Stephen Sprunk wrote:
Does an OS really need to be aware of the difference between two
cores on the same chip?

Linux has a concept of a NUMA "node", where all of the processors in
a node are considered equivalent. It'll still try to schedule
threads on the same CPU they last ran on, but next it will try other
CPUs in the same node before giving up and sending it to any
available node.

IIRC, the code already understands two-CPU nodes, because that is how
Intel's SMT chips are handled. Treating K8 CMP the same way sounds
correct, once AMD releases specs on how to recognize dual-core chips.

I'm sure as a first cut, not treating them specially is the right way to go.
But eventually everybody tries to optimize down to the bone. AMD is even
suggesting not treating Hypertransport as NUMA but as simple SMP is quite
acceptable, and this suggestion is likely to hold for dual-cores too
(probably even more so).

Yousuf Khan