Remove hard-coded -j8 argument for make

[julianoes]

The current Makefile is sort of a wrapper script around cmake and that's a bit confusing.

Especially annoying is actually the hard-coded -j8 argument for make. It would be better if this was taken from the CPU count or your settings for make (MAKEFLAGS).

https://github.com/Dronecode/DronecodeSDK/blob/ef45e4ddb7a8c5dcd0ac20df9a330afdaa9a7be6/Makefile#L22

More thoughts: https://stackoverflow.com/questions/10567890/parallel-make-set-j8-as-the-default-option

[simrankedia]

Hi,
I would like to start working on this. Please guide me as I am new to open source contribution. I specifically want to know the following:

1. What OS will be used for the build?
2. How many cores should be used for the build, given total number of cores are n.

[julianoes]

Hi @simrankedia,

1. The Makefile is used on Linux and macOS. For Windows we directly use cmake and don't use this Makefile helper.
2. I usually build with n if the CPU has n cores/hyperthreads.

[simrankedia]

Hi @julianoes,
Thanks for the prompt reply. Just a clarification regarding point 2 above:
The machine is supposed to be doing nothing else while the build is going on? (trying to understand if we should use less than n cores for the build.)

Also, please let me know how to build all the required components, so that I can test the edit I have made.

[julianoes]

The machine is supposed to be doing nothing else while the build is going on? (trying to understand if we should use less than n cores for the build.)

You can still do other things but they will be slowed down. I think it's common practice to use -jX for X hypercores.

Check the build instructions here:
https://sdk.dronecode.org/en/contributing/build.html

[JonasVautherin]

You can still do other things but they will be slowed down. I think it's common practice to use -jX for X hypercores.

Agreed. And there is always nice that does process scheduling if you don't want it to take too many resources.

[simrankedia]

Hi @julianoes
I am done with the changes. However, looks like I don't have the permission to create a branch. Please guide me on how to submit the changes for review.

Thanks.

[julianoes]

Nice @simrankedia! So the way it works is that you fork this repository and then create a pull request from there.
You can find some instructions here: https://akrabat.com/the-beginners-guide-to-contributing-to-a-github-project/

[simrankedia]

Hi @julianoes I have raised a pull request. Kindly have a look.

[JonasVautherin]

@simrankedia: I see your branch here on your fork, but not a PR. Are you sure you opened a pull request to this repo? From your branch, click "Pull Request", add a description (add "Resolves #610" in the description), and hit "Create pull request".

Then it will appear here on the DronecodeSDK repo :-).

[simrankedia]

Hi @JonasVautherin, Sorry my bad. I have raised the PR now.