Re: [gentoo-user] Re: Simultaneously emerging multiple packages with same dependencies

[J. Roeleveld]

On Thursday 27 January 2011 15:05:25 YoYo Siska wrote:
> On Thu, Jan 27, 2011 at 03:33:21PM +0200, Nikos Chantziaras wrote:
> > On 01/27/2011 03:11 PM, Dale wrote:
> > >[...]
> > >I am using the -j option for the first time now. I'm updating KDE. It
> > >seems to work fine. It doesn't scroll all the stuff like with a regular
> > >emerges but this new rig is so fast, I can't read it anyway. I did have
> > >a package to fail and it spit out the error for me to read.
> >
> > You don't need that if you have MAKEOPTS set in your make.conf,
> > which is preferred.  The -j option of emerge emerges multiple
> > packages, while with MAKEOPTS set to "-j4" or whatever does a
> > parallel build in the same package (meaning compiling multiple
> > source files at the same time).
> >
> > It's preferred because with "emerge -jN" the last package will only
> > use one CPU, while with "-jN" in MAKEOPTS even the last package will
> > use N CPUs.  Furthermore, emerge can't always build N packages at
> > the same time because one can depend on the other, so it will have
> > to wait until the dependency is built.
>
> On the other hand, unpacking, configure and install stages are not
> parallel and emerge can do those in parallel for different packages...
> The best would be somewhere in the middle ;)
>
>
> There are also the load-average options to -j, i.e.:
> MAKEOPTS="-j -l5" emerge -j --load-average=5  ....
>
> which makes make spawn parallel processes while load average is below 5
> and the same for emerge spawning parallel ebuilds (when make isn't
> parallel enough)
>
> yoyo

Hmmm... didn't know about that one yet.
Does that mean that by doing it like that, the emerge-process (and compile-
processes) will try to keep the load average at 5 and if that is lower, it 
will keep adding more processes?

--
Joost