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Commit d110235d authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: Avoid creating superfluous NUMA domains on non-NUMA systems 



When creating sched_domains, stop when we've covered the entire
target span instead of continuing to create domains, only to
later find they're redundant and throw them away again.

This avoids single node systems from touching funny NUMA
sched_domain creation code and reduces the risks of the new
SD_OVERLAP code.

Requested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Anton Blanchard <anton@samba.org>
Cc: mahesh@linux.vnet.ibm.com
Cc: benh@kernel.crashing.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1311180177.29152.57.camel@twins


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e3589f6c

kernel/sched.c

+2 −0
Original line number Diff line number Diff line
@@ -7436,6 +7436,8 @@ static int build_sched_domains(const struct cpumask *cpu_map, 
			sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);

			if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))

				sd->flags |= SD_OVERLAP;

			if (cpumask_equal(cpu_map, sched_domain_span(sd)))

				break;

		}



		while (sd->child)