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CPU Pegged - Cannot stop app

Posted: 7. May 2009, 17:53
by brawney
Host is Windows XP SP3. Host is an HP box running Pentium with 2gb ram.
VB 2.2.2 r46594
I have seen this problem with Windows 2003 Server guest as well as Fedora guests.
I'm somewhat new to VB.

For no apparent reason the CPU will run at 50% utilization and the guest box will freeze. I cannot kill the VB app thats running @ 50% using Task Manager. I've seen Fedora guests do this, as well as windows 2003 Server guests.

In both cases the guest box was not running a long running app or anything like that. I was just experimenting with this setup, trying to learn the Linux OS, etc.

I can't even shut down my host PC. That VB app won't stop so the PC won't shut down. I have to hold power button.

Any ideas what causes this kind of behavior?

Re: CPU Pegged - Cannot stop app

Posted: 7. May 2009, 18:10
by Perryg
How much RAM have you given to the guest?

Re: CPU Pegged - Cannot stop app

Posted: 7. May 2009, 23:24
by brawney
I give Fedora 768mb and Windows 2003 Server 1024mb.

Re: CPU Pegged - Cannot stop app

Posted: 7. May 2009, 23:43
by fixedwheel
I give Fedora 768mb and Windows 2003 Server 1024mb.
2048 - 768 - 1024 = 256

do you expect windows xp host to run well with 256MB?

Re: CPU Pegged - Cannot stop app

Posted: 8. May 2009, 00:44
by brawney
I wasn't running both guests at the same time. One guest at a time and this happened to me with each guest. All other guests are completely shut down, no snapshot, no hibernate, nothing like that. Dead cold.

Fedora : 2048 - 768 = 1280
Win 2003 Server : 2048 - 1024 = 1024

But that is still eating into memory a little. I'll try cutting it back and see if the problems continue.

I had used Virtual PC in the past but got tired of having so many issues with Linux in VPC, so I switched over to VB. I've never had any issued with Virtual PC giving a Windows Server 2003 guest 1024mb of memory on this same machine.

Re: CPU Pegged - Cannot stop app

Posted: 8. May 2009, 08:45
by fixedwheel
I wasn't running both guests at the same time.
ok, lack of host ram should not be the cause of your problem

as for the fedora guest, try with adding divider=10 to the linux kernel parms found in /boot/grub/menu.lst to avoid the 1000Hz kernel timer interrupt

Re: CPU Pegged - Cannot stop app

Posted: 14. May 2009, 10:12
by karthik
Hi,

I am very new to VB and Linux so pardon my ignorance. I'm running RHEL 5 guest on a Windows 2003 Host (T2500 @2.00Ghz 2 GB RAM). When the guest is idle its still eating up 1 core of the dual core CPU. I've tried setting processor affinity but that didn't work. I checked the param.h and the HZ was #defined as 100. Any help on this will be great.

Thanks

Re: CPU Pegged - Cannot stop app

Posted: 14. May 2009, 10:43
by fixedwheel
karthik wrote:checked the param.h and the HZ was #defined as 100.
what HZ and param.h?

Code: Select all

grep CONFIG_HZ /boot/config-$(uname -r)
if you dont want to recompile a RHEL or Centos or fedora 1000hz kernel then add divider=10 to the kernel parms, as i already wrote

example cut-n-paste from a Centos 4.7 /boot/grub/menu.lst alias of grub.conf:

Code: Select all

title CentOS (2.6.9-78.0.13.EL)
        root (hd0,0)
        kernel /boot/vmlinuz-2.6.9-78.0.13.EL ro root=LABEL=/ rhgb quiet divider=10
        initrd /boot/initrd-2.6.9-78.0.13.EL.img
HTH

Re: CPU Pegged - Cannot stop app

Posted: 3. Jun 2009, 10:51
by karthik
Hi,

Apologies for the delayed response. Thanks a lot it worked.

Thanks again.

Best Regards
Karthik