Thanks for your reply Raymond, by 'If you got 96% both times, then I would say there's a problem.', did you mean if make performed like this, it means this project can't use make -jN? BTW, does CMake support some options to turn on hardware acceleration?
Raymond Wan-2 wrote > Hi Chao, > > > On Wed, Jul 13, 2016 at 10:54 AM, Chaos Zhang < > zcsd2012@ > > wrote: >> I was trying to compile my project using CMake, after CMake generated >> Makefile. >> I used `/usr/bin/time -v make` to make the Makefile, got the result: >> 'Percent of CPU this job got: 96%'. >> Then i used `/usr/bin/time -v make -j8` to make the Makefile, the result >> of >> CPU used is 'Percent of CPU this job got: 648%'. >> So i wonder if Makefile generated by CMake support make -jN, BTW my CPU >> is >> I7-4790, and after i use 'cat /proc/cpuinfo', there are 8 processors. > > > I'm not sure what you are asking... > > You ran make with -j 8 and you got a percentage greater than 96% ... > this implies that the Makefile does support -jN, doesn't it? If you > got 96% both times, then I would say there's a problem. > > Is what you're wondering why it is 648% and not 800%? I think that > depends on the dependencies in your Makefile. It's possible that some > of them depend on each other in such a way that 8 parallel threads is > not possible. > > Also, I can't remember the value returned by /usr/bin/time -v, but I > guess 648% is the average and not maximum. So, perhaps there are > parts within the Makefile that only one thread could be used and then > it gets averaged out? > > Ray > -- > > Powered by www.kitware.com > > Please keep messages on-topic and check the CMake FAQ at: > http://www.cmake.org/Wiki/CMake_FAQ > > Kitware offers various services to support the CMake community. For more > information on each offering, please visit: > > CMake Support: http://cmake.org/cmake/help/support.html > CMake Consulting: http://cmake.org/cmake/help/consulting.html > CMake Training Courses: http://cmake.org/cmake/help/training.html > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Follow this link to subscribe/unsubscribe: > http://public.kitware.com/mailman/listinfo/cmake -- View this message in context: http://cmake.3232098.n2.nabble.com/Does-Makefile-generated-by-CMake-support-make-jN-tp7593949p7593951.html Sent from the CMake mailing list archive at Nabble.com. -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake