Ubuntu VM not utilizing both cores

theheyes

theheyes

theheyes

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Joined
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Hi guys,

I'm having a very strange problem and I wondered if anyone could help shed some light on it.

I'm running Ubuntu Linux (7.10-64) in a virtual machine on top of Windows Vista. The free version of VMServer I'm using only lets you allocate two "processors" to each VM, which is fine since I'm running a Q6600. Now, as far as Ubuntu is concerned, it is running on a 2-core processor with 512mb RAM and 3GB hard disk space. I'm using the computer to run folding@home so I downloaded the SMP client (which utilizes more than one cpu/core) and set that to work in Ubuntu.

Back in windows, I open up the task manager and notice the Virtual Machine process is only using 25% of the CPU i.e. one core. So, I switched to the virtual machine and ran Ubuntu's System Monitor which shows (correctly) cpu0 and cpu1. However, only "100%" of the system resources are being used. I'll explain it as I understand it:

1 core = 100%
2 cores = 200%

When SMP client is running the following is true:

core0 = 0% core1 = 100%

Now, if I open an application such as firefox and keep an eye on the system monitor the readout is:

core0 = 30% core1 = 70%

The operating system seems to only be using a 100% split over both cores.

Truth be told, I don't know if this is an Ubuntu issue, a VMWare issue or even a folding@home issue. I just wondered if anyone had any ideas before I delete the machine and reinstall it.

I'm a bit of a Linux newb so please don't assume I've tried things that might seem obvious to yourselves.

Thanks for your time. :)
 
I've just shut down the VM while I install a second one, once I've done I'll fire it up and have a look at what top outputs.

Cheers. :)
 
It's a VMWare thing.

Ubuntu thinks it has 2 cores - whereas what it actually has is two virtual cores. Big difference.

I don't know much about Ubuntu's system monitor - but it would be silly for it to have 200% of system resources if it was using 2 cores... as this would be impossible!

EDIT: Also, I don't know how the default Ubuntu kernel is configured: i.e. is it compiled for smp with an smp scheduler? - Billy should be able to help with that one
 
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Thanks for your input.

When I say "200%" its a bit misleading, what I mean is 1 core at full tilt would represent 100%, 2 cores at 100% would represent 200% etc etc. I use OS X and this is how multiple cores are represented. Depends on the OS and what you are used to I suppose.

IRT BTI, top is outputting only one process owned by me which is FahCore_79.exe using 100% of the CPU. I know on Windows and OSX there are 4 or 5 processes belonging to folding@home SMP - do you think this is the problem? A misconfigured SMP client?

I knew it would be my fault! :D
 
Dude, I think I've cracked it. Apparently the new client is defaulted to NOT use SMP work units and needs an argument passed to it on set up. This explains why only one core is in use and only one process- its running a standard work unit. It makes perfect sense now. It also explains why the units completed and uploaded successfully.

I am officially a fool. (although to be fair on myself a little I was following a guide that hadnt been updated to reflect the changes made to the client, still, serves me right)

Thanks for your help, I think we can consider this thread closed now. :)
 
Yep, just as I expected, you didn't pass it the -smp option. :D :p

You should really consider using finstall. It takes care of all the download, configuration, and service installation.
 
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