ksoftirqd Using 20-25% of CPU with only GUI running

Discussions related to using VirtualBox on Linux hosts.
poet_imp
Posts: 3
Joined: 7. Aug 2007, 20:10

ksoftirqd Using 20-25% of CPU with only GUI running

Post by poet_imp »

When I start VirtualBox, before I even think of starting a virtual machine, I look at system utilization and notice ksoftirqd using a very significant portion of my box; usually 20-25%.

Here is what I see in top:

Code: Select all

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
    7 root      15  -5     0    0    0 S   21  0.0   0:11.80 ksoftirqd/1
Is this a known issue? Is there something I can do to make it not do this?

$ uname -a
Linux xxx.xxx.com 2.6.22.1-41.fc7 #1 SMP Fri Jul 27 18:10:34 EDT 2007 i686 i686 i386 GNU/Linux

$ rpm -qa | grep -i virt
VirtualBox-1.4.0_21864_fedora7-1

$ sudo /usr/bin/smoltSendProfile
<snip>
Platform: i686
BogoMIPS: 6403.40
CPU Vendor: GenuineIntel
CPU Model: Intel(R) Pentium(R) 4 CPU 3.20GHz
Number of CPUs: 2
CPU Speed: 3199
System Memory: 2026
System Swap: 1983
Vendor: BUYMPC
System:
Form factor: unknown
Kernel: 2.6.22.1-41.fc7
<snip>
poet_imp
Posts: 3
Joined: 7. Aug 2007, 20:10

Am I the only one?

Post by poet_imp »

Interesting... I was hoping for at least a "I am noticing the same things... " post. Am I the only one seeing this?
vor
Posts: 2
Joined: 19. Aug 2007, 23:56

Post by vor »

I was seeing this too using a 2.6.22 kernel and VirtualBox from svn. Just starting the VirtualBox gui was causing the problem even if no VM's were running. Getting the latest bits from svn today made the problem go away so it would seem the problem will be fixed with the new version of VirtualBox.
vor
Posts: 2
Joined: 19. Aug 2007, 23:56

Post by vor »

Actually, I take that back. It appeared to be fixed but then I realized I didn't have the kernel module loaded. Once the kernel module is loaded, it still uses the 20% CPU while idle even with the latest bits from svn.
c0nv1ct
Posts: 2
Joined: 19. Aug 2007, 20:07

Post by c0nv1ct »

Same issue here, seems to have started around the time i upgraded my kernel to 2.6.22. I get 2 processes, ksoftirqd/0 and ksoftirqd/1, both using 10-20% cpu. I'm using vbox 1.4.0 though, havent tried svn version yet.
c0nv1ct
Posts: 2
Joined: 19. Aug 2007, 20:07

Post by c0nv1ct »

Problem still exists in 1.5.0 OSE :(
frank
Oracle Corporation
Posts: 3362
Joined: 7. Jun 2007, 09:11
Primary OS: Debian Sid
VBox Version: PUEL
Guest OSses: Linux, Windows
Location: Dresden, Germany
Contact:

Post by frank »

Please could you attach your kernel configuration?

Thanks,

Frank
frank
Oracle Corporation
Posts: 3362
Joined: 7. Jun 2007, 09:11
Primary OS: Debian Sid
VBox Version: PUEL
Guest OSses: Linux, Windows
Location: Dresden, Germany
Contact:

Post by frank »

Please could you try to boot with the
nohz=off
Linux kernel command line parameter?
nc42
Posts: 3
Joined: 10. Sep 2007, 04:25

Post by nc42 »

What does nohz=no do? It seems to work
frank
Oracle Corporation
Posts: 3362
Joined: 7. Jun 2007, 09:11
Primary OS: Debian Sid
VBox Version: PUEL
Guest OSses: Linux, Windows
Location: Dresden, Germany
Contact:

Post by frank »

This option prevents the host Linux to enter the tickless mode. In this mode the kernel timer is programmed in one-shot mode, contrary to the periodic mode which is normally used. VirtualBox currently does not play well with host kernels in one-shot mode. We are working on a solution. Until we fixed it, use this option to restore the old behavior.
thripsi
Posts: 1
Joined: 9. Nov 2007, 11:52

Kubuntu 7.10 gutsy

Post by thripsi »

I had the same problem with ksoftirqd on (k)ubuntu 7.10
(linux 2.6.22-14-generic, VirtualBox 1.5.0 OSE).
The boot option "nohz=off" did solve the problem .
Pépou
Posts: 5
Joined: 9. Jan 2008, 21:36

Post by Pépou »

Frank Mehnert wrote:Please could you try to boot with the
nohz=off
Linux kernel command line parameter?
Sorry but I've got the CPU problem too. Where can we change the kernel configuration ??

Thank you. My guest is ubuntu gusty.
frank
Oracle Corporation
Posts: 3362
Joined: 7. Jun 2007, 09:11
Primary OS: Debian Sid
VBox Version: PUEL
Guest OSses: Linux, Windows
Location: Dresden, Germany
Contact:

Post by frank »

The guest is not relevant, only the host in that case.
Pépou
Posts: 5
Joined: 9. Jan 2008, 21:36

Post by Pépou »

Sorry I confused myself. My host is ubuntu gusty, and my guest is windows XP.. So I need to do this modification !

Thank you in advance for your help.
Ingo
Volunteer
Posts: 731
Joined: 22. Aug 2007, 10:13
Location: Germany

Post by Ingo »

In / boot/grub/menu.list for bootloader grub or in /etc/lilo.conf for bootloader lilo.
The simplest way to a complex system is to start with a simple system.
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