[ubuntu-studio-devel] check-in and reminder release candidate on April 6th

Ralf Mardorf ralf.mardorf at alice-dsl.net
Sat Apr 1 19:43:21 UTC 2017

On Fri, 31 Mar 2017 15:27:15 -0700 (PDT), Len Ovens wrote:
>On Fri, 31 Mar 2017, Ross Gammon wrote:
>> On 03/31/2017 10:50 PM, Ralf Mardorf wrote:  
>>> VitualBox emulates a CPU, by using the real CPU. The guest is not
>>> able to change settings of host and I could imagine there's no
>>> simulated CPU frequency scaling available.  
>> Makes sense! Hopefully Len can confirm all is OK on real hardware.  
>Ross, the package you have in testing performs to the extent of 
>development at that time. That is performance is only during the
>current session and will reset at boot.
>we do not install cpufrequtils at this time either. The new -controls
>will depend on it for booting in the governor mode the session was at
>session end. (so if I upload a new version without that in depends I
>made a mistake)

Apart from this,

it would be good to know how VMs or at least VBox handles CPU frequency
scaling settings of the virtual/guests environment.

To be honest, I simply could restore any of my current Ubuntu or
Arch Linux Backups in at least VBox (other VMs are to complicated), but
at the moment I dislike to do this ;).

The crux here is that virtualisation vs real hardware. Theoretically
for the guest there could be a virtual CPU frequency scaling, OTOH it
doesn't make much sense to emulate this, given that VMs likely relay
on CPU features for virtualisation. OTOH if the virtual CPU should be
a very old CPU, then a gov set to performance likely would be slower
than the slowest possible governor for a modern AMD or Intel CPU of
the host. I doubt that VM hosts "play" with this, since here are already
enough problems VM developers have to fight, so I doubt that something
quasi useless, like a CPU freq gov for guests is available.

I try to remember this and will test it, if I have nothing better to
do ;).


"Michael" described Floyd as "an idiot savant", and added, "Give him
any two numbers, and he can multiply them in his head, just like that."
Homer, testing Floyd, said, "Five times nine", and Floyd instantly
responded "Forty-five", which impressed Homer.

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