Arch under VirtualBox and Strange CPU load report

jarhead70 · 2012-06-09 04:55:02

Hi,

First of all, I don't know if this is the right forum to post this question, but here goes.

I just finished installing LXDE on Arch, as VirtualBox guest. The default LXDE install run a CPU load applet, which almost always shows full CPU load (all green). At first, I thought it was caused by NetworkManager, hence my post in the App and DE forum. However, upon more investigation I became skeptical.

What I found is after the 1st boot after starting the VM from VirtualBox, the CPU load is normal (below 5% when idle, as reported by atop/htop). Booting the VM after that and the CPU load will almost always stay at 100%, regardless if I start X/LXDE or not, or just login and immediately reboot. Almost always, cos there's instances where after rebooting CPU load stays normal, but most often that's not the case. Shutting down the VM and restarting it will restart the cycle.

My question is: is this one of the quirk of installing Arch as VBox guest? As headkase noted on another thread, Arch under VBox will randomly crash (which I also experience). Is the full CPU load after reboot also a "VBox thing"? Curiously the system is not unresponsive as it is with systems under full CPU load.

Thanks

headkase · 2012-06-09 04:58:46

It's worth noting that when I stated that Arch under VirtualBox crashes that VirtualBox was running in a Windows 7 64-bit host. There is also a setting, at least in the Windows VirtualBox, to limit the amount of CPU workload allowed to the guest. You can try to reduce that slider bar. However, this is a global setting: if you only let the guest use 50%, say, of the CPU then that is all it will ever be able to use. Other than that, I don't know, maybe the guest is busy-waiting for something.

Last edited by headkase (2012-06-09 05:00:10)

Inxsible · 2012-06-09 05:24:19

jarhead70, if you feel that you have posted in the wrong sub forum, please dont start another thread. Use the report functionality to ask a moderator to move the thread to the appropriate sub-forum.

Closing the other one now..

On topic, I use Arch guest on Win7 64 bit all the time. Never seen a high CPU load.

DSpider · 2012-06-09 09:12:12

Crashes, in my experience are because the VM doesn't have enough RAM. For me, a virtualized Windows XP crashed all the time when I had Firefox open. Now with Firefox 13 they seem to have reduced (almost by half) the RAM usage and now it doesn't crash anymore. My advice is to keep the VirtualBox VM the only thing running and you won't experience any crashes, or at least install some sort of monitoring application (Rainmeter, Samurize?) so that you can keep an eye on your RAM usage.

Running top will tell you exactly which process is using up resources. Post the output when you see it at 100%.

jarhead70 · 2012-06-09 15:10:49

@Inxsible:
Sorry about that. I've been wondering how to close that other thread. Thanks for the help.

@headkase:
I've throttled the CPU usage in VBox VM settings to 70% from the start.

@Dspider:
I haven't watching the RAM usage of the host, but in the guest atop/htop reports below than 100MB. I've set the VM to use 512MB, and I got 4GB on the Host.

As to what process taking up the CPU cycles, curiously atop/htop reports itself using 100% CPU. If it is the 1st boot after VM starts, hence normal CPU load, atop/htop both report it selves using 2.3-3% of CPU.

@all:
If I'm not clear before, what I meant is the CPU load as reported by Arch guest. I have no monitoring on the host, other than watching the CPU temperature. When Arch reported full CPU load, the temp at very most jump 2 degrees, but more often 1 or none at all from baseline. As comparison, when playing games at the host, the temp jumps 4-5 degrees.

And when Arch reports full CPU load, both Arch and the host can perform other tasks at ease as if there's no strain to the CPU.

BTW, can you all please post your VM settings? Here's mine:

General/Basic
OS: Linux
Version: Arch Linux

General/Advanced
Shared Clipboard: Bidirectional
Removable Media: Remember runtime changes: Yes
Mini Toolbar: 
  - Show in Fullscreen/seamless: Yes
  - Show at Top of Screen: No

System/Motherboard
Base Memory: 512MB
Boot Order: CD/DVD-ROM, HDD
Chipset: PIIX3
Extended Features:
  - Enable IO APIC: No
  - Enable EFI: No
  - HW Clock in UTC time: Yes
  - Enable absolute pointing device: Yes

System/Processor
Processors: 1
Execution Cap: 70%
Enable PAE/NX: No

System/Acceleration
Enable VT-x/AMD-v: Yes
Enable Nested Paging: Yes

Display/Video
Video Memory: 12MB
Monitor Count: 1
Enable 3D Acceleration: Yes
Enable 2D Acceleration: No

Display/Remote Display
Enabled: No

Storage
IDE Controller (CD/DVD-ROM):
  - Type: PIIX4
  - Use host I/O Cache: Yes

SATA Controler (HDD)
  - Type: AHCI
  - Port Count: 1
  - Use host I/O Cache: No
  - Note: the HDD is emulated using dynamic VDI file

Audio
Host Audio Driver: Windows Direct Sound
Audio Controller: ICH AC97

Network/Adapter 1
Enable: Yes
Attached to: NAT
Adapter Type: Intel PRO/1000 MT Desktop (82540EM)
Cable Connected: Yes

Network/Adapter 2-4
Enable: No

Serial/Port 1-2
Enable: No

USB
Enable: Yes
Enable USB 2.0 (EHCI) Controller: No

Shared Folders
1 shared folder

DSpider · 2012-06-10 09:13:41

If top (not htop or atop) reports itself using 100% CPU, try monitoring it with conky then. I trust top to be more well written than any derivatives.

http://htop.sourceforge.net/index.php?page=comparison

'top' is older, hence, more used and tested.

Do you have Guest Additions installed?

https://wiki.archlinux.org/index.php/Vi … ns_package

Try running it without them.

jarhead70 · 2012-06-10 12:40:20

When in "CPU full load" mode, atop/htop/conky reports are the same, each corresponding processes are in 100%, while top reports 0.3-0.7% when idle, 15-25% if I play around with it then revert to 0.3-0.7%.

Yes, I have virtualbox-archlinux-additions package installed.

Removing the 3 VBox guest modules (vboxguest, vboxsf, and vboxvideo) does make the CPU load normal. I got mixed results playing with them. At first, with the 3 modules loaded, rebooting won't make full CPU load as long as I login as root and reboot. Only after I login as non-root user and reboot (using sudo) does the CPU go to full load. Removing the 3 modules from /etc/rc.conf afterward and reboot made the CPU load normal.

After that, I tried to add the modules one by one, starting with vboxsf, then vboxvideo, then vboxguest. I got normal load with vboxsf and vboxvideo, both by themselves or together. Adding vboxguest while removing the others made the CPU goes full load. That pattern goes for a while (several reboot attempts). Then, no matter what module of the 3 loaded, even each by themselves, made the CPU full load, regardless I login and reboot as root or non-root user. After that even shutting down the VM and restart it, and login as root reports full CPU load at 1st boot. I wonder why this happens.

Without vboxvideo, X run at 1024x768 and mouse-wheel don't work. With it X run at 800x600 and mouse-wheel works. So how can I turn on mouse-wheel without vboxvideo?

Also, what's the use of the other 2 modules then? I could mount the shared folder without vboxsf loaded, and it updates if there's change in the host side. The only difference without vboxsf loaded is the files in the mounted volume are not color coded.

What's the use of vboxguest module?

Why atop/htop/conky/LXDE CPU applet seems to agree to each other regarding CPU load but only top differs? Which report to trust?

Last edited by jarhead70 (2012-06-10 12:42:42)

Arch Linux

#1 2012-06-09 04:55:02

Arch under VirtualBox and Strange CPU load report

#2 2012-06-09 04:58:46

Re: Arch under VirtualBox and Strange CPU load report

#3 2012-06-09 05:24:19

Re: Arch under VirtualBox and Strange CPU load report

#4 2012-06-09 09:12:12

Re: Arch under VirtualBox and Strange CPU load report

#5 2012-06-09 15:10:49

Re: Arch under VirtualBox and Strange CPU load report

#6 2012-06-10 09:13:41

Re: Arch under VirtualBox and Strange CPU load report

#7 2012-06-10 12:40:20

Re: Arch under VirtualBox and Strange CPU load report

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