Hi, On 17/05/18 16:55, Waiman Long wrote: > This patch enables us to report sched domain generation information. > > If DYNAMIC_DEBUG is enabled, issuing the following command > > echo "file cpuset.c +p" > /sys/kernel/debug/dynamic_debug/control > > and setting loglevel to 8 will allow the kernel to show what scheduling > domain changes are being made. > > Signed-off-by: Waiman Long <longman@xxxxxxxxxx> > --- > kernel/cgroup/cpuset.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c > index fb8aa82b..8f586e8 100644 > --- a/kernel/cgroup/cpuset.c > +++ b/kernel/cgroup/cpuset.c > @@ -820,6 +820,12 @@ static int generate_sched_domains(cpumask_var_t **domains, > } > BUG_ON(nslot != ndoms); > > +#ifdef CONFIG_DEBUG_KERNEL > + for (i = 0; i < ndoms; i++) > + pr_debug("generate_sched_domains dom %d: %*pbl\n", i, > + cpumask_pr_args(doms[i])); > +#endif > + While I'm always in favor of adding debug output, in this case I'm not sure it's adding much to what we already print when booting with sched_debug kernel command-line param, e.g. --->8--- Kernel command line: BOOT_IMAGE=/vmlinuz-4.17.0-rc5+ ... sched_debug [...] smp: Bringing up secondary CPUs ... x86: Booting SMP configuration: .... node #0, CPUs: #1 #2 #3 #4 #5 .... node #1, CPUs: #6 #7 #8 #9 #10 #11 smp: Brought up 2 nodes, 12 CPUs smpboot: Max logical packages: 2 smpboot: Total of 12 processors activated (45636.50 BogoMIPS) CPU0 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 0:{ span=0 cap=1016 }, 1:{ span=1 cap=1011 }, 2:{ span=2 }, 3:{ span=3 cap=1023 }, 4:{ span=4 }, 5:{ span=5 } domain-1: span=0-11 level=NUMA groups: 0:{ span=0-5 cap=6122 }, 6:{ span=6-11 cap=6141 } CPU1 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 1:{ span=1 cap=1011 }, 2:{ span=2 }, 3:{ span=3 cap=1023 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 cap=1016 } domain-1: span=0-11 level=NUMA groups: 0:{ span=0-5 cap=6122 }, 6:{ span=6-11 cap=6141 } CPU2 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 2:{ span=2 }, 3:{ span=3 cap=1023 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 cap=1016 }, 1:{ span=1 cap=1011 } domain-1: span=0-11 level=NUMA groups: 0:{ span=0-5 cap=6122 }, 6:{ span=6-11 cap=6141 } CPU3 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 3:{ span=3 cap=1023 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 cap=1016 }, 1:{ span=1 cap=1011 }, 2:{ span=2 } domain-1: span=0-11 level=NUMA groups: 0:{ span=0-5 cap=6122 }, 6:{ span=6-11 cap=6141 } CPU4 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 cap=1016 }, 1:{ span=1 cap=1011 }, 2:{ span=2 }, 3:{ span=3 cap=1023 } domain-1: span=0-11 level=NUMA groups: 0:{ span=0-5 cap=6122 }, 6:{ span=6-11 cap=6141 } CPU5 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 5:{ span=5 }, 0:{ span=0 cap=1016 }, 1:{ span=1 cap=1011 }, 2:{ span=2 }, 3:{ span=3 cap=1023 }, 4:{ span=4 } domain-1: span=0-11 level=NUMA groups: 0:{ span=0-5 cap=6122 }, 6:{ span=6-11 cap=6141 } CPU6 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 6:{ span=6 }, 7:{ span=7 }, 8:{ span=8 cap=1021 }, 9:{ span=9 }, 10:{ span=10 }, 11:{ span=11 } domain-1: span=0-11 level=NUMA groups: 6:{ span=6-11 cap=6141 }, 0:{ span=0-5 cap=6122 } CPU7 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 7:{ span=7 }, 8:{ span=8 cap=1021 }, 9:{ span=9 }, 10:{ span=10 }, 11:{ span=11 }, 6:{ span=6 } domain-1: span=0-11 level=NUMA groups: 6:{ span=6-11 cap=6141 }, 0:{ span=0-5 cap=6122 } CPU8 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 8:{ span=8 cap=1021 }, 9:{ span=9 }, 10:{ span=10 }, 11:{ span=11 }, 6:{ span=6 }, 7:{ span=7 } domain-1: span=0-11 level=NUMA groups: 6:{ span=6-11 cap=6141 }, 0:{ span=0-5 cap=6122 } CPU9 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 9:{ span=9 }, 10:{ span=10 }, 11:{ span=11 }, 6:{ span=6 }, 7:{ span=7 }, 8:{ span=8 cap=1021 } domain-1: span=0-11 level=NUMA groups: 6:{ span=6-11 cap=6141 }, 0:{ span=0-5 cap=6122 } CPU10 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 10:{ span=10 }, 11:{ span=11 }, 6:{ span=6 }, 7:{ span=7 }, 8:{ span=8 cap=1021 }, 9:{ span=9 } domain-1: span=0-11 level=NUMA groups: 6:{ span=6-11 cap=6141 }, 0:{ span=0-5 cap=6122 } CPU11 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 11:{ span=11 }, 6:{ span=6 }, 7:{ span=7 }, 8:{ span=8 cap=1021 }, 9:{ span=9 }, 10:{ span=10 } domain-1: span=0-11 level=NUMA groups: 6:{ span=6-11 cap=6141 }, 0:{ span=0-5 cap=6122 } span: 0-11 (max cpu_capacity = 1024) [...] generate_sched_domains dom 0: 6-11 <-- this and the one below is what generate_sched_domains dom 1: 0-5 you are adding CPU0 attaching NULL sched-domain. CPU1 attaching NULL sched-domain. CPU2 attaching NULL sched-domain. CPU3 attaching NULL sched-domain. CPU4 attaching NULL sched-domain. CPU5 attaching NULL sched-domain. CPU6 attaching NULL sched-domain. CPU7 attaching NULL sched-domain. CPU8 attaching NULL sched-domain. CPU9 attaching NULL sched-domain. CPU10 attaching NULL sched-domain. CPU11 attaching NULL sched-domain. CPU6 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 6:{ span=6 }, 7:{ span=7 }, 8:{ span=8 }, 9:{ span=9 }, 10:{ span=10 }, 11:{ span=11 } CPU7 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 7:{ span=7 }, 8:{ span=8 }, 9:{ span=9 }, 10:{ span=10 }, 11:{ span=11 }, 6:{ span=6 } CPU8 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 8:{ span=8 }, 9:{ span=9 }, 10:{ span=10 }, 11:{ span=11 }, 6:{ span=6 }, 7:{ span=7 } CPU9 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 9:{ span=9 }, 10:{ span=10 }, 11:{ span=11 }, 6:{ span=6 }, 7:{ span=7 }, 8:{ span=8 } CPU10 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 10:{ span=10 }, 11:{ span=11 }, 6:{ span=6 }, 7:{ span=7 }, 8:{ span=8 }, 9:{ span=9 } CPU11 attaching sched-domain(s): domain-0: span=6-11 level=MC groups: 11:{ span=11 }, 6:{ span=6 }, 7:{ span=7 }, 8:{ span=8 }, 9:{ span=9 }, 10:{ span=10 } span: 6-11 (max cpu_capacity = 1024) 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 } CPU2 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 }, 1:{ span=1 } CPU3 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 }, 1:{ span=1 }, 2:{ span=2 } CPU4 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 }, 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 } CPU5 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 5:{ span=5 }, 0:{ span=0 }, 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 } span: 0-5 (max cpu_capacity = 1024) --->8--- Do you think there is still a benefit in printing out what generate_sched_domains does? Best, - Juri -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html