Re: [PATCH 12/15] sched: Allow NODE domain to be parent of MCinstead of CPU domain

From: Peter Zijlstra
Date: Mon Aug 24 2009 - 11:33:32 EST

On Thu, 2009-08-20 at 15:42 +0200, Andreas Herrmann wrote:
> The level of NODE domain's child domain is provided in s_data.numa_child_level.
> Then several adaptions are required when creating the domain hierarchy.
> In case NODE domain is parent of MC domain we have to:
> - limit NODE domains' span in sched_domain_node_span() to not exceed
> corresponding topology_core_cpumask.
> - fix CPU domain span to cover entire cpu_map
> - fix CPU domain sched groups to cover entire physical groups instead of
> covering a node (a node sched_group might be a proper subset of a CPU
> sched_group).
> - use correct child domain in init_numa_sched_groups_power() when
> calculating sched_group.__cpu_power in NODE domain
> - calculate group_power of NODE domain after its child domain
> Note: As I have no idea when the ALLNODES domain is required
> I assumed that an ALLNODES domain exists only if NODE domain
> is parent of CPU domain.

I think its only used when the regular node level is too large, then we
split it into smaller bits. SGI folks who run crazy large machines use

/me mumbels about renaming the domain level, CPU is the physical socket
level, right? stupid names.

Patch sounds funky though, numa_child_level should be effident from the
tree build.
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