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Subject: Re: [OMPI devel] RFC: s/ENABLE_MPI_THREADS/ENABLE_THREAD_SAFETY/g
From: Barrett, Brian W (bwbarre_at_[hidden])
Date: 2010-02-08 22:50:34


Well, does --disable-multi-threads disable progress threads? And do you want to disable thread support in ORTE because you don't want MPI_THREAD_MULTIPLE? Perhaps a third option is a rational way to go?

Brain

On Feb 8, 2010, at 6:54 PM, Jeff Squyres wrote:

> How about
>
> --enable-mpi-threads ==> --enable-multi-threads
> ENABLE_MPI_THREADS ==> ENABLE_MULTI_THREADS
>
> Essentially, s/mpi/multi/ig. This gives us "progress thread" support and "multi thread" support. Similar, but different.
>
> Another possibility instead of "mpi" could be "concurrent".
>
>
>
> On Jan 28, 2010, at 9:24 PM, Barrett, Brian W wrote:
>
>> Jeff -
>>
>> I think the idea is ok, but I think the name needs some thought. There's currently two ways to have the lower layers be thread safe -- enabling MPI threads or progress threads. The two can be done independently -- you can disable MPI threads and still enable thread support by enabling progress threads.
>>
>> So either that behavior would need to change or we need a better name (in my opinion...).
>>
>> Brian
>>
>> On Jan 28, 2010, at 8:53 PM, Jeff Squyres wrote:
>>
>>> WHAT: Rename --enable-mpi-threads and ENABLE_MPI_THREADS to --enable-thread-safety and ENABLE_THREAD_SAFETY, respectively (--enable-mpi-threads will be maintained as a synonym to --enable-thread-safety for backwards compat, of course).
>>>
>>> WHY: Other projects are starting to use ORTE and OPAL without OMPI. The fact that thread safety in OPAL and ORTE requires a configure switch with "mpi" in the name is very non-intuitive.
>>>
>>> WHERE: A bunch of places in the code; see attached patch.
>>>
>>> WHEN: Next Friday COB
>>>
>>> TIMEOUT: COB, Friday, Feb 5, 2010
>>>
>>> ------------------------
>>>
>>> More details:
>>>
>>> Cisco is starting to investigate using ORTE and OPAL in various threading scenarios -- without the OMPI layer. The fact that you need to enable thread safety in ORTE/OPAL with a configure switch that has the word "mpi" in it is extremely counter-intuitive (it bit some of our engineers very badly, and they were mighty annoyed!!).
>>>
>>> Since this functionality actually has nothing to do with MPI (it's actually the other way around -- MPI_THREAD_MULTIPLE needs this functionality), we really should rename this switch and the corresponding AC_DEFINE -- I suggest:
>>>
>>> --enable|disable-thread-safety
>>> ENABLE_THREAD_SAFETY
>>>
>>> Of course, we need to keep the configure switch "--enable|disable-mpi-threads" for backwards compatibility, so that can be a synonym to --enable-thread-safety.
>>>
>>> See the attached patch (the biggest change is in opal/config/opal_config_threads.m4). If there are no objections, I'll commit this next Friday COB.
>>>
>>> --
>>> Jeff Squyres
>>> jsquyres_at_[hidden]
>>> <opal-thread-safety.diff>_______________________________________________
>>> devel mailing list
>>> devel_at_[hidden]
>>> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>>
>> --
>> Brian W. Barrett
>> Dept. 1423: Scalable System Software
>> Sandia National Laboratories
>>
>>
>>
>>
>>
>> _______________________________________________
>> devel mailing list
>> devel_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>>
>
>
> --
> Jeff Squyres
> jsquyres_at_[hidden]
>
> For corporate legal information go to:
> http://www.cisco.com/web/about/doing_business/legal/cri/
>
>
> _______________________________________________
> devel mailing list
> devel_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>

--
  Brian W. Barrett
  Dept. 1423: Scalable System Software
  Sandia National Laboratories