I have a Makefile on a machine that has a ton of cores in it, but I always seem to forget to write -jX when compiling my project and it takes way longer than it should.
Is there some way I can set the -j flag through an environment variable or some other persistent config file so that make will automatically execute multiple jobs in parallel on this machine?
I'm assuming you're using Linux. This is from my ~/.bashrc
# parallel make
export NUMCPUS=`grep -c '^processor' /proc/cpuinfo`
alias pmake='time nice make -j$NUMCPUS --load-average=$NUMCPUS'
sample usage
samm@host src> echo $NUMCPUS
8
samm@host src> pmake
becomes time nice make -j8 --load-average=8.
To answer your specific question about putting this into a Makefile, I don't find it practical to sprinkle this logic all over my Makefiles. Putting this into a top level Makefile also isn't a great solution since I often build from sub-directories and wish to build them in parallel as well. However, if you have a fairly flat source hierarchy, it may work for you.
