Affinity Issues with Core i7

hpc-matt — Wed, 10 Mar 2010 21:29:32 GMT

Greets everyone,

I am writing some C Code using MKL to run on a dual socket Core i7 Alienware machine. I have installed Ubuntu 9.04, and when I go to change the affinity, (using KMP_AFFINITY), it only sees one package, 4 cores, 2 threads per core.

How can I change the affinity to reflect 2 packages, 4 cores each, 1 thread per core? I know that I can shut off hyper threading in the bios, and am wiling ot do so, but how can I get the multiple packages to show up?

Thanks in advance!

hpc-matt

Hi Hpc-matt,

Ying_H_Intel — Wed, 05 Jun 2013 02:15:00 GMT

Hi Hpc-matt,

I search in the forum, there are some discussion, like http://software.intel.com/en-us/forums/topic/296195, http://software.intel.com/en-us/forums/topic/294973.

It may be a known bug. as the thread 294973. Could you please let us know some details, like

1. what mkl version

2. what function, what library are used

3. what value of KMP_AFFINITY

Generally, by default , the OMP thread of MKL should be able to see the two packages. and run on 8 threads on each core.

Anyway, could you please do a test on your machine

>export KMP_AFFINITY=verbose,granularity=fine,compact,1,0

and let us know the result?

Best Regards,

Ying

topic Affinity Issues with Core i7 in Intel® oneAPI Math Kernel Library

Affinity Issues with Core i7

Hi Hpc-matt,