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From: Gleb Natapov (glebn_at_[hidden])
Date: 2006-11-02 14:56:42

On Thu, Nov 02, 2006 at 10:37:24AM -0800, Brian Budge wrote:
> Hi all -
> I'm wondering how DMA is handled in OpenMPI when using the infiniband
> protocol. In particular, will I get a speed gain if my read/write buffers
> are already pinned via mlock?
No you will not. mlock has nothing to do with memory registration that
is needed for RDMA. If you'll allocate your read/write buffers with
MPI_Alloc_mem() that will help because this function register memory
for you.