[dcmf] 32-bit ROMIO: What is the best solution?

Thu Feb 28 12:42:30 CST 2008

There's an mpich2-bg list that I just created if you want to move there.

  -- Pavan

On 02/28/2008 12:39 PM, Rob Ross wrote:
> Rajeev had suggested this too. Let's go with mpich2-dev. Can you give us 
> a list of people that should be added to the list?
> 
> Thanks,
> 
> Rob
> 
> On Feb 28, 2008, at 12:29 PM, Michael Blocksome wrote:
> 
>>
>> I agree .. we need to get over the discussion about the discussion as 
>> fast as possible. :)
>>
>> The dcmf list has worked well, but I think we started using it because 
>> there were no alternatives to the issue at hand.  Given that the 
>> mpich2 and global arrays communities have different licenses, our long 
>> term direction for the dcmf community should be to support the dcmf 
>> library and move discussion of other "external" libraries (like mpich2 
>> and global arrays) into thier communities.
>>
>> I just noticed that there is a mpich2-dev at mcs.anl.gov mailing list 
>> already set up.  Could we use this list to collaborate on the mpich2 
>> implementation?
>>
>> Michael Blocksome
>> Blue Gene Messaging Team Lead
>> Advanced Systems SW Development
>> blocksom at us.ibm.com
>>
>>
>> Rob Ross <rross at mcs.anl.gov> wrote on 02/28/2008 12:17:06 PM:
>>
>> > Hi,
>> >
>> > We've been using the DCMF list for all sorts of things that aren't
>> > directly related to DCMF without any issues (as far as I know); it has
>> > become the successful technical communication path between IBM and ANL
>> > so far.
>> >
>> > However, if you'd like to create a separate list for discussing this,
>> > we can do that. Is that what you would like to do? If so, can you give
>> > us a list of people on the IBM side that should be on the new list?
>> > I'd like to be done discussing where we're going to talk about this
>> > issue ASAP and concentrate on fixing it.
>> >
>> > Thanks,
>> >
>> > Rob
>> >
>> > On Feb 28, 2008, at 11:18 AM, Michael Blocksome wrote:
>> >
>> > >
>> > > Unfortunately, this MPI_Aint discussion really has nothing to do
>> > > with DCMF.  The entrire problem and solution is with MPICH2.
>> > >
>> > > Is there another, less broad, mpich mailing list that we could use?
>> > > Maybe a "mpich-development" or something like that?
>> > >
>> > > Michael Blocksome
>> > > Blue Gene Messaging Team Lead
>> > > Advanced Systems SW Development
>> > > blocksom at us.ibm.com
>> > >
>> > >
>> > > dcmf-bounces at lists.anl-external.org wrote on 02/28/2008 11:01:09 AM:
>> > >
>> > > > I'd say this mailing list is better for it right now. Posting on 
>> the
>> > > > broader mpich-discuss might just distract us.
>> > > >
>> > > > Rajeev
>> > > >
>> > > > From: dcmf-bounces at lists.anl-external.org [mailto:dcmf-
>> > > > bounces at lists.anl-external.org] On Behalf Of Bob Cernohous
>> > > > Sent: Wednesday, February 27, 2008 4:19 PM
>> > > > To: dcmf at lists.anl-external.org
>> > > > Subject: Re: [dcmf] 32-bit ROMIO: What is the best solution?
>> > >
>> > > >
>> > > > bobc at us.ibm.com wrote on 02/08/2008 02:41:40 PM:
>> > > >
>> > > > >We all realize there are issues with MPI_Aint's in 32 bit
>> > > implementations.
>> > > > >Using signed 32 bit addresses along with 64 bit offsets can
>> > > result in
>> > > > >some pretty broken code.  I've reproduced several problems on
>> > > > >BGL/BGP/linux.   The problems are most obvious with romio files >
>> > > 2G or
>> > > > >virtual addresses > 2G.
>> > > >
>> > > > Earlier this month I posted some comments to this mailing list 
>> about
>> > > > 32-bit MPICH/ROMIO/MPI_Aint issues (see above and the archive).
>> > > >
>> > > > We've started to work on the problem.   We're (optionally) making
>> > > > MPI_Aint a 64 bit signed value even when integers/pointers are 32
>> > > bit
>> > > > values.
>> > > >
>> > > > We'd like to start sending fix patches to the community for 
>> comment.
>> > > >
>> > > > However, since we are (in parallel) contributing our BGP code back
>> > > > to MPICH and trying to converge on a common code base of 1.0.7,
>> > > > and because this problem applies to any 32-bit platform,
>> > > > we thought we should move the discussion to mpich-discuss to get
>> > > > the larger community's comments.
>> > > >
>> > > > It's unlikely, at this point, that our patches would apply to
>> > > MPICH2,
>> > > > but that is our goal after the 1.0.7/BGP patch settles.   For now,
>> > > we'd
>> > > > be sending these as RFC (request for comment) patches.
>> > > >
>> > > > Please let us know if you agree with discussing this on mpich-
>> > > discuss,
>> > > > or if there is a better place.
>> > > >
>> > > > Bob Cernohous:  (T/L 553) 507-253-6093
>> > > >
>> > > > BobC at us.ibm.com
>> > > > IBM Rochester, Building 030-2(C335), Department 61L
>> > > > 3605 Hwy 52 North, Rochester,  MN 55901-7829
>> > > >
>> > > > > Chaos reigns within.
>> > > > > Reflect, repent, and reboot.
>> > > > > Order shall 
>> return._______________________________________________
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>> > org/wiki_______________________________________________
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>> >
> 
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-- 
Pavan Balaji
http://www.mcs.anl.gov/~balaji