[mpich-discuss] Fix for Hydra/blaunch in MPICH2-1.3

[Pavan Balaji]

On 07/23/2010 03:41 PM, Yauheni Zelenko wrote:
> It works! Thank you for help!

Great.

> I have just question about query_node_list(). Is it default which may
>  be overwritten with mpiexec command line parameters or not?

Yes, that's correct. If you pass the "-f" option for the host list, 
Hydra will not query for the node list from LSF.

> Our application may use multi-threading in each process launch from 
> MPI, so sometimes we need to run one instance per host and use host's
>  CPUs given by LSF, so it'll be problem if query_node_list() could 
> not be overwritten.

In this case, you should use the -ppn option (processes per node) to 
mpiexec. This will overwrite the number of cores mpiexec detects, and 
use the number specified by the user. This way, you can still let Hydra 
query LSF for the node list, but force it to just run one process per 
each node.

  -- Pavan

-- 
Pavan Balaji
http://www.mcs.anl.gov/~balaji