On Jan 30, 2014, at 12:38 AM, Victor <victor.major@gmail.com> wrote:

I use htop and top....and until now I did not make the connection that each listed process is actually a thread...

Thus the application that I am running is single threaded. How does that affect the CPU affinity and rank settings?


It affects it very much - there is no value in running a rank on multiple cores in that case. Just do "mpirun --bind-to-core"

Threading the app is a mixed bag - it might help, but there is a penalty as well since you have to do all that thread locking. For now, just bind-to-core


<-- as mentioned earlier I am a novice, and very easily confused :-)



On 30 January 2014 15:59, John Hearns <hearnsj@googlemail.com> wrote:

Ps. 'htop' is a good tool for looking at where processes are running.


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