Hi Ludo, * Ludovic CourtÃs wrote on Thu, Mar 03, 2011 at 04:42:52PM CET: > I ran a series of build time measurements on a 32-core machine, with > make -jX, with X in [1..32], and the results are available at: > > http://hubble.gforge.inria.fr/parallel-builds.html Thank you! Would you be so kind and also describe what we see in the graphs? I'm sorry but I fail to understand what they are showing, what the axes really mean, and how to interpret the results. > There are packages whose configuration phase is noticeably longer than > the build time. Yes, we knew that. Can you please also mention whether you used a config.site file? Since using a config.cache file for one-time builds is not relevant, I'm assuming that is not necessary to know. But it would be fairly cool to know how development could be sped up. E.g., one thing you could try is, after configure -C once, save the config.cache file somewhere, remove the build directory, rerun configure with CONFIG_SITE pointing to that moved cached file. That could give a more realistic impression of how expensive configure overhead is while developing. (I understand that that isn't so interesting for a distribution.) Packages with many configure scripts (like GCC, binutils) will not benefit in the same way, of course. > OTOH, packages with a long build time (with a sequential time in > boldface) donât scale well either, but that is not configureâs fault. I suppose several packages' check bits would benefit from Automake's parallel-tests feature. A few of the packages (using an Autotest test suite: Autoconf, Bison) would benefit from you passing TESTSUITEFLAGS=-jN to make. FWIW, parallelizability of Automake's own 'make check' has been improved in the git tree (or so at least I hope). I am fairly surprised GCC build times scaled so little. IIRC I've seen way higher numbers. Is you I/O hardware adequate? Did you use only -j or also -l for the per-package times (I would recommend to not use -l). Thanks, Ralf _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
