[PATCH v3 00/12] cpuset: separate configured masks and effective masks

[Li Zefan <lizefan@huawei.com>]

This patcheset introduces behavior changes, but only for default hierarchy

- We introduce new interfaces cpuset.effective_cpus and cpuset.effective_mems,
  while cpuset.cpus and cpuset.mems will be configured masks.

- The configured masks can be changed by writing cpuset.cpus/mems only. They
  won't be changed when hotplug happens.

- Users can config cpus and mems without restrictions from the parent cpuset.
  effective masks will enforce the hierarchical behavior.

- Users can also config cpus and mems to have already offlined CPU/nodes.

- When a CPU/node is onlined, it will be brought back to the effective masks
  if it's in the configured masks.

- We build sched domains based on effective cpumask but not configured cpumask.

v3:
- rebased against "cgroup: remove sane_behavior support on non-default hierarchies"
- addressed previous review comments
- adjusted some code, comment and changelog slightly

v2:
- fixed two bugs
- made changelogs more verbose
- added more comments
- changed cs->real_{mems,cpus}_allowed to cs->effective_{mems, cpus}
- splitted "cpuset: enable onlined cpu/node in effective masks" into 2 patches
- exported cpuset.effective_{cpus,mems} unconditionally


Li Zefan (12):
  cpuset: add cs->effective_cpus and cs->effective_mems
  cpuset: update cpuset->effective_{cpus,mems} at hotplug
  cpuset: update cs->effective_{cpus,mems} when config changes
  cpuset: inherit ancestor's masks if effective_{cpus,mems} becomes
    empty
  cpuset: use effective cpumask to build sched domains
  cpuset: initialize top_cpuset's configured masks at mount
  cpuset: apply cs->effective_{cpus,mems}
  cpuset: make cs->{cpus,mems}_allowed as user-configured masks
  cpuset: refactor cpuset_hotplug_update_tasks()
  cpuset: enable onlined cpu/node in effective masks
  cpuset: allow writing offlined masks to cpuset.cpus/mems
  cpuset: export effective masks to userspace

 kernel/cpuset.c | 493 ++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 304 insertions(+), 189 deletions(-)

-- 
1.8.0.2