Commit 7308e024 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Make rcu_read_unlock_special() expedite strict grace periods 



In kernels built with CONFIG_RCU_STRICT_GRACE_PERIOD=y, every grace
period is an expedited grace period.  However, rcu_read_unlock_special()
does not treat them that way, instead allowing the deferred quiescent
state to be reported whenever.  This commit therefore adds a check of
this Kconfig option that causes rcu_read_unlock_special() to treat all
grace periods as expedited for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels.

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 5e59fba5

kernel/rcu/tree_plugin.h

+1 −0
Original line number Diff line number Diff line
@@ -615,6 +615,7 @@ static void rcu_read_unlock_special(struct task_struct *t) 


		expboost = (t->rcu_blocked_node && READ_ONCE(t->rcu_blocked_node->exp_tasks)) ||

			   (rdp->grpmask & READ_ONCE(rnp->expmask)) ||

			   IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) ||

			   (IS_ENABLED(CONFIG_RCU_BOOST) && irqs_were_disabled &&

			    t->rcu_blocked_node);

		// Need to defer quiescent state until everything is enabled.