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QtCreator 4.0.0 no more mingw parallel compilation

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creator4.0.0qtcreatorparallelcompilation
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  • K Offline
    K Offline
    Keyos
    wrote on last edited by
    #2

    I just updated QtCreator from 4.0.0 to 4.0.1 but the the mingw target still compile using one single core, there is a way to set the mingw kit to spread compilations on all avaiable cores like it was doing in the QtCreator 3.xx version?

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    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #3

      Hi,

      You should compare the build output of both version of Qt Creator so see if there's anything changed between the two.

      Interested in AI ? www.idiap.ch
      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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      • K Offline
        K Offline
        Keyos
        wrote on last edited by Keyos
        #4

        Looks like i have to manually override the make setting for every project changing:
        MAKE: C:\Qt\Tools\mingw492_32\bin\mingw32-make.exe
        to
        MAKE: C:\Qt\Tools\QtCreator\bin\jom.exe
        than i can build quickly again taking advantage of all cpu cores.
        I have no idea how i can set this override globally.

        I can't remember what was the compile output when i was using the creator 3.6.1 about 2 weeks ago, but it was distributing the compilations automatically on all cpu cores without the need to change any settings.
        In the "build & run" options the "use jom" checkbox is checked like it was before, so i have no idea why old kits was using multiple compilation threads out of the box and now since the creator 4.0.0 you have to manually force it for mingw.

        jsulmJ D 2 Replies Last reply
        0
        • K Keyos

          Looks like i have to manually override the make setting for every project changing:
          MAKE: C:\Qt\Tools\mingw492_32\bin\mingw32-make.exe
          to
          MAKE: C:\Qt\Tools\QtCreator\bin\jom.exe
          than i can build quickly again taking advantage of all cpu cores.
          I have no idea how i can set this override globally.

          I can't remember what was the compile output when i was using the creator 3.6.1 about 2 weeks ago, but it was distributing the compilations automatically on all cpu cores without the need to change any settings.
          In the "build & run" options the "use jom" checkbox is checked like it was before, so i have no idea why old kits was using multiple compilation threads out of the box and now since the creator 4.0.0 you have to manually force it for mingw.

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by jsulm
          #5

          @Keyos make does not use multiple cores by default, you need to pass -j NUMBER_OF_THREADS as parameter to it (in Projects tab).

          https://forum.qt.io/topic/113070/qt-code-of-conduct

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          • K Keyos

            Looks like i have to manually override the make setting for every project changing:
            MAKE: C:\Qt\Tools\mingw492_32\bin\mingw32-make.exe
            to
            MAKE: C:\Qt\Tools\QtCreator\bin\jom.exe
            than i can build quickly again taking advantage of all cpu cores.
            I have no idea how i can set this override globally.

            I can't remember what was the compile output when i was using the creator 3.6.1 about 2 weeks ago, but it was distributing the compilations automatically on all cpu cores without the need to change any settings.
            In the "build & run" options the "use jom" checkbox is checked like it was before, so i have no idea why old kits was using multiple compilation threads out of the box and now since the creator 4.0.0 you have to manually force it for mingw.

            D Offline
            D Offline
            Devopia53
            wrote on last edited by Devopia53
            #6

            @Keyos

            Hi,

            You can set the system environment variable.
            like this: MAKE_COMMAND=C:\Qt\Tools\QtCreator\bin\jom.exe

            or

            Tools -> Options -> Build & Run -> Kits -> Select kit -> Environment -> Change... -> Add : MAKE_COMMAND=C:\Qt\Tools\QtCreator\bin\jom.exe -> Ok

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            • K Offline
              K Offline
              Keyos
              wrote on last edited by
              #7

              Thank you very much for the informations!
              Than i presume the old creator (3.6.1) was using jom or pasing "-j NUMBER_OF_THREADS" to mingw32-make by default and somehow this feature have been lost in the passage to the new 4.x.x as i can see the variable NUMBER_OF_THREADS is set correctly to 4 on my setup

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              • K Offline
                K Offline
                Keyos
                wrote on last edited by
                #8

                Sorry i meant "NUMBER_OF_PROCESSORS=4" wich is set by default correctly after the installation, but i suppoose the meaning and purpose is the same as "NUMBER_OF_THREADS" when calling mingw32-make with -j option

                jsulmJ K 2 Replies Last reply
                0
                • K Keyos

                  Sorry i meant "NUMBER_OF_PROCESSORS=4" wich is set by default correctly after the installation, but i suppoose the meaning and purpose is the same as "NUMBER_OF_THREADS" when calling mingw32-make with -j option

                  jsulmJ Offline
                  jsulmJ Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on last edited by
                  #9

                  @Keyos You should use number of threads. On CPUs with hyper threading it means: number of cores * 2. Then you can utilize your CPU better.

                  https://forum.qt.io/topic/113070/qt-code-of-conduct

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                  • K Offline
                    K Offline
                    Keyos
                    wrote on last edited by
                    #10

                    I wonder why they stopped using jom or passing the -j option when using the mingw kit by default since the qtcreator 4.0.0
                    There is a reason like for example jom is not reliable or they just forgot to call it?

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                    0
                    • jsulmJ Offline
                      jsulmJ Offline
                      jsulm
                      Lifetime Qt Champion
                      wrote on last edited by
                      #11

                      As far as I know -j was never passed by default.
                      Not sure about jom.

                      https://forum.qt.io/topic/113070/qt-code-of-conduct

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                      • K Keyos

                        Sorry i meant "NUMBER_OF_PROCESSORS=4" wich is set by default correctly after the installation, but i suppoose the meaning and purpose is the same as "NUMBER_OF_THREADS" when calling mingw32-make with -j option

                        K Offline
                        K Offline
                        koahnig
                        wrote on last edited by
                        #12

                        @Keyos said:

                        Sorry i meant "NUMBER_OF_PROCESSORS=4" wich is set by default correctly after the installation, but i suppoose the meaning and purpose is the same as "NUMBER_OF_THREADS" when calling mingw32-make with -j option

                        I have updated today (unfortunately, I had to) from an old Qt creator version 3.2 to Qt creator version 4.0.2 and assumed that I have encountered the same problem.

                        My standard environment has also "NUMBER_OF_PROCESSORS=4" and suddenly the compilation took ages after upgrading. With a couple of trials I have found that also adding this seting to project environment and "NUMBER_OF_THREADS=4" does not influence the compiling.

                        Either you need to add "-j4" as make parameter to each of your projects. Otherwise you can set also "MAKEFLAGS=-j4" to your environment (e.g. for a kit as suggested above).

                        jom was created as a substitute for nmake ( MS flavor of make). nmake does not support outside of VS multi core compilations. jom does support this when used in combination with ms compilers.

                        This blog suggest that jom detects the number of available cores automatically:
                        "To install jom, just extract the zip file to a directory which is in your PATH. Now, instead of calling nmake to build Qt, call jom. It automatically detects the number of processor cores in your PC by calling QThread::idealThreadCount().
                        You also can use the -j command line argument to set the number of concurrent processes."

                        Vote the answer(s) that helped you to solve your issue(s)

                        K 1 Reply Last reply
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                        • K koahnig

                          @Keyos said:

                          Sorry i meant "NUMBER_OF_PROCESSORS=4" wich is set by default correctly after the installation, but i suppoose the meaning and purpose is the same as "NUMBER_OF_THREADS" when calling mingw32-make with -j option

                          I have updated today (unfortunately, I had to) from an old Qt creator version 3.2 to Qt creator version 4.0.2 and assumed that I have encountered the same problem.

                          My standard environment has also "NUMBER_OF_PROCESSORS=4" and suddenly the compilation took ages after upgrading. With a couple of trials I have found that also adding this seting to project environment and "NUMBER_OF_THREADS=4" does not influence the compiling.

                          Either you need to add "-j4" as make parameter to each of your projects. Otherwise you can set also "MAKEFLAGS=-j4" to your environment (e.g. for a kit as suggested above).

                          jom was created as a substitute for nmake ( MS flavor of make). nmake does not support outside of VS multi core compilations. jom does support this when used in combination with ms compilers.

                          This blog suggest that jom detects the number of available cores automatically:
                          "To install jom, just extract the zip file to a directory which is in your PATH. Now, instead of calling nmake to build Qt, call jom. It automatically detects the number of processor cores in your PC by calling QThread::idealThreadCount().
                          You also can use the -j command line argument to set the number of concurrent processes."

                          K Offline
                          K Offline
                          koahnig
                          wrote on last edited by
                          #13

                          @koahnig said:

                          Either you need to add "-j4" as make parameter to each of your projects. Otherwise you can set also "MAKEFLAGS=-j4" to your environment (e.g. for a kit as suggested above).

                          Correction to above post. I have set it to system environment. I did not get it to work in kit environment. Both were set due to my trials, but the latter alone (in kit environment) does not help.

                          Vote the answer(s) that helped you to solve your issue(s)

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