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Subject: Re: [hwloc-users] lstopo and GPus
From: Samuel Thibault (samuel.thibault_at_[hidden])
Date: 2012-08-28 08:47:48


Brice Goglin, le Tue 28 Aug 2012 14:43:53 +0200, a écrit :
> > $ lstopo
> > Socket #0
> > Socket #1
> > PCI...
> > (connected to socket #1)
> >
> > vs
> >
> > $ lstopo
> > Socket #0
> > Socket #1
> > PCI...
> > (connected to both sockets)
>
> Fortunately, this won't occur in most cases (including Gabriele's
> machines) because there's a NUMAnode object above each socket.

Oops, I actually meant NUMAnode above

> Both the socket and the PCI bus are drawn inside the NUMA box, so
> things appear OK in graphics to.

Indeed, if the PCI bus was connected to one NUMAnode/socket only, it
would be drawn inside, which is not the case.

> Gabriele, assuming you have a dual Xeon X56xx Westmere machine, there
> are plenty of such platforms where the GPU is indeed connected to both
> sockets. Or it could be a buggy BIOS.

Agreed.

Samuel