cpufreq: interactive: handle errors from cpufreq_frequency_table_target
[firefly-linux-kernel-4.4.55.git] / drivers / cpufreq / cpufreq_interactive.c
index d0d51ee30727dda728a9a9902a04b45d3f6b2460..1b5d9301e2d7812b41e4b85ab535a9faa2e3ad14 100644 (file)
@@ -21,7 +21,7 @@
 #include <linux/cpufreq.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/mutex.h>
+#include <linux/rwsem.h>
 #include <linux/sched.h>
 #include <linux/sched/rt.h>
 #include <linux/tick.h>
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 #include <linux/kthread.h>
-#include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/kernel_stat.h>
 #include <asm/cputime.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/cpufreq_interactive.h>
 
-static atomic_t active_count = ATOMIC_INIT(0);
+static int active_count;
 
 struct cpufreq_interactive_cpuinfo {
        struct timer_list cpu_timer;
-       int timer_idlecancel;
+       struct timer_list cpu_slack_timer;
        spinlock_t load_lock; /* protects the next 4 fields */
        u64 time_in_idle;
        u64 time_in_idle_timestamp;
@@ -52,6 +52,7 @@ struct cpufreq_interactive_cpuinfo {
        unsigned int floor_freq;
        u64 floor_validate_time;
        u64 hispeed_validate_time;
+       struct rw_semaphore enable_sem;
        int governor_enabled;
 };
 
@@ -61,13 +62,14 @@ static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
 static struct task_struct *speedchange_task;
 static cpumask_t speedchange_cpumask;
 static spinlock_t speedchange_cpumask_lock;
+static struct mutex gov_lock;
 
 /* Hi speed to bump to from lo speed when load burst (default max) */
 static unsigned int hispeed_freq;
 
 /* Go to hi speed when CPU load at or above this value. */
-#define DEFAULT_GO_HISPEED_LOAD 85
-static unsigned long go_hispeed_load;
+#define DEFAULT_GO_HISPEED_LOAD 99
+static unsigned long go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
 
 /* Target load.  Lower values result in higher CPU speeds. */
 #define DEFAULT_TARGET_LOAD 90
@@ -80,31 +82,40 @@ static int ntarget_loads = ARRAY_SIZE(default_target_loads);
  * The minimum amount of time to spend at a frequency before we can ramp down.
  */
 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
-static unsigned long min_sample_time;
+static unsigned long min_sample_time = DEFAULT_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 unsigned long timer_rate = DEFAULT_TIMER_RATE;
 
 /*
  * Wait this long before raising speed above hispeed, by default a single
  * timer interval.
  */
 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
-static unsigned long above_hispeed_delay_val;
+static unsigned int default_above_hispeed_delay[] = {
+       DEFAULT_ABOVE_HISPEED_DELAY };
+static spinlock_t above_hispeed_delay_lock;
+static unsigned int *above_hispeed_delay = default_above_hispeed_delay;
+static int nabove_hispeed_delay = ARRAY_SIZE(default_above_hispeed_delay);
+
+/* Non-zero means indefinite speed boost active */
+static int boost_val;
+/* Duration of a boot pulse in usecs */
+static int boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
+/* End time of boost pulse in ktime converted to usecs */
+static u64 boostpulse_endtime;
 
 /*
- * Non-zero means longer-term speed boost active.
+ * Max additional time to wait in idle, beyond timer_rate, at speeds above
+ * minimum before wakeup to reduce speed, or -1 if unnecessary.
  */
+#define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
+static int timer_slack_val = DEFAULT_TIMER_SLACK;
 
-static int boost_val;
-
-static bool governidle;
-module_param(governidle, bool, S_IWUSR | S_IRUGO);
-MODULE_PARM_DESC(governidle,
-       "Set to 1 to wake up CPUs from idle to reduce speed (default 0)");
+static bool io_is_busy;
 
 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
                unsigned int event);
@@ -119,32 +130,93 @@ struct cpufreq_governor cpufreq_gov_interactive = {
        .owner = THIS_MODULE,
 };
 
+static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
+                                                 cputime64_t *wall)
+{
+       u64 idle_time;
+       u64 cur_wall_time;
+       u64 busy_time;
+
+       cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
+
+       busy_time  = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
+       busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
+       busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
+       busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
+       busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
+       busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
+
+       idle_time = cur_wall_time - busy_time;
+       if (wall)
+               *wall = jiffies_to_usecs(cur_wall_time);
+
+       return jiffies_to_usecs(idle_time);
+}
+
+static inline cputime64_t get_cpu_idle_time(unsigned int cpu,
+                                           cputime64_t *wall)
+{
+       u64 idle_time = get_cpu_idle_time_us(cpu, wall);
+
+       if (idle_time == -1ULL)
+               idle_time = get_cpu_idle_time_jiffy(cpu, wall);
+       else if (!io_is_busy)
+               idle_time += get_cpu_iowait_time_us(cpu, wall);
+
+       return idle_time;
+}
+
 static void cpufreq_interactive_timer_resched(
        struct cpufreq_interactive_cpuinfo *pcpu)
 {
-       mod_timer_pinned(&pcpu->cpu_timer,
-                        jiffies + usecs_to_jiffies(timer_rate));
-       spin_lock(&pcpu->load_lock);
+       unsigned long expires = jiffies + usecs_to_jiffies(timer_rate);
+       unsigned long flags;
+
+       mod_timer_pinned(&pcpu->cpu_timer, expires);
+       if (timer_slack_val >= 0 && pcpu->target_freq > pcpu->policy->min) {
+               expires += usecs_to_jiffies(timer_slack_val);
+               mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
+       }
+
+       spin_lock_irqsave(&pcpu->load_lock, flags);
        pcpu->time_in_idle =
-               get_cpu_idle_time_us(smp_processor_id(),
+               get_cpu_idle_time(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);
+       spin_unlock_irqrestore(&pcpu->load_lock, flags);
+}
+
+static unsigned int freq_to_above_hispeed_delay(unsigned int freq)
+{
+       int i;
+       unsigned int ret;
+       unsigned long flags;
+
+       spin_lock_irqsave(&above_hispeed_delay_lock, flags);
+
+       for (i = 0; i < nabove_hispeed_delay - 1 &&
+                       freq >= above_hispeed_delay[i+1]; i += 2)
+               ;
+
+       ret = above_hispeed_delay[i];
+       spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
+       return ret;
 }
 
 static unsigned int freq_to_targetload(unsigned int freq)
 {
        int i;
        unsigned int ret;
+       unsigned long flags;
 
-       spin_lock(&target_loads_lock);
+       spin_lock_irqsave(&target_loads_lock, flags);
 
        for (i = 0; i < ntarget_loads - 1 && freq >= target_loads[i+1]; i += 2)
                ;
 
        ret = target_loads[i];
-       spin_unlock(&target_loads_lock);
+       spin_unlock_irqrestore(&target_loads_lock, flags);
        return ret;
 }
 
@@ -174,9 +246,10 @@ static unsigned int choose_freq(
                 * than or equal to the target load.
                 */
 
-               cpufreq_frequency_table_target(
-                       pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
-                       CPUFREQ_RELATION_L, &index);
+               if (cpufreq_frequency_table_target(
+                           pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
+                           CPUFREQ_RELATION_L, &index))
+                       break;
                freq = pcpu->freq_table[index].frequency;
 
                if (freq > prevfreq) {
@@ -188,10 +261,11 @@ static unsigned int choose_freq(
                                 * Find the highest frequency that is less
                                 * than freqmax.
                                 */
-                               cpufreq_frequency_table_target(
-                                       pcpu->policy, pcpu->freq_table,
-                                       freqmax - 1, CPUFREQ_RELATION_H,
-                                       &index);
+                               if (cpufreq_frequency_table_target(
+                                           pcpu->policy, pcpu->freq_table,
+                                           freqmax - 1, CPUFREQ_RELATION_H,
+                                           &index))
+                                       break;
                                freq = pcpu->freq_table[index].frequency;
 
                                if (freq == freqmin) {
@@ -214,10 +288,11 @@ static unsigned int choose_freq(
                                 * Find the lowest frequency that is higher
                                 * than freqmin.
                                 */
-                               cpufreq_frequency_table_target(
-                                       pcpu->policy, pcpu->freq_table,
-                                       freqmin + 1, CPUFREQ_RELATION_L,
-                                       &index);
+                               if (cpufreq_frequency_table_target(
+                                           pcpu->policy, pcpu->freq_table,
+                                           freqmin + 1, CPUFREQ_RELATION_L,
+                                           &index))
+                                       break;
                                freq = pcpu->freq_table[index].frequency;
 
                                /*
@@ -245,7 +320,7 @@ static u64 update_load(int cpu)
        unsigned int delta_time;
        u64 active_time;
 
-       now_idle = get_cpu_idle_time_us(cpu, &now);
+       now_idle = get_cpu_idle_time(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;
@@ -268,17 +343,18 @@ static void cpufreq_interactive_timer(unsigned long data)
        unsigned int loadadjfreq;
        unsigned int index;
        unsigned long flags;
+       bool boosted;
 
-       smp_rmb();
-
+       if (!down_read_trylock(&pcpu->enable_sem))
+               return;
        if (!pcpu->governor_enabled)
                goto exit;
 
-       spin_lock(&pcpu->load_lock);
+       spin_lock_irqsave(&pcpu->load_lock, flags);
        now = update_load(data);
        delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
        cputime_speedadj = pcpu->cputime_speedadj;
-       spin_unlock(&pcpu->load_lock);
+       spin_unlock_irqrestore(&pcpu->load_lock, flags);
 
        if (WARN_ON_ONCE(!delta_time))
                goto rearm;
@@ -286,16 +362,25 @@ static void cpufreq_interactive_timer(unsigned long data)
        do_div(cputime_speedadj, delta_time);
        loadadjfreq = (unsigned int)cputime_speedadj * 100;
        cpu_load = loadadjfreq / pcpu->target_freq;
+       boosted = boost_val || now < boostpulse_endtime;
+
+       if (cpu_load >= go_hispeed_load || boosted) {
+               if (pcpu->target_freq < hispeed_freq) {
+                       new_freq = hispeed_freq;
+               } else {
+                       new_freq = choose_freq(pcpu, loadadjfreq);
 
-       if ((cpu_load >= go_hispeed_load || boost_val) &&
-           pcpu->target_freq < hispeed_freq)
-               new_freq = hispeed_freq;
-       else
+                       if (new_freq < hispeed_freq)
+                               new_freq = hispeed_freq;
+               }
+       } else {
                new_freq = choose_freq(pcpu, loadadjfreq);
+       }
 
        if (pcpu->target_freq >= hispeed_freq &&
            new_freq > pcpu->target_freq &&
-           now - pcpu->hispeed_validate_time < above_hispeed_delay_val) {
+           now - pcpu->hispeed_validate_time <
+           freq_to_above_hispeed_delay(pcpu->target_freq)) {
                trace_cpufreq_interactive_notyet(
                        data, cpu_load, pcpu->target_freq,
                        pcpu->policy->cur, new_freq);
@@ -306,11 +391,8 @@ static void cpufreq_interactive_timer(unsigned long data)
 
        if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
                                           new_freq, CPUFREQ_RELATION_L,
-                                          &index)) {
-               pr_warn_once("timer %d: cpufreq_frequency_table_target error\n",
-                            (int) data);
+                                          &index))
                goto rearm;
-       }
 
        new_freq = pcpu->freq_table[index].frequency;
 
@@ -327,8 +409,18 @@ static void cpufreq_interactive_timer(unsigned long data)
                }
        }
 
-       pcpu->floor_freq = new_freq;
-       pcpu->floor_validate_time = now;
+       /*
+        * Update the timestamp for checking whether speed has been held at
+        * or above the selected frequency for a minimum of min_sample_time,
+        * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
+        * allow the speed to drop as soon as the boostpulse duration expires
+        * (or the indefinite boost is turned off).
+        */
+
+       if (!boosted || new_freq > hispeed_freq) {
+               pcpu->floor_freq = new_freq;
+               pcpu->floor_validate_time = now;
+       }
 
        if (pcpu->target_freq == new_freq) {
                trace_cpufreq_interactive_already(
@@ -355,19 +447,11 @@ rearm_if_notmax:
                goto exit;
 
 rearm:
-       if (!timer_pending(&pcpu->cpu_timer)) {
-               /*
-                * If governing speed in idle and already at min, cancel the
-                * timer if that CPU goes idle.  We don't need to re-evaluate
-                * speed until the next idle exit.
-                */
-               if (governidle && pcpu->target_freq == pcpu->policy->min)
-                       pcpu->timer_idlecancel = 1;
-
+       if (!timer_pending(&pcpu->cpu_timer))
                cpufreq_interactive_timer_resched(pcpu);
-       }
 
 exit:
+       up_read(&pcpu->enable_sem);
        return;
 }
 
@@ -377,8 +461,12 @@ static void cpufreq_interactive_idle_start(void)
                &per_cpu(cpuinfo, smp_processor_id());
        int pending;
 
-       if (!pcpu->governor_enabled)
+       if (!down_read_trylock(&pcpu->enable_sem))
+               return;
+       if (!pcpu->governor_enabled) {
+               up_read(&pcpu->enable_sem);
                return;
+       }
 
        pending = timer_pending(&pcpu->cpu_timer);
 
@@ -391,23 +479,11 @@ static void cpufreq_interactive_idle_start(void)
                 * min indefinitely.  This should probably be a quirk of
                 * the CPUFreq driver.
                 */
-               if (!pending) {
-                       pcpu->timer_idlecancel = 0;
+               if (!pending)
                        cpufreq_interactive_timer_resched(pcpu);
-               }
-       } else if (governidle) {
-               /*
-                * 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);
-                       pcpu->timer_idlecancel = 0;
-               }
        }
 
+       up_read(&pcpu->enable_sem);
 }
 
 static void cpufreq_interactive_idle_end(void)
@@ -415,18 +491,23 @@ static void cpufreq_interactive_idle_end(void)
        struct cpufreq_interactive_cpuinfo *pcpu =
                &per_cpu(cpuinfo, smp_processor_id());
 
-       if (!pcpu->governor_enabled)
+       if (!down_read_trylock(&pcpu->enable_sem))
+               return;
+       if (!pcpu->governor_enabled) {
+               up_read(&pcpu->enable_sem);
                return;
+       }
 
        /* Arm the timer for 1-2 ticks later if not already. */
        if (!timer_pending(&pcpu->cpu_timer)) {
-               pcpu->timer_idlecancel = 0;
                cpufreq_interactive_timer_resched(pcpu);
-       } else if (!governidle &&
-                  time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
+       } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
                del_timer(&pcpu->cpu_timer);
+               del_timer(&pcpu->cpu_slack_timer);
                cpufreq_interactive_timer(smp_processor_id());
        }
+
+       up_read(&pcpu->enable_sem);
 }
 
 static int cpufreq_interactive_speedchange_task(void *data)
@@ -461,10 +542,12 @@ static int cpufreq_interactive_speedchange_task(void *data)
                        unsigned int max_freq = 0;
 
                        pcpu = &per_cpu(cpuinfo, cpu);
-                       smp_rmb();
-
-                       if (!pcpu->governor_enabled)
+                       if (!down_read_trylock(&pcpu->enable_sem))
                                continue;
+                       if (!pcpu->governor_enabled) {
+                               up_read(&pcpu->enable_sem);
+                               continue;
+                       }
 
                        for_each_cpu(j, pcpu->policy->cpus) {
                                struct cpufreq_interactive_cpuinfo *pjcpu =
@@ -481,6 +564,8 @@ static int cpufreq_interactive_speedchange_task(void *data)
                        trace_cpufreq_interactive_setspeed(cpu,
                                                     pcpu->target_freq,
                                                     pcpu->policy->cur);
+
+                       up_read(&pcpu->enable_sem);
                }
        }
 
@@ -528,19 +613,27 @@ static int cpufreq_interactive_notifier(
        struct cpufreq_freqs *freq = data;
        struct cpufreq_interactive_cpuinfo *pcpu;
        int cpu;
+       unsigned long flags;
 
        if (val == CPUFREQ_POSTCHANGE) {
                pcpu = &per_cpu(cpuinfo, freq->cpu);
+               if (!down_read_trylock(&pcpu->enable_sem))
+                       return 0;
+               if (!pcpu->governor_enabled) {
+                       up_read(&pcpu->enable_sem);
+                       return 0;
+               }
 
                for_each_cpu(cpu, pcpu->policy->cpus) {
                        struct cpufreq_interactive_cpuinfo *pjcpu =
                                &per_cpu(cpuinfo, cpu);
-                       spin_lock(&pjcpu->load_lock);
+                       spin_lock_irqsave(&pjcpu->load_lock, flags);
                        update_load(cpu);
-                       spin_unlock(&pjcpu->load_lock);
+                       spin_unlock_irqrestore(&pjcpu->load_lock, flags);
                }
-       }
 
+               up_read(&pcpu->enable_sem);
+       }
        return 0;
 }
 
@@ -548,51 +641,32 @@ 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)
-{
-       int i;
-       ssize_t ret = 0;
-
-       spin_lock(&target_loads_lock);
-
-       for (i = 0; i < ntarget_loads; i++)
-               ret += sprintf(buf + ret, "%u%s", target_loads[i],
-                              i & 0x1 ? ":" : " ");
-
-       ret += sprintf(buf + ret, "\n");
-       spin_unlock(&target_loads_lock);
-       return ret;
-}
-
-static ssize_t store_target_loads(
-       struct kobject *kobj, struct attribute *attr, const char *buf,
-       size_t count)
+static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
 {
-       int ret;
        const char *cp;
-       unsigned int *new_target_loads = NULL;
-       int ntokens = 1;
        int i;
+       int ntokens = 1;
+       unsigned int *tokenized_data;
+       int err = -EINVAL;
 
        cp = buf;
        while ((cp = strpbrk(cp + 1, " :")))
                ntokens++;
 
        if (!(ntokens & 0x1))
-               goto err_inval;
+               goto err;
 
-       new_target_loads = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
-       if (!new_target_loads) {
-               ret = -ENOMEM;
+       tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
+       if (!tokenized_data) {
+               err = -ENOMEM;
                goto err;
        }
 
        cp = buf;
        i = 0;
        while (i < ntokens) {
-               if (sscanf(cp, "%u", &new_target_loads[i++]) != 1)
-                       goto err_inval;
+               if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
+                       goto err_kfree;
 
                cp = strpbrk(cp, " :");
                if (!cp)
@@ -601,27 +675,104 @@ static ssize_t store_target_loads(
        }
 
        if (i != ntokens)
-               goto err_inval;
+               goto err_kfree;
+
+       *num_tokens = ntokens;
+       return tokenized_data;
+
+err_kfree:
+       kfree(tokenized_data);
+err:
+       return ERR_PTR(err);
+}
+
+static ssize_t show_target_loads(
+       struct kobject *kobj, struct attribute *attr, char *buf)
+{
+       int i;
+       ssize_t ret = 0;
+       unsigned long flags;
+
+       spin_lock_irqsave(&target_loads_lock, flags);
+
+       for (i = 0; i < ntarget_loads; i++)
+               ret += sprintf(buf + ret, "%u%s", target_loads[i],
+                              i & 0x1 ? ":" : " ");
+
+       ret += sprintf(buf + ret, "\n");
+       spin_unlock_irqrestore(&target_loads_lock, flags);
+       return ret;
+}
+
+static ssize_t store_target_loads(
+       struct kobject *kobj, struct attribute *attr, const char *buf,
+       size_t count)
+{
+       int ntokens;
+       unsigned int *new_target_loads = NULL;
+       unsigned long flags;
 
-       spin_lock(&target_loads_lock);
+       new_target_loads = get_tokenized_data(buf, &ntokens);
+       if (IS_ERR(new_target_loads))
+               return PTR_RET(new_target_loads);
+
+       spin_lock_irqsave(&target_loads_lock, flags);
        if (target_loads != default_target_loads)
                kfree(target_loads);
        target_loads = new_target_loads;
        ntarget_loads = ntokens;
-       spin_unlock(&target_loads_lock);
+       spin_unlock_irqrestore(&target_loads_lock, flags);
        return count;
-
-err_inval:
-       ret = -EINVAL;
-err:
-       kfree(new_target_loads);
-       return ret;
 }
 
 static struct global_attr target_loads_attr =
        __ATTR(target_loads, S_IRUGO | S_IWUSR,
                show_target_loads, store_target_loads);
 
+static ssize_t show_above_hispeed_delay(
+       struct kobject *kobj, struct attribute *attr, char *buf)
+{
+       int i;
+       ssize_t ret = 0;
+       unsigned long flags;
+
+       spin_lock_irqsave(&above_hispeed_delay_lock, flags);
+
+       for (i = 0; i < nabove_hispeed_delay; i++)
+               ret += sprintf(buf + ret, "%u%s", above_hispeed_delay[i],
+                              i & 0x1 ? ":" : " ");
+
+       ret += sprintf(buf + ret, "\n");
+       spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
+       return ret;
+}
+
+static ssize_t store_above_hispeed_delay(
+       struct kobject *kobj, struct attribute *attr, const char *buf,
+       size_t count)
+{
+       int ntokens;
+       unsigned int *new_above_hispeed_delay = NULL;
+       unsigned long flags;
+
+       new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
+       if (IS_ERR(new_above_hispeed_delay))
+               return PTR_RET(new_above_hispeed_delay);
+
+       spin_lock_irqsave(&above_hispeed_delay_lock, flags);
+       if (above_hispeed_delay != default_above_hispeed_delay)
+               kfree(above_hispeed_delay);
+       above_hispeed_delay = new_above_hispeed_delay;
+       nabove_hispeed_delay = ntokens;
+       spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
+       return count;
+
+}
+
+static struct global_attr above_hispeed_delay_attr =
+       __ATTR(above_hispeed_delay, S_IRUGO | S_IWUSR,
+               show_above_hispeed_delay, store_above_hispeed_delay);
+
 static ssize_t show_hispeed_freq(struct kobject *kobj,
                                 struct attribute *attr, char *buf)
 {
@@ -690,15 +841,14 @@ static ssize_t store_min_sample_time(struct kobject *kobj,
 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_above_hispeed_delay(struct kobject *kobj,
-                                       struct attribute *attr, char *buf)
+static ssize_t show_timer_rate(struct kobject *kobj,
+                       struct attribute *attr, char *buf)
 {
-       return sprintf(buf, "%lu\n", above_hispeed_delay_val);
+       return sprintf(buf, "%lu\n", timer_rate);
 }
 
-static ssize_t store_above_hispeed_delay(struct kobject *kobj,
-                                        struct attribute *attr,
-                                        const char *buf, size_t count)
+static ssize_t store_timer_rate(struct kobject *kobj,
+                       struct attribute *attr, const char *buf, size_t count)
 {
        int ret;
        unsigned long val;
@@ -706,33 +856,35 @@ static ssize_t store_above_hispeed_delay(struct kobject *kobj,
        ret = strict_strtoul(buf, 0, &val);
        if (ret < 0)
                return ret;
-       above_hispeed_delay_val = val;
+       timer_rate = val;
        return count;
 }
 
-define_one_global_rw(above_hispeed_delay);
+static struct global_attr timer_rate_attr = __ATTR(timer_rate, 0644,
+               show_timer_rate, store_timer_rate);
 
-static ssize_t show_timer_rate(struct kobject *kobj,
-                       struct attribute *attr, char *buf)
+static ssize_t show_timer_slack(
+       struct kobject *kobj, struct attribute *attr, char *buf)
 {
-       return sprintf(buf, "%lu\n", timer_rate);
+       return sprintf(buf, "%d\n", timer_slack_val);
 }
 
-static ssize_t store_timer_rate(struct kobject *kobj,
-                       struct attribute *attr, const char *buf, size_t count)
+static ssize_t store_timer_slack(
+       struct kobject *kobj, struct attribute *attr, const char *buf,
+       size_t count)
 {
        int ret;
        unsigned long val;
 
-       ret = strict_strtoul(buf, 0, &val);
+       ret = kstrtol(buf, 10, &val);
        if (ret < 0)
                return ret;
-       timer_rate = val;
+
+       timer_slack_val = val;
        return count;
 }
 
-static struct global_attr timer_rate_attr = __ATTR(timer_rate, 0644,
-               show_timer_rate, store_timer_rate);
+define_one_global_rw(timer_slack);
 
 static ssize_t show_boost(struct kobject *kobj, struct attribute *attr,
                          char *buf)
@@ -774,6 +926,7 @@ static ssize_t store_boostpulse(struct kobject *kobj, struct attribute *attr,
        if (ret < 0)
                return ret;
 
+       boostpulse_endtime = ktime_to_us(ktime_get()) + boostpulse_duration_val;
        trace_cpufreq_interactive_boost("pulse");
        cpufreq_interactive_boost();
        return count;
@@ -782,15 +935,63 @@ static ssize_t store_boostpulse(struct kobject *kobj, struct attribute *attr,
 static struct global_attr boostpulse =
        __ATTR(boostpulse, 0200, NULL, store_boostpulse);
 
+static ssize_t show_boostpulse_duration(
+       struct kobject *kobj, struct attribute *attr, char *buf)
+{
+       return sprintf(buf, "%d\n", boostpulse_duration_val);
+}
+
+static ssize_t store_boostpulse_duration(
+       struct kobject *kobj, struct attribute *attr, const char *buf,
+       size_t count)
+{
+       int ret;
+       unsigned long val;
+
+       ret = kstrtoul(buf, 0, &val);
+       if (ret < 0)
+               return ret;
+
+       boostpulse_duration_val = val;
+       return count;
+}
+
+define_one_global_rw(boostpulse_duration);
+
+static ssize_t show_io_is_busy(struct kobject *kobj,
+                       struct attribute *attr, char *buf)
+{
+       return sprintf(buf, "%u\n", io_is_busy);
+}
+
+static ssize_t store_io_is_busy(struct kobject *kobj,
+                       struct attribute *attr, const char *buf, size_t count)
+{
+       int ret;
+       unsigned long val;
+
+       ret = kstrtoul(buf, 0, &val);
+       if (ret < 0)
+               return ret;
+       io_is_busy = val;
+       return count;
+}
+
+static struct global_attr io_is_busy_attr = __ATTR(io_is_busy, 0644,
+               show_io_is_busy, store_io_is_busy);
+
 static struct attribute *interactive_attributes[] = {
        &target_loads_attr.attr,
+       &above_hispeed_delay_attr.attr,
        &hispeed_freq_attr.attr,
        &go_hispeed_load_attr.attr,
-       &above_hispeed_delay.attr,
        &min_sample_time_attr.attr,
        &timer_rate_attr.attr,
+       &timer_slack.attr,
        &boost.attr,
        &boostpulse.attr,
+       &boostpulse_duration.attr,
+       &io_is_busy_attr.attr,
        NULL,
 };
 
@@ -832,12 +1033,16 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
                if (!cpu_online(policy->cpu))
                        return -EINVAL;
 
+               mutex_lock(&gov_lock);
+
                freq_table =
                        cpufreq_frequency_get_table(policy->cpu);
                if (!hispeed_freq)
                        hispeed_freq = policy->max;
 
                for_each_cpu(j, policy->cpus) {
+                       unsigned long expires;
+
                        pcpu = &per_cpu(cpuinfo, j);
                        pcpu->policy = policy;
                        pcpu->target_freq = policy->cur;
@@ -847,46 +1052,63 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
                                ktime_to_us(ktime_get());
                        pcpu->hispeed_validate_time =
                                pcpu->floor_validate_time;
-                       pcpu->governor_enabled = 1;
-                       smp_wmb();
-                       pcpu->cpu_timer.expires =
-                               jiffies + usecs_to_jiffies(timer_rate);
+                       down_write(&pcpu->enable_sem);
+                       expires = jiffies + usecs_to_jiffies(timer_rate);
+                       pcpu->cpu_timer.expires = expires;
                        add_timer_on(&pcpu->cpu_timer, j);
+                       if (timer_slack_val >= 0) {
+                               expires += usecs_to_jiffies(timer_slack_val);
+                               pcpu->cpu_slack_timer.expires = expires;
+                               add_timer_on(&pcpu->cpu_slack_timer, j);
+                       }
+                       pcpu->governor_enabled = 1;
+                       up_write(&pcpu->enable_sem);
                }
 
                /*
                 * Do not register the idle hook and create sysfs
                 * entries if we have already done so.
                 */
-               if (atomic_inc_return(&active_count) > 1)
+               if (++active_count > 1) {
+                       mutex_unlock(&gov_lock);
                        return 0;
+               }
 
                rc = sysfs_create_group(cpufreq_global_kobject,
                                &interactive_attr_group);
-               if (rc)
+               if (rc) {
+                       mutex_unlock(&gov_lock);
                        return rc;
+               }
 
                idle_notifier_register(&cpufreq_interactive_idle_nb);
                cpufreq_register_notifier(
                        &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
+               mutex_unlock(&gov_lock);
                break;
 
        case CPUFREQ_GOV_STOP:
+               mutex_lock(&gov_lock);
                for_each_cpu(j, policy->cpus) {
                        pcpu = &per_cpu(cpuinfo, j);
+                       down_write(&pcpu->enable_sem);
                        pcpu->governor_enabled = 0;
-                       smp_wmb();
                        del_timer_sync(&pcpu->cpu_timer);
+                       del_timer_sync(&pcpu->cpu_slack_timer);
+                       up_write(&pcpu->enable_sem);
                }
 
-               if (atomic_dec_return(&active_count) > 0)
+               if (--active_count > 0) {
+                       mutex_unlock(&gov_lock);
                        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);
+               mutex_unlock(&gov_lock);
 
                break;
 
@@ -902,31 +1124,32 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
        return 0;
 }
 
+static void cpufreq_interactive_nop_timer(unsigned long data)
+{
+}
+
 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;
-       above_hispeed_delay_val = DEFAULT_ABOVE_HISPEED_DELAY;
-       timer_rate = DEFAULT_TIMER_RATE;
-
        /* Initalize per-cpu timers */
        for_each_possible_cpu(i) {
                pcpu = &per_cpu(cpuinfo, i);
-               if (governidle)
-                       init_timer(&pcpu->cpu_timer);
-               else
-                       init_timer_deferrable(&pcpu->cpu_timer);
+               init_timer_deferrable(&pcpu->cpu_timer);
                pcpu->cpu_timer.function = cpufreq_interactive_timer;
                pcpu->cpu_timer.data = i;
+               init_timer(&pcpu->cpu_slack_timer);
+               pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
                spin_lock_init(&pcpu->load_lock);
+               init_rwsem(&pcpu->enable_sem);
        }
 
        spin_lock_init(&target_loads_lock);
        spin_lock_init(&speedchange_cpumask_lock);
+       spin_lock_init(&above_hispeed_delay_lock);
+       mutex_init(&gov_lock);
        speedchange_task =
                kthread_create(cpufreq_interactive_speedchange_task, NULL,
                               "cfinteractive");