[Pkg-openmpi-maintainers] Ugly error messages when using openmpi

Dirk Eddelbuettel edd at debian.org
Thu Nov 8 12:56:29 UTC 2007


Hi Ondrej,

On 8 November 2007 at 12:38, Ondrej Certik wrote:
| Hi,
| 
| I created a new python-petsc4py package, available here:
| 
| http://debian.certik.cz/
| 
| It's depending on a new versin of petsc also available there and
| openmpi. See that link for all instructions how to use the archive.
| 
| $ apt-get install python-petsc4py
| $ python
| Python 2.4.4 (#2, Aug 16 2007, 02:03:40)
| [GCC 4.1.3 20070812 (prerelease) (Debian 4.1.2-15)] on linux2
| Type "help", "copyright", "credits" or "license" for more information.
| >>> from petsc4py.PETSc import Mat
| [fuji:06162] mca: base: component_find: unable to open osc pt2pt: file
| not found (ignored)
| libibverbs: Fatal: couldn't read uverbs ABI version.
| --------------------------------------------------------------------------
| [0,0,0]: OpenIB on host fuji was unable to find any HCAs.
| Another transport will be used instead, although this may result in
| lower performance.
| --------------------------------------------------------------------------
| >>> A=Mat()
| >>> A.createSeqAIJ(1000)
| <Mat object at 0xb5ee98ec (0x82cac40)>
| 
| 
| The petsc4py seems to work, but those error messages are weird. Either
| there should be nothing printed out if it works, or it should fail.
| But if it works (as it seems so) and it still prints those errors,
| that's I think unfortunate.

There are several things at play. 

i) The easiest is the 'OpenIB on host...'  which you can suppress by
commenting out the line	
	btl = ^openib
in /etc/openmpi/openmpi-mca-params.conf 

ii) The libibverbs message is, IIRC, gone in the 1.1 branch of libibverbs. 

iii) The 'unable to open osc pt2pt' is the hardest.  I had that with Rmpi and
upstream there found the right solution in one of the Open MPI FAQs: you an
explicit dlopen before MPI_Init is called. It is important that this happens
'early'.  Now, when that was discussed on the ompi lists, someone with
parallel python experience chimed and said that it was much harder to do for
Python do to some internal.  I am a bit mushy on the details now and in a
rush, but I could follow up or you could try the list archives.

Hth, Dirk


| I am currently investigating, if the problem is in petsc,
| python-petsc4py or openmpi, but I suspect openmpi. Did you ever see
| these errors before? What to do about it?
| When those issues are resolved, the new package will be uploaded in unstable.
| 
| Ondrej
| 
| P.S. Please CC me.
| 
| _______________________________________________
| Pkg-openmpi-maintainers mailing list
| Pkg-openmpi-maintainers at lists.alioth.debian.org
| http://lists.alioth.debian.org/mailman/listinfo/pkg-openmpi-maintainers

-- 
Three out of two people have difficulties with fractions.



More information about the Pkg-openmpi-maintainers mailing list