Open MPI logo

Hardware Locality Users' Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Hardware Locality Users mailing list

Subject: Re: [hwloc-users] Understanding hwloc-ps output
From: Brice Goglin (Brice.Goglin_at_[hidden])
Date: 2012-05-30 10:06:46


Jeff,
What is the displayed bitmask in OMPI 1.6? Is it the hwloc bitmask? Or
the OMPI bitmask made of OMPI indexes?
Brice

Le 30/05/2012 16:01, Jeff Squyres a écrit :
> You might want to try the OMPI tarball that is about to become OMPI v1.6.1 -- we made a bunch of affinity-related fixes, and it should be much more predictable / stable in what it does in terms of process binding:
>
> http://www.open-mpi.org/~jsquyres/unofficial/
>
> (these affinity fixes are not yet in a nightly 1.6 tarball because we're testing them before they get committed to the OMPI v1.6 SVN branch)
>
>
> On May 30, 2012, at 9:54 AM, Brice Goglin wrote:
>
>> Hello Youri,
>> When using openmpi 1.4.4 with --np 2 --bind-to-core --bycore” it reports the following:
>>> [hostname:03339] [[17125,0],0] odls:default:fork binding child [[17125,1],0] to cpus 0001
>>>
>>> [hostname:03339] [[17125,0],0] odls:default:fork binding child [[17125,1],1] to cpus 0002
>>>
>> Bitmask 0001 and 0002 mean CPUs with physical indexes 0 and 1 in OMPI 1.4. So that corresponds to the first core of each socket, and that matches what hwloc-ps says. Try "hwloc-ps -c" should show the same bitmask.
>>
>> However, I agree that these are not adjacent cores, but I don't know enough of OMPI binding options to understand what it was supposed to do in your case.
>>
>> Brice
>>
>> _______________________________________________
>> hwloc-users mailing list
>> hwloc-users_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-users
>