I am working with OpenMPI and I don't have sysfs on my computer.

When I running a very basic MPI program (source attached), I get the
error :
libibverbs: Fatal: couldn't read uverbs ABI version.
--------------------------------------------------------------------------
[0,0,0]: OpenIB on host gabiniere was unable to find any HCAs.
Another transport will be used instead, although this may result in
lower performance.
--------------------------------------------------------------------------

Looking into the source of this lib, I saw that it tries to
check the abi of Infiniband (which I don't have and don't want to use).

Maybe it is more an OpenMPI bug which should not force the user to use
InfiniBand but there is anyway a bug in the lib : it should detect that
I don't have sysfs on my computer and display that.

My test program :
================
#include <mpi.h>

#define BUFSIZE 128

int main(int argc, char *argv[])
{
  MPI_Init(&argc,&argv);

  return 0;
}
================
# gcc -o testMPI testMpi.c  -lmpi && ./testMPI
libibverbs: Fatal: couldn't read uverbs ABI version.
--------------------------------------------------------------------------
[0,0,0]: OpenIB on host gabiniere was unable to find any HCAs.
Another transport will be used instead, although this may result in
lower performance.
--------------------------------------------------------------------------
================

I'm not sure what is being asked for here.  Would you like libibverbs1
to work if sysfs is not mounted, or are you just looking for a better
error message that explains the cause of the failure better?

Roland,

I came across the same issue today which Sylvestre reported earlier. Like
Sylvestre, I am working with OpenMPI, and I am unable 'suppress' these very
verbose libibverbs messages on startup.  I don't have Infiniband hardware,
and I would prefer it if this subsystem could be made more (or, preferably:
completely) silent so that I can get on with my simple OpenMPI work.

edd@basebud:~> r -e 'library(ROpenMPI)'
libibverbs: Fatal: couldn't read uverbs ABI version.
--------------------------------------------------------------------------
[0,0,0]: OpenIB on host basebud was unable to find any HCAs.
Another transport will be used instead, although this may result in
lower performance.
--------------------------------------------------------------------------

(ROpenMPI is a so-far port of Rmpi from LAM to OpenMPI. I may contribute that
back to Rmpi if I get it sorted out right).

Is there a way to achieve that?

I am running a standard Debian testing system with 2.6.17 or newer, depending
on the box, or Ubuntu 7.04 with 2.6.18/2.6.20.  Standard kernels as packaged.

Thanks, Dirk

Hello

Roland, I think both would be great.

Cheers,
Sylvestre

 > libibverbs: Fatal: couldn't read uverbs ABI version.

This is the libibverbs message.  For future versions I will look at
making this more informative and also providing a way to silence it
completely.

 > --------------------------------------------------------------------------
 > [0,0,0]: OpenIB on host basebud was unable to find any HCAs.
 > Another transport will be used instead, although this may result in
 > lower performance.
 > --------------------------------------------------------------------------

This (including the '-' lines) is coming from Open MPI.

However I'm a little confused about why this is a problem for you.  If
you don't have IB hardware and don't want to use IB, can't you just
disable the openib BTL at runtime (I would assume something like
"--mca btl ^openib" would work, and there's probably some way to put
that in your default config)?  Or just build Open MPI completely
without the openib BTL?

 - R.

Hi Roland,

On 25 May 2007 at 17:11, Roland Dreier wrote:
|  > libibverbs: Fatal: couldn't read uverbs ABI version.
|
| This is the libibverbs message.  For future versions I will look at
| making this more informative and also providing a way to silence it
| completely.

Excellent. That sounds like the right way.
|
|  > --------------------------------------------------------------------------
|  > [0,0,0]: OpenIB on host basebud was unable to find any HCAs.
|  > Another transport will be used instead, although this may result in
|  > lower performance.
|  > --------------------------------------------------------------------------
|
| This (including the '-' lines) is coming from Open MPI.

Ahh.

| However I'm a little confused about why this is a problem for you.  If
| you don't have IB hardware and don't want to use IB, can't you just
| disable the openib BTL at runtime (I would assume something like
| "--mca btl ^openib" would work, and there's probably some way to put
| that in your default config)?  Or just build Open MPI completely
| without the openib BTL?

Probably.  I am new to OpenMPI as I am just exploring it as an alternative for
an lam setup.

Thanks for the quick reply!

Dirk

Hi Roland,

On 25 May 2007 at 17:11, Roland Dreier wrote:
|  > libibverbs: Fatal: couldn't read uverbs ABI version.
|
| This is the libibverbs message.  For future versions I will look at
| making this more informative and also providing a way to silence it
| completely.

'apt-get source libibverbs' being as convenient as it is, it would indeed be
nice if you could, say, change

	if (check_abi_version(sysfs_path))
		return 0;

to also accept a 'verbosity' or 'silence' argument to just quietly exit here.

|  > --------------------------------------------------------------------------
|  > [0,0,0]: OpenIB on host basebud was unable to find any HCAs.
|  > Another transport will be used instead, although this may result in
|  > lower performance.
|  > --------------------------------------------------------------------------
|
| This (including the '-' lines) is coming from Open MPI.

I'll go digging there next -- thanks!

Dirk

| However I'm a little confused about why this is a problem for you.  If
| you don't have IB hardware and don't want to use IB, can't you just
| disable the openib BTL at runtime (I would assume something like
| "--mca btl ^openib" would work, and there's probably some way to put
| that in your default config)?  Or just build Open MPI completely
| without the openib BTL?
|
|  - R.

-- 
reply me please very importantant