Linux MultiCore

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AaronLS
Posts: 2
Joined: Mon Nov 23, 2015 5:08 am

Linux MultiCore

Post by AaronLS »

Seems like my 7.3.6 linux installation is only using a single core. I have used the Advanced Control to change the slot configuration to explicitly use 8 CPUs. However, it is still only using 13% of the CPUs according to a system monitor, which would correspond to 1/8th of the CPUs.

System information from Advnaced Control showing it is aware of the 8 cores:

CPUs: 8
Memnory 1.97Gib
Free Memory 1.88 GiB
Threads POSIC_THREADS
PID 832
OS Linux 3.8.0-19-generic i686
OS Arch X86

This is running under a Xen Node. I've given the node 8 vCpu's, which FAH can clearly see. However, total CPU usage of the node is 13%, which correponds to .125 or 12.5% rounded up. I can also see CPU graph and it is using only one CPU at any one time. Now I say CPU here because that's how FAH sees them. In reality each vCPU exposed through the Xen node is really a core on the physical processor. I wouldn't think that would matter though. Main thing is FAH seems to be running singlethreaded.

Here is my configuration:

Code: Select all

05:31:48:<config>
05:31:48:  <!-- Client Control -->
05:31:48:  <fold-anon v='true'/>
05:31:48:
05:31:48:  <!-- Folding Core -->
05:31:48:  <checkpoint v='30'/>
05:31:48:
05:31:48:  <!-- Folding Slot Configuration -->
05:31:48:  <power v='full'/>
05:31:48:
05:31:48:  <!-- HTTP Server -->
05:31:48:  <allow v='127.0.0.1,192.168.1.0/24'/>
05:31:48:
05:31:48:  <!-- Network -->
05:31:48:  <proxy v=':8080'/>
05:31:48:
05:31:48:  <!-- Remote Command Server -->
05:31:48:  <command-allow-no-pass v='127.0.0.1,192.168.1.0/24'/>
05:31:48:
05:31:48:  <!-- User Information -->
05:31:48:  <passkey v='omitted'/>
05:31:48:  <team v='123456789'/>
05:31:48:  <user v='omitted'/>
05:31:48:
05:31:48:  <!-- Folding Slots -->
05:31:48:  <slot id='0' type='CPU'>
05:31:48:    <cpus v='8'/>
05:31:48:  </slot>
05:31:48:</config>

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bruce
Posts: 20910
Joined: Thu Nov 29, 2007 10:13 pm
Location: So. Cal.

Re: Linux MultiCore

Post by bruce »

1) Is this your first assignment? If so, let it finish and I expect the new assignment will use whatver number of cores you've set. This is a known problem.
2) There have been a lot of changes between FAH V7.3.6 and V7.4.4. I recommend you upgrade.
3) How many real CPUs are supporting 8 vCPUs? If you try to use resources that are not fully available to FAH, you'll actually slow it down rather than speeding it up.
toTOW
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Posts: 6307
Joined: Sun Dec 02, 2007 10:38 am
Location: Bordeaux, France
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Re: Linux MultiCore

Post by toTOW »

He seems to be running a 32 bit Linux ... there's no SMP cores for 32 bits on Linux, so I guess he just got an assignment using an old uniprocessor core.

What project is it (just being curious since I thought most uniprocessor projects were finished) ?
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Folding@Home beta tester since 2002. Folding Forum moderator since July 2008.
AaronLS
Posts: 2
Joined: Mon Nov 23, 2015 5:08 am

Re: Linux MultiCore

Post by AaronLS »

@bruce, You called it. It was first work unit since boot up. Took a day or so to complete, but now it is maxing out 100% all 8 cores. (There's nothing else running on this machine.)

Not sure if this node has ever completed a work unit before. I only ran it a couple days at a time until now.

So I'm wondering, is this an issue that I will see per bootup? I.e. next time I restart, will it use a single core until that unit completes? Or should it in general use all cores from now on even after rebooting?
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bruce
Posts: 20910
Joined: Thu Nov 29, 2007 10:13 pm
Location: So. Cal.

Re: Linux MultiCore

Post by bruce »

The known issue only happens if the installation has never completed a WU. Rebooting won't be a problem except that the active WU has to resume work from the previous checkpoint.
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