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Subject: Re: [OMPI devel] [EXTERNAL] OpenSHMEM round 2
From: Barrett, Brian W (bwbarre_at_[hidden])
Date: 2013-08-15 12:41:11


On 8/15/13 10:30 AM, "George Bosilca" <bosilca_at_[hidden]> wrote:

>
>On Aug 15, 2013, at 18:06 , Joshua Ladd <joshual_at_[hidden]> wrote:
>
>> Maybe this is a stupid question, but in this case (I believe this goes
>>all the way back to our initial discussion on OSHMEM), how does one fall
>>back onto send/recv semantics when the call is made at the SHMEM level
>>to do a put?
>
>The same way our current OSC (one-sided component) is falling back on the
>pt2pt component when no underlying BTL supports RDMA operation.

in general, I agree with everything George said. Except that if the OSC
rdma component finds BTLs that don't support RDMA, it falls back to the AM
interface. The pt2pt component is only used when there are no BTLs (such
as when the CM PML is used). Which, by the way, is a case that OSHMEM
should figure out how to deal with (if only by initializing the BML/BTLs)

Brian

--
  Brian W. Barrett
  Scalable System Software Group
  Sandia National Laboratories


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