linux-kernel - [PATCH 2/2] sched: Use iowait boost policy option in schedutil

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Date:   Thu, 18 May 2017 11:30:20 -0700
From:   Joel Fernandes <joelaf@...gle.com>
To:     linux-kernel@...r.kernel.org
Cc:     rafael@...nel.org, Joel Fernandes <joelaf@...gle.com>
Subject: [PATCH 2/2] sched: Use iowait boost policy option in schedutil

If cpufreq policy has iowait boost enabled, use it. Also make it a schedutil
configuration from sysfs so it can be turned on/off if needed (by default use
the policy value).

Signed-off-by: Joel Fernandes <joelaf@...gle.com>
---
 kernel/sched/cpufreq_schedutil.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 76877a62b5fa..6915925bc947 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -24,6 +24,7 @@
 struct sugov_tunables {
 	struct gov_attr_set attr_set;
 	unsigned int rate_limit_us;
+	unsigned int iowait_boost_enable;
 };
 
 struct sugov_policy {
@@ -47,6 +48,7 @@ struct sugov_policy {
 	bool work_in_progress;
 
 	bool need_freq_update;
+	unsigned int iowait_boost_enable;
 };
 
 struct sugov_cpu {
@@ -171,6 +173,11 @@ static void sugov_get_util(unsigned long *util, unsigned long *max)
 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) {
 		sg_cpu->iowait_boost = sg_cpu->iowait_boost_max;
 	} else if (sg_cpu->iowait_boost) {
@@ -386,10 +393,34 @@ static ssize_t rate_limit_us_store(struct gov_attr_set *attr_set, const char *bu
 	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 sprintf(buf, "%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);
+	unsigned int enable;
+
+	if (kstrtouint(buf, 10, &enable))
+		return -EINVAL;
+
+	tunables->iowait_boost_enable = enable;
+
+	return count;
+}
+
 static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us);
+static struct governor_attr iowait_boost_enable = __ATTR_RW(iowait_boost_enable);
 
 static struct attribute *sugov_attributes[] = {
 	&rate_limit_us.attr,
+	&iowait_boost_enable.attr,
 	NULL
 };
 
@@ -543,6 +574,9 @@ static int sugov_init(struct cpufreq_policy *policy)
 			tunables->rate_limit_us *= lat;
 	}
 
+	if (policy->iowait_boost_enable)
+		tunables->iowait_boost_enable = policy->iowait_boost_enable;
+
 	policy->governor_data = sg_policy;
 	sg_policy->tunables = tunables;
 
-- 
2.13.0.303.g4ebf302169-goog