Re: [hwloc-users] lstopo and GPus

[Samuel Thibault]

Gabriele Fatigati, le Wed 29 Aug 2012 16:56:30 +0200, a écrit :
> The id showed in the GPU box from lstopo, is the same device_id CUDA 
> numeration
> used in some function like setDevice() for example?

Exactly.

Samuel

Re: [hwloc-users] lstopo and GPus

[Gabriele Fatigati]

Just another things:

The id showed in the GPU box from lstopo, is the same device_id CUDA
numeration used in some function like setDevice() for example?

More better:

gpu 1 from lstopo = ? gpu 1  for CUDA runtime?


Thanks.

2012/8/29 Gabriele Fatigati 

> Good!
>
> Now it works well.
>
> Many tanks!
>
> 2012/8/28 Samuel Thibault 
>
>> Gabriele Fatigati, le Tue 28 Aug 2012 18:10:41 +0200, a écrit :
>> > How can cuda branch help me? lstopo output of that branch is the same
>> of the
>> > trunk.
>>
>> You need to make sure that hwloc found the cuda runtime during
>> ./configure. You will then get new "cuda" devices.
>>
>> > Another question: the GPU IDs are the same (10de: 06d2). How is it
>> possible?
>>
>> Because the ID identifies the product type, not the physical device.
>>
>> 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
>



-- 
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

[Gabriele Fatigati]

Good!

Now it works well.

Many tanks!

2012/8/28 Samuel Thibault 

> Gabriele Fatigati, le Tue 28 Aug 2012 18:10:41 +0200, a écrit :
> > How can cuda branch help me? lstopo output of that branch is the same of
> the
> > trunk.
>
> You need to make sure that hwloc found the cuda runtime during
> ./configure. You will then get new "cuda" devices.
>
> > Another question: the GPU IDs are the same (10de: 06d2). How is it
> possible?
>
> Because the ID identifies the product type, not the physical device.
>
> 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]

Gabriele Fatigati, le Tue 28 Aug 2012 18:10:41 +0200, a écrit :
> How can cuda branch help me? lstopo output of that branch is the same of the
> trunk.

You need to make sure that hwloc found the cuda runtime during
./configure. You will then get new "cuda" devices.

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

Because the ID identifies the product type, not the physical device.

Samuel

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

Re: [hwloc-users] lstopo and GPus

[Samuel Thibault]

Gabriele Fatigati, le Tue 28 Aug 2012 14:19:44 +0200, a écrit :
> I attach the figure. The system has two GPUs, but I don't understand how to
> find that information from PCI boxes.

The 10de: devices are the GPUs (or alternatively, use the cuda
branch from the svn repository).  The figure shows that they are both
connected to the same bus.  You can additionally run lstopo as root to
get the bus speed.

Samuel

Re: [hwloc-users] lstopo and GPus

[Brice Goglin]

Hello,
For now, you have to look at PCI ids. NVIDIA GPUs have "10de:" as
vendor/device ids, that's what is shown in your boxes on the right.
We should have better GPU support in the future. Right now, we only use
what Linux knows, and it knows pretty much nothing about NVIDIA GPUs
because of the closed-source driver :/
Brice



Le 28/08/2012 14:18, Gabriele Fatigati a écrit :
> 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.it Tel:   +39 051
> 6171722 
>
> g.fatigati [AT] cineca.it   
>
>
> ___
> hwloc-users mailing list
> hwloc-us...@open-mpi.org
> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-users