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cpufreq: schedutil: Call sugov_update_next_freq() before check to fast_switch_enabled 

Note that sugov_update_next_freq() may return false, that means the
caller sugov_fast_switch() will do nothing except fast switch check.

Similarly, sugov_deferred_update() also has unnecessary operations
of raw_spin_{lock,unlock} in sugov_update_single_freq() for that case.

So, let's call sugov_update_next_freq() before the fast switch check
to avoid unnecessary behaviors above. Accordingly, update interface
definition to sugov_deferred_update() and remove sugov_fast_switch()
since we will call cpufreq_driver_fast_switch() directly instead.

Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Yue Hu 2021-02-24 14:39:27 +08:00 committed by Rafael J. Wysocki
parent 1e28eed176
commit 389e4ecf5f
1 changed files with 14 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
kernel/sched/cpufreq_schedutil.c
View File

@ -114,19 +114,8 @@ static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
return true;
}
static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time,
unsigned int next_freq)
static void sugov_deferred_update(struct sugov_policy *sg_policy)
{
if (sugov_update_next_freq(sg_policy, time, next_freq))
cpufreq_driver_fast_switch(sg_policy->policy, next_freq);
}
static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time,
unsigned int next_freq)
{
if (!sugov_update_next_freq(sg_policy, time, next_freq))
return;
if (!sg_policy->work_in_progress) {
sg_policy->work_in_progress = true;
irq_work_queue(&sg_policy->irq_work);
@ -366,16 +355,19 @@ static void sugov_update_single_freq(struct update_util_data *hook, u64 time,
sg_policy->cached_raw_freq = cached_freq;
}
if (!sugov_update_next_freq(sg_policy, time, next_f))
return;
/*
* This code runs under rq->lock for the target CPU, so it won't run
* concurrently on two different CPUs for the same target and it is not
* necessary to acquire the lock in the fast switch case.
*/
if (sg_policy->policy->fast_switch_enabled) {
sugov_fast_switch(sg_policy, time, next_f);
cpufreq_driver_fast_switch(sg_policy->policy, next_f);
} else {
raw_spin_lock(&sg_policy->update_lock);
sugov_deferred_update(sg_policy, time, next_f);
sugov_deferred_update(sg_policy);
raw_spin_unlock(&sg_policy->update_lock);
}
}
@ -454,12 +446,15 @@ sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags)
if (sugov_should_update_freq(sg_policy, time)) {
next_f = sugov_next_freq_shared(sg_cpu, time);
if (sg_policy->policy->fast_switch_enabled)
sugov_fast_switch(sg_policy, time, next_f);
else
sugov_deferred_update(sg_policy, time, next_f);
}
if (!sugov_update_next_freq(sg_policy, time, next_f))
goto unlock;
if (sg_policy->policy->fast_switch_enabled)
cpufreq_driver_fast_switch(sg_policy->policy, next_f);
else
sugov_deferred_update(sg_policy);
}
unlock:
raw_spin_unlock(&sg_policy->update_lock);
}