Parallel port building

FreeBSD 8.0 has brought a long-awaited feature to the table: Parallel port building. This can drastically decrease the time it takes to build ports on multicore machines. The catch is that it is a huge job to go through the 20000+ ports in FreeBSD and check if they can be built in parallel. Each port needs to be checked by a maintainer and then marked as MAKE_JOBS_SAFE=yes to take advantage of the new feature. The thing is, most of the ports work - only a small number have problems. If you are brave, you can enable parallel building of all the ports that has not been marked as MAKE_JOBS_SAFE or MAKE_JOBS_UNSAFE yet. I haven't had any problems, but I am keeping in mind if I am unable to build a port, I will remember to remove this from /etc/make.conf and try again, before panicking.

To enable parallel port building for all ports, except the ones marked as MAKE_JOBS_UNSAFE, add the following to /etc/make.conf:

FORCE_MAKE_JOBS=yes
MAKE_JOBS_NUMBER=4

The number 4 is how many jobs should run at once (-j4 to make) - I normally use double the number of cores. The default is the number of cores. I haven't really measured the difference. #cores*2 is just old habit from countless buildworld runs.