Commit e5e96faf authored Aug 10, 2018 by Srikar Dronamraju Committed by Ingo Molnar Sep 10, 2018

sched/topology: Set correct NUMA topology type



With the following commit:

  051f3ca0 ("sched/topology: Introduce NUMA identity node sched domain")

the scheduler introduced a new NUMA level. However this leads to the NUMA topology
on 2 node systems to not be marked as NUMA_DIRECT anymore.

After this commit, it gets reported as NUMA_BACKPLANE, because
sched_domains_numa_level is now 2 on 2 node systems.

Fix this by allowing setting systems that have up to 2 NUMA levels as
NUMA_DIRECT.

While here remove code that assumes that level can be 0.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andre Wild <wild@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Fixes: 051f3ca0 "Introduce NUMA identity node sched domain"
Link: http://lkml.kernel.org/r/1533920419-17410-1-git-send-email-srikar@linux.vnet.ibm.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent e73e8197

kernel/sched/topology.c

+1 −4

Original line number	Original line	Diff line number	Diff line
	@@ -1295,7 +1295,7 @@ static void init_numa_topology_type(void)

	n = sched_max_numa_distance;		n = sched_max_numa_distance;

	if (sched_domains_numa_levels <= 1) {		if (sched_domains_numa_levels <= 2) {
	sched_numa_topology_type = NUMA_DIRECT;		sched_numa_topology_type = NUMA_DIRECT;
	return;		return;
	}		}
	@@ -1380,9 +1380,6 @@ void sched_init_numa(void)
	break;		break;
	}		}

	if (!level)
	return;

	/*		/*
	* 'level' contains the number of unique distances		* 'level' contains the number of unique distances
	*		*