sched: rt-group: refure unrunnable tasks

Refuse to accept or create RT tasks in groups that can't run them. Signed-off-by: Peter Zijlstra <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
iegor · Feb 13, 2008 · b68aa23 · b68aa23
1 parent bccbe08
commit b68aa23
Showing 1 changed file with 15 additions and 0 deletions.
diff --git a/kernel/sched.c b/kernel/sched.c
@@ -4584,6 +4584,15 @@ int sched_setscheduler(struct task_struct *p, int policy,
 			return -EPERM;
 	}
 
+#ifdef CONFIG_RT_GROUP_SCHED
+	/*
+	 * Do not allow realtime tasks into groups that have no runtime
+	 * assigned.
+	 */
+	if (rt_policy(policy) && task_group(p)->rt_runtime == 0)
+		return -EPERM;
+#endif
+
 	retval = security_task_setscheduler(p, policy, param);
 	if (retval)
 		return retval;
@@ -8028,9 +8037,15 @@ static int
 cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
 		      struct task_struct *tsk)
 {
+#ifdef CONFIG_RT_GROUP_SCHED
+	/* Don't accept realtime tasks when there is no way for them to run */
+	if (rt_task(tsk) && cgroup_tg(cgrp)->rt_runtime == 0)
+		return -EINVAL;
+#else
 	/* We don't support RT-tasks being in separate groups */
 	if (tsk->sched_class != &fair_sched_class)
 		return -EINVAL;
+#endif
 
 	return 0;
 }