Re: [Qemu-devel] virtual machine halting and loosing connections

["Kyle Hubert" <khubert@gmail.com>]

On 3/28/07, WaxDragon <waxdragon@gmail.com> wrote:
> On 3/27/07, Kyle Hubert <khubert@gmail.com> wrote:
>
> > Also, I have noticed that when using the ondemand governor for the
> > host OS (AMD PowerNow) that QEMU doesn't register for some reason. My
> > host CPU stays running at 1GHz, when it is capable of 2.6GHz. I can
> > run anything on the host OS, and I see the cpu freq jump up, so it
> > works on the host OS. I believe this may have something to do with
> > kqemu's acceleration.
>
> I have seen the same behavior with cpufreq, but I run the
> 'conservative' governor on my AMD.  Haven't decided if it's a bug or a
> feature yet. ;0)

I was running ondemand, and I came to the conclusion it's a bug. If
you see this paper:

http://linux.inet.hr/ols2006_the_ondemand_governor.html

You'll see that the ondemand governor policy is based on the idle/busy
statistics from scheduler ticks. I believe that kqemu runs off of
ioctl's from /dev/kqemu, and perhaps the system call doesn't
accurately change this?

How do the processes run in kqemu? Is it a kernel thread? Section 7.3
in that PDF talks of real time threads affecting the ondemand
scheduler.

NOTE: conservative is a fork of ondemand, so it applies here.

I'll try running without kqemu, and see if I still have the problem.

-Kyle