[vsipl++] Number of Processes General Question

Stefan Seefeld stefan at codesourcery.com
Thu Mar 4 17:29:20 UTC 2010


Bill,

On 03/04/2010 12:07 PM, Cassanova, Bill wrote:
> Hi folks,
>
> Just wondering why would vsipl++ report a different number of processors
> than sysconf?

This is because they have different notions of what a "processor" is. 
One uses it for a piece of hardware, the other for an MPI-enabled 
process that participates in a parallel computation.

> Do I need to necessarily run a vsipl++ program using mpirun, i.e:
>
> “mpirun –np${num_processors} ./vsipl_tester”
>
> In order for vsipl++ to recognize that there are multiple processors
> installed on the machine?

Yes. Or more specifically, Sourcery VSIPL++ still won't recognize the 
number of CPUs or cores. It will report the number of processes started 
via `mpirun`, which is the number of processes potentially participating 
in the computations of your program.

Regards,
		Stefan


-- 
Stefan Seefeld
CodeSourcery
stefan at codesourcery.com
(650) 331-3385 x718



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