[FLASH-BUGS] MPI_REQUEST_MAX

[Tomasz Plewa]

Peter -

This is for the first time I see this kind of error.

I Can you associate this error with any part of the code? Having a
checkpoint file saved prior to suspected crash and restarting the code
would tell us whether such error is really due to accumulation of
requests. Writing some trace messages from master processor around
major modules in flash.F90 evolution loop would tell us where this
error might be occuring.

Tomek
--
On Thu, Dec 02, 2004 at 02:14:47PM +0100, Peter Woitke wrote:
> Dear developers,
> 
> for long runs (more than 12 hours on 32 Processors) my flash-job
> crashes with error message
> 
> *** MPI has run out of request entries.
> *** The current allocation level is:
> ***     MPI_REQUEST_MAX = 16384
> 
> Here is some advice from google:
> http://www.cray.com/craydoc/manuals/004-3687-001/html-004-3687-001/zfixe
> dlqtgeczn.htmlD
> 8.5. Why do I keep getting error messages about MPI_REQUEST_MAX being
> too small, no matter how large I set it?
> You are probably calling MPI_Isend(3) or MPI_Irecv(3) and not completing
> or freeing your request objects. You should use MPI_Request_free(3), as
> described in the previous question.
> 
> I checked that, indeed, MPI_Isend and MPI_Irecv are called from the 
> FLASH-code, but MPI_Request_free is never called.
> 
> Have you thought about this?
> 
> Thanx,
> 
> Peter Woitke

-- 
Thu, 09:31 CST (15:31 GMT), Dec-02-2004
_______________________________________________________________________________

   Tomasz Plewa                                      www:   flash.uchicago.edu
   Computational Physics and Validation Group        email: tomek at uchicago.edu
   The ASC FLASH Center, The University of Chicago   phone: 773.834.3227
   5640 South Ellis Ave, RI 475, Chicago, IL 60637   fax:   773.834.3230
_______________________________________________________________________________