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Diffstat (limited to 'kernel/sched_autogroup.c')
-rw-r--r--kernel/sched_autogroup.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/kernel/sched_autogroup.c b/kernel/sched_autogroup.c
index 938d52f80a2d..9fb656283157 100644
--- a/kernel/sched_autogroup.c
+++ b/kernel/sched_autogroup.c
@@ -27,6 +27,11 @@ static inline void autogroup_destroy(struct kref *kref)
{
struct autogroup *ag = container_of(kref, struct autogroup, kref);
+#ifdef CONFIG_RT_GROUP_SCHED
+ /* We've redirected RT tasks to the root task group... */
+ ag->tg->rt_se = NULL;
+ ag->tg->rt_rq = NULL;
+#endif
sched_destroy_group(ag->tg);
}
@@ -55,6 +60,10 @@ static inline struct autogroup *autogroup_task_get(struct task_struct *p)
return ag;
}
+#ifdef CONFIG_RT_GROUP_SCHED
+static void free_rt_sched_group(struct task_group *tg);
+#endif
+
static inline struct autogroup *autogroup_create(void)
{
struct autogroup *ag = kzalloc(sizeof(*ag), GFP_KERNEL);
@@ -72,6 +81,19 @@ static inline struct autogroup *autogroup_create(void)
init_rwsem(&ag->lock);
ag->id = atomic_inc_return(&autogroup_seq_nr);
ag->tg = tg;
+#ifdef CONFIG_RT_GROUP_SCHED
+ /*
+ * Autogroup RT tasks are redirected to the root task group
+ * so we don't have to move tasks around upon policy change,
+ * or flail around trying to allocate bandwidth on the fly.
+ * A bandwidth exception in __sched_setscheduler() allows
+ * the policy change to proceed. Thereafter, task_group()
+ * returns &root_task_group, so zero bandwidth is required.
+ */
+ free_rt_sched_group(tg);
+ tg->rt_se = root_task_group.rt_se;
+ tg->rt_rq = root_task_group.rt_rq;
+#endif
tg->autogroup = ag;
return ag;
@@ -106,6 +128,11 @@ task_wants_autogroup(struct task_struct *p, struct task_group *tg)
return true;
}
+static inline bool task_group_is_autogroup(struct task_group *tg)
+{
+ return tg != &root_task_group && tg->autogroup;
+}
+
static inline struct task_group *
autogroup_task_group(struct task_struct *p, struct task_group *tg)
{