When scheduler debug is enabled, building scheduling domains outputs information about how the domains are laid out and to which root domain each CPU (or sets of CPUs) belongs, e.g.:
CPU0 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 0:{ span=0 }, 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 } CPU1 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 } [...] span: 0-5 (max cpu_capacity = 1024) The fact that latest line refers to CPUs 0-5 root domain doesn't however look immediately obvious to me: one might wonder why span 0-5 is reported "again". Make it more clear by adding "root domain" to it, as to end with the following. CPU0 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 0:{ span=0 }, 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 } CPU1 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 } [...] root domain span: 0-5 (max cpu_capacity = 1024) Signed-off-by: Juri Lelli <juri.le...@redhat.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Dietmar Eggemann <dietmar.eggem...@arm.com> Cc: Patrick Bellasi <patrick.bell...@arm.com> Cc: linux-kernel@vger.kernel.org --- kernel/sched/topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 64cc564f5255..61a1125c1ae4 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1708,7 +1708,7 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att rcu_read_unlock(); if (rq && sched_debug_enabled) { - pr_info("span: %*pbl (max cpu_capacity = %lu)\n", + pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n", cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity); } -- 2.14.3