Decouple cpu mem build export

[davidmmiller]

This change will allow decoupling the cpu and memory settings during box build/install and the final exported box.

[ghost]

I like the idea yet it gets tricky with Gentoo since base.sh populates /etc/portage/make.conf with entries based on $nr_cpus from settings.sh during the build time. As you export the box, you'd really want make.conf to change as well. /cc @pierreozoux

[pierreozoux]

@vaskas I agree with you, we would have to handle that before the export.

Recreate make.conf with the right amount of cpu just before the export. Like in the reboot script : https://github.com/jedi4ever/veewee/blob/master/templates/gentoo-latest-i686-experimental/reboot.sh

[davidmmiller]

There are two values that get set within make.conf with nr_cpus MAKEOPTS and EMERGE_DEFAULT_OPTS

Neither one is end of the world terrible at the current level on the smaller box exported.

MAKEOPTS="-j$((1 + $nr_cpus)) -l$nr_cpus.5"
from the make.conf man page:
MAKEOPTS
Use this variable if you want to use parallel make. For example, if you have a dual-processor sys-
tem, set this variable to "-j2" or "-j3" for enhanced build performance with many packages. Suggested
settings are between CPUs+1 and 2*CPUs+1. In order to avoid excess load, the --load-average option is
recommended. For more information, see make(1). Also see emerge(1) for information about analogous
--jobs and --load-average options.

from the make man page:
-l [load], --load-average[=load]
Specifies that no new jobs (commands) should be started if there are others jobs running and the load
average is at least load (a floating-point number). With no argument, removes a previous load limit.

EMERGE_DEFAULT_OPTS="-j$nr_cpus --quiet-build=y"
from the emerge man page:
-j [JOBS], --jobs[=JOBS]
Specifies the number of packages to build simultaneously. If this option is given without an argu-
ment, emerge will not limit the number of jobs that can run simultaneously. Also see the related
--load-average option. Similarly to the --quiet-build option, the --jobs option causes all build
output to be redirected to logs. Note that interactive packages currently force a setting of
--jobs=1. This issue can be temporarily avoided by specifying --accept-properties=-interactive.

There is a cleanup.sh script run right before the zerodisk.sh script and this is where I would put the change to the make.conf values. I'll push an update to this pull request that does this.

[ghost]

Thanks @davidmmiller, sounds great! Also, If you are looking at the current template, I created a pull request that fixes it (#674).

[pierreozoux]

👍 Thanks to you both :)

[mpapis]

hey, is this PR still valid? if it is could you rebase it on current master so it could be merged?

[davidmmiller]

Valid? Yes.
Most likely valid beyond just Gentoo - as it could be useful to decouple the cpu_num and memory allocation of the end box from those available during creation/installation.

[mpapis]

ok then, can you please rebase on master, there were to many changes preventing simple merge and I would prefer not to loos anything in manual merge.