Commit 88ca472f authored by Zqiang's avatar Zqiang Committed by Paul E. McKenney
Browse files

rcu: Check for successful spawn of ->boost_kthread_task 



For the spawning of the priority-boost kthreads can fail, improbable
though this might seem.  This commit therefore refrains from attemoting
to initiate RCU priority boosting when The ->boost_kthread_task pointer
is NULL.

Signed-off-by: default avatarZqiang <qiang1.zhang@intel.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 70ae7b0c

kernel/rcu/tree_plugin.h

+2 −1
Original line number Diff line number Diff line
@@ -1125,7 +1125,8 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) 
	__releases(rnp->lock)

{

	raw_lockdep_assert_held_rcu_node(rnp);

	if (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks == NULL) {

	if (!rnp->boost_kthread_task ||

	    (!rcu_preempt_blocked_readers_cgp(rnp) && !rnp->exp_tasks)) {

		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);

		return;

	}