diff mbox

[V3,15/16] cpufreq: stats: don't update stats on false notifiers

Message ID de372ca3df4ad156f54cc82ae830b213125c8423.1420558386.git.viresh.kumar@linaro.org
State New
Headers show

Commit Message

Viresh Kumar Jan. 6, 2015, 3:39 p.m. UTC 
We need to call cpufreq_stats_update() to update 'time_in_state' for the last
frequency. This is achieved by calling it from cpufreq_stat_notifier_trans(),
which is called after frequency transition.

But if we detect that the cpu's frequency haven't really changed and its a false
POSTCHANGE notification, we don't really need to update time_in_state.

It wouldn't cause any harm in calling cpufreq_stats_update() but we can avoid
calling it here and call it when the frequency really changes. The result will
be the same but more efficient.

Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/cpufreq_stats.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 6e87dd9c4083..71fcc7c198a1 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -289,11 +289,11 @@  static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
 	if (old_index == -1 || new_index == -1)
 		return 0;
 
-	cpufreq_stats_update(stats);
-
 	if (old_index == new_index)
 		return 0;
 
+	cpufreq_stats_update(stats);
+
 	spin_lock(&cpufreq_stats_lock);
 	stats->last_index = new_index;
 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS