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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thanks for the reply Chuck.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Unfortunately there is no such message. I’m not even sure the GNU make jobserver is the problem. It’s just that the symptom is the same as if that were happening.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Am I comparing apples to apples when I go into the build directory created via ctest and invoking gmake manually, and comparing that to the way ctest is invoking
gmake? Manually, after I notice the ctest build has regressed to a single compile at a time, I kill ctest then I go to the build directory it created and do<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">gmake clean<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">find . –name ‘*.o’ –print|xargs rm<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">touch CMakeCache.txt<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">gmake –j 10<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">As I said, there’s a dramatic difference between the two. The manual build proceeds as I would expect and is done within an hour. The ctest build takes many
times longer. <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I should’ve mentioned that I’m using the 2.8.12.2 version of the tools.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Gary<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Chuck Atkins [mailto:chuck.atkins@kitware.com]
<br>
<b>Sent:</b> Thursday, September 11, 2014 1:03 PM<br>
<b>To:</b> Hennigan, Gary L<br>
<b>Cc:</b> cmake@cmake.org<br>
<b>Subject:</b> [EXTERNAL] Re: [CMake] FW: Parallel GNU make issue<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Hi Gary,<o:p></o:p></p>
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<p class="MsoNormal">Do you see either of these two warning messages show up:<br>
<br>
"warning: -jN forced in submake: disabling jobserver mode."<o:p></o:p></p>
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<p class="MsoNormal">or<br>
"warning: jobserver unavailable: using -j1. Add `+' to parent make rule."<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">These warnings often accompany the forced serialization of a parallel make build, although usually they show up regardless of the launch method, i.e. ctests vs manual make. These warnings are often indicative of a particular problem in
super-build scenarios..<o:p></o:p></p>
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<p class="MsoNormal"><br clear="all">
<o:p></o:p></p>
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<p class="MsoNormal">- Chuck<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Thu, Sep 11, 2014 at 2:29 PM, Hennigan, Gary L <<a href="mailto:glhenni@sandia.gov" target="_blank">glhenni@sandia.gov</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I have a strange, and very frustrating, problem. I have a pretty large piece of software that I build nightly as part of regression testing of my own software. All of the
software uses CMake and I use a ctest script, via “ctest –S [script file]”, for my nightly regression testing . As I stated, this is a pretty large collection of software but during development it’s not a huge issue because the build is quite parallelizable
via GNU make’s “-j N” option. On my nightly test platform, a 64-core machine, I can build the whole thing in about an hour. A nice manageable amount of time for a nightly regression test. Unfortunately when I run the build process via ctest something is causing
the parallel make to fail and I’m lucky if the build takes under 15 hours. Barely practical for a nightly test.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I’m not sure how to find out what’s going on. After the ctest build I can go into the build directory, do a “make clean” and then a “make –j 12”, for example, and the build
flies. Of course I can build the software entirely outside of ctest and it too flies. Only when the build happens as part of ctest does it seem to revert to, essentially, a “make –j 1” and slow to a crawl.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I can look at the process tree, via “ps –ef”, during the ctest build and I see the root invocation of gmake and it’s fine. For example, it typically looks something like:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New""> PID PPID C STIME TTY TIME CMD</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">6141 6283 96 11:41 pts/0 00:24:40 ctest -VV -S ctest_nightly.cmake -DPROCESSORCOUNT=12</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">8032 6141 0 11:42 pts/0 00:00:00 /usr/bin/gmake -i
<b>-j 12</b></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">8035 8032 0 11:42 pts/0 00:00:00 /usr/bin/gmake -f CMakeFiles/Makefile2 all</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New""> 851 8035 0 11:52 pts/0 00:00:00 /usr/bin/gmake -f packages/ml/src/CMakeFiles/ml.dir/build.make</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">27797 8035 0 11:46 pts/0 00:00:00 /usr/bin/gmake -f packages/moocho/src/CMakeFiles/moocho.dir/build.make</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New""> </span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">You can see that the parent make, PID 8032 which is started via ctest (PID 6141), has the appropriate flag, “-j 12”, but at this point in the build it’s compiling one file
at a time. Another odd thing is that I think the build starts out fine, invoking multiple file compilations simultaneously, but after a couple of minutes it reverts to essentially the “make –j 1” behavior. It’s like the GNU make jobserver is failing, but I’m
not getting any error messages from GNU make to that affect.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">If anyone has any suggestions on how I can figure this out I’d appreciate it.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Apologies for the lengthy explanation. I’ve been pulling my hair out trying to figure out how to solve this issue.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Thanks in advance,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Gary<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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