[PATCH] cpufreq_ondemand: keep ignore_nice_load value when it is reselected
[pandora-kernel.git] / drivers / cpufreq / cpufreq_ondemand.c
index 9ee9411..cd846f5 100644 (file)
 #define MIN_FREQUENCY_UP_THRESHOLD             (11)
 #define MAX_FREQUENCY_UP_THRESHOLD             (100)
 
-/* 
- * The polling frequency of this governor depends on the capability of 
+/*
+ * The polling frequency of this governor depends on the capability of
  * the processor. Default polling frequency is 1000 times the transition
- * latency of the processor. The governor will work on any processor with 
- * transition latency <= 10mS, using appropriate sampling 
+ * latency of the processor. The governor will work on any processor with
+ * transition latency <= 10mS, using appropriate sampling
  * rate.
  * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
  * this governor will not work.
  * All times here are in uS.
  */
-static unsigned int                            def_sampling_rate;
+static unsigned int def_sampling_rate;
 #define MIN_SAMPLING_RATE_RATIO                        (2)
 /* for correct statistics, we need at least 10 ticks between each measure */
 #define MIN_STAT_SAMPLING_RATE                 (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10))
@@ -62,28 +62,29 @@ static unsigned int                                 def_sampling_rate;
 static void do_dbs_timer(void *data);
 
 struct cpu_dbs_info_s {
-       struct cpufreq_policy   *cur_policy;
-       unsigned int            prev_cpu_idle_up;
-       unsigned int            prev_cpu_idle_down;
-       unsigned int            enable;
+       struct cpufreq_policy *cur_policy;
+       unsigned int prev_cpu_idle_up;
+       unsigned int prev_cpu_idle_down;
+       unsigned int enable;
 };
 static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
 
 static unsigned int dbs_enable;        /* number of CPUs using this policy */
 
-static DEFINE_MUTEX    (dbs_mutex);
+static DEFINE_MUTEX (dbs_mutex);
 static DECLARE_WORK    (dbs_work, do_dbs_timer, NULL);
 
 struct dbs_tuners {
-       unsigned int            sampling_rate;
-       unsigned int            sampling_down_factor;
-       unsigned int            up_threshold;
-       unsigned int            ignore_nice;
+       unsigned int sampling_rate;
+       unsigned int sampling_down_factor;
+       unsigned int up_threshold;
+       unsigned int ignore_nice;
 };
 
 static struct dbs_tuners dbs_tuners_ins = {
-       .up_threshold           = DEF_FREQUENCY_UP_THRESHOLD,
-       .sampling_down_factor   = DEF_SAMPLING_DOWN_FACTOR,
+       .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
+       .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
+       .ignore_nice = 0,
 };
 
 static inline unsigned int get_cpu_idle_time(unsigned int cpu)
@@ -106,8 +107,8 @@ static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
        return sprintf (buf, "%u\n", MIN_SAMPLING_RATE);
 }
 
-#define define_one_ro(_name)                                   \
-static struct freq_attr _name =                                \
+#define define_one_ro(_name)           \
+static struct freq_attr _name =                \
 __ATTR(_name, 0444, show_##_name, NULL)
 
 define_one_ro(sampling_rate_max);
@@ -125,7 +126,7 @@ show_one(sampling_down_factor, sampling_down_factor);
 show_one(up_threshold, up_threshold);
 show_one(ignore_nice_load, ignore_nice);
 
-static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused, 
+static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
                const char *buf, size_t count)
 {
        unsigned int input;
@@ -144,7 +145,7 @@ static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
        return count;
 }
 
-static ssize_t store_sampling_rate(struct cpufreq_policy *unused, 
+static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
                const char *buf, size_t count)
 {
        unsigned int input;
@@ -163,7 +164,7 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
        return count;
 }
 
-static ssize_t store_up_threshold(struct cpufreq_policy *unused, 
+static ssize_t store_up_threshold(struct cpufreq_policy *unused,
                const char *buf, size_t count)
 {
        unsigned int input;
@@ -171,7 +172,7 @@ static ssize_t store_up_threshold(struct cpufreq_policy *unused,
        ret = sscanf (buf, "%u", &input);
 
        mutex_lock(&dbs_mutex);
-       if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || 
+       if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
                        input < MIN_FREQUENCY_UP_THRESHOLD) {
                mutex_unlock(&dbs_mutex);
                return -EINVAL;
@@ -190,14 +191,14 @@ static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
        int ret;
 
        unsigned int j;
-       
+
        ret = sscanf (buf, "%u", &input);
        if ( ret != 1 )
                return -EINVAL;
 
        if ( input > 1 )
                input = 1;
-       
+
        mutex_lock(&dbs_mutex);
        if ( input == dbs_tuners_ins.ignore_nice ) { /* nothing to do */
                mutex_unlock(&dbs_mutex);
@@ -259,16 +260,16 @@ static void dbs_check_cpu(int cpu)
                return;
 
        policy = this_dbs_info->cur_policy;
-       /* 
+       /*
         * Every sampling_rate, we check, if current idle time is less
         * than 20% (default), then we try to increase frequency
         * Every sampling_rate*sampling_down_factor, we look for a the lowest
         * frequency which can sustain the load while keeping idle time over
         * 30%. If such a frequency exist, we try to decrease to this frequency.
         *
-        * Any frequency increase takes it to the maximum frequency. 
-        * Frequency reduction happens at minimum steps of 
-        * 5% (default) of current frequency 
+        * Any frequency increase takes it to the maximum frequency.
+        * Frequency reduction happens at minimum steps of
+        * 5% (default) of current frequency
         */
 
        /* Check for frequency increase */
@@ -298,14 +299,14 @@ static void dbs_check_cpu(int cpu)
                        struct cpu_dbs_info_s *j_dbs_info;
 
                        j_dbs_info = &per_cpu(cpu_dbs_info, j);
-                       j_dbs_info->prev_cpu_idle_down = 
+                       j_dbs_info->prev_cpu_idle_down =
                                        j_dbs_info->prev_cpu_idle_up;
                }
                /* if we are already at full speed then break out early */
                if (policy->cur == policy->max)
                        return;
-               
-               __cpufreq_driver_target(policy, policy->max, 
+
+               __cpufreq_driver_target(policy, policy->max,
                        CPUFREQ_RELATION_H);
                return;
        }
@@ -347,7 +348,7 @@ static void dbs_check_cpu(int cpu)
         * policy. To be safe, we focus 10 points under the threshold.
         */
        freq_next = ((total_ticks - idle_ticks) * 100) / total_ticks;
-       freq_next = (freq_next * policy->cur) / 
+       freq_next = (freq_next * policy->cur) /
                        (dbs_tuners_ins.up_threshold - 10);
 
        if (freq_next <= ((policy->cur * 95) / 100))
@@ -355,15 +356,15 @@ static void dbs_check_cpu(int cpu)
 }
 
 static void do_dbs_timer(void *data)
-{ 
+{
        int i;
        mutex_lock(&dbs_mutex);
        for_each_online_cpu(i)
                dbs_check_cpu(i);
-       schedule_delayed_work(&dbs_work, 
+       schedule_delayed_work(&dbs_work,
                        usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
        mutex_unlock(&dbs_mutex);
-} 
+}
 
 static inline void dbs_timer_init(void)
 {
@@ -390,22 +391,25 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 
        switch (event) {
        case CPUFREQ_GOV_START:
-               if ((!cpu_online(cpu)) || 
+               if ((!cpu_online(cpu)) ||
                    (!policy->cur))
                        return -EINVAL;
 
                if (policy->cpuinfo.transition_latency >
-                               (TRANSITION_LATENCY_LIMIT * 1000))
+                               (TRANSITION_LATENCY_LIMIT * 1000)) {
+                       printk(KERN_WARNING "ondemand governor failed to load "
+                              "due to too long transition latency\n");
                        return -EINVAL;
+               }
                if (this_dbs_info->enable) /* Already enabled */
                        break;
-                
+
                mutex_lock(&dbs_mutex);
                for_each_cpu_mask(j, policy->cpus) {
                        struct cpu_dbs_info_s *j_dbs_info;
                        j_dbs_info = &per_cpu(cpu_dbs_info, j);
                        j_dbs_info->cur_policy = policy;
-               
+
                        j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(j);
                        j_dbs_info->prev_cpu_idle_down
                                = j_dbs_info->prev_cpu_idle_up;
@@ -431,11 +435,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                                def_sampling_rate = MIN_STAT_SAMPLING_RATE;
 
                        dbs_tuners_ins.sampling_rate = def_sampling_rate;
-                       dbs_tuners_ins.ignore_nice = 0;
-
                        dbs_timer_init();
                }
-               
+
                mutex_unlock(&dbs_mutex);
                break;
 
@@ -448,9 +450,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                 * Stop the timerschedule work, when this governor
                 * is used for first time
                 */
-               if (dbs_enable == 0) 
+               if (dbs_enable == 0)
                        dbs_timer_exit();
-               
+
                mutex_unlock(&dbs_mutex);
 
                break;
@@ -460,11 +462,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                if (policy->max < this_dbs_info->cur_policy->cur)
                        __cpufreq_driver_target(
                                        this_dbs_info->cur_policy,
-                                       policy->max, CPUFREQ_RELATION_H);
+                                       policy->max, CPUFREQ_RELATION_H);
                else if (policy->min > this_dbs_info->cur_policy->cur)
                        __cpufreq_driver_target(
                                        this_dbs_info->cur_policy,
-                                       policy->min, CPUFREQ_RELATION_L);
+                                       policy->min, CPUFREQ_RELATION_L);
                mutex_unlock(&dbs_mutex);
                break;
        }