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Subject: Re: [OMPI devel] [Fwd: multi-threaded test]
From: N.M. Maclaren (nmm1_at_[hidden])
Date: 2011-03-11 03:54:33


On Mar 11 2011, Eugene Loh wrote:
>
>The idea would be to hardwire support for MPI_THREAD_MULTIPLE to be off,
>just as we have done for progress threads. Threads might still be used
>for other purposes -- e.g., ORTE, openib async thread, etc.

That's what I was assuming, too. Threads used behind the scene are not
a problem - IF you can solve the infernal synchronisation and signalling
problems and stop them causing trouble in other ways!

Whether this should be done for MPI_THREAD_SERIALIZED, too, is debatable,
but it can't be done using a cautious interpretation of any published
standards that I know of, and in my experience can't be done reliably.
That's not nice, and I don't want to go there :-(

Regards,
Nick Maclaren.