RFC: Primary architecture promotion requirements

[Kevin Kofler]

Brendan Conoboy wrote:
> In couple years the hardware is going to be surprisingly comparable or
> exceed to what you're see on x86, especially as the number of cores
> skyrockets while the GHz continue to climb.

Then let's rediscuss making ARM a primary architecture when that happens. 
Right now the speed is just not acceptable.

> It's not a gimmick, we're just preparing for the future before it gets
> here.  The only problem we face is that those cores are in multiple CPUs
> so we can't 'make -j' our way out of the build system problem.

That alone means it's not a solution.

Also note that not everything in builds is parallelizable:
* not all upstream build systems use make -j,
* configure (or cmake etc.) and make install are usually not parallelized,
* often there are makefile dependencies requiring at least some amount of
  serialization
etc. So even if you have -j working, you STILL need a comparable speed in 
ONE core compared to the x86 builders.

        Kevin Kofler