From d6111cf45c5787282b2e20d77bdb6b28881d516a Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 31 Oct 2023 11:12:01 -0700 Subject: [PATCH] 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: "Paul E. McKenney" Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/e4896e0b-eacc-45a2-a7a8-de2280a51ecc@paulmck-laptop --- kernel/sched/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a708d225c28e8..9d5099d02dbce 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -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); } -- 2.30.2