Re: [PATCH v10 0/9] cpuset: Enable cpuset controller in default hierarchy

Waiman Long
2018-06-18T15:07:32Z

On 06/18/2018 10:20 PM, Juri Lelli wrote:
> Hi,
>
> On 18/06/18 12:13, Waiman Long wrote:
>> v10:
>> - Remove the cpuset.sched.load_balance patch for now as it may not
>> be that useful.
>> - Break the large patch 2 into smaller patches to make them a bit
>> easier to review.
>> - Test and fix issues related to changing "cpuset.cpus" and cpu
>> online/offline in a domain root.
>> - Rename isolated_cpus to reserved_cpus as this cpumask holds CPUs
>> reserved for child sched domains.
>> - Rework the scheduling domain debug printing code in the last patch.
>> - Document update to the newly moved
>> Documentation/admin-guide/cgroup-v2.rst.
> There seem to be two (similar but different) 6/9 in the set. Something
> went wrong?

The isolated_cpus patch is old, I forgot to remove it before sending out
the patch.

> Also I can't seem to be able to create a subgroup with an isolated
> domain root. I think that, when doing the following
>
> # mount -t cgroup2 none /sys/fs/cgroup
> # echo "+cpuset" >/sys/fs/cgroup/cgroup.subtree_control
> # mkdir /sys/fs/cgroup/g1
> # echo 0-1 >/sys/fs/cgroup/g1/cpuset.cpus
> # echo 1 >/sys/fs/cgroup/g1/cpuset.sched.domain_root
>
> rebuild_sched_domains_locked exits early, since
> top_cpuset.effective_cpus != cpu_active_mask. (effective_cpus being 2-3
> at this point since I'm testing this on a 0-3 system)
>
> In your v9 this [1] was adding a special condition to make rebuilding of
> domains happen. Was the change intentional?

Can you reply to the relevant patch to pinpoint what condition are you
talking about? I do try to eliminate domain rebuild as much as possible,
but I am just not sure which condition you have question about.

Cheers,
Longman