From 6ae72dff37596f736b795426306404f0793e4b1b Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 22 Jul 2014 11:47:40 +0200 Subject: [PATCH] sched: Robustify topology setup 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: Dietmar Eggemann Signed-off-by: Peter Zijlstra Cc: Josh Boyer Cc: "H. Peter Anvin" Cc: Bruno Wolff III Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20140722094740.GJ12054@laptop.lan Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 415ab0268b51..2a36a74c16ae 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -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); child->parent = sd; 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); -- 2.11.0