[mpich-discuss] Max Communicators Limit

[Rob Latham]

On 09/09/2014 01:19 PM, Venkat Vishwanath wrote:

> There is  a maximum # of communicators one can create. How can I query this 
limit for MPICH? Is there a standard way to query this limit across MPI 
implementations?
>

Huh. It would appear not:
Cray uses an environment variable:
http://docs.cray.com/books/S-2310-50/html-S-2310-50/z1026396842smg.html
Intel asserts it's ~16k:
- https://software.intel.com/en-us/forums/topic/279324
MPICH limit used to be 8189:
- http://www.mcs.anl.gov/papers/P1621A.pdf

I guess the way to query is "create until it fails" ?
==rob

-- 
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA