Em quarta-feira, 8 de março de 2017, às 14:44:51 CET, Ulf Hermann escreveu: > > That said, look at the numbers: it increased from ~100 µs to 16.9 ms in > > the > > worst case. You can't perceive that difference. > > This limits the number of processes you can spawn per second to about 60 > (and it goes lower if you eat more RAM).
Why would Qt Creator want to spawn more than 60 processes per second? > I certainly can notice this > when using the version of qbs compiled into QtCreator to compile a > project. In order to keep an 8-core CPU loaded and send extra jobs to > icecream you need a higher rate. > > There is a workaround for that by now, which just uses a separate > process to spawn the children, but it used to be a problem. Oh, that explains.Separate process is the correct solution. I 've just tried gmake in a very simple project and it called vfork() 26 times in a total runtime of 0.5 seconds -- that is, 52 times per second. That's a total count in the same order than the overhead inside Qt Creator. Note: gmake uses vfork(), whose stated goal is to avoid doing a page table duplication; QProcess and forkfd cannot do that. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center _______________________________________________ Development mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/development
