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Message-Id: <1445967059-6897-31-git-send-email-czoborbalint@gmail.com>
Date: Tue, 27 Oct 2015 18:30:19 +0100
From: Bálint Czobor <czoborbalint@...il.com>
To: "Rafael J. Wysocki" <rjw@...ysocki.net>,
Viresh Kumar <viresh.kumar@...aro.org>
Cc: linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
Todd Poynor <toddpoynor@...gle.com>,
Bálint Czobor <czoborbalint@...il.com>
Subject: [PATCH 31/70] cpufreq: interactive: adjust load for changes in speed
From: Todd Poynor <toddpoynor@...gle.com>
Add notifier for speed transitions. Keep a count of CPU active
microseconds times current frequency, converted to a percentage relative
to the current frequency when load is evaluated.
Change-Id: I5c27adb11081c50490219784ca57cc46e97fc28c
Signed-off-by: Todd Poynor <toddpoynor@...gle.com>
Signed-off-by: Bálint Czobor <czoborbalint@...il.com>
---
drivers/cpufreq/cpufreq_interactive.c | 87 +++++++++++++++++++++++++++------
1 file changed, 71 insertions(+), 16 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index 3d8e7b4..d0d51ee 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -41,8 +41,11 @@ static atomic_t active_count = ATOMIC_INIT(0);
struct cpufreq_interactive_cpuinfo {
struct timer_list cpu_timer;
int timer_idlecancel;
+ spinlock_t load_lock; /* protects the next 4 fields */
u64 time_in_idle;
u64 time_in_idle_timestamp;
+ u64 cputime_speedadj;
+ u64 cputime_speedadj_timestamp;
struct cpufreq_policy *policy;
struct cpufreq_frequency_table *freq_table;
unsigned int target_freq;
@@ -121,9 +124,13 @@ static void cpufreq_interactive_timer_resched(
{
mod_timer_pinned(&pcpu->cpu_timer,
jiffies + usecs_to_jiffies(timer_rate));
+ spin_lock(&pcpu->load_lock);
pcpu->time_in_idle =
get_cpu_idle_time_us(smp_processor_id(),
&pcpu->time_in_idle_timestamp);
+ pcpu->cputime_speedadj = 0;
+ pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
+ spin_unlock(&pcpu->load_lock);
}
static unsigned int freq_to_targetload(unsigned int freq)
@@ -148,10 +155,9 @@ static unsigned int freq_to_targetload(unsigned int freq)
*/
static unsigned int choose_freq(
- struct cpufreq_interactive_cpuinfo *pcpu, unsigned int curload)
+ struct cpufreq_interactive_cpuinfo *pcpu, unsigned int loadadjfreq)
{
unsigned int freq = pcpu->policy->cur;
- unsigned int loadadjfreq = freq * curload;
unsigned int prevfreq, freqmin, freqmax;
unsigned int tl;
int index;
@@ -230,16 +236,36 @@ static unsigned int choose_freq(
return freq;
}
-static void cpufreq_interactive_timer(unsigned long data)
+static u64 update_load(int cpu)
{
+ struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
u64 now;
+ u64 now_idle;
unsigned int delta_idle;
unsigned int delta_time;
+ u64 active_time;
+
+ now_idle = get_cpu_idle_time_us(cpu, &now);
+ delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
+ delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
+ active_time = delta_time - delta_idle;
+ pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
+
+ pcpu->time_in_idle = now_idle;
+ pcpu->time_in_idle_timestamp = now;
+ return now;
+}
+
+static void cpufreq_interactive_timer(unsigned long data)
+{
+ u64 now;
+ unsigned int delta_time;
+ u64 cputime_speedadj;
int cpu_load;
struct cpufreq_interactive_cpuinfo *pcpu =
&per_cpu(cpuinfo, data);
- u64 now_idle;
unsigned int new_freq;
+ unsigned int loadadjfreq;
unsigned int index;
unsigned long flags;
@@ -248,26 +274,24 @@ static void cpufreq_interactive_timer(unsigned long data)
if (!pcpu->governor_enabled)
goto exit;
- now_idle = get_cpu_idle_time_us(data, &now);
- delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
- delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
+ spin_lock(&pcpu->load_lock);
+ now = update_load(data);
+ delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
+ cputime_speedadj = pcpu->cputime_speedadj;
+ spin_unlock(&pcpu->load_lock);
- /*
- * If timer ran less than 1ms after short-term sample started, retry.
- */
- if (delta_time < 1000)
+ if (WARN_ON_ONCE(!delta_time))
goto rearm;
- if (delta_idle > delta_time)
- cpu_load = 0;
- else
- cpu_load = 100 * (delta_time - delta_idle) / delta_time;
+ do_div(cputime_speedadj, delta_time);
+ loadadjfreq = (unsigned int)cputime_speedadj * 100;
+ cpu_load = loadadjfreq / pcpu->target_freq;
if ((cpu_load >= go_hispeed_load || boost_val) &&
pcpu->target_freq < hispeed_freq)
new_freq = hispeed_freq;
else
- new_freq = choose_freq(pcpu, cpu_load);
+ new_freq = choose_freq(pcpu, loadadjfreq);
if (pcpu->target_freq >= hispeed_freq &&
new_freq > pcpu->target_freq &&
@@ -498,6 +522,32 @@ static void cpufreq_interactive_boost(void)
wake_up_process(speedchange_task);
}
+static int cpufreq_interactive_notifier(
+ struct notifier_block *nb, unsigned long val, void *data)
+{
+ struct cpufreq_freqs *freq = data;
+ struct cpufreq_interactive_cpuinfo *pcpu;
+ int cpu;
+
+ if (val == CPUFREQ_POSTCHANGE) {
+ pcpu = &per_cpu(cpuinfo, freq->cpu);
+
+ for_each_cpu(cpu, pcpu->policy->cpus) {
+ struct cpufreq_interactive_cpuinfo *pjcpu =
+ &per_cpu(cpuinfo, cpu);
+ spin_lock(&pjcpu->load_lock);
+ update_load(cpu);
+ spin_unlock(&pjcpu->load_lock);
+ }
+ }
+
+ return 0;
+}
+
+static struct notifier_block cpufreq_notifier_block = {
+ .notifier_call = cpufreq_interactive_notifier,
+};
+
static ssize_t show_target_loads(
struct kobject *kobj, struct attribute *attr, char *buf)
{
@@ -817,6 +867,8 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
return rc;
idle_notifier_register(&cpufreq_interactive_idle_nb);
+ cpufreq_register_notifier(
+ &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
break;
case CPUFREQ_GOV_STOP:
@@ -830,6 +882,8 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
if (atomic_dec_return(&active_count) > 0)
return 0;
+ cpufreq_unregister_notifier(
+ &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
idle_notifier_unregister(&cpufreq_interactive_idle_nb);
sysfs_remove_group(cpufreq_global_kobject,
&interactive_attr_group);
@@ -868,6 +922,7 @@ static int __init cpufreq_interactive_init(void)
init_timer_deferrable(&pcpu->cpu_timer);
pcpu->cpu_timer.function = cpufreq_interactive_timer;
pcpu->cpu_timer.data = i;
+ spin_lock_init(&pcpu->load_lock);
}
spin_lock_init(&target_loads_lock);
--
1.7.9.5
--
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