[PATCH 3/3] cpuset: remove cpuset->parent

Tejun Heo
2013-01-03T21:44:25Z

cgroup already tracks the hierarchy. Follow cgroup->parent to find
the parent and drop cpuset->parent.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
---
kernel/cpuset.c | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index b2f8dad..afadbb99 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -87,8 +87,6 @@ struct cpuset {
cpumask_var_t cpus_allowed; /* CPUs allowed to tasks in cpuset */
nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */

- struct cpuset *parent; /* my parent */
-
struct fmeter fmeter; /* memory_pressure filter */

/*
@@ -120,6 +118,15 @@ static inline struct cpuset *task_cs(struct task_struct *task)
struct cpuset, css);
}

+static inline struct cpuset *parent_cs(const struct cpuset *cs)
+{
+ struct cgroup *pcgrp = cs->css.cgroup->parent;
+
+ if (pcgrp)
+ return cgroup_cs(pcgrp);
+ return NULL;
+}
+
#ifdef CONFIG_NUMA
static inline bool task_has_mempolicy(struct task_struct *task)
{
@@ -323,7 +330,7 @@ static void guarantee_online_cpus(const struct cpuset *cs,
struct cpumask *pmask)
{
while (cs && !cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
- cs = cs->parent;
+ cs = parent_cs(cs);
if (cs)
cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask);
else
@@ -348,7 +355,7 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
{
while (cs && !nodes_intersects(cs->mems_allowed,
node_states[N_MEMORY]))
- cs = cs->parent;
+ cs = parent_cs(cs);
if (cs)
nodes_and(*pmask, cs->mems_allowed,
node_states[N_MEMORY]);
@@ -461,7 +468,7 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
if (cur == &top_cpuset)
goto out;

- par = cur->parent;
+ par = parent_cs(cur);

/* We must be a subset of our parent cpuset */
ret = -EACCES;
@@ -1866,7 +1873,6 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont)
fmeter_init(&cs->fmeter);
INIT_WORK(&cs->hotplug_work, cpuset_propagate_hotplug_workfn);
cs->relax_domain_level = -1;
- cs->parent = cgroup_cs(cont->parent);

return &cs->css;
}
@@ -1874,7 +1880,7 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont)
static int cpuset_css_online(struct cgroup *cgrp)
{
struct cpuset *cs = cgroup_cs(cgrp);
- struct cpuset *parent = cs->parent;
+ struct cpuset *parent = parent_cs(cs);
struct cpuset *tmp_cs;
struct cgroup *pos_cg;

@@ -2058,10 +2064,10 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
* Find its next-highest non-empty parent, (top cpuset
* has online cpus, so can't be empty).
*/
- parent = cs->parent;
+ parent = parent_cs(cs);
while (cpumask_empty(parent->cpus_allowed) ||
nodes_empty(parent->mems_allowed))
- parent = parent->parent;
+ parent = parent_cs(parent);

move_member_tasks_to_cpuset(cs, parent);
}
@@ -2373,8 +2379,8 @@ int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
*/
static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs)
{
- while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && cs->parent)
- cs = cs->parent;
+ while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && parent_cs(cs))
+ cs = parent_cs(cs);
return cs;
}

--
1.8.0.2