On Wed, Feb 20, 2008 at 6:59 AM, Wilco Beekhuizen <[EMAIL PROTECTED]> wrote: > The use of make -j 3 really speeds up compilation on my new dual core > laptop. I noticed some problems with autoconf and make -j. > Furthermore, I checked the gentoo portage and it seems a lot of > packages are broken and need -j 1. So changing everything to -j 3 is > not an option.
Yep. It's not autoconf that's the problem since that's run synchronously from a shell script, but the Makefiles, whether hand written or generated by automake. It's actually somewhat difficult to write correct Makefiles so make will block on dependencies at correct times. Automake generated makefiles do an excellent job with this. The problems usually come when people write their own Makefiles or add custom rules in addition to default automake rules. What I was doing before was setting MAKEFLAGS=-j3 and passing -j1 when necessary. There aren't tons of packages that are broken in this sense, but it happens. > I think the future of make is to use multiple cores by default, or GCC > should support multi-core compilation since every new processor is a > dual or quad core processor. I don't think make will be defaulting to multiple jobs at any time since the result is so dependent on the Makefile, which make doesn't control. Sort of like compiler optimization, it has to be a buy-in type of thing. -- Dan -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
