cpufreq_stats_update() has only two callers, one of them is already taking locks and other one don't.
To make locking efficient for cpufreq_stat_notifier_trans(), lets call cpufreq_stats_update() from within locks. Also update show_time_in_state() to call cpufreq_stats_update() after taking locks.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/cpufreq/cpufreq_stats.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c index e18735816908..955abb54f9ec 100644 --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -39,12 +39,10 @@ static int cpufreq_stats_update(struct cpufreq_stats *stat) { unsigned long long cur_time = get_jiffies_64();
- spin_lock(&cpufreq_stats_lock); if (stat->time_in_state) stat->time_in_state[stat->last_index] += cur_time - stat->last_time; stat->last_time = cur_time; - spin_unlock(&cpufreq_stats_lock); return 0; }
@@ -61,7 +59,10 @@ static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf) ssize_t len = 0; int i;
+ spin_lock(&cpufreq_stats_lock); cpufreq_stats_update(stat); + spin_unlock(&cpufreq_stats_lock); + for (i = 0; i < stat->state_num; i++) { len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i], (unsigned long long) @@ -302,9 +303,9 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb, if (old_index == new_index) return 0;
+ spin_lock(&cpufreq_stats_lock); cpufreq_stats_update(stat);
- spin_lock(&cpufreq_stats_lock); stat->last_index = new_index; #ifdef CONFIG_CPU_FREQ_STAT_DETAILS stat->trans_table[old_index * stat->max_state + new_index]++;