[mpich-discuss] running out of communicators

[Ryan Crocker]

Hi Jim, 

That's the thing, i'm not sure where they are being created.  I initialize my MPI environment, then that program never gets called again.  The only think i can think of is that it's something to do with my MPI IO, but after every open file, i just double checked, there is a corresponding close file call. I also do not call MPI_Comm_dup, unless that is called by another mpi call that i am not aware of.

-Ryan

On Mar 19, 2013, at 6:13 PM, Jim Dinan wrote:

> Hi Ryan,
> 
> Every time you call MPI_Comm_dup a new communicator is created.  Are you ever freeing these, using MPI_Comm_free?
> 
> Also, what are you trying to achieve by using multiple communicators, and why does it require so many?
> 
> Best,
> ~Jim.
> 
> On 3/19/13 7:57 PM, Ryan Crocker wrote:
>> I realized i forgot to attach the error:
>> 
>> Fatal error in PMPI_Comm_dup: Other MPI error, error stack:
>> PMPI_Comm_dup(176)............: MPI_Comm_dup(comm=0x84000000, new_comm=0x7fff5fbfe9a4) failed
>> PMPI_Comm_dup(161)............:
>> MPIR_Comm_dup_impl(55)........:
>> MPIR_Comm_copy(967)...........:
>> MPIR_Get_contextid(521).......:
>> MPIR_Get_contextid_sparse(752): Too many communicators
>> 
>> Hi all,
>> 
>> So i can't seem to find the answer to this question.  I keep getting the failure "Too many communicators".  Could someone explain what calls "use up" communicators, and could i be calling/using more than the default total?.  I'm trying to debug my code so i can free up the communicators and not just repeatedly create them.  I'm a bit perplexed with this, probably a lack of  in depth knowledge, but i only run any of my MPI initializations one time then all my calls with mpi are either sums, max, min, allreduce, alltoall.
>> 
>> thanks
>> 
>> Ryan Crocker
>> University of Vermont, School of Engineering
>> Mechanical Engineering Department
>> rcrocker at uvm.edu
>> 315-212-7331
>> 
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Ryan Crocker
University of Vermont, School of Engineering
Mechanical Engineering Department
rcrocker at uvm.edu
315-212-7331