Commit 54577e23 authored by Alison Chaiken's avatar Alison Chaiken Committed by Paul E. McKenney
Browse files

rcu: Make priority of grace-period thread consistent 



The priority of RCU grace period threads is set to kthread_prio when
they are launched from rcu_spawn_gp_kthread().  The same is not true
of rcu_spawn_one_nocb_kthread().  Accordingly, add priority elevation
to rcu_spawn_one_nocb_kthread().

Signed-off-by: default avatarAlison Chaiken <achaiken@aurora.tech>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent c8db27dd

kernel/rcu/tree_nocb.h

+4 −0
Original line number Original line Diff line number Diff line
@@ -1239,6 +1239,7 @@ static void rcu_spawn_cpu_nocb_kthread(int cpu) 
	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);

	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);

	struct rcu_data *rdp_gp;

	struct rcu_data *rdp_gp;

	struct task_struct *t;

	struct task_struct *t;

	struct sched_param sp;





	if (!rcu_scheduler_fully_active || !rcu_nocb_is_setup)

	if (!rcu_scheduler_fully_active || !rcu_nocb_is_setup)

		return;

		return;
@@ -1248,6 +1249,7 @@ static void rcu_spawn_cpu_nocb_kthread(int cpu) 
		return;

		return;





	/* If we didn't spawn the GP kthread first, reorganize! */

	/* If we didn't spawn the GP kthread first, reorganize! */

	sp.sched_priority = kthread_prio;

	rdp_gp = rdp->nocb_gp_rdp;

	rdp_gp = rdp->nocb_gp_rdp;

	mutex_lock(&rdp_gp->nocb_gp_kthread_mutex);

	mutex_lock(&rdp_gp->nocb_gp_kthread_mutex);

	if (!rdp_gp->nocb_gp_kthread) {

	if (!rdp_gp->nocb_gp_kthread) {
@@ -1258,6 +1260,8 @@ static void rcu_spawn_cpu_nocb_kthread(int cpu) 
			return;

			return;

		}

		}

		WRITE_ONCE(rdp_gp->nocb_gp_kthread, t);

		WRITE_ONCE(rdp_gp->nocb_gp_kthread, t);

		if (kthread_prio)

			sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);

	}

	}

	mutex_unlock(&rdp_gp->nocb_gp_kthread_mutex);

	mutex_unlock(&rdp_gp->nocb_gp_kthread_mutex);