cpufreq: trace frequency limits change

systrace used for tracing for Android systems has carried a patch for
many years in the Android tree that traces when the cpufreq limits
change.  With the help of this information, systrace can know when the
policy limits change and can visually display the data. Lets add
upstream support for the same.

Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/Documentation/trace/events-power.rst b/Documentation/trace/events-power.rst
index a77daca..2ef3189 100644 (file)
--- a/Documentation/trace/events-power.rst
+++ b/Documentation/trace/events-power.rst
@@ -27,6 +27,7 @@ cpufreq.
 
   cpu_idle             "state=%lu cpu_id=%lu"
   cpu_frequency                "state=%lu cpu_id=%lu"
+  cpu_frequency_limits "min=%lu max=%lu cpu_id=%lu"
 
 A suspend event is used to indicate the system going in and out of the
 suspend mode:

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b0dfd32..52566f1 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2236,6 +2236,7 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy,
 
        policy->min = new_policy->min;
        policy->max = new_policy->max;
+       trace_cpu_frequency_limits(policy);
 
        policy->cached_target_freq = UINT_MAX;
 

diff --git a/include/trace/events/power.h b/include/trace/events/power.h
index 908977d..f7aece7 100644 (file)
--- a/include/trace/events/power.h
+++ b/include/trace/events/power.h
@@ -5,6 +5,7 @@
 #if !defined(_TRACE_POWER_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_POWER_H
 
+#include <linux/cpufreq.h>
 #include <linux/ktime.h>
 #include <linux/pm_qos.h>
 #include <linux/tracepoint.h>
@@ -148,6 +149,30 @@ DEFINE_EVENT(cpu, cpu_frequency,
        TP_ARGS(frequency, cpu_id)
 );
 
+TRACE_EVENT(cpu_frequency_limits,
+
+       TP_PROTO(struct cpufreq_policy *policy),
+
+       TP_ARGS(policy),
+
+       TP_STRUCT__entry(
+               __field(u32, min_freq)
+               __field(u32, max_freq)
+               __field(u32, cpu_id)
+       ),
+
+       TP_fast_assign(
+               __entry->min_freq = policy->min;
+               __entry->max_freq = policy->max;
+               __entry->cpu_id = policy->cpu;
+       ),
+
+       TP_printk("min=%lu max=%lu cpu_id=%lu",
+                 (unsigned long)__entry->min_freq,
+                 (unsigned long)__entry->max_freq,
+                 (unsigned long)__entry->cpu_id)
+);
+
 TRACE_EVENT(device_pm_callback_start,
 
        TP_PROTO(struct device *dev, const char *pm_ops, int event),