Re: make -j does not work on RedHat7.7 VM

[Henrik Carlqvist]

On Thu, 23 Dec 2021 12:49:51 +0000
"Zhu, Mason" <mason.zhu@sap.com> wrote:
> I checked our project make file. Yes, we are using recursive Make, but does
> not explicitly set -j options in MAKEFLAGS.
> 
> In GNU Make 3.82, it seems that -j option will be finally added if Make
> determines my VM has the parallel build capability. However in GNU Make
> 4.2.1, there is no parallel build if I does not explicitly set -jN option.
> 
> Does it mean that I have to explicitly set -jN in MAKEFLAGS  for GNU Make
> 4.2.1 now?

My guess is that you in your Makefile are making recursive calls to "make"
instead of recursive calls to $(MAKE)

If you failed to call $(MAKE) and instead called "make" the "make" you called
will be the first one in your path, probably not the "make" you intended to
call in this case.

Having one version of make calling another version of make might work less
good for parallell jobs as those version might not be able to communicate
between each other about tyhe parallell jobs.

regards Henrik