And here are the final proposed changes.  When not configured in, these changes 
do not change the code at all.

https://bitbucket.org/rolfv/ompi-trunk-cuda-rfc3

Rolf

-----Original Message-----
From: devel-boun...@open-mpi.org [mailto:devel-boun...@open-mpi.org] On Behalf 
Of Jeff Squyres
Sent: Thursday, April 21, 2011 6:19 PM
To: Open MPI Developers
Subject: Re: [OMPI devel] RFC: Second Try: Add support to send/receive CUDA 
device memory directly

George -- what say you?

On Apr 19, 2011, at 4:54 PM, Rolf vandeVaart wrote:

> Forgot the link...
>  
> https://bitbucket.org/rolfv/ompi-trunk-cuda-rfc2
>  
>  
>  
> From: devel-boun...@open-mpi.org [mailto:devel-boun...@open-mpi.org] On 
> Behalf Of Rolf vandeVaart
> Sent: Tuesday, April 19, 2011 4:45 PM
> To: Open MPI Developers
> Subject: [OMPI devel] RFC: Second Try: Add support to send/receive CUDA 
> device memory directly
>  
> WHAT: Second try to add support to send data directly from CUDA device memory 
> via MPI calls.
>  
> TIMEOUT: 4/26/2011
>  
> DETAILS: Based on all the feedback (thanks to everyone who looked at it),  I 
> have whittled down what I hope to accomplish with this RFC.  There were 
> suggestions to better modularize the CUDA registration code so I will take a 
> look at that separately.  Since the registration code is a performance 
> feature, it will be dropped from this RFC and investigated separately.  This 
> significantly reduced the changes being proposed here.  With this RFC, all 
> the changes are isolated in datatype and convertor code.   As mentioned 
> before, the changes mostly boil down to replacing memcpy with cuMemcpy when 
> moving the data to or from a CUDA device buffer.
>  
> Per suggestions, the choice to disable the large memory RDMA now happens on a 
> per message basis.  This is done by adding a flag to the convertor which 
> tells the BTLs that an intermediate buffer is needed when dealing with device 
> memory.
>  
> As before, this code would be enabled via a configure option.  A mostly 
> completed version is viewable on bitbucket although I know the configure code 
> is sorely lacking.
>  
> This is the new list of changed files.
>  
> M       opal/config/opal_configure_options.m4
> A       opal/datatype/opal_datatype_cuda.c
> A       opal/datatype/opal_datatype_cuda.h
> M       opal/datatype/opal_convertor.h
> M       opal/datatype/opal_datatype_copy.c
> M       opal/datatype/opal_datatype_unpack.c
> M       opal/datatype/Makefile.am
> M       opal/datatype/opal_datatype_pack.h
> M       opal/datatype/opal_convertor.c
> M       opal/datatype/opal_datatype_unpack.h
> M       ompi/mca/pml/ob1/pml_ob1_sendreq.h
>  
> Thanks,
> Rolf
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-- 
Jeff Squyres
jsquy...@cisco.com
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