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Subject: Re: [OMPI users] Problem with repeatedly spawning a few processes
From: Tim Miller (btamiller_at_[hidden])
Date: 2009-08-31 21:25:01


Thanks -- I downloaded the latest 1.4 snapshot after I saw your message and
verified that this issue does not seem to occur in it. However, I ran into
other stability issues (not necessarily surprising for a development
snapshot). Is there any idea on when 1.3.4 will be out and if this fix will
be migrated in?

Thanks again very much for your help.


On Wed, Aug 26, 2009 at 6:07 PM, Ralph Castain <rhc_at_[hidden]> wrote:

> This is a known issue - I'll test to see if it has been fixed for the
> upcoming 1.3.4. We know the problem does not exist in our devel trunk, but I
> don't know if the fix propagated to the 1.3 branch.
> On Aug 26, 2009, at 3:40 PM, Tim Miller wrote:
> Hello Everyone,
>> I have a problem that I can't seem to figure out from searching the
>> mailing list archive. I have a code that repeatedly spawns (via
>> MPI_COMM_SPAWN) a group of 8 processes and then waits for them to finish.
>> The problem is that OpenMPI (I've tried 1.3.1 and 1.3.3) opens a pipe each
>> time MPI_COMM_SPAWN is called, but this pipe never gets closed (even if I
>> call MPI_COMM_FREE on both the parent and child). Therefore, eventually my
>> master process hits the limit of open file descriptors and cannot spawn any
>> more. I cannot figure out why this is happening since I am only spawning 8
>> jobs at a time.
>> I should note that I don't exchange any data over the child
>> intercommunicators -- they exist solely so I can call MPI_BARRIER on them
>> (the spawned processes are programed to call MPI_BARRIER directly before
>> they call MPI_FINALIZE, thus indicating that they are done doing their
>> work).
>> I'd appreciate any suggestions as to what I might be doing wrong with this
>> that is causing OpenMPI to hold the pipes open.
>> Thanks,
>> Tim M.
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
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