Commit b68aa230 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: rt-group: refure unrunnable tasks 



Refuse to accept or create RT tasks in groups that can't run them.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent bccbe08a

kernel/sched.c

+15 −0
Original line number Diff line number Diff line
@@ -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;

}