<p>You shouldn't see timeouts. Sounds like a misconfiguration or a bug in the code. If you want an MPI_Allreduce, then MPI_Allreduce is the best way to get it. VecScatter is intended for less structured operations.</p>
<div class="gmail_quote">On Nov 7, 2011 10:42 PM, "Robert Ellis" <<a href="mailto:Robert.Ellis@geosoft.com">Robert.Ellis@geosoft.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal">Hello Petsc Developers,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I have a predominantly Petsc application but for simplicity it uses a very few MPI_AllReduce calls. I am finding that the MPI_AllReduce operations are sometimes causing problems (appears to be semaphore time outs) if the interprocess communication
is slow. I never have any problem with the Petsc operations. Is it reasonable that Petsc would be more robust that MPI_AllReduce?<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Also, is the VecScatterCreateToAll set of operations the best way to replace the MPI_AllReduce?<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Thanks for any advice,<u></u><u></u></p>
<p class="MsoNormal">Rob<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
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