You shouldn't have to do anything special; just write normal MPI
programs. There are a variety of MPI tutorials available on the web;
a particularly good one is available here:
http://webct.ncsa.uiuc.edu:8900/public/MPI/
I think someone mentioned that you can use MPI_ALLOC_MEM to get pr
Ha, yeah, I should have been more clear there. I'm simply writing an MPI
application.
Thanks,
Brian
On 11/2/06, Jeff Squyres wrote:
It depends on what you're trying to do. Are you writing new
components internal to Open MPI, or are you just trying to leverage
OMPI's PML for some other proj
It depends on what you're trying to do. Are you writing new
components internal to Open MPI, or are you just trying to leverage
OMPI's PML for some other project? Or are you writing MPI
applications? Or ...?
On Nov 2, 2006, at 2:22 PM, Brian Budge wrote:
Thanks for the pointer, it was
On Thu, Nov 02, 2006 at 11:57:16AM -0800, Brian Budge wrote:
> Thanks for the help guys.
>
> In my case the memory will be allocated and pinned by my other device
> driver. Is it safe to simply use that memory? My pages won't be unpinned
> as a result?
>
If your driver plays nicely with openib
Thanks for the help guys.
In my case the memory will be allocated and pinned by my other device
driver. Is it safe to simply use that memory? My pages won't be unpinned
as a result?
As far as registration, I am sure that OpenMPI will do a better job of that
than I could, so I won't even attemp
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
Locking a page with mlock() is not all that is required for RDMA
using InfiniBand (or Myrinet, for that matter). You have to call
that device's registration function first. In Open MPI, that can be
done implicitly with the mpi_leave_pinned option, which will pin
memory as needed and then
Thanks for the pointer, it was a very interesting read.
It seems that by default OpenMPI uses the nifty pipelining trick with
pinning pages while transfer is happening. Also the pinning can be
(somewhat) perminant and the state is cached so that next usage requires no
registration. I guess it i
This paper explains it pretty well:
http://www.open-mpi.org/papers/euro-pvmmpi-2006-hpc-protocols/
On Nov 2, 2006, at 1:37 PM, 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
re
