additional command line switches / extensions for mpiexec?

[Thomas Zeiser]

Dear all,

some ideas for additional command line switches / extensions for
mpiexec came to my mind and I'd like to hear if they would be of
general interest. 

1) mpiexec already has "-pernode" but thinking of n-way nodes with
dual-core CPUs, a switch like "-Npernode <n>" might be very useful
(and probably easy to implement, i.e. in get_hosts.c one probably
only would have to set nodes[i].availcpu to the correct n)

2) mpiexec currently does a block distribution of processes (i.e.
first fill one node before going to the next one); for some
applications a round-robin assignment could improve performance.
This round-robin assignment of course can be done with the help of
a config file given to mpiexec but if it is of interest for more
people, a command line switch might be easier to use.

3) to further improve performance processes, it is sometimes
necessary to pin processes to certain CPUs (e.g. via
taskset/PLPA). It would be very helpful if mpiexec could set an
environment variable which tells the "local rank" of the process on
the current node, i.e. how many processes have been started via
pbs_mom before (not including mpiexec shepherd processes)


Regards,

thomas
-- 
Dipl.-Ing. Thomas ZEISER
Regionales Rechenzentrum Erlangen
Martensstr. 1, 91058 Erlangen, GERMANY