If you had a month to improve gcc build parallelization, where would you begin?

[Joern Rennecke]

Quoting Jeff Law <law@redhat.com>:

> Using distcc and ccache is trivial; I spread my builds across ~20
> processors around the house...
>
>
> CC=distcc
> CXX=distcc g++
> CC_FOR_BUILD=distcc
> CXX_FOR_BUILD=distcc

It's not quite that simple if you want bootstraps and/or Canadian crosses.

> STAGE_CC_WRAPPER=distcc
> STAGE_CXX_WRAPPER=distcc

How does that work?
The binaries have to get the all the machines of the clusters somewhere.
Does this assume you are using NFS or similar for your build directory?
Won't the overhead of using that instead of local disk kill most of the
parallelization benefit of a cluster over a single SMP machine?