Re: v4.8-rc1: thinkpad x60: running at low frequency even during kernel build

From: Pavel Machek
Date: Fri Nov 04 2016 - 18:16:22 EST


Hi!

> I'd prefer mails over bugzilla for now...
>
> 4.9-rc2 has bios_limit:
>
> pavel@duo:~$ cat /sys/devices/system/cpu/cpu0/cpufreq/bios_limit
> 1833000
>
> and it has thermal zones:
>
> /sys/devices/virtual/thermal/thermal_zone0/trip_point_0_temp 127000
> /sys/devices/virtual/thermal/thermal_zone0/trip_point_0_type critical
> /sys/devices/virtual/thermal/thermal_zone1/trip_point_0_temp 97000
> /sys/devices/virtual/thermal/thermal_zone1/trip_point_0_type critical
> /sys/devices/virtual/thermal/thermal_zone1/trip_point_1_temp 92500
> /sys/devices/virtual/thermal/thermal_zone1/trip_point_1_type passive
>
> ..so it should slow down CPU at 92C.
>
> So lets push the temperature up a bit...
>
> sudo watch cat /proc/acpi/ibm/thermal
> /sys/devices/system/cpu/cpu0/cpufreq/bios_limit
> /sys/devices/virtual/thermal/thermal_zone1/temp /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
>
> temperatures: 98 49 -128 85 28 -128 28 -128 49 58 -128 -128 -128
> -128 -128 -128
> 1833000
> 95000
> 1833000
>
> Hmm. bios_limit does not seem to change, even when the temperature is
> clearly above the trip point. (It is also interestng that acpi/ibm
> reports bigger temperatures than
> /sys/devices/virtual/thermal/thermal_zone1/temp . I have seen 103C
> there.)

Under v4.8-rc, behaviour is different: bios_limit goes to 1GHz there
when temperature is around 84C at the thermal zone. That keeps
ibm/thermal temperatures under 90C, and no "thermal emergency"
messages in syslog.

So we seem to have thermal or ACPI regression in v4.9-rc3.

Best regards,

Pavel

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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