On Tue, Nov 10, 2009 at 11:40 AM, Cedric Brisseau <[email protected]> wrote:
> I have the impression that 'make -j' is only effective when just
> invoking "make" in a kernel compile or "make build" in a
> userland/xenocara build.
>
> It doesn't seem to have an effect on targets like 'depend', 'obj',
> 'distrib-dears', 'clean', etc.
make can only parallelize dependencies, but not the work in a target.
Targets like depend and clean don't have much in the way of
dependencies.
Also, a makefile like the below can't be parallelized, even though
there's plenty of opportunity if it's rewritten. So don't write
makefiles like this.
program:
cc -c a.c
cc -c b.c
cc -c c.c
cc -o prog a.o b.o c.o
