Commit 54b7429e authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
Browse files

rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers 



Deferred wakeup of rcuog kthreads upon RCU idle mode entry is going to
be handled differently whether initiated by idle, user or guest. Prepare
with pulling that control up to rcu_eqs_enter() callers.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210131230548.32970-2-frederic@kernel.org
parent e0ee463c

kernel/rcu/tree.c

+10 −1
Original line number Diff line number Diff line
@@ -644,7 +644,6 @@ static noinstr void rcu_eqs_enter(bool user) 
	trace_rcu_dyntick(TPS("Start"), rdp->dynticks_nesting, 0, atomic_read(&rdp->dynticks));

	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));

	rdp = this_cpu_ptr(&rcu_data);

	do_nocb_deferred_wakeup(rdp);

	rcu_prepare_for_idle();

	rcu_preempt_deferred_qs(current);
@@ -672,7 +671,10 @@ static noinstr void rcu_eqs_enter(bool user) 
 */

void rcu_idle_enter(void)

{

	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);



	lockdep_assert_irqs_disabled();

	do_nocb_deferred_wakeup(rdp);

	rcu_eqs_enter(false);

}

EXPORT_SYMBOL_GPL(rcu_idle_enter);
@@ -691,7 +693,14 @@ EXPORT_SYMBOL_GPL(rcu_idle_enter); 
 */

noinstr void rcu_user_enter(void)

{

	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);



	lockdep_assert_irqs_disabled();



	instrumentation_begin();

	do_nocb_deferred_wakeup(rdp);

	instrumentation_end();



	rcu_eqs_enter(true);

}

#endif /* CONFIG_NO_HZ_FULL */