[libfabric-users] Help with implementing OpenCoarrays using OFI

[Alessandro Fanfarillo]

Jeff is right, our goal is to go to a bare metal transport layer
specifically designed for CAF.
I'm definitively aware of the fact that implementing OpenCoarrays on
OFI is a major effort but we don't need to cover all the CAF features
in one shot.
The plan is to start with a minimal implementation of put/get
operations and see if there is a significant benefit over MPI or
GASNet.

Cheers,
Alessandro

On Sat, Nov 18, 2017 at 9:16 AM, Jeff Hammond <jeff.science at gmail.com> wrote:
> I suspect the goal is to move down the stack to eliminate dependencies that
> make robust integration with GCC harder.
>
> As far as I know, GASNet isn’t capable of dynamically loading different
> conduits, which is what one would want for shipping GCC binaries  that
> needed to be used on systems with a range of interconnects.
>
> OpenCoarrays already uses OFI transparently when it’s behind an MPI-3
> library. In theory - but rarely in practice - MPI-3 RMA performs as well if
> not better than GASNet.
>
> Jeff
>
> On Fri, Nov 17, 2017 at 8:31 PM Howard Pritchard <hppritcha at gmail.com>
> wrote:
>>
>> Hi Alessandro,
>>
>> Looking at the code at https://github.com/sourceryinstitute/OpenCoarrays,
>> I'd say the fastest way to get OpenCoarrays to work on top of OFI would
>> just be to get the latest GASNet with OFI support, and make sure you
>> build/install GASNet with the OFI conduit enabled.
>>
>> the OFI libfabric API is pretty complex, and looking at the code at the
>> above repo, it would be a major effort to interface a low level API like
>> libfabric directly in to this OpenCoarrays code.
>>
>> But then again, if you have an abundance of time, it might be worth
>> investigating.
>>
>> Howard
>>
>>
>> 2017-11-17 18:06 GMT-07:00 Alessandro Fanfarillo
>> <alessandro.fanfarillo at gmail.com>:
>>>
>>> Thanks Jeff, very helpful.
>>>
>>> On Fri, Nov 17, 2017 at 3:02 PM, Jeff Hammond <jeff.science at gmail.com>
>>> wrote:
>>> > https://github.com/charlesarcher/openshmem-tutorial should be relevant.
>>> > Might not be using the latest API but it should be easy enough to fix.
>>> >
>>> > Jeff
>>> >
>>> > Sent from my iPhone
>>> >
>>> > On Nov 17, 2017, at 1:57 PM, Alessandro Fanfarillo
>>> > <alessandro.fanfarillo at gmail.com> wrote:
>>> >
>>> > Dear all,
>>> > I would like to implement the OpenCoarrays library (opencoarrays.org),
>>> > used by the GNU Fortran to support Coarray Fortran, on top of OFI.
>>> > Having some kind of guidance to start this new effort would be very
>>> > helpful, do you have any recommended readings (I've already read
>>> > https://github.com/ofiwg/ofi-guide/blob/master/OFIGuide.md)? Do you
>>> > plan to provide a course anytime soon?
>>> >
>>> > Thank you in advance.
>>> >
>>> > Alessandro
>>> >
>>> > --
>>> >
>>> > Alessandro Fanfarillo
>>> > _______________________________________________
>>> > Libfabric-users mailing list
>>> > Libfabric-users at lists.openfabrics.org
>>> > http://lists.openfabrics.org/mailman/listinfo/libfabric-users
>>>
>>>
>>>
>>> --
>>>
>>> Alessandro Fanfarillo
>>> _______________________________________________
>>> Libfabric-users mailing list
>>> Libfabric-users at lists.openfabrics.org
>>> http://lists.openfabrics.org/mailman/listinfo/libfabric-users
>>
>>
> --
> Jeff Hammond
> jeff.science at gmail.com
> http://jeffhammond.github.io/



-- 

Alessandro Fanfarillo