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Are there any updates on this issue? Thanks.</div>
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Kent</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Raffenetti, Kenneth J. <raffenet@mcs.anl.gov><br>
<b>Sent:</b> 24 June 2020 17:04<br>
<b>To:</b> discuss@mpich.org <discuss@mpich.org><br>
<b>Cc:</b> Kent Cheung <Kent.Cheung@arm.com><br>
<b>Subject:</b> Re: [mpich-discuss] Intermittent hang in MPI_Finalize with PGI 20.1</font>
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<div class="PlainText">Hi Kent,<br>
<br>
Thanks for your report. We have not seen this issue with any compiler/OS combination in our nightly tests. We are using PGI 19.4 at this time. I will request 20.1 be installed so we can investigate further.<br>
<br>
Ken <br>
<br>
On 6/23/20, 8:26 AM, "Kent Cheung via discuss" <discuss@mpich.org> wrote:<br>
<br>
I'm running into an issue where processes sometimes hang when calling MPI_Finalize. This happens with both versions 3.3.2 and 3.4a2 on a single node RedHat 7.5 x86-64 machine, when MPICH is compiled with PGI 20.1 with these configuration flags<br>
<br>
<br>
--enable-debug --enable-shared --enable-debuginfo --enable-sharedlib=gcc<br>
<br>
If I change the default optimization level (-O2) by configuring with<br>
<br>
--enable-fast=O1<br>
<br>
<br>
as well, the hang doesn't occur. Another data point is that the hang does not occur with PGI 19.5 with either optimization levels.<br>
<br>
I have been testing with the cpi.c code in the examples folder built with just<br>
<br>
mpicc cpi.c<br>
mpiexec -n 3 ./a.out<br>
<br>
<br>
Here is a the backtrace from one of the processes that is hanging<br>
<br>
(gdb) bt<br>
#0 MPID_nem_mpich_blocking_recv ()<br>
<br>
at /tmp/mpich-3.3.2/build/../src/mpid/ch3/channels/nemesis/include/mpid_nem_inline.h:1038<br>
<br>
#1 MPIDI_CH3I_Progress () at ../src/mpid/ch3/channels/nemesis/src/ch3_progress.c:506<br>
<br>
#2 0x00000000004fc88d in MPIDI_CH3U_VC_WaitForClose ()<br>
<br>
at ../src/mpid/ch3/src/ch3u_handle_connection.c:383<br>
<br>
#3 0x0000000000442364 in MPID_Finalize () at ../src/mpid/ch3/src/mpid_finalize.c:110<br>
<br>
#4 0x0000000000408621 in PMPI_Finalize () at ../src/mpi/init/finalize.c:260<br>
<br>
#5 0x00000000004023e5 in main () at cpi.c:59<br>
<br>
<br>
<br>
Is there a potential fix to be made to MPICH to prevent processes hanging when MPICH is compiled with the default optimization level?<br>
<br>
Thanks,<br>
Kent<br>
<br>
<br>
<br>
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