Make parallelism is to high by default

[stv0g]

DPsim's build system uses make -j$(nproc) in many places which undesirable as this degree of parallelism is quite high for some systems.

I see that my machine (64GB, 16-core i7 workstation) quickly fills up all of the memory and slows down. So a make -j6 is a lot faster than a make -j16 as we dont need to do demand paging..

I propose the make the make parallelism configurable via a environment variable named MAKE_PROCS

[dinkelbachjan]

Thanks, that's very good to know! I agree with your proprosal. Should we go for a default value of 8 then?

[stv0g]

I think 8 could be a reasonable default. But its also more important that we can easily change this in the scripts by settings an environment variable. E.g. MAKE_PROCS as mentioned above.

[n-eiling]

Cmake also has -j

-j [<jobs>], --parallel [<jobs>]

    New in version 3.12.

    The maximum number of concurrent processes to use when building. If <jobs> is omitted the native build tool's default number is used.

    The CMAKE_BUILD_PARALLEL_LEVEL environment variable, if set, specifies a default parallel level when this option is not given.

    Some native build tools always build in parallel. The use of <jobs> value of 1 can be used to limit to a single job.

[stv0g]

Yes, we might want to switch to cmake --build anyways instead of calling make as there might be platforms for which make is not the default CMake build tool