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<DIV dir=ltr align=left><SPAN class=088190422-29052007><FONT face=Arial
color=#0000ff size=2>One way is to try to simplify the program and get the
smallest version that fails. For example, delete all the computation, leave only
the communication and see if it still hangs. Does it hang on a small number of
processes (2 or 4)?</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=088190422-29052007><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=088190422-29052007><FONT face=Arial
color=#0000ff size=2>Rajeev</FONT></SPAN></DIV><BR>
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<FONT face=Tahoma size=2><B>From:</B> owner-mpich-discuss@mcs.anl.gov
[mailto:owner-mpich-discuss@mcs.anl.gov] <B>On Behalf Of </B>Christian
Zemlin<BR><B>Sent:</B> Tuesday, May 29, 2007 4:02 PM<BR><B>To:</B>
mpich-discuss@mcs.anl.gov<BR><B>Subject:</B> [MPICH] MPICH2 freezes at
Send/Recv pair that it previously executed<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV><FONT face=Arial size=2>I am running a parallel simulation using MPICH2,
and occasionally this simulation freezes in the middle of the execution, as
far as I can tell at a point where two slave nodes exchange data.
</FONT></DIV>
<DIV><FONT face=Arial size=2>What I don't understand is that this happens
although the Send/Recv pair is executed thousands of times without problems,
and then it still freezes, as if the nodes cannot communicate.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Any ideas how I can solve or better understand
what is going wrong?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Christian</FONT></DIV></BLOCKQUOTE></BODY></HTML>