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Commit cb349ca9 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Frederic Weisbecker
Browse files

rcu: Apply micro-optimization and int/bool fixes to RCU's idle handling 



Checking "user" before "is_idle_task()" allows better optimizations
in cases where inlining is possible.  Also, "bool" should be passed
"true" or "false" rather than "1" or "0".  This commit therefore makes
these changes, as noted in Josh's review.

Reported-by: default avatarJosh Triplett <josh@joshtriplett.org>
Signed-off-by: default avatarPaul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
parent 1fd2b442

kernel/rcutree.c

+8 −8
Original line number Diff line number Diff line
@@ -335,7 +335,7 @@ static void rcu_eqs_enter_common(struct rcu_dynticks *rdtp, long long oldval, 
				bool user)

{

	trace_rcu_dyntick("Start", oldval, 0);

	if (!is_idle_task(current) && !user) {

	if (!user && !is_idle_task(current)) {

		struct task_struct *idle = idle_task(smp_processor_id());



		trace_rcu_dyntick("Error on entry: not idle task", oldval, 0);
@@ -399,7 +399,7 @@ void rcu_idle_enter(void) 
	unsigned long flags;



	local_irq_save(flags);

	rcu_eqs_enter(0);

	rcu_eqs_enter(false);

	local_irq_restore(flags);

}

EXPORT_SYMBOL_GPL(rcu_idle_enter);
@@ -435,7 +435,7 @@ void rcu_user_enter(void) 
	rdtp = &__get_cpu_var(rcu_dynticks);

	if (!rdtp->ignore_user_qs && !rdtp->in_user) {

		rdtp->in_user = true;

		rcu_eqs_enter(1);

		rcu_eqs_enter(true);

	}

	local_irq_restore(flags);

}
@@ -492,7 +492,7 @@ void rcu_irq_exit(void) 
	if (rdtp->dynticks_nesting)

		trace_rcu_dyntick("--=", oldval, rdtp->dynticks_nesting);

	else

		rcu_eqs_enter_common(rdtp, oldval, 1);

		rcu_eqs_enter_common(rdtp, oldval, true);

	local_irq_restore(flags);

}
@@ -513,7 +513,7 @@ static void rcu_eqs_exit_common(struct rcu_dynticks *rdtp, long long oldval, 
	WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));

	rcu_cleanup_after_idle(smp_processor_id());

	trace_rcu_dyntick("End", oldval, rdtp->dynticks_nesting);

	if (!is_idle_task(current) && !user) {

	if (!user && !is_idle_task(current)) {

		struct task_struct *idle = idle_task(smp_processor_id());



		trace_rcu_dyntick("Error on exit: not idle task",
@@ -560,7 +560,7 @@ void rcu_idle_exit(void) 
	unsigned long flags;



	local_irq_save(flags);

	rcu_eqs_exit(0);

	rcu_eqs_exit(false);

	local_irq_restore(flags);

}

EXPORT_SYMBOL_GPL(rcu_idle_exit);
@@ -592,7 +592,7 @@ void rcu_user_exit(void) 
	rdtp = &__get_cpu_var(rcu_dynticks);

	if (rdtp->in_user) {

		rdtp->in_user = false;

		rcu_eqs_exit(1);

		rcu_eqs_exit(true);

	}

	local_irq_restore(flags);

}
@@ -653,7 +653,7 @@ void rcu_irq_enter(void) 
	if (oldval)

		trace_rcu_dyntick("++=", oldval, rdtp->dynticks_nesting);

	else

		rcu_eqs_exit_common(rdtp, oldval, 1);

		rcu_eqs_exit_common(rdtp, oldval, true);

	local_irq_restore(flags);

}