Yeah, I understand your concerns; so are you leaning toward an additional
MPI define, such that for mpich2, one would have -DMPI -DMPI2 in config.h?
Seems the easiest thing to do to me, and least disruptive. So if this is
really only needed for a GB finalization step, it is no big deal indeed.
Regards - Bob
----- Original Message -----
From: "Ross Walker" <ross.rosswalker.co.uk>
To: "'AMBER Developers Mailing List'" <amber-developers.ambermd.org>
Sent: Tuesday, April 13, 2010 8:07 PM
Subject: RE: [AMBER-Developers] Issues with MPICH-1.2.1p1
>> I like the "don't support MPICH-1.2.1p1" option myself as a first
>> guess. I
>
> This would be a great option is this wasn't the 'latest and greatest
> MPICH2
> release' .AND. this same issue is likely to occur with ALL future releases
> of MPICH2.
>
>> have not looked at the code to see whether there is potential trouble
>> there,
>> but there are a lot of performance implications in parts of the mpi
>> code...
>
> Of course... Although I am not sure it is huge. From what I can see this
> all_gatherv is only called (in pmemd at least) at the end of a GB run.
> E.g.
> the test cases crash at step 10 of 10. That said we should probably
> address
> it in a nice way.
>
>> I will try to find some time to look at this further...
>> (the principle I am applying here is you don't dink up your own code to
>> support stuff that is broken, unless you absolutely have to...)
>
> I agree except:
>
> 1) Convincing the MPICH2 people that they are wrong will likely be hard.
> 2) Having to keep telling the same thing to users again and again will be
> tiring.
> 3) These days I just want a peaceful life so I can actually do some
> research.
>
> All the best
> Ross
>
> /\
> \/
> |\oss Walker
>
> | Assistant Research Professor |
> | San Diego Supercomputer Center |
> | Tel: +1 858 822 0854 | EMail:- ross.rosswalker.co.uk |
> | http://www.rosswalker.co.uk | http://www.wmd-lab.org/ |
>
> Note: Electronic Mail is not secure, has no guarantee of delivery, may not
> be read every day, and should not be used for urgent or sensitive issues.
>
>
>
>
>
>
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Received on Tue Apr 13 2010 - 20:30:03 PDT
