<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><DIV>Sorry can't do that. The benchmark involves 2 things. One from my customer which</DIV>
<DIV>I am not allowed to distribute. I may be able to get a limited license of my product</DIV>
<DIV>for you to try, but I definately can not send source code.</DIV>
<DIV> </DIV>
<DIV>tan</DIV>
<DIV> </DIV>
<DIV style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"><BR>
<DIV style="FONT-FAMILY: arial, helvetica, sans-serif; FONT-SIZE: 13px"><FONT size=2 face=Tahoma>
<HR SIZE=1>
<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Darius Buntinas <buntinas@mcs.anl.gov><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> mpich-discuss@mcs.anl.gov<BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Monday, July 13, 2009 10:54:50 AM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [mpich-discuss] version 1.1 strange behavior : all processes become idle for extensive period<BR></FONT><BR><BR>Can you send us the benchmark you're using? This will help us figure<BR>out what's going on.<BR><BR>Thanks,<BR>-d<BR><BR>On 07/13/2009 12:36 PM, chong tan wrote:<BR>> <BR>> thanks darius,<BR>> <BR>> When I did the comparison (or benchmarking), I have 2 identical source<BR>> trees. Everything<BR>> were recompiled group up and compiled/linked accordinglyto the version<BR>> of MPICH2<BR>> to be used.<BR>> <BR>> I have many tests, this is the only one showing this behavior,
and is<BR>> predictably repeatable.<BR>> most of my tests are showing comaptible performance and many do better<BR>> with 1.1.<BR>> <BR>> The 'weirdest' thing is the ~1 minute span where there is no activity on<BR>> the box at all, zipo<BR>> activity except 'top', with machine load at around 0.12. I don't know<BR>> how to explain this<BR>> 'behavior', and I am extremely curious if anyone can explain this.<BR>> <BR>> I can't repeat this on AMD boxes as I don't have one that has only 32G<BR>> of memory. I can't<BR>> repeat this on Niagara box as thread multiple won't build.<BR>> <BR>> I will try to rebuild 1.1 without thread-multiple. Will keep you posted.<BR>> <BR>> Meanwhile, if anyone has any speculations on this, please bring them up.<BR>> <BR>> thanks<BR>> tan<BR>> <BR>>
------------------------------------------------------------------------<BR>> *From:* Darius Buntinas <<A href="mailto:buntinas@mcs.anl.gov" ymailto="mailto:buntinas@mcs.anl.gov">buntinas@mcs.anl.gov</A>><BR>> *To:* <A href="mailto:mpich-discuss@mcs.anl.gov" ymailto="mailto:mpich-discuss@mcs.anl.gov">mpich-discuss@mcs.anl.gov</A><BR>> *Sent:* Monday, July 13, 2009 8:30:19 AM<BR>> *Subject:* Re: [mpich-discuss] version 1.1 strange behavior : all<BR>> processes become idle for extensive period<BR>> <BR>> Tan,<BR>> <BR>> Did you just re-link the applications, or did you recompile them?<BR>> Version 1.1 is most likely not binary compatible with 1.0.6, so you<BR>> really need to recompile the application.<BR>> <BR>> Next, don't use the --enable-threads=multiple flag when configuring<BR>> mpich2. By default, mpich2 supports all thread levels and will select<BR>> the thread level at run time (depending
on the parameters passed to<BR>> MPI_Init_thread). By allowing the thread level to be selected<BR>> automatically at run time, you'll avoid the overhead of thread safety<BR>> when it's not needed, allowing your non-threaded applications to run faster.<BR>> <BR>> Let us know if either of these fixes the problem, especially if just<BR>> removing the --enable-threads option fixes this.<BR>> <BR>> Thanks,<BR>> -d<BR>> <BR>> On 07/10/2009 06:19 PM, chong tan wrote:<BR>>> I am seeing this funny situation which I did not see on 1.0.6 and<BR>>> 1.0.8. Some background:<BR>>> <BR>>> machine : INTEL 4Xcore 2<BR>>> <BR>>> running mpiexec -n 4<BR>>> <BR>>> machine has 32G of mem.<BR>>> <BR>>> when my application runs, almost all memory are used. However, there<BR>>> is no swapping.<BR>>> I have exclusive use of the machine, so contention
is not an issue.<BR>>> <BR>>> issue #1 : processes take extra long to be initialized, compared to 1.0.6<BR>>> issue #2 : during the run, at time all of them will become idle at the<BR>>> same time, for almost a<BR>>> minute. We never observed this with 1.0.6<BR>>> <BR>>> <BR>>> The codes are the same, only linked with different versions of MPICH2.<BR>>> <BR>>> MPICH2 was built with --enable-threads=multiple for 1.1. without for<BR>>> 1.0.6 or 1.0.8<BR>>> <BR>>> MPI calls are all in the main application thread. I used only 4 MPI<BR>>> functions :<BR>>> init(), Send(), Recv() and Barrier().<BR>>> <BR>>> <BR>>> <BR>>> any suggestion ?<BR>>> <BR>>> thanks<BR>>> tan<BR>>><BR>>> <BR>>><BR>>>
<BR>>><BR>>><BR>> <BR></DIV></DIV></div><br>
</body></html>