linux-kernel - [PATCH V3 3/5] cpufreq: stats: Mark few conditionals with unlikely()

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Date:   Mon,  5 Oct 2020 13:26:03 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Rafael Wysocki <rjw@...ysocki.net>,
        Viresh Kumar <viresh.kumar@...aro.org>
Cc:     linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Lukasz Luba <lukasz.luba@....com>, cristian.marussi@....com,
        sudeep.holla@....com, linux-kernel@...r.kernel.org
Subject: [PATCH V3 3/5] cpufreq: stats: Mark few conditionals with unlikely()

Since this will be part of scheduler's hotpath in some cases, use
unlikely() for few of the obvious conditionals.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/cpufreq/cpufreq_stats.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 45a067855367..bba04da3a278 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -260,7 +260,7 @@ void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
 	struct cpufreq_stats *stats = policy->stats;
 	int old_index, new_index;
 
-	if (!stats)
+	if (unlikely(!stats))
 		return;
 
 	if (unlikely(READ_ONCE(stats->reset_pending)))
@@ -270,7 +270,7 @@ void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
 	new_index = freq_table_get_index(stats, new_freq);
 
 	/* We can't do stats->time_in_state[-1]= .. */
-	if (old_index == -1 || new_index == -1 || old_index == new_index)
+	if (unlikely(old_index == -1 || new_index == -1 || old_index == new_index))
 		return;
 
 	cpufreq_stats_update(stats, stats->last_time);
-- 
2.25.0.rc1.19.g042ed3e048af