Parallelization of recursive jobs in GNU make

Question

I am looking for an elegant way for the parallelization of jobs in GNU make. Here is a sample of what I did so far. Make processes the directories dir-1, dir-2 and dir-3 in a se

Answer 1

Are dir-1, dir-2 and dir-3 interdependent or independent?

I have a similar structure but dependence between the subdirectories so with that I preferred to just use parallel builds within each of the subdirectories. You'd get that via

## default to four parallel runs
MAKEFLAGS += -j 4  

all:
  @for dir in $(SUBDIRS); do (cd $$dir; $(MAKE) ); done

But another trick is to read up on SUBDIRS in the make manual -- you do not need the for loop as make can unroll this for you. Try something like

## default to four parallel runs
MAKEFLAGS += -j 4  

SUBDIRS =    dir-1 dir-2 dir-3

$(SUBDIRS):  #whatever your depends here
             $(MAKE) -C $@