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

From: Zhang Rui <rui.zhang@intel.com>
To: Pavel Machek <pavel@ucw.cz>,
	kernel list <linux-kernel@vger.kernel.org>,
	linux-acpi@vger.kernel.org, rjw@rjwysocki.net,
	viresh.kumar@linaro.org, linux-pm@vger.kernel.org,
	tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
	hpa@zytor.com, x86@kernel.org
Subject: Re: 5.2-rc2: low framerate in flightgear, cpu not running at full speed, thermal related?
Date: Sun, 09 Jun 2019 22:13:00 +0800	[thread overview]
Message-ID: <1560089580.2363.10.camel@intel.com> (raw)
In-Reply-To: <20190609121212.GA4520@amd>

On 日, 2019-06-09 at 14:12 +0200, 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:  +98.0°C  (high = +86.0°C, crit = +100.0°C)
> > > Core 0:        +98.0°C  (high = +86.0°C, crit = +100.0°C)
> > > Core 1:        +91.0°C  (high = +86.0°C, crit = +100.0°C)
> > > 
> > > 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.

what temperature does coretemp report?
can you please provide the sensors output in 4.6 during kernel
compiling?

can you attach the output of "grep . /sys/class/thermal/thermal*/*"
when the temperature goes high in both kernels?

thanks,
rui
> 
> 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.
> 
> Best regards,
> 									
> Pavel