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<p class="MsoNormal">The worker should call `MPI_Finalize` before exit. If somehow it hangs, assuming all the resources have been freed/disconnected, it must be a bug, please file an issue and we’ll track it down. Each spawned process has a different `MPI_COMM_WORLD`
from the process who spawned it.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">-- <br>
Hui Zhou<o:p></o:p></p>
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<b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">Mccall, Kurt E. (MSFC-EV41) via discuss <discuss@mpich.org><br>
<b>Date: </b>Sunday, February 21, 2021 at 3:06 PM<br>
<b>To: </b>discuss@mpich.org <discuss@mpich.org><br>
<b>Cc: </b>Mccall, Kurt E. (MSFC-EV41) <kurt.e.mccall@nasa.gov><br>
<b>Subject: </b>[mpich-discuss] Calling MPI_Finalize or not<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in">Two questions:<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in"> <o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in">I have a group of manager processes, each of which uses MPI_Comm_spawn() to create individual worker processes one at a time.
<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in">Occasionally, a worker has to exit and is replaced by another worker via MPI_Comm_spawn(). If the exiting worker calls MPI_Finalize(),
<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in">will it sit there waiting for all other managers and workers in MPI_COMM_WORLD to do the same, or will it wait only for the manager
<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in">that created its inter-communicator to call MPI_Finalize?<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in"> <o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in">In either case, maybe it is better for the worker to NOT call MPI_Finalize at all so that it doesn’t sit there taking up a core’s resources
<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in">while it waits for the others. What are the implications of not calling MPI_Finalize in the workers?<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in"> <o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in">Thanks,<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in">Kurt<o:p></o:p></p>
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