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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Is he actually talking about a
heterogeneous system? All I see are different operating systems.
Unless the Xeon is 64 bit, it seems like byte ordering and type sizes should
all be equal, which as far as I know is the only kind of heterogeneity that
would affect MPI. Am I wrong?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Matt Chambers<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Vanderbilt Bioinformatics<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
owner-mpich-discuss@mcs.anl.gov [mailto:owner-mpich-discuss@mcs.anl.gov] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Rajeev Thakur<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, November 29, 2006
1:11 PM<br>
<b><span style='font-weight:bold'>To:</span></b> 'Salvatore Sorce'; mpich-discuss@mcs.anl.gov<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [MPICH] Communication
problem on a small heterogeneous ring involving Red Hat Linux - Enterprise
Edition</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>MPICH2 does not work on heterogeneous
systems yet, although we plan to support it in the future.</span></font><o:p></o:p></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Rajeev</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
owner-mpich-discuss@mcs.anl.gov [mailto:owner-mpich-discuss@mcs.anl.gov] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Salvatore Sorce<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, November 29, 2006
8:51 AM<br>
<b><span style='font-weight:bold'>To:</span></b> mpich-discuss@mcs.anl.gov<br>
<b><span style='font-weight:bold'>Subject:</span></b> [MPICH] Communication
problem on a small heterogeneous ring involving Red Hat Linux - Enterprise
Edition</span></font><o:p></o:p></p>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Dear all,</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I have a small cluster composed by four machines: two
double-PIII running Scientific Linux CERN release 3.0.8 (kernel 2.4.21-37.EL),
one double-Xeon running Red Hat Enterprise Linux WS release 3 (Taroon update 4,
kernel 2.4.21-27 EL), and one single-PIV running Red Hat Linux Release 9
(Shrike, kernel 2.4.20-8). All machines have MPICH2 1.0.4p1 installed.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Tests on whatever kind of ring I set up are OK, and
processes are correctly spawned and started on right hosts.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I experienced problems when processes need to communicate
each other, and one side of the communication is the machine with Red Hat
Enterprise Linux OS. If I do not involve the Enterprise Linux machine in
communications, all runs right.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I am using a simple send-and-receive Fortran test program,
where process #1 sends an array of real to process #0. Both processes use
blocking communication functions (mpi_send and mpi_recv).</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>When process #0 (the receiving one) runs on the Red Hat
Enterprise Linux machine, all hangs up at the mpi_send (maybe because on the
Enterprise Linux side the mpi_recv do not accomplish its task).</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>When process #1 (the sending one) runs on the Red Hat
Enterprise Linux machine, I obtain the following output:</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>[cli_0]: aborting job:<br>
Fatal error in MPI_Recv: Other MPI error, error stack:<br>
MPI_Recv(186)................................: MPI_Recv(buf=0xbfff2368,
count=2, MPI_REAL, src=1, tag=17, MPI_COMM_WORLD, status=0xbfff2010) failed<br>
MPIDI_CH3_Progress_wait(217).................: an error occurred while handling
an event returned by MPIDU_Sock_Wait()<br>
MPIDI_CH3I_Progress_handle_sock_event(590)...: <br>
MPIDI_CH3_Sockconn_handle_connopen_event(791): unable to find the process group
structure with id <><br>
[cli_1]: aborting job:<br>
Fatal error in MPI_Send: Other MPI error, error stack:<br>
MPI_Send(173).............................: MPI_Send(buf=0x7fbffebdf0, count=2,
MPI_REAL, dest=0, tag=17, MPI_COMM_WORLD) failed<br>
MPIDI_CH3_Progress_wait(217)..............: an error occurred while handling an
event returned by MPIDU_Sock_Wait()<br>
MPIDI_CH3I_Progress_handle_sock_event(415): <br>
MPIDU_Socki_handle_read(670)..............: connection failure
(set=0,sock=1,errno=104:Connection reset by peer)<br>
rank 0 in job 1 mpitemp_32877 caused collective abort of all
ranks<br>
exit status of rank 0: return code 1</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I understand that in both cases mpi_recv causes an error,
what is the problem?</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thank you in advance for your attention.</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Regards,</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Salvatore.</span></font><o:p></o:p></p>
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