Commit d6111cf4 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Peter Zijlstra
Browse files

sched: Use WRITE_ONCE() for p->on_rq 



Since RCU-tasks uses READ_ONCE(p->on_rq), ensure the write-side
matches with WRITE_ONCE().

Signed-off-by: default avatar"Paul E. McKenney" <paulmck@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/e4896e0b-eacc-45a2-a7a8-de2280a51ecc@paulmck-laptop
parent 6d7e4782

kernel/sched/core.c

+4 −2
Original line number Diff line number Diff line
@@ -2124,12 +2124,14 @@ void activate_task(struct rq *rq, struct task_struct *p, int flags) 


	enqueue_task(rq, p, flags);



	p->on_rq = TASK_ON_RQ_QUEUED;

	WRITE_ONCE(p->on_rq, TASK_ON_RQ_QUEUED);

	ASSERT_EXCLUSIVE_WRITER(p->on_rq);

}



void deactivate_task(struct rq *rq, struct task_struct *p, int flags)

{

	p->on_rq = (flags & DEQUEUE_SLEEP) ? 0 : TASK_ON_RQ_MIGRATING;

	WRITE_ONCE(p->on_rq, (flags & DEQUEUE_SLEEP) ? 0 : TASK_ON_RQ_MIGRATING);

	ASSERT_EXCLUSIVE_WRITER(p->on_rq);



	dequeue_task(rq, p, flags);

}