Re: [Qemu-devel] Re: Irregular response times

[Mulyadi Santosa <mulyadi.santosa@gmail.com>]

On Sun, Jul 4, 2010 at 06:42, Pascal J. Bourguignon
<pjb@informatimago.com> wrote:
> pjb@informatimago.com (Pascal J. Bourguignon) writes:
>
>> I've got various Qemu running linux (gentoo or debian, all running the
>> same kernel).  On one of them,  I get very irregular response time.
>>
>> During a few seconds, it works normally.  Eg. thru a ssh connection, I
>> can type commands at bash, and I get the character echoed right away.
>> And then, for a few tens of seconds, it hangs, with no output and no
>> way to interrupt it or whatever.   The qemu process is in S state,
>> waiting in poll_s WCHAN.

Did you notice the qemu or kvm version? Also, is it happen in pure
qemu or qemu utilizing kvm? or both?

I somewhat "smell" buggy spurious interrupt handling..... try to set
your processor to use constant clock frequency.

And....few month ago, I learned quite funny tricks. Sometimes qemu/kvm
window hangs if I place it on different workspace other than my
current workspace in my GNOME desktop. Moving out focus from Qemu's
workspace somehow make it hang for few seconds (qemu-kvm 0.10.6). So,
the trick is, always place it on your current active workspace.

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com