On 05/24/2018 05:29 PM, Juri Lelli wrote:
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);
}
Looks good to me. Probably especially helpful when setting up exclusive
cpusets.
Juno with big and little exclusive cpuset:
...
[ 124.231333] CPU1 attaching sched-domain(s):
[ 124.235482] domain-0: span=1-2 level=MC
[ 124.239382] groups: 1:{ span=1 }, 2:{ span=2 }
[ 124.243969] CPU2 attaching sched-domain(s):
[ 124.248112] domain-0: span=1-2 level=MC
[ 124.251998] groups: 2:{ span=2 }, 1:{ span=1 }
[ 124.256585] root domain span: 1-2 (max cpu_capacity = 1024)
[ 124.262150] CPU0 attaching sched-domain(s):
[ 124.266307] domain-0: span=0,3-5 level=MC
[ 124.270366] groups: 0:{ span=0 cap=446 }, 3:{ span=3 cap=446 }, 4:{
span=4 cap=446 }, 5:{ span=5 cap=446 }
[ 124.280131] CPU3 attaching sched-domain(s):
[ 124.284273] domain-0: span=0,3-5 level=MC
[ 124.288334] groups: 3:{ span=3 cap=446 }, 4:{ span=4 cap=446 }, 5:{
span=5 cap=446 }, 0:{ span=0 cap=446 }
[ 124.298096] CPU4 attaching sched-domain(s):
[ 124.302239] domain-0: span=0,3-5 level=MC
[ 124.306298] groups: 4:{ span=4 cap=446 }, 5:{ span=5 cap=446 }, 0:{
span=0 cap=446 }, 3:{ span=3 cap=446 }
[ 124.316063] CPU5 attaching sched-domain(s):
[ 124.320205] domain-0: span=0,3-5 level=MC
[ 124.324265] groups: 5:{ span=5 cap=446 }, 0:{ span=0 cap=446 }, 3:{
span=3 cap=446 }, 4:{ span=4 cap=446 }
[ 124.334031] root domain span: 0,3-5 (max cpu_capacity = 446)
