[mpich-discuss] Issue related to MPI_Comm_Spawn_Multiple

[Dave Goodell]

On Apr 8, 2013, at 4:47 AM CDT, Mahesh Doijade <maheshdoijade at gmail.com> wrote:

> Is there any upper limit for command line arguments passed to MPI_Comm_Spawn_Multiple. 

There is no intentional, specific upper limit, though there will probably be two limits in practice:

* an OS limit on number of arguments and/or total size (in bytes) of arguments: http://www.in-ulm.de/~mascheck/various/argmax/

* some limitations in our internal PMI protocols, which hopefully are at least being error checked right now

The first limit will probably result in an understandable error message.  I have no idea what will happen if you hit the second limit.

-Dave