Commit 4cf5d77a authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: fix incorrect irq lock usage in normalize_rt_tasks() 



lockdep spotted this bogus irq locking. normalize_rt_tasks() can be called
from hardirq context through sysrq-n

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 8ed36996

kernel/sched.c

+4 −4
Original line number Diff line number Diff line
@@ -7291,7 +7291,7 @@ void normalize_rt_tasks(void) 
	unsigned long flags;

	struct rq *rq;



	read_lock_irq(&tasklist_lock);

	read_lock_irqsave(&tasklist_lock, flags);

	do_each_thread(g, p) {

		/*

		 * Only normalize user tasks:
@@ -7317,16 +7317,16 @@ void normalize_rt_tasks(void) 
			continue;

		}



		spin_lock_irqsave(&p->pi_lock, flags);

		spin_lock(&p->pi_lock);

		rq = __task_rq_lock(p);



		normalize_task(rq, p);



		__task_rq_unlock(rq);

		spin_unlock_irqrestore(&p->pi_lock, flags);

		spin_unlock(&p->pi_lock);

	} while_each_thread(g, p);



	read_unlock_irq(&tasklist_lock);

	read_unlock_irqrestore(&tasklist_lock, flags);

}



#endif /* CONFIG_MAGIC_SYSRQ */