PM / devfreq: Add tracepoint for frequency changes

Add a tracepoint for frequency changes of devfreq devices and
use it.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
[cw00.choi: Move print position of tracepoint and add more information]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index ab5dd9d5fdc79c71072d56545830c66d673607f7..1b236b9e4d9e8add776a334c1ea79af2ee1e0f69 100644 (file)
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -367,6 +367,14 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
                return err;
        }
 
+       /*
+        * Print devfreq_frequency trace information between DEVFREQ_PRECHANGE
+        * and DEVFREQ_POSTCHANGE because for showing the correct frequency
+        * change order of between devfreq device and passive devfreq device.
+        */
+       if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
+               trace_devfreq_frequency(devfreq, new_freq, cur_freq);
+
        freqs.new = new_freq;
        devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
 

diff --git a/include/trace/events/devfreq.h b/include/trace/events/devfreq.h
index bd36d28d16bc966457c706bd348389c06b18992c..7627c620bbda248f9dbad214fed9cdfda6c7c1d2 100644 (file)
--- a/include/trace/events/devfreq.h
+++ b/include/trace/events/devfreq.h
@@ -8,6 +8,34 @@
 #include <linux/devfreq.h>
 #include <linux/tracepoint.h>
 
+TRACE_EVENT(devfreq_frequency,
+       TP_PROTO(struct devfreq *devfreq, unsigned long freq,
+                unsigned long prev_freq),
+
+       TP_ARGS(devfreq, freq, prev_freq),
+
+       TP_STRUCT__entry(
+               __string(dev_name, dev_name(&devfreq->dev))
+               __field(unsigned long, freq)
+               __field(unsigned long, prev_freq)
+               __field(unsigned long, busy_time)
+               __field(unsigned long, total_time)
+       ),
+
+       TP_fast_assign(
+               __assign_str(dev_name, dev_name(&devfreq->dev));
+               __entry->freq = freq;
+               __entry->prev_freq = prev_freq;
+               __entry->busy_time = devfreq->last_status.busy_time;
+               __entry->total_time = devfreq->last_status.total_time;
+       ),
+
+       TP_printk("dev_name=%-30s freq=%-12lu prev_freq=%-12lu load=%-2lu",
+               __get_str(dev_name), __entry->freq, __entry->prev_freq,
+               __entry->total_time == 0 ? 0 :
+                       (100 * __entry->busy_time) / __entry->total_time)
+);
+
 TRACE_EVENT(devfreq_monitor,
        TP_PROTO(struct devfreq *devfreq),