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Subject: Re: [hwloc-devel] PCI device location in hwloc
From: Brice Goglin (Brice.Goglin_at_[hidden])
Date: 2010-11-18 18:04:43

Le 18/11/2010 16:58, Samuel Thibault a écrit :
> Hello,
> Christopher Samuel, le Thu 18 Nov 2010 23:47:20 +0100, a écrit :
>> Does the information occur to the right of the socket with
>> the closest distance to the devices ?
> If your case, hwloc was apparently unable to decide whether the devices
> where "inside" one or the other NUMA node. Could you also post the
> output of gather-topology?

Many dual-nehalem-EP boxes have a single I/O hub which is connected to
both sockets, so no I/O affinity there. If your machine wasn't designed
to have many big PCIe slots (e.g. to plug multiple GPUs), that's
probably what's happening here.

Otherwise, it could be a machine with two I/O hubs (any multiple big
PCIe slots) and the BIOS not saying which one is close to which socket.