Re: 5.2-rc2: low framerate in flightgear, cpu not running at full speed, thermal related?

[Daniel Lezcano]

On 09/06/2019 14:12, Pavel Machek wrote:
> Hi!
> 
>>> When I start flightgear, I get framerates around 20 fps and cpu at
>>> 3GHz:
>>>
>>> pavel@duo:~/bt$ cat /proc/cpuinfo  | grep MHz
>>> cpu MHz		    : 3027.471
>>> cpu MHz		      : 2981.863
>>> cpu MHz		      	: 2958.352
>>> cpu MHz			  : 2864.001
>>> pavel@duo:~/bt$
>>>
>>> (Ok, fgfs is really only running at single core, so why do both cores
>>> run at 3GHz?)
>>>
>>> But temperatures get quite high:
>>>
>>> pavel@duo:~/bt$ sensors
>>> thinkpad-isa-0000
>>> Adapter: ISA adapter
>>> fan1:        4485 RPM
>>>
>>> coretemp-isa-0000
>>> Adapter: ISA adapter
>>> Package id 0:  +98.0ÂC  (high = +86.0ÂC, crit = +100.0ÂC)
>>> Core 0:        +98.0ÂC  (high = +86.0ÂC, crit = +100.0ÂC)
>>> Core 1:        +91.0ÂC  (high = +86.0ÂC, crit = +100.0ÂC)
>>>
>>> And soon cpu goes to 1.5GHz range, with framerates going down to
>>> 12fps. That's a bit low.
>>>
>>> Room temperature is 26Celsius.
>>>
>>> The CPU is Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz . I guess it means
>>> it should be able to sustain both cores running at 2.5GHz?
>>>
>>> Any ideas? Were there any recent changes in that area?
>>
>> I tried kernel compile. It keeps both cores at 3GHz, temperature goes
>> up over 95C, and then cpus start going down to 2.3GHz... and then down
>> to 2GHz... and down to 1.9GHz.
>>
>> watch bash -c 'sensors;  cat /proc/cpuinfo | grep MHz'
> 
> Situation is very different with v4.6 distro based kernel.
> 
> CPU MHz is only getting values round to 100MHz. It does not go above
> 2.5GHz, but it does not go below 2.5GHz under the load, either.
> 
> ACPI adapter appears in sensors output.
> 
> Now I tried going to 5.2-rc4. It behaves the same as 5.2-rc2. Goes up
> to 3GHz briefly but then down to 2.0GHz and below under load.
> 
> Ideas welcome.

What is the cpufreq governor for v4.6 and v5.2-rc4?



-- 
 <http://www.linaro.org/> Linaro.org â Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

Attachment: signature.asc
Description: OpenPGP digital signature