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Subject: Re: [hwloc-devel] Merging the PCI branch?
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2011-03-31 14:47:02

On Mar 31, 2011, at 2:41 PM, Samuel Thibault wrote:

> [re: making PCI the default]
> I'm unsure about it. We need to keep the simple things simple, and many
> people will only care about CPU placement first, so that should remain
> simple.

Ok. I guess I don't have too strong of an opinion here.

>> How / where do these new devices show up in the tree that is returned from hwloc? For example, are PCI busses children of NUMA nodes, or siblings?
> They show up according to the corresponding cpuset. In the case of a
> NUMA node, since PCI busses are typically close to the whole set of cpus
> of the NUMA node, it'll be a child (else you wouldn't know which NUMA
> node it's close to). Of course, more complexe hardware will have
> different relations.

That's exactly what I was hoping.

Brice's text of "They have no cpusets / may appear at random places in the topology" could be interpreted multiple ways, so I wasn't sure.

>> Is libpci available on all platforms? Or is it only needed on Linux?
> It is said to work on linux, free/net/openbsd, solaris, aix, and
> whatever OS that lets it access x86 io ports.


Are we *requiring* libpci to build? Or do we allow building without it (and therefore you just don't get the PCI functionality)?

Jeff Squyres
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