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Subject: Re: [OMPI devel] RFC: new btl descriptor flags
From: George Bosilca (bosilca_at_[hidden])
Date: 2011-11-29 17:08:38


On Nov 29, 2011, at 15:52 , Nathan Hjelm wrote:

>
>
> On Tue, 29 Nov 2011, George Bosilca wrote:
>
>> These two functions target at defining a memory layout (contiguous or not) that can be target for a one-sided communication. I don't see why there is a need to know what type of communication that will be … What is so different in the xpmem that requires the memory to be prepared based on the operations that will follow?
>
> This would be for the ugni btl, not xpmem. Some uGNI rdma operations do not require registration (FMA put). If we know the type of operation at prepare_src we can avoid registering memory in these cases.

Go for it.

  george.

>
>> Moreover, the prepare_src is used outside the context of one-sided, in the send protocol. How do you plan to address send operations?
>
> Send operations can be detected by neither MCA_BTL_DES_PUT or MCA_BTL_DES_GET being set or a non-zero reserve value (which some btls already use).
>
> -Nathan_______________________________________________
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