2012-09-24 01:59, Claudio Freire skrev: > On Sun, Sep 23, 2012 at 6:29 PM, Paul Dreik <sl...@pauldreik.se> wrote: >>> I just added: >>> make pkg able to supply extra configure and make flags, useful for >>> distributions, including -j for make >> Just curios, are there any octave packages that benefit from parallel >> compilation? > > Well, for openSUSE, we build all packages at once, and it takes a very > long time, like an hour and a half, for about 80 packages. That's an > average build time of a minute per package, big enough to make a > difference with parallel compilation. > > I actually haven't tried though, convincing pkg.m to add extra flags > wasn't documented and seemed left out. Packaging would benefit from > being able to send config and make-time flags, besides the parallel > compilation aspect. Things like CFLAGS, for instance. > I think this is good and I do not oppose it at all! My thought was that make -j makes child processes of make run in parallel, which is different from having several instances of make run in parallel. That is why I asked if there is a package that improves from it - I guess a package has to use multiple source files, where at least some are nondependent so they can be compiled in parallel.
One could of course imagine a situation where a Makefile spanning several packages is possible, made from the dependency information in the packages. Invoking make at the root of the package tree would certainly improve package generation if -j is used for that make invokation. But that is maybe what you do for opensuse? @Stephen: no, I did not mean the benefit was negligible, I meant if -j would make any difference at all because it requires the build to be possible to parallelize. @Juan Pablo: You answered my question! I tried with -j4 and the compilation time dropped certainly dropped, but only when the slicot library has been built. Below, the "real" time output from the time command is used: cd control/src time make 72 seconds make clean (to get the caches warm. note, make clean does not remove slicotlibrary.a. Maybe it should?) time make 18 seconds make clean time make -j4 12 seconds make clean rm slicotlibrary.a time make -j4 63 seconds Paul ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Octave-dev mailing list Octave-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/octave-dev
