[GIT PULL] cgroup fixes for v4.0-rc3

[Tejun Heo <tj@kernel.org>]

Hello, Linus.

The cgroup iteration update two years ago and the recent cpuset
restructuring introduced regressions in subset of cpuset
configurations.  Three patches to fix them.  All are marked for
-stable.

Thanks.

The following changes since commit c517d838eb7d07bbe9507871fab3931deccff539:

  Linux 4.0-rc1 (2015-02-22 18:21:14 -0800)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git for-4.0-fixes

for you to fetch changes up to 283cb41f426b723a0255702b761b0fc5d1b53a81:

  cpuset: Fix cpuset sched_relax_domain_level (2015-03-02 11:55:04 -0500)

----------------------------------------------------------------
Jason Low (1):
      cpuset: Fix cpuset sched_relax_domain_level

Zefan Li (2):
      cpuset: initialize effective masks when clone_children is enabled
      cpuset: fix a warning when clearing configured masks in old hierarchy

 kernel/cpuset.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 1d1fe93..fc7f474 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -548,9 +548,6 @@ static void update_domain_attr_tree(struct sched_domain_attr *dattr,
 
 	rcu_read_lock();
 	cpuset_for_each_descendant_pre(cp, pos_css, root_cs) {
-		if (cp == root_cs)
-			continue;
-
 		/* skip the whole subtree if @cp doesn't have any CPU */
 		if (cpumask_empty(cp->cpus_allowed)) {
 			pos_css = css_rightmost_descendant(pos_css);
@@ -873,7 +870,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus)
 		 * If it becomes empty, inherit the effective mask of the
 		 * parent, which is guaranteed to have some CPUs.
 		 */
-		if (cpumask_empty(new_cpus))
+		if (cgroup_on_dfl(cp->css.cgroup) && cpumask_empty(new_cpus))
 			cpumask_copy(new_cpus, parent->effective_cpus);
 
 		/* Skip the whole subtree if the cpumask remains the same. */
@@ -1129,7 +1126,7 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems)
 		 * If it becomes empty, inherit the effective mask of the
 		 * parent, which is guaranteed to have some MEMs.
 		 */
-		if (nodes_empty(*new_mems))
+		if (cgroup_on_dfl(cp->css.cgroup) && nodes_empty(*new_mems))
 			*new_mems = parent->effective_mems;
 
 		/* Skip the whole subtree if the nodemask remains the same. */
@@ -1979,7 +1976,9 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 
 	spin_lock_irq(&callback_lock);
 	cs->mems_allowed = parent->mems_allowed;
+	cs->effective_mems = parent->mems_allowed;
 	cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
+	cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
 	spin_unlock_irq(&callback_lock);
 out_unlock:
 	mutex_unlock(&cpuset_mutex);