[arch-general] MAKEFLAGS and dragon.archlinux.org

[mike lojkovic]

I usually use something like virtual core count plus half. If I'm compiling
the Linux kernel my system might slow down in other areas for a bit, but
it's still usable depending on the compile task.

Personally, I want to pick up one of those new 64 core Ryzen cpus. Hear it
can compile Unreal in like a minute.

On Wed, Mar 31, 2021 at 6:33 AM Archange via arch-general <
arch-general at lists.archlinux.org> wrote:

> Le 31/03/2021 à 15:25, u34--- via arch-general a écrit :
> > I think there are no real machines with 5 cores, or 5 cpus. If
> > dragon.archlinux.org actually has 5 cpus then do skip this message.
>
> Actually this box does not exist anymore, but IIRC it had 32 cores.
>
> > Refering to
> https://wiki.archlinux.org/index.php/DeveloperWiki:PKGBUILD.com :
> > It states it describes the build server at dragon.archlinux.org. At
> >
> https://wiki.archlinux.org/index.php/DeveloperWiki:PKGBUILD.com#Packager_&&_Makeflags
> > it suggests to use
> >
> >      MAKEFLAGS=-j5
> >
> > https://wiki.archlinux.org/index.php/Makepkg#Parallel_compilation
> > suggets to use the number of cores here.
> > I don't know what the implications of using a wrong number in MAKEFLAGS.
> > Or even if there are any implications at all. Still, why not state the
> > correct number, or use $(nproc)?
>
> Implications are only on build time. Generally it’s a good idea to use
> nproc+1 to avoid waiting threads, but using a lower value could be for
> ressources sharing. We are numerous users on the build machine, so not
> using all the ressources for very big projects is a good idea (even if
> they are very few of them that would block the machine for a long time).
> Also, they are not many projects than can leverage the 64 threads
> available.
>
> But I actually built ParaView using -j65, and it was amazing to have it
> built in ~10 min.
>
> Regards,
> Archange
>