Chris Tyler wrote:
On Thu, 2012-03-22 at 02:38 +0100, Kevin Kofler wrote:
> And finally, for our build speed issue, the practical consideration will
> be whether the parallelism will actually speed our builds up. Right now
> our builds are either serial or have portions parallelized with "make
> -j", which assumes a single multi-CPU computer (but the "multi-core"
ARM
> setups actually present themselves as a multi-computer cluster, which is
> not supported by "make -j", not as a multi-CPU computer), so the
> parallelism does little to the latency of an individual build (though of
> course it does help the overall throughput).
Actually, there's both: ARM scales to multiple cores per CPU (dual-core
and quad-core are common, and very high core counts are on the horizon),
and vendors are preparing many-CPU boxes (e.g., HP Redstone, with 288
quad core (+1 management core) systems in 4U).
But there are x86 CPUs with more than 4 cores, and multi-CPU SMP systems
which still present themselves as one (multi-CPU/core) computer. IIRC, our
x86 Koji builders have 16 cores per machine (might be even more by now, not
sure).
Kevin Kofler