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Subject: Re: [hwloc-devel] hwloc support added in Grid Engine / Grid Scheduler
From: Brice Goglin (brice.goglin_at_[hidden])
Date: 2011-04-14 05:52:43


I added a FAQ section about this
  https://svn.open-mpi.org/trac/hwloc/changeset/3442
and fixed some other comments
  https://svn.open-mpi.org/trac/hwloc/changeset/3440
If that looks good, I'll backport in the v1.2 branch before releasing the final 1.2.

Brice

----- Mail original -----
> De: "Jeff Squyres" <jsquyres_at_[hidden]>
> À: "Hardware locality development list" <hwloc-devel_at_[hidden]>
> Envoyé: Mercredi 13 Avril 2011 22:47:45
> Objet: Re: [hwloc-devel] hwloc support added in Grid Engine / Grid Scheduler
> On Apr 13, 2011, at 1:32 PM, Brice Goglin wrote:
>
> > Don't worry about the depth. Even if you have less levels of caches
> > in
> > some parts of the machine, or no hyperthreading or whatever
> > different,
> > we still build levels of identical objects. So you still get a
> > consistent depth for all cores, threads, sockets, and different
> > levels
> > of caches. But obviously, you will see less objects when iterating
> > through levels within the "smaller" part of the machine.
>
> This would be good to add to the documentation; I've been doing manual
> traversals of hwloc trees just to future-proof/heterogeneous-proof my
> code (because I didn't know that the depth would always be the same
> for a given object type even if some branches don't have all object
> types).
>
> So let's say I have a (fictitious) machine with one socket with an L1
> and L2 cache for its cores, and another socket that only has an L1
> cache for its cores:
>
> numa_node
> / \
> socket 0 socket 1
> L2 L1
> L1 core
> core
>
> If I traverse down through children in the tree, are you saying that
> there will be some kind of fake/empty object in the right sub tree
> corresponding to where the L2 is in the left sub tree?
>
> --
> Jeff Squyres
> jsquyres_at_[hidden]
> For corporate legal information go to:
> http://www.cisco.com/web/about/doing_business/legal/cri/
>
>
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