190)
> of a major performance drop on various bench marks and general system
> sluggishness with the 4.4.4 kernel update. The benchmarks were showing a
> reduction to about 18% performance (not minor).
> 
> Bisection showed the first bad commit was
> 
> commit 774ac8b7eff69e0786970157de2157e68b22f456
> Author: Zhang Rui <rui.zhang@intel.com>
> Date:   Fri Oct 30 16:31:47 2015 +0800
> 
>      Thermal: initialize thermal zone device correctly
> 
>      commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream.
> 
>      After thermal zone device registered, as we have not read any
>      temperature before, thus tz->temperature should not be 0,
>      which actually means 0C, and thermal trend is not available.
>      In this case, we need specially handling for the first
>      thermal_zone_device_update().
> 
>      Both thermal core framework and step_wise governor is
>      enhanced to handle this. And since the step_wise governor
>      is the only one that uses trends, so it's the only thermal
>      governor that needs to be updated.
> 
>      Tested-by: Manuel Krause <manuelkrause@netscape.net>
>      Tested-by: szegad <szegadlo@poczta.onet.pl>
>      Tested-by: prash <prash.n.rao@gmail.com>
>      Tested-by: amish <ammdispose-arch@yahoo.com>
>      Tested-by: Matthias <morpheusxyz123@yahoo.de>
>      Reviewed-by: Javi Merino <javi.merino@arm.com>
>      Signed-off-by: Zhang Rui <rui.zhang@intel.com>
>      Signed-off-by: Chen Yu <yu.c.chen@intel.com>
>      Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> 
> 
> Reverting this plus to other commits in the series (a67208e94d94
> "Thermal: handle thermal zone device properly during system sleep"
> and 27f356149d59 "Thermal: do thermal zone update after a cooling device
> registered") confirmed the performance was back to normal.
> 
> Bugzilla has the full discussion but this comment from one of the reporters
> sums it up:
> 
> "In 4.4.3 and prior, my 2.40 MHz processor would fluctuate between
> 1000 and 3400 MHz.  In 4.4.4, the processor would fluctuate between
> 400 and 700 MHz, according to /proc/cpuinfo.
> 
> Setting /sys/devices/system/cpu/cpufreq/policy0/scaling_governor to
> performance, instead of the default "powersave" forces the CPU to
> 2400 MHz, and improves performance greatly, but still not to the same level
> as in 4.4.3."
> 
> Any ideas?
> 
> Thanks,
> Laura

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