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-rw-r--r--drivers/cpufreq/Kconfig27
-rw-r--r--drivers/cpufreq/Makefile1
-rw-r--r--drivers/cpufreq/cpufreq_interactive.c708
-rw-r--r--include/linux/cpu.h8
-rw-r--r--include/linux/cpufreq.h3
-rw-r--r--kernel/cpu.c20
6 files changed, 767 insertions, 0 deletions
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 9fb84853d8e3..194708850ede 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -99,6 +99,16 @@ config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
Be aware that not all cpufreq drivers support the conservative
governor. If unsure have a look at the help section of the
driver. Fallback governor will be the performance governor.
+
+config CPU_FREQ_DEFAULT_GOV_INTERACTIVE
+ bool "interactive"
+ select CPU_FREQ_GOV_INTERACTIVE
+ help
+ Use the CPUFreq governor 'interactive' as default. This allows
+ you to get a full dynamic cpu frequency capable system by simply
+ loading your cpufreq low-level hardware driver, using the
+ 'interactive' governor for latency-sensitive workloads.
+
endchoice
config CPU_FREQ_GOV_PERFORMANCE
@@ -156,6 +166,23 @@ config CPU_FREQ_GOV_ONDEMAND
If in doubt, say N.
+config CPU_FREQ_GOV_INTERACTIVE
+ tristate "'interactive' cpufreq policy governor"
+ help
+ 'interactive' - This driver adds a dynamic cpufreq policy governor
+ designed for latency-sensitive workloads.
+
+ This governor attempts to reduce the latency of clock
+ increases so that the system is more responsive to
+ interactive workloads.
+
+ To compile this driver as a module, choose M here: the
+ module will be called cpufreq_interactive.
+
+ For details, take a look at linux/Documentation/cpu-freq.
+
+ If in doubt, say N.
+
config CPU_FREQ_GOV_CONSERVATIVE
tristate "'conservative' cpufreq governor"
depends on CPU_FREQ
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index e2fc2d21fa61..c371bb46d4c4 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_CPU_FREQ_GOV_POWERSAVE) += cpufreq_powersave.o
obj-$(CONFIG_CPU_FREQ_GOV_USERSPACE) += cpufreq_userspace.o
obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND) += cpufreq_ondemand.o
obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE) += cpufreq_conservative.o
+obj-$(CONFIG_CPU_FREQ_GOV_INTERACTIVE) += cpufreq_interactive.o
# CPUfreq cross-arch helpers
obj-$(CONFIG_CPU_FREQ_TABLE) += freq_table.o
diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
new file mode 100644
index 000000000000..e342910d8374
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -0,0 +1,708 @@
+/*
+ * drivers/cpufreq/cpufreq_interactive.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Author: Mike Chan (mike@android.com)
+ *
+ */
+
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/cpufreq.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
+#include <linux/time.h>
+#include <linux/timer.h>
+#include <linux/workqueue.h>
+#include <linux/kthread.h>
+#include <linux/mutex.h>
+
+#include <asm/cputime.h>
+
+static atomic_t active_count = ATOMIC_INIT(0);
+
+struct cpufreq_interactive_cpuinfo {
+ struct timer_list cpu_timer;
+ int timer_idlecancel;
+ u64 time_in_idle;
+ u64 idle_exit_time;
+ u64 timer_run_time;
+ int idling;
+ u64 freq_change_time;
+ u64 freq_change_time_in_idle;
+ struct cpufreq_policy *policy;
+ struct cpufreq_frequency_table *freq_table;
+ unsigned int target_freq;
+ int governor_enabled;
+};
+
+static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
+
+/* Workqueues handle frequency scaling */
+static struct task_struct *up_task;
+static struct workqueue_struct *down_wq;
+static struct work_struct freq_scale_down_work;
+static cpumask_t up_cpumask;
+static spinlock_t up_cpumask_lock;
+static cpumask_t down_cpumask;
+static spinlock_t down_cpumask_lock;
+static struct mutex set_speed_lock;
+
+/* Hi speed to bump to from lo speed when load burst (default max) */
+static u64 hispeed_freq;
+
+/* Go to hi speed when CPU load at or above this value. */
+#define DEFAULT_GO_HISPEED_LOAD 95
+static unsigned long go_hispeed_load;
+
+/*
+ * The minimum amount of time to spend at a frequency before we can ramp down.
+ */
+#define DEFAULT_MIN_SAMPLE_TIME (20 * USEC_PER_MSEC)
+static unsigned long min_sample_time;
+
+/*
+ * The sample rate of the timer used to increase frequency
+ */
+#define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
+static unsigned long timer_rate;
+
+static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
+ unsigned int event);
+
+#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
+static
+#endif
+struct cpufreq_governor cpufreq_gov_interactive = {
+ .name = "interactive",
+ .governor = cpufreq_governor_interactive,
+ .max_transition_latency = 10000000,
+ .owner = THIS_MODULE,
+};
+
+static void cpufreq_interactive_timer(unsigned long data)
+{
+ unsigned int delta_idle;
+ unsigned int delta_time;
+ int cpu_load;
+ int load_since_change;
+ u64 time_in_idle;
+ u64 idle_exit_time;
+ struct cpufreq_interactive_cpuinfo *pcpu =
+ &per_cpu(cpuinfo, data);
+ u64 now_idle;
+ unsigned int new_freq;
+ unsigned int index;
+ unsigned long flags;
+
+ smp_rmb();
+
+ if (!pcpu->governor_enabled)
+ goto exit;
+
+ /*
+ * Once pcpu->timer_run_time is updated to >= pcpu->idle_exit_time,
+ * this lets idle exit know the current idle time sample has
+ * been processed, and idle exit can generate a new sample and
+ * re-arm the timer. This prevents a concurrent idle
+ * exit on that CPU from writing a new set of info at the same time
+ * the timer function runs (the timer function can't use that info
+ * until more time passes).
+ */
+ time_in_idle = pcpu->time_in_idle;
+ idle_exit_time = pcpu->idle_exit_time;
+ now_idle = get_cpu_idle_time_us(data, &pcpu->timer_run_time);
+ smp_wmb();
+
+ /* If we raced with cancelling a timer, skip. */
+ if (!idle_exit_time)
+ goto exit;
+
+ delta_idle = (unsigned int) cputime64_sub(now_idle, time_in_idle);
+ delta_time = (unsigned int) cputime64_sub(pcpu->timer_run_time,
+ idle_exit_time);
+
+ /*
+ * If timer ran less than 1ms after short-term sample started, retry.
+ */
+ if (delta_time < 1000)
+ goto rearm;
+
+ if (delta_idle > delta_time)
+ cpu_load = 0;
+ else
+ cpu_load = 100 * (delta_time - delta_idle) / delta_time;
+
+ delta_idle = (unsigned int) cputime64_sub(now_idle,
+ pcpu->freq_change_time_in_idle);
+ delta_time = (unsigned int) cputime64_sub(pcpu->timer_run_time,
+ pcpu->freq_change_time);
+
+ if ((delta_time == 0) || (delta_idle > delta_time))
+ load_since_change = 0;
+ else
+ load_since_change =
+ 100 * (delta_time - delta_idle) / delta_time;
+
+ /*
+ * Choose greater of short-term load (since last idle timer
+ * started or timer function re-armed itself) or long-term load
+ * (since last frequency change).
+ */
+ if (load_since_change > cpu_load)
+ cpu_load = load_since_change;
+
+ if (cpu_load >= go_hispeed_load) {
+ if (pcpu->policy->cur == pcpu->policy->min)
+ new_freq = hispeed_freq;
+ else
+ new_freq = pcpu->policy->max * cpu_load / 100;
+ } else {
+ new_freq = pcpu->policy->cur * cpu_load / 100;
+ }
+
+ if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
+ new_freq, CPUFREQ_RELATION_H,
+ &index)) {
+ pr_warn_once("timer %d: cpufreq_frequency_table_target error\n",
+ (int) data);
+ goto rearm;
+ }
+
+ new_freq = pcpu->freq_table[index].frequency;
+
+ if (pcpu->target_freq == new_freq)
+ goto rearm_if_notmax;
+
+ /*
+ * Do not scale down unless we have been at this frequency for the
+ * minimum sample time.
+ */
+ if (new_freq < pcpu->target_freq) {
+ if (cputime64_sub(pcpu->timer_run_time, pcpu->freq_change_time)
+ < min_sample_time)
+ goto rearm;
+ }
+
+ if (new_freq < pcpu->target_freq) {
+ pcpu->target_freq = new_freq;
+ spin_lock_irqsave(&down_cpumask_lock, flags);
+ cpumask_set_cpu(data, &down_cpumask);
+ spin_unlock_irqrestore(&down_cpumask_lock, flags);
+ queue_work(down_wq, &freq_scale_down_work);
+ } else {
+ pcpu->target_freq = new_freq;
+ spin_lock_irqsave(&up_cpumask_lock, flags);
+ cpumask_set_cpu(data, &up_cpumask);
+ spin_unlock_irqrestore(&up_cpumask_lock, flags);
+ wake_up_process(up_task);
+ }
+
+rearm_if_notmax:
+ /*
+ * Already set max speed and don't see a need to change that,
+ * wait until next idle to re-evaluate, don't need timer.
+ */
+ if (pcpu->target_freq == pcpu->policy->max)
+ goto exit;
+
+rearm:
+ if (!timer_pending(&pcpu->cpu_timer)) {
+ /*
+ * If already at min: if that CPU is idle, don't set timer.
+ * Else cancel the timer if that CPU goes idle. We don't
+ * need to re-evaluate speed until the next idle exit.
+ */
+ if (pcpu->target_freq == pcpu->policy->min) {
+ smp_rmb();
+
+ if (pcpu->idling)
+ goto exit;
+
+ pcpu->timer_idlecancel = 1;
+ }
+
+ pcpu->time_in_idle = get_cpu_idle_time_us(
+ data, &pcpu->idle_exit_time);
+ mod_timer(&pcpu->cpu_timer,
+ jiffies + usecs_to_jiffies(timer_rate));
+ }
+
+exit:
+ return;
+}
+
+static void cpufreq_interactive_idle_start(void)
+{
+ struct cpufreq_interactive_cpuinfo *pcpu =
+ &per_cpu(cpuinfo, smp_processor_id());
+ int pending;
+
+ if (!pcpu->governor_enabled)
+ return;
+
+ pcpu->idling = 1;
+ smp_wmb();
+ pending = timer_pending(&pcpu->cpu_timer);
+
+ if (pcpu->target_freq != pcpu->policy->min) {
+#ifdef CONFIG_SMP
+ /*
+ * Entering idle while not at lowest speed. On some
+ * platforms this can hold the other CPU(s) at that speed
+ * even though the CPU is idle. Set a timer to re-evaluate
+ * speed so this idle CPU doesn't hold the other CPUs above
+ * min indefinitely. This should probably be a quirk of
+ * the CPUFreq driver.
+ */
+ if (!pending) {
+ pcpu->time_in_idle = get_cpu_idle_time_us(
+ smp_processor_id(), &pcpu->idle_exit_time);
+ pcpu->timer_idlecancel = 0;
+ mod_timer(&pcpu->cpu_timer,
+ jiffies + usecs_to_jiffies(timer_rate));
+ }
+#endif
+ } else {
+ /*
+ * If at min speed and entering idle after load has
+ * already been evaluated, and a timer has been set just in
+ * case the CPU suddenly goes busy, cancel that timer. The
+ * CPU didn't go busy; we'll recheck things upon idle exit.
+ */
+ if (pending && pcpu->timer_idlecancel) {
+ del_timer(&pcpu->cpu_timer);
+ /*
+ * Ensure last timer run time is after current idle
+ * sample start time, so next idle exit will always
+ * start a new idle sampling period.
+ */
+ pcpu->idle_exit_time = 0;
+ pcpu->timer_idlecancel = 0;
+ }
+ }
+
+}
+
+static void cpufreq_interactive_idle_end(void)
+{
+ struct cpufreq_interactive_cpuinfo *pcpu =
+ &per_cpu(cpuinfo, smp_processor_id());
+
+ pcpu->idling = 0;
+ smp_wmb();
+
+ /*
+ * Arm the timer for 1-2 ticks later if not already, and if the timer
+ * function has already processed the previous load sampling
+ * interval. (If the timer is not pending but has not processed
+ * the previous interval, it is probably racing with us on another
+ * CPU. Let it compute load based on the previous sample and then
+ * re-arm the timer for another interval when it's done, rather
+ * than updating the interval start time to be "now", which doesn't
+ * give the timer function enough time to make a decision on this
+ * run.)
+ */
+ if (timer_pending(&pcpu->cpu_timer) == 0 &&
+ pcpu->timer_run_time >= pcpu->idle_exit_time &&
+ pcpu->governor_enabled) {
+ pcpu->time_in_idle =
+ get_cpu_idle_time_us(smp_processor_id(),
+ &pcpu->idle_exit_time);
+ pcpu->timer_idlecancel = 0;
+ mod_timer(&pcpu->cpu_timer,
+ jiffies + usecs_to_jiffies(timer_rate));
+ }
+
+}
+
+static int cpufreq_interactive_up_task(void *data)
+{
+ unsigned int cpu;
+ cpumask_t tmp_mask;
+ unsigned long flags;
+ struct cpufreq_interactive_cpuinfo *pcpu;
+
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ spin_lock_irqsave(&up_cpumask_lock, flags);
+
+ if (cpumask_empty(&up_cpumask)) {
+ spin_unlock_irqrestore(&up_cpumask_lock, flags);
+ schedule();
+
+ if (kthread_should_stop())
+ break;
+
+ spin_lock_irqsave(&up_cpumask_lock, flags);
+ }
+
+ set_current_state(TASK_RUNNING);
+ tmp_mask = up_cpumask;
+ cpumask_clear(&up_cpumask);
+ spin_unlock_irqrestore(&up_cpumask_lock, flags);
+
+ for_each_cpu(cpu, &tmp_mask) {
+ unsigned int j;
+ unsigned int max_freq = 0;
+
+ pcpu = &per_cpu(cpuinfo, cpu);
+ smp_rmb();
+
+ if (!pcpu->governor_enabled)
+ continue;
+
+ mutex_lock(&set_speed_lock);
+
+ for_each_cpu(j, pcpu->policy->cpus) {
+ struct cpufreq_interactive_cpuinfo *pjcpu =
+ &per_cpu(cpuinfo, j);
+
+ if (pjcpu->target_freq > max_freq)
+ max_freq = pjcpu->target_freq;
+ }
+
+ if (max_freq != pcpu->policy->cur)
+ __cpufreq_driver_target(pcpu->policy,
+ max_freq,
+ CPUFREQ_RELATION_H);
+ mutex_unlock(&set_speed_lock);
+
+ pcpu->freq_change_time_in_idle =
+ get_cpu_idle_time_us(cpu,
+ &pcpu->freq_change_time);
+ }
+ }
+
+ return 0;
+}
+
+static void cpufreq_interactive_freq_down(struct work_struct *work)
+{
+ unsigned int cpu;
+ cpumask_t tmp_mask;
+ unsigned long flags;
+ struct cpufreq_interactive_cpuinfo *pcpu;
+
+ spin_lock_irqsave(&down_cpumask_lock, flags);
+ tmp_mask = down_cpumask;
+ cpumask_clear(&down_cpumask);
+ spin_unlock_irqrestore(&down_cpumask_lock, flags);
+
+ for_each_cpu(cpu, &tmp_mask) {
+ unsigned int j;
+ unsigned int max_freq = 0;
+
+ pcpu = &per_cpu(cpuinfo, cpu);
+ smp_rmb();
+
+ if (!pcpu->governor_enabled)
+ continue;
+
+ mutex_lock(&set_speed_lock);
+
+ for_each_cpu(j, pcpu->policy->cpus) {
+ struct cpufreq_interactive_cpuinfo *pjcpu =
+ &per_cpu(cpuinfo, j);
+
+ if (pjcpu->target_freq > max_freq)
+ max_freq = pjcpu->target_freq;
+ }
+
+ if (max_freq != pcpu->policy->cur)
+ __cpufreq_driver_target(pcpu->policy, max_freq,
+ CPUFREQ_RELATION_H);
+
+ mutex_unlock(&set_speed_lock);
+ pcpu->freq_change_time_in_idle =
+ get_cpu_idle_time_us(cpu,
+ &pcpu->freq_change_time);
+ }
+}
+
+static ssize_t show_hispeed_freq(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ return sprintf(buf, "%llu\n", hispeed_freq);
+}
+
+static ssize_t store_hispeed_freq(struct kobject *kobj,
+ struct attribute *attr, const char *buf,
+ size_t count)
+{
+ int ret;
+ u64 val;
+
+ ret = strict_strtoull(buf, 0, &val);
+ if (ret < 0)
+ return ret;
+ hispeed_freq = val;
+ return count;
+}
+
+static struct global_attr hispeed_freq_attr = __ATTR(hispeed_freq, 0644,
+ show_hispeed_freq, store_hispeed_freq);
+
+
+static ssize_t show_go_hispeed_load(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", go_hispeed_load);
+}
+
+static ssize_t store_go_hispeed_load(struct kobject *kobj,
+ struct attribute *attr, const char *buf, size_t count)
+{
+ int ret;
+ unsigned long val;
+
+ ret = strict_strtoul(buf, 0, &val);
+ if (ret < 0)
+ return ret;
+ go_hispeed_load = val;
+ return count;
+}
+
+static struct global_attr go_hispeed_load_attr = __ATTR(go_hispeed_load, 0644,
+ show_go_hispeed_load, store_go_hispeed_load);
+
+static ssize_t show_min_sample_time(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", min_sample_time);
+}
+
+static ssize_t store_min_sample_time(struct kobject *kobj,
+ struct attribute *attr, const char *buf, size_t count)
+{
+ int ret;
+ unsigned long val;
+
+ ret = strict_strtoul(buf, 0, &val);
+ if (ret < 0)
+ return ret;
+ min_sample_time = val;
+ return count;
+}
+
+static struct global_attr min_sample_time_attr = __ATTR(min_sample_time, 0644,
+ show_min_sample_time, store_min_sample_time);
+
+static ssize_t show_timer_rate(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", timer_rate);
+}
+
+static ssize_t store_timer_rate(struct kobject *kobj,
+ struct attribute *attr, const char *buf, size_t count)
+{
+ int ret;
+ unsigned long val;
+
+ ret = strict_strtoul(buf, 0, &val);
+ if (ret < 0)
+ return ret;
+ timer_rate = val;
+ return count;
+}
+
+static struct global_attr timer_rate_attr = __ATTR(timer_rate, 0644,
+ show_timer_rate, store_timer_rate);
+
+static struct attribute *interactive_attributes[] = {
+ &hispeed_freq_attr.attr,
+ &go_hispeed_load_attr.attr,
+ &min_sample_time_attr.attr,
+ &timer_rate_attr.attr,
+ NULL,
+};
+
+static struct attribute_group interactive_attr_group = {
+ .attrs = interactive_attributes,
+ .name = "interactive",
+};
+
+static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
+ unsigned int event)
+{
+ int rc;
+ unsigned int j;
+ struct cpufreq_interactive_cpuinfo *pcpu;
+ struct cpufreq_frequency_table *freq_table;
+
+ switch (event) {
+ case CPUFREQ_GOV_START:
+ if (!cpu_online(policy->cpu))
+ return -EINVAL;
+
+ freq_table =
+ cpufreq_frequency_get_table(policy->cpu);
+
+ for_each_cpu(j, policy->cpus) {
+ pcpu = &per_cpu(cpuinfo, j);
+ pcpu->policy = policy;
+ pcpu->target_freq = policy->cur;
+ pcpu->freq_table = freq_table;
+ pcpu->freq_change_time_in_idle =
+ get_cpu_idle_time_us(j,
+ &pcpu->freq_change_time);
+ pcpu->governor_enabled = 1;
+ smp_wmb();
+ }
+
+ if (!hispeed_freq)
+ hispeed_freq = policy->max;
+
+ /*
+ * Do not register the idle hook and create sysfs
+ * entries if we have already done so.
+ */
+ if (atomic_inc_return(&active_count) > 1)
+ return 0;
+
+ rc = sysfs_create_group(cpufreq_global_kobject,
+ &interactive_attr_group);
+ if (rc)
+ return rc;
+
+ break;
+
+ case CPUFREQ_GOV_STOP:
+ for_each_cpu(j, policy->cpus) {
+ pcpu = &per_cpu(cpuinfo, j);
+ pcpu->governor_enabled = 0;
+ smp_wmb();
+ del_timer_sync(&pcpu->cpu_timer);
+
+ /*
+ * Reset idle exit time since we may cancel the timer
+ * before it can run after the last idle exit time,
+ * to avoid tripping the check in idle exit for a timer
+ * that is trying to run.
+ */
+ pcpu->idle_exit_time = 0;
+ }
+
+ flush_work(&freq_scale_down_work);
+ if (atomic_dec_return(&active_count) > 0)
+ return 0;
+
+ sysfs_remove_group(cpufreq_global_kobject,
+ &interactive_attr_group);
+
+ break;
+
+ case CPUFREQ_GOV_LIMITS:
+ if (policy->max < policy->cur)
+ __cpufreq_driver_target(policy,
+ policy->max, CPUFREQ_RELATION_H);
+ else if (policy->min > policy->cur)
+ __cpufreq_driver_target(policy,
+ policy->min, CPUFREQ_RELATION_L);
+ break;
+ }
+ return 0;
+}
+
+static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
+ unsigned long val,
+ void *data)
+{
+ switch (val) {
+ case IDLE_START:
+ cpufreq_interactive_idle_start();
+ break;
+ case IDLE_END:
+ cpufreq_interactive_idle_end();
+ break;
+ }
+
+ return 0;
+}
+
+static struct notifier_block cpufreq_interactive_idle_nb = {
+ .notifier_call = cpufreq_interactive_idle_notifier,
+};
+
+static int __init cpufreq_interactive_init(void)
+{
+ unsigned int i;
+ struct cpufreq_interactive_cpuinfo *pcpu;
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+
+ go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
+ min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
+ timer_rate = DEFAULT_TIMER_RATE;
+
+ /* Initalize per-cpu timers */
+ for_each_possible_cpu(i) {
+ pcpu = &per_cpu(cpuinfo, i);
+ init_timer(&pcpu->cpu_timer);
+ pcpu->cpu_timer.function = cpufreq_interactive_timer;
+ pcpu->cpu_timer.data = i;
+ }
+
+ up_task = kthread_create(cpufreq_interactive_up_task, NULL,
+ "kinteractiveup");
+ if (IS_ERR(up_task))
+ return PTR_ERR(up_task);
+
+ sched_setscheduler_nocheck(up_task, SCHED_FIFO, &param);
+ get_task_struct(up_task);
+
+ /* No rescuer thread, bind to CPU queuing the work for possibly
+ warm cache (probably doesn't matter much). */
+ down_wq = alloc_workqueue("knteractive_down", 0, 1);
+
+ if (!down_wq)
+ goto err_freeuptask;
+
+ INIT_WORK(&freq_scale_down_work,
+ cpufreq_interactive_freq_down);
+
+ spin_lock_init(&up_cpumask_lock);
+ spin_lock_init(&down_cpumask_lock);
+ mutex_init(&set_speed_lock);
+
+ idle_notifier_register(&cpufreq_interactive_idle_nb);
+
+ return cpufreq_register_governor(&cpufreq_gov_interactive);
+
+err_freeuptask:
+ put_task_struct(up_task);
+ return -ENOMEM;
+}
+
+#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
+fs_initcall(cpufreq_interactive_init);
+#else
+module_init(cpufreq_interactive_init);
+#endif
+
+static void __exit cpufreq_interactive_exit(void)
+{
+ cpufreq_unregister_governor(&cpufreq_gov_interactive);
+ kthread_stop(up_task);
+ put_task_struct(up_task);
+ destroy_workqueue(down_wq);
+}
+
+module_exit(cpufreq_interactive_exit);
+
+MODULE_AUTHOR("Mike Chan <mike@android.com>");
+MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
+ "Latency sensitive workloads");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 5f09323ee880..7681360ba60c 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -163,6 +163,7 @@ static inline void cpu_hotplug_driver_unlock(void)
#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_PM_SLEEP_SMP
+
extern int suspend_cpu_hotplug;
extern int disable_nonboot_cpus(void);
@@ -174,4 +175,11 @@ static inline int disable_nonboot_cpus(void) { return 0; }
static inline void enable_nonboot_cpus(void) {}
#endif /* !CONFIG_PM_SLEEP_SMP */
+#define IDLE_START 1
+#define IDLE_END 2
+
+void idle_notifier_register(struct notifier_block *n);
+void idle_notifier_unregister(struct notifier_block *n);
+void idle_notifier_call_chain(unsigned long val);
+
#endif /* _LINUX_CPU_H_ */
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 11be48e0d168..ae06dc9a0cda 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -358,6 +358,9 @@ extern struct cpufreq_governor cpufreq_gov_ondemand;
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
extern struct cpufreq_governor cpufreq_gov_conservative;
#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
+#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE)
+extern struct cpufreq_governor cpufreq_gov_interactive;
+#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_interactive)
#endif
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 12b7458f23b1..404770761a4e 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -594,3 +594,23 @@ void init_cpu_online(const struct cpumask *src)
{
cpumask_copy(to_cpumask(cpu_online_bits), src);
}
+
+static ATOMIC_NOTIFIER_HEAD(idle_notifier);
+
+void idle_notifier_register(struct notifier_block *n)
+{
+ atomic_notifier_chain_register(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_register);
+
+void idle_notifier_unregister(struct notifier_block *n)
+{
+ atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_unregister);
+
+void idle_notifier_call_chain(unsigned long val)
+{
+ atomic_notifier_call_chain(&idle_notifier, val, NULL);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_call_chain);