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

[Paul Hartman <paul.hartman+gentoo@gmail.com>]

On Thu, Jan 27, 2011 at 7:33 AM, Nikos Chantziaras <realnc@arcor.de> 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.

I use MAKEOPTS = -j12 along with emerge --jobs for portage. Needless
to say my CPU is fully utilized during an emerge of KDE. :)