Re: [gentoo-cluster] Switchable MPI

[Eric Thibodeau]

Well... I'm presently working on and OpenMPI ebuild that follows the belowmentionned path specs to be able to slot the MPI implementation as per:
$implementation/$version/$compiler/

But I don't think this structure will change wether we use modules or eselect (we still need a separate place to store the mutually exclusive packages). But DO poke me if I am going in the wrong direction with this so that I don't waste too much time in the wrong direction.

Thanks,

Eric

PS: couldn't eselect also work for a normal user...and just set the proper environment variable also....??...it's just a BASH script so we should be able to do it the "eselect" way ;)

Le 12 Février 2006 18:33, Donnie Berkholz a écrit :
> Andrew D. Fant wrote:
> > I'll dig around and forward the ebuild to the list later tonight or
> > tomorrow. At the risk of going off on a rant, I think that the
> > /etc/env.d model is a core part of the problem.   If two users want to
> > use two different mpi implementations, will eselect allow them to both
> > use them at the same time, or will it have to be one or the other at
> > once?   As I see it, something will have to be tweaking $LD_LIBRARY_PATH
> > for each user's environment,
>
> Yep, that's the plan. Some things just won't work as well because they
> don't really respect variables, like the includes.
>
> Something like this:
>
> MPI_IMPLEMENTATION="$implementation"
> PATH="/usr/lib/mpi/$implementation/$version/$compiler/bin:$PATH"
> LD_LIBRARY_PATH="/usr/lib/mpi/$implementation/$version/$compiler/lib:$LD_LIBRARY_PATH"
> CPPFLAGS="-I/usr/lib/mpi/$implementation/$version/$compiler/include:$CPPFLAGS"
> MANPATH="/usr/lib/mpi/$implementation/$version/$compiler/share/man:$MANPATH"
> INFOPATH="/usr/lib/mpi/$implementation/$version/$compiler/share/info:$INFOPATH"
>
> > or /etc/ld.so.cache will have to be changed
> > for each user's login to reflect their prefered mpi environment.
>
> That totally screws with multiple simultaneous logins. Environment
> variables will have to be the way to go.
>
> > $PATH
> > and $MANPATH can be handled by judicious checks in /etc/csh.cshrc and
> > /etc/profile, but since /etc/env.d insists on manipulating the shared
> > object cache directly, this has the potential to get really ugly without
> > some cooperation from the core system team.  I don't think that the
> > cluster herd can fix it on it's own.
>
> I think we can, but I could certainly be proven wrong on this.
>
> > I would love to be proven wrong and will gladly defer to anyone who does
> > so,  I just know that I've been trying to outthink this problem for a
> > year or so on our cluster and haven't come up with a sane solution for a
> > true multi-user environment.
>
> I would love to find a way that works too. =)
>
> Thanks,
> Donnie
>
>

-- 
Eric Thibodeau
Neural Bucket Solutions Inc.
T. [phone]
C. [phone]

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