cpufreq: interactive: Make window alignment optional

Make sampling window alignment optional when scheduler inputs
are not enabled.

Change-Id: If69c111a3efe219cdd1e38c1f46f03404789c0bb
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>

drivers/cpufreq/cpufreq_interactive.c

@@ -127,6 +127,13 @@ struct cpufreq_interactive_tunables {
 	bool use_sched_load;
 	bool use_migration_notif;
 
+	/*
+	 * Whether to align timer windows across all CPUs. When
+	 * use_sched_load is true, this flag is ignored and windows
+	 * will always be aligned.
+	 */
+	bool align_windows;
+
 	/*
 	 * Stay at max freq for at least max_freq_hysteresis before dropping
 	 * frequency.
@@ -166,9 +173,16 @@ static u64 round_to_nw_start(u64 jif,
 			     struct cpufreq_interactive_tunables *tunables)
 {
 	unsigned long step = usecs_to_jiffies(tunables->timer_rate);
+	u64 ret;
 
-	do_div(jif, step);
+	if (tunables->use_sched_load || tunables->align_windows) {
-	return (jif + 1) * step;
+		do_div(jif, step);
+		ret = (jif + 1) * step;
+	} else {
+		ret = jiffies + usecs_to_jiffies(tunables->timer_rate);
+	}
+
+	return ret;
 }
 
 static inline int set_window_helper(
@@ -946,6 +960,7 @@ static ssize_t store_##file_name(					\
 	return count;							\
 }
 show_store_one(max_freq_hysteresis);
+show_store_one(align_windows);
 
 static ssize_t show_go_hispeed_load(struct cpufreq_interactive_tunables
 		*tunables, char *buf)
@@ -1328,6 +1343,7 @@ show_store_gov_pol_sys(io_is_busy);
 show_store_gov_pol_sys(use_sched_load);
 show_store_gov_pol_sys(use_migration_notif);
 show_store_gov_pol_sys(max_freq_hysteresis);
+show_store_gov_pol_sys(align_windows);
 
 #define gov_sys_attr_rw(_name)						\
 static struct global_attr _name##_gov_sys =				\
@@ -1354,6 +1370,7 @@ gov_sys_pol_attr_rw(io_is_busy);
 gov_sys_pol_attr_rw(use_sched_load);
 gov_sys_pol_attr_rw(use_migration_notif);
 gov_sys_pol_attr_rw(max_freq_hysteresis);
+gov_sys_pol_attr_rw(align_windows);
 
 static struct global_attr boostpulse_gov_sys =
 	__ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_sys);
@@ -1377,6 +1394,7 @@ static struct attribute *interactive_attributes_gov_sys[] = {
 	&use_sched_load_gov_sys.attr,
 	&use_migration_notif_gov_sys.attr,
 	&max_freq_hysteresis_gov_sys.attr,
+	&align_windows_gov_sys.attr,
 	NULL,
 };
 
@@ -1401,6 +1419,7 @@ static struct attribute *interactive_attributes_gov_pol[] = {
 	&use_sched_load_gov_pol.attr,
 	&use_migration_notif_gov_pol.attr,
 	&max_freq_hysteresis_gov_pol.attr,
+	&align_windows_gov_pol.attr,
 	NULL,
 };
 
@@ -1468,6 +1487,7 @@ static struct cpufreq_interactive_tunables *alloc_tunable(
 	tunables->timer_rate = DEFAULT_TIMER_RATE;
 	tunables->boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
 	tunables->timer_slack_val = DEFAULT_TIMER_SLACK;
+	tunables->align_windows = true;
 
 	spin_lock_init(&tunables->target_loads_lock);
 	spin_lock_init(&tunables->above_hispeed_delay_lock);