linux-kernel - [PATCH v3 7/7] drivers: devfreq: add tracing for scheduling work

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Date:   Tue, 12 Feb 2019 23:23:58 +0100
From:   Lukasz Luba <l.luba@...tner.samsung.com>
To:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org
Cc:     b.zolnierkie@...sung.com, myungjoo.ham@...sung.com,
        cw00.choi@...sung.com, kyungmin.park@...sung.com,
        m.szyprowski@...sung.com, s.nawrocki@...sung.com, tkjos@...gle.com,
        joel@...lfernandes.org, chris.diamand@....com, mka@...omium.org,
        rostedt@...dmis.org, mingo@...hat.com,
        Lukasz Luba <l.luba@...tner.samsung.com>
Subject: [PATCH v3 7/7] drivers: devfreq: add tracing for scheduling work

This patch add basic tracing of the devfreq workqueue and delayed work.
It aims to capture changes of the polling intervals and device state.

Signed-off-by: Lukasz Luba <l.luba@...tner.samsung.com>
---
 drivers/devfreq/devfreq.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 29e99ce..c1d0d8c 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -29,6 +29,9 @@
 #include <linux/of.h>
 #include "governor.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/devfreq.h>
+
 /* The ~30% load threshold used for load calculation (due to fixed point
  * arithmetic) */
 #define LOAD_THRESHOLD_IN_DEVICE_USAGE (300)
@@ -418,6 +421,7 @@ static void devfreq_monitor(struct work_struct *work)
 	struct devfreq *devfreq = container_of(work,
 					struct devfreq, work.work);
 	unsigned int polling_ms;
+	const char *df_name = dev_name(&devfreq->dev);
 
 	mutex_lock(&devfreq->lock);
 	polling_ms = devfreq_get_polling_delay(devfreq);
@@ -429,6 +433,10 @@ static void devfreq_monitor(struct work_struct *work)
 	schedule_delayed_work(&devfreq->work,
 			      msecs_to_jiffies(polling_ms));
 	mutex_unlock(&devfreq->lock);
+
+	trace_devfreq_monitor(df_name, devfreq->previous_freq, polling_ms,
+			      devfreq->last_status.busy_time,
+			      devfreq->last_status.total_time);
 }
 
 /**
-- 
2.7.4