Marcello,
Normally the operating system will schedule your process on any available CPU at
the next sceduling interval (the time it needs to use a CPU). This means that if
you have a multi-CPU system (SMP) each MPI process will skip around from CPU to
CPU (maybe using each one for only a few microseconds at a time), so knowing
which CPU you are executing on at any one instant doesn't really help.
There are systems which allow you to bind to a CPU, but these normally require
that you call a system routine to explicitly state which CPU you want to bind to
(e.g. the "bindprocessor" utility/function on AIX). This is usually done to
exploit cache or memory affinity. In this case you know which CPU it is running
on- it's the one you asked for.
That's why 'MPI_Get_processor_name' usually just gives you the hostname.
Regards
Neil
Marcelo Roitburd wrote:
> Dear All!
>
> I know that have the function MPI_Get_processor_name , this return the the
> hostname to the processor, if one computer have more than 1 cpu , how i
> can know what cpu it run the processor not just the hostname?
>
> thankx
>
> Marcelo
>
> _______________________________________________
> This list is archived at http://www.lam-mpi.org/MailArchives/lam/
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