sched: Robustify topology setup (6ae72dff) · Commits · 戴 / test

We hard assume that higher topology levels are supersets of lower levels. Detect, warn and try to fixup when we encounter this violated. Tested-by:

Peter Zijlstra <peterz@infradead.org> Cc: Josh Boyer <jwboyer@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Bruno Wolff III <bruno@wolff.to> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140722094740.GJ12054@laptop.lan Signed-off-by:

kernel/sched/core.c

+14 −0

Original line number	Original line	Diff line number	Diff line
	@@ -6481,6 +6481,20 @@ struct sched_domain build_sched_domain(struct sched_domain_topology_level tl,
	sched_domain_level_max = max(sched_domain_level_max, sd->level);		sched_domain_level_max = max(sched_domain_level_max, sd->level);
	child->parent = sd;		child->parent = sd;
	sd->child = child;		sd->child = child;

			if (!cpumask_subset(sched_domain_span(child),
			sched_domain_span(sd))) {
			pr_err("BUG: arch topology borken\n");
			#ifdef CONFIG_SCHED_DEBUG
			pr_err(" the %s domain not a subset of the %s domain\n",
			child->name, sd->name);
			#endif
			/* Fixup, ensure @sd has at least @child cpus. */
			cpumask_or(sched_domain_span(sd),
			sched_domain_span(sd),
			sched_domain_span(child));
			}

	}		}
	set_domain_attribute(sd, attr);		set_domain_attribute(sd, attr);