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Subject: Re: [OMPI devel] amd64 atomic.h warnings
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2010-06-09 08:06:34


On Jun 8, 2010, at 2:44 PM, Eugene Loh wrote:

> What does "disabling threads" mean?

I was specifically referring to --disable-opal-multi-threads and --disable-mpi-thread-multiple (couldn't remember the names of the options when I typed this up).

One thing I just noticed -- these warnings only applied to the C++ compiler. Everything appeared to be fine for the C compiler. Hmm.

> E.g., does it mean disabling single
> receive queues? Sorry for asking bonehead questions, but I thought
> these atomics weren't just needed for multithreading usage, but for
> managing interactions of multiple (even single-threaded) processes in
> shared memory.

Oy. That sounds right... ouch.

George -- can you confirm? (I only have a hazy understanding of the issue) Is this problem that at least some of the atomics are not supported, and therefore the sm btl is borked?

The compiler warnings that I cited at the beginning of this thread can be seen here:

    http://www.open-mpi.org/community/lists/devel/2010/06/8060.php

Given that these only appear with the C++ compiler, I wonder if we should just disable the C++ bindings and VT...?

Additionally, all the stuff I sent to George was for the C compiler -- George -- did those show problems, too? Or should I send the assembly from the C++ compiler, too?

-- 
Jeff Squyres
jsquyres_at_[hidden]
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