On 04/06/2012 03:18 AM, Stephen John Smoogen wrote:
> On 5 April 2012 10:47, Wil Irwin<[log in to unmask]>  wrote:
>> Hi-
>>
>> I am totally stumped and at a complete loss on this one.
>>
>> In an 'old school' manner (a.k.a poor man's grid engine), it is a common
>> practice (at least for me) to open multiple terminal windows on a
>> mullti-core machine. Submitting a job in each terminal window will send it
>> to a core which is not being used. On this particular set of machines I have
>> been doing this for about 2 years.
>
> To be honest I have no idea why it worked before. Setting a process to
> a certain core takes definitive coding to say "x will have affinity to
> CPU y" or using a program like taskset to set the affinity.
>
> I would try the following:
> 1) man taskset
> 2) see if taskset works on your system.
>
> Then see if it works. If it doesn't then I would assume that the CPU
> or some other hardware in the box is having issues and not allowing
> processes on the other cores for some reason.

In addition to the excellent advice here, I've seen a very similar 
problem before with some faulty BIOS code telling the system to kick in 
to a very conservative processing mode when certain voltage indicators 
were met. This came out of the blue and was extremely frustrating to 
troubleshoot because it like what you're seeing but was a hardware issue 
born of a special combination of dirty power input, a slowly fading PSU 
and a cranky mainboard.

The odds of that ever happening again anywhere are probably pretty low, 
especially with server type boards, but its worth considering.

Good luck finding your solution. That must be annoying.

-z