Plumbers: Tweaking scheduler policy micro-conf RFP

[Peter Zijlstra]

On Thu, 2012-05-17 at 00:19 +0530, Vaidyanathan Srinivasan wrote:

> Let me take a case of two-socket,quad-core,HT x86 (Nehalem):
> 
> SDTL_SHARE_POWERLINE should be passed along with a cpumask that
> represents sd_init_CPU or cpu_cpu_mask today.  So the number of
> domains we build per-cpu will depend on the topology and the
> sched_powersavings settings. 

No, the topology should at all time be independent of powersavings,
current x86's topology depending on that is one of the biggest warts
ever. Also sched_powersavings, doesn't actually exist anymore.

The NHM-EP from your example should do just two levels since mc and cpu
are identical, I guess we could add a pass that merges identical masks
so you can still specify 3 levels if you want.

The NUMA stuff is done automatically based on SLIT, so you don't need to
go above the socket level.