[wplug] Fedora 19, KVM, screensavers, and thermal shutdowns....

[Pat Barron]

This particular VM is set up with 1 core and 2 gig of RAM (out of 8 gig 
in the laptop).  When this happens, the VM is literally doing nothing 
other than running the screensaver.

This just started happening yesterday.  Up until now, I've had the VM 
running for hours (even sitting in the screensaver) without getting the 
"thermal emergency" shutdown.  I still have the previous kernel on the 
machine and may go back to it for a while, to see if maybe there was a 
change with power management, or something like that.  Of course, I 
haven't ruled out a hardware failure, such as a faulty fan (I mean, the 
fan seems to be running, but I really don't know if it's running 
properly and/or at the right speed, moving enough air, etc.), or a heat 
sink issue as you suggest.

--Pat.

On 1/22/2014 9:58 PM, Justin Smith wrote:
> I can tell you without a doubt that those temperatures are, in fact, degrees Celsius.
> Call it overclocker's intuition. Honestly, I'm surprised that your laptop got that hot...I've
> only ever seen temperatures like that from overclocking torture tools like Furmark.
>
> How many cores did you give the Fedora 20 virtual machine? If you're anything like
> me, you'd give it a single core and maybe a gig of RAM. That shouldn't be enough to
> drive your CPU to thermal shutdown.
>
> I know that laptops, by nature, don't have the best cooling, but you shouldn't be
> seeing temperatures approaching 90 under a full load. You should have fresh  thermal
> paste applied to your laptop's heatsink.
>
> --
> *Justin Smith*
>
> "UNIX is basically a simple operating system, but you have to be a genius to
> understand the simplicity."
> -Dennis Ritchie
>
>
>> So, this happened to me twice today on my ThinkPad T400:
>>
>> 1)  Boot Fedora 19.
>> 2)  Start Fedora 20 as a KVM guest.
>> 3)  KVM guest goes into screensaver.
>> 4)  Fedora 19 KVM host executes "thermal emergency" shutdown shortly
>> thereafter.
>>
>> I've been running a loop that looks at the thermal sensors (just cat'ing
>> /proc/acpi/ibm/thermal every 60 seconds); I don't know if the values
>> listed for the temperatures are degrees Celsius, or just some arbitrary
>> numbers, or whatever.  But whatever they are, the temperature of the
>> first sensor value reported was pretty stable around 47 for a long time,
>> even with the KVM guest running.  Then as soon as the screensaver kicked
>> in, the value shot up to 73 within sixty seconds.  Then 78, 81. 83. 85,
>> 87, and 88, in sixty second increments thereafter.  The value of the
>> third sensor reported was also going up, but not as high, and not as fast.
>>
>> As soon as I brought it out of screensaver (which I did because I didn't
>> want it to keep heating up), the first sensor went back down to 72
>> within sixty seconds.
>>
>> I'm assuming that the screensaver graphics are highly CPU-bound, and
>> working the CPU so hard is what's making the temperature shoot up. But
>> I've never seen this behavior (with the spontaneous "thermal emergency"
>> shutdowns) before today.  This is just after running "yum update" and
>> updating to kernel-3.12.8-200.fc19.x86_64, though this may just be a
>> coincidence.
>>
>> Anyone ever see anything like this before?
>>
>> --Pat.
>>
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