cgroup: add css_parent()

[mirror_ubuntu-hirsute-kernel.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9b1f2e533b95cf2532ffcadfc62476b18d9e27f5..7a10742b389a61511e8c09854fff5b4a30a54a21 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6761,7 +6761,7 @@ void sched_move_task(struct task_struct *tsk)
        if (unlikely(running))
                tsk->sched_class->put_prev_task(rq, tsk);
 
-       tg = container_of(task_subsys_state_check(tsk, cpu_cgroup_subsys_id,
+       tg = container_of(task_css_check(tsk, cpu_cgroup_subsys_id,
                                lockdep_is_held(&tsk->sighand->siglock)),
                          struct task_group, css);
        tg = autogroup_task_group(tsk, tg);
@@ -7083,11 +7083,15 @@ int sched_rt_handler(struct ctl_table *table, int write,
 
 #ifdef CONFIG_CGROUP_SCHED
 
+static inline struct task_group *css_tg(struct cgroup_subsys_state *css)
+{
+       return css ? container_of(css, struct task_group, css) : NULL;
+}
+
 /* return corresponding task_group object of a cgroup */
 static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
 {
-       return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
-                           struct task_group, css);
+       return css_tg(cgroup_css(cgrp, cpu_cgroup_subsys_id));
 }
 
 static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp)
@@ -7110,13 +7114,10 @@ static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp)
 static int cpu_cgroup_css_online(struct cgroup *cgrp)
 {
        struct task_group *tg = cgroup_tg(cgrp);
-       struct task_group *parent;
+       struct task_group *parent = css_tg(css_parent(&tg->css));
 
-       if (!cgrp->parent)
-               return 0;
-
-       parent = cgroup_tg(cgrp->parent);
-       sched_online_group(tg, parent);
+       if (parent)
+               sched_online_group(tg, parent);
        return 0;
 }