Re: [Starpu-devel] Question about MPI usage

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Xavier Lacoste, le Tue 25 Feb 2014 11:52:21 +0100, a écrit :
> Thanks, this is due to a read only array that I only register on the node 
> which will execute the task.

And no other task will need the array?

> Do I need to register it on every node ?

No, only on nodes which will actually pass it to starpu_mpi_task_insert.

You can also pass NULL to starpu_mpi_task_insert, it will just return
EINVAL.

> Is there an option to tell StarPU that this buffer is already on the
> node that will execute the kernel ?

Well, you at least need to specify an MPI rank for the data, so that
StarPU knows it is here and doesn't have to transfer anything.

Samuel