On Tue, 16 Sep 2014 05:29:20 +0200 Peter Zijlstra <pet...@infradead.org> wrote:
> On Mon, Sep 15, 2014 at 03:26:41PM -0700, Dave Hansen wrote: > > > > I'm getting the spew below when booting with Haswell (Xeon > > E5-2699) CPUs and the "Cluster-on-Die" (CoD) feature enabled in > > the BIOS. > > What is that cluster-on-die thing? I've heard it before but never could > find anything on it. > Each CPU has 2.5MB of L3 connected together in a ring that makes it all act like a single shared cache. The HW tries to place the data so it's closest to the CPU that uses it. On the larger processors there are two rings with an interconnect between them that adds latency if a cache fetch has to cross that. CoD breaks that connection and effectively gives you two nodes on one die. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
