Re: Improvement on parallel make

[Christophe Lyon]

On 12/12/06, Philip Guenther <address@hidden> wrote:

> [Dang it, fingers slipped and I sent while still editting.  So to continue...]
>
> Note that the desired makefile mentioned above:
> local_objects = a.o b.o c.o d.o
> all: all-recursive .WAIT all-local
> all-recursive:
>       $(MAKE) -C subdir all
> all-local: $(local_objects)
>
> can *currently* be implemented like this:
>
> local_objects = 
> a.o b.o c.o d.o
> all: all-recursive
>      $(MAKE) all-local
> all-recursive:
>      $(MAKE) -C subdir all
> all-local: $(local_objects)
>
> The choice to use recursive make means you've given up on maximizing
> your parallelism (because your dependency tree has to be a superset of
> the real tree).  As long as you've burned that bridge, why not use it
> here to express the ordering?

 

OK, this is the solution I am currently forced to use, but I really don't like to call make recursively just to solve this issue. As a side effect, you get plently messages saying that your targets are up-to-date.

 

Maintaining the various levels of Makefiles of large projects can quickly become impracticable.

 

I try to advocate good Makefile writing, but I also try to avoid recursive Makefiles, and having a feature such as this .WAIT implementation would be quite handy. Note that I am not defending some BSD compatibility, as I don't use BSD...

Christophe.