kernel: sched: cpufreq_schedutil: Make iowait boost optional.

Bug: 120438505
Change-Id: I59e3675a320ce71c3c90be3904756b125300ba6b
Signed-off-by: Miguel de Dios <migueldedios@google.com>
Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

kernel/sched/cpufreq_schedutil.c

@@ -25,6 +25,7 @@ struct sugov_tunables {
 	struct gov_attr_set attr_set;
 	unsigned int		up_rate_limit_us;
 	unsigned int		down_rate_limit_us;
+	bool iowait_boost_enable;
 };
 
 struct sugov_policy {
@@ -238,6 +239,11 @@ static void sugov_get_util(unsigned long *util, unsigned long *max, int cpu)
 static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,
 				   unsigned int flags)
 {
+	struct sugov_policy *sg_policy = sg_cpu->sg_policy;
+
+	if (!sg_policy->tunables->iowait_boost_enable)
+		return;
+
 	if (flags & SCHED_CPUFREQ_IOWAIT) {
 		if (sg_cpu->iowait_boost_pending)
 			return;
@@ -534,12 +540,35 @@ static ssize_t down_rate_limit_us_store(struct gov_attr_set *attr_set,
 	return count;
 }
 
+static ssize_t iowait_boost_enable_show(struct gov_attr_set *attr_set,
+                                        char *buf)
+{
+        struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
+        return snprintf(buf, PAGE_SIZE, "%u\n",
+                        tunables->iowait_boost_enable);
+}
+
+static ssize_t iowait_boost_enable_store(struct gov_attr_set *attr_set,
+                                         const char *buf, size_t count)
+{
+        struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
+        bool enable;
+        if (kstrtobool(buf, &enable))
+                return -EINVAL;
+
+        tunables->iowait_boost_enable = enable;
+        return count;
+}
+
 static struct governor_attr up_rate_limit_us = __ATTR_RW(up_rate_limit_us);
 static struct governor_attr down_rate_limit_us = __ATTR_RW(down_rate_limit_us);
+static struct governor_attr iowait_boost_enable =
+	__ATTR_RW(iowait_boost_enable);
 
 static struct attribute *sugov_attributes[] = {
 	&up_rate_limit_us.attr,
 	&down_rate_limit_us.attr,
+	&iowait_boost_enable.attr,
 	NULL
 };
 
@@ -726,6 +755,7 @@ static int sugov_init(struct cpufreq_policy *policy)
 				cpufreq_policy_transition_delay_us(policy);
 	tunables->down_rate_limit_us =
 				cpufreq_policy_transition_delay_us(policy);
+	tunables->iowait_boost_enable = false;
 
 	policy->governor_data = sg_policy;
 	sg_policy->tunables = tunables;