Commit 27c744e3 authored Jun 27, 2018 by Paul E. McKenney

rcu: Allow processing deferred QSes for exiting RCU-preempt readers



If an RCU-preempt read-side critical section is exiting, that is,
->rcu_read_lock_nesting is negative, then it is a good time to look
at the possibility of reporting deferred quiescent states.  This
commit therefore updates the checks in rcu_preempt_need_deferred_qs()
to allow exiting critical sections to report deferred quiescent states.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

parent c0335743

kernel/rcu/tree_plugin.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -602,7 +602,7 @@ static bool rcu_preempt_need_deferred_qs(struct task_struct *t)
		{
		return (this_cpu_ptr(&rcu_preempt_data)->deferred_qs \|\|
		READ_ONCE(t->rcu_read_unlock_special.s)) &&
		!t->rcu_read_lock_nesting;
		t->rcu_read_lock_nesting <= 0;
		}

		/*

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