@@ -11,6 +11,7 @@
struct sugov_tunables {
struct gov_attr_set attr_set;
unsigned int rate_limit_us;
+ unsigned int iowait_boost_cap;
};
struct sugov_policy {
@@ -35,6 +36,8 @@ struct sugov_policy {
bool limits_changed;
bool need_freq_update;
+
+ unsigned int iowait_boost_cap;
};
struct sugov_cpu {
@@ -316,6 +319,9 @@ static unsigned long sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time,
sg_cpu->iowait_boost_pending = false;
+ if (sg_cpu->iowait_boost > sg_cpu->sg_policy->iowait_boost_cap)
+ sg_cpu->iowait_boost = sg_cpu->sg_policy->iowait_boost_cap;
+
/*
* sg_cpu->util is already in capacity scale; convert iowait_boost
* into the same scale so we can compare.
@@ -554,6 +560,14 @@ static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf)
return sprintf(buf, "%u\n", tunables->rate_limit_us);
}
+
+static ssize_t iowait_boost_cap_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_cap);
+}
+
static ssize_t
rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count)
{
@@ -572,10 +586,30 @@ rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count
return count;
}
+static ssize_t
+iowait_boost_cap_store(struct gov_attr_set *attr_set, const char *buf, size_t count)
+{
+ struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
+ struct sugov_policy *sg_policy;
+ unsigned int iowait_boost_cap;
+
+ if (kstrtouint(buf, 10, &iowait_boost_cap))
+ return -EINVAL;
+
+ tunables->iowait_boost_cap = iowait_boost_cap;
+
+ list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook)
+ sg_policy->iowait_boost_cap = iowait_boost_cap;
+
+ return count;
+}
+
static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us);
+static struct governor_attr iowait_boost_cap = __ATTR_RW(iowait_boost_cap);
static struct attribute *sugov_attrs[] = {
&rate_limit_us.attr,
+ &iowait_boost_cap.attr,
NULL
};
ATTRIBUTE_GROUPS(sugov);
@@ -765,6 +799,8 @@ static int sugov_init(struct cpufreq_policy *policy)
tunables->rate_limit_us = cpufreq_policy_transition_delay_us(policy);
+ tunables->iowait_boost_cap = SCHED_CAPACITY_SCALE;
+
policy->governor_data = sg_policy;
sg_policy->tunables = tunables;
@@ -834,6 +870,8 @@ static int sugov_start(struct cpufreq_policy *policy)
sg_policy->limits_changed = false;
sg_policy->cached_raw_freq = 0;
+ sg_policy->iowait_boost_cap = SCHED_CAPACITY_SCALE;
+
sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS);
if (policy_is_shared(policy))
Add a knob to cap applied iowait_boost per sysfs. This is to test for potential regressions. Signed-off-by: Christian Loehle <christian.loehle@arm.com> --- kernel/sched/cpufreq_schedutil.c | 38 ++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+)