Hello Viresh,

On Sat, Oct 20, 2012 at 01:42:06AM +0530, Viresh Kumar wrote:

+static inline int delay_for_sampling_rate(unsigned int sampling_rate)
+{
+	int delay = usecs_to_jiffies(sampling_rate);
+
+	/* We want all CPUs to do sampling nearly on same jiffy */
+	if (num_online_cpus() > 1)
+		delay -= jiffies % delay;
+
+	return delay;
+}

[...]

+static void od_dbs_timer(struct work_struct *work)
+{
+	struct od_cpu_dbs_info_s *dbs_info =
+		container_of(work, struct od_cpu_dbs_info_s, cdbs.work.work);
+	unsigned int cpu = dbs_info->cdbs.cpu;
+	int delay, sample_type = dbs_info->sample_type;
+
+	mutex_lock(&dbs_info->cdbs.timer_mutex);
 
-/* cpufreq_ondemand Governor Tunables */
-#define show_one(file_name, object)					\
-static ssize_t show_##file_name						\
-(struct kobject *kobj, struct attribute *attr, char *buf)              \
-{									\
-	return sprintf(buf, "%u\n", dbs_tuners_ins.object);		\
+	/* Common NORMAL_SAMPLE setup */
+	dbs_info->sample_type = OD_NORMAL_SAMPLE;
+	if (sample_type == OD_SUB_SAMPLE) {
+		delay = dbs_info->freq_lo_jiffies;
+		__cpufreq_driver_target(dbs_info->cdbs.cur_policy,
+			dbs_info->freq_lo, CPUFREQ_RELATION_H);
+	} else {
+		dbs_check_cpu(&od_dbs_data, cpu);
+		if (dbs_info->freq_lo) {
+			/* Setup timer for SUB_SAMPLE */
+			dbs_info->sample_type = OD_SUB_SAMPLE;
+			delay = dbs_info->freq_hi_jiffies;
+		} else {
+			delay = delay_for_sampling_rate(dbs_info->rate_mult);

                                                        ^^^^^^^^^^^^^^^^^^^

I think this one should be:

delay = delay_for_sampling_rate(od_tuners.sampling_rate * dbs_info->rate_mult);

as currently the timer is firing every jiffy.  This was the old code:

-static void do_dbs_timer(struct work_struct *work)

[...]

-			delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate
-				* dbs_info->rate_mult);
-
-			if (num_online_cpus() > 1)
-				delay -= jiffies % delay;

I'm sending a patch for this one.

Fabio

-- 
Fabio Baltieri