linux-kernel - [PATCH 2/4] cpufreq: stats: Remove locking

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Message-Id: <d4a64a4310805b1641c2582e56fbda503688b789.1599031227.git.viresh.kumar@linaro.org>
Date:   Wed,  2 Sep 2020 12:54:42 +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 2/4] cpufreq: stats: Remove locking

The locking isn't required anymore as stats can get updated only from
one place at a time. Remove it.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/cpufreq/cpufreq_stats.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index fdf9e8556a49..d86ea9744649 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -19,7 +19,6 @@ struct cpufreq_stats {
 	unsigned int state_num;
 	unsigned int last_index;
 	u64 *time_in_state;
-	spinlock_t lock;
 	unsigned int *freq_table;
 	unsigned int *trans_table;
 
@@ -41,7 +40,6 @@ static void cpufreq_stats_reset_table(struct cpufreq_stats *stats)
 {
 	unsigned int count = stats->max_state;
 
-	spin_lock(&stats->lock);
 	memset(stats->time_in_state, 0, count * sizeof(u64));
 	memset(stats->trans_table, 0, count * count * sizeof(int));
 	stats->last_time = get_jiffies_64();
@@ -50,7 +48,6 @@ static void cpufreq_stats_reset_table(struct cpufreq_stats *stats)
 	/* Adjust for the time elapsed since reset was requested */
 	atomic_set(&stats->reset_pending, 0);
 	cpufreq_stats_update(stats, stats->reset_time);
-	spin_unlock(&stats->lock);
 }
 
 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
@@ -244,7 +241,6 @@ void cpufreq_stats_create_table(struct cpufreq_policy *policy)
 	stats->state_num = i;
 	stats->last_time = get_jiffies_64();
 	stats->last_index = freq_table_get_index(stats, policy->cur);
-	spin_lock_init(&stats->lock);
 
 	policy->stats = stats;
 	ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
@@ -277,11 +273,9 @@ void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
 	if (old_index == -1 || new_index == -1 || old_index == new_index)
 		return;
 
-	spin_lock(&stats->lock);
 	cpufreq_stats_update(stats, stats->last_time);
 
 	stats->last_index = new_index;
 	stats->trans_table[old_index * stats->max_state + new_index]++;
 	stats->total_trans++;
-	spin_unlock(&stats->lock);
 }
-- 
2.25.0.rc1.19.g042ed3e048af