Re: [PATCH v2] x86,sched: allow topologies where NUMA nodes share an LLC

[Dave Hansen]

On 03/22/2018 04:20 PM, Peter Zijlstra wrote:
>> +		/*
>> +		 * Return value doesn't actually matter because we
>> +		 * are throwing away coregroups for scheduling anyway.
>> +		 * Return false to bypass topology broken bug messages
>> +		 * and fixups in sched_domain().
>> +		 */
>> +		return false;
> IIRC that return value _does_ matter because the resulting mask still
> ends up user visible in sysfs.
> 
> IIRC I went over with this dhansen a week or so ago, but I cannot now
> recall what we settled on as being the right return value and for what
> reason.

IIRC, a 'return true' true keeps the topology information and a 'return
false' throws it away.  We chose 'false' here because without it some
other warnings showed up in another part of the code:

BUG: arch topology borken the MC domain not a subset of the NODE domain

I think the right thing to do is just remove the first sentence of the
comment.