Re: [hwloc-users] lstopo and GPus

[Gabriele Fatigati]

Hi,

thanks for the reply.

How can cuda branch help me? lstopo output of that branch is the same of
the trunk.

Another question: the GPU IDs are the same (10de: 06d2). How is it possible?

Thanks.

2012/8/28 Samuel Thibault 

> 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
> ___
> hwloc-users mailing list
> hwloc-us...@open-mpi.org
> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-users
>



-- 
Ing. Gabriele Fatigati

HPC specialist

SuperComputing Applications and Innovation Department

Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy

www.cineca.itTel:   +39 051 6171722

g.fatigati [AT] cineca.it

Re: [hwloc-users] lstopo and GPus

[Samuel Thibault]

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

Re: [hwloc-users] lstopo and GPus

[Brice Goglin]

Le 28/08/2012 14:23, Samuel Thibault a écrit :
> Gabriele Fatigati, le Tue 28 Aug 2012 14:19:44 +0200, a écrit :
>> I'm using hwloc 1.5. I would to see how GPUs are connected with the processor
>> socket using lstopo command. 
> About connexion with the socket, there is indeed no real graphical
> difference between "connected to socket #1" and "connected to all
> sockets". You can use the text output for that:
>
> $ 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. Both the
socket and the PCI bus are drawn inside the NUMA box, so things appear
OK in graphics to.

I've never seen the problem on a real machine, but a fake topology with
a PCI bus attached to a socket that is not strictly equal to the above
NUMA node is indeed wrongly displayed.


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.

Brice

Re: [hwloc-users] lstopo and GPus

[Samuel Thibault]

Gabriele Fatigati, le Tue 28 Aug 2012 14:19:44 +0200, a écrit :
> I'm using hwloc 1.5. I would to see how GPUs are connected with the processor
> socket using lstopo command. 

About connexion with the socket, there is indeed no real graphical
difference between "connected to socket #1" and "connected to all
sockets". You can use the text output for that:

$ lstopo
  Socket #0
  Socket #1
PCI...
(connected to socket #1)

vs

$ lstopo
  Socket #0
  Socket #1
  PCI...
(connected to both sockets)

Samuel

[hwloc-users] lstopo and GPus

[Gabriele Fatigati]

Dear hwloc user,

I'm using hwloc 1.5. I would to see how GPUs are connected with the
processor socket using lstopo command.

I attach the figure. The system has two GPUs, but I don't understand how to
find that information from PCI boxes.

Thanks in advance.



-- 
Ing. Gabriele Fatigati

HPC specialist

SuperComputing Applications and Innovation Department

Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy

www.cineca.itTel:   +39 051 6171722

g.fatigati [AT] cineca.it