@@ -207,12 +207,10 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
cpufreq_for_each_valid_entry(pos, table)
if (freq_table_get_index(stats, pos->frequency) == -1)
stats->freq_table[i++] = pos->frequency;
- stats->state_num = i;
- spin_lock(&cpufreq_stats_lock);
+ stats->state_num = i;
stats->last_time = get_jiffies_64();
stats->last_index = freq_table_get_index(stats, policy->cur);
- spin_unlock(&cpufreq_stats_lock);
policy->stats = stats;
ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
@@ -294,13 +292,11 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
cpufreq_stats_update(stats);
- spin_lock(&cpufreq_stats_lock);
stats->last_index = new_index;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
stats->trans_table[old_index * stats->max_state + new_index]++;
#endif
stats->total_trans++;
- spin_unlock(&cpufreq_stats_lock);
put_policy:
cpufreq_cpu_put(policy);
There is no possibility of any race on updating last_index, trans_table or total_trans as these are updated only by cpufreq_stat_notifier_trans() which will be called sequentially. The only place where locking is still relevant is: cpufreq_stats_update(), which updates time_in_state and last_time. This can be called by two thread in parallel, that may result in races. The two threads being: - sysfs read of time_in_state - and frequency transition that calls cpufreq_stat_notifier_trans(). Remove locking from the first case mentioned above. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/cpufreq/cpufreq_stats.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)