3 files changed, 99 insertions, 128 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index aed80e6..9b6ae7d 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -52,9 +52,8 @@ static void handle_update(void *data);
  * changes to devices when the CPU clock speed changes.
  * The mutex locks both lists.
  */
-static struct notifier_block *cpufreq_policy_notifier_list;
-static struct notifier_block *cpufreq_transition_notifier_list;
-static DECLARE_RWSEM (cpufreq_notifier_rwsem);
+static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
+static BLOCKING_NOTIFIER_HEAD(cpufreq_transition_notifier_list);
 
 
 static LIST_HEAD(cpufreq_governor_list);
@@ -247,8 +246,6 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
 	dprintk("notification %u of frequency transition to %u kHz\n",
 		state, freqs->new);
 
-	down_read(&cpufreq_notifier_rwsem);
-
 	policy = cpufreq_cpu_data[freqs->cpu];
 	switch (state) {
 
@@ -266,20 +263,19 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
 				freqs->old = policy->cur;
 			}
 		}
-		notifier_call_chain(&cpufreq_transition_notifier_list,
-					CPUFREQ_PRECHANGE, freqs);
+		blocking_notifier_call_chain(&cpufreq_transition_notifier_list,
+				CPUFREQ_PRECHANGE, freqs);
 		adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
 		break;
 
 	case CPUFREQ_POSTCHANGE:
 		adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
-		notifier_call_chain(&cpufreq_transition_notifier_list,
-					CPUFREQ_POSTCHANGE, freqs);
+		blocking_notifier_call_chain(&cpufreq_transition_notifier_list,
+				CPUFREQ_POSTCHANGE, freqs);
 		if (likely(policy) && likely(policy->cpu == freqs->cpu))
 			policy->cur = freqs->new;
 		break;
 	}
-	up_read(&cpufreq_notifier_rwsem);
 }
 EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
 
@@ -1007,7 +1003,7 @@ static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
 		freqs.old = cpu_policy->cur;
 		freqs.new = cur_freq;
 
-		notifier_call_chain(&cpufreq_transition_notifier_list,
+		blocking_notifier_call_chain(&cpufreq_transition_notifier_list,
 				    CPUFREQ_SUSPENDCHANGE, &freqs);
 		adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs);
 
@@ -1088,7 +1084,8 @@ static int cpufreq_resume(struct sys_device * sysdev)
 			freqs.old = cpu_policy->cur;
 			freqs.new = cur_freq;
 
-			notifier_call_chain(&cpufreq_transition_notifier_list,
+			blocking_notifier_call_chain(
+					&cpufreq_transition_notifier_list,
 					CPUFREQ_RESUMECHANGE, &freqs);
 			adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs);
 
@@ -1125,24 +1122,24 @@ static struct sysdev_driver cpufreq_sysdev_driver = {
  *      changes in cpufreq policy.
  *
  *	This function may sleep, and has the same return conditions as
- *	notifier_chain_register.
+ *	blocking_notifier_chain_register.
  */
 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
 {
 	int ret;
 
-	down_write(&cpufreq_notifier_rwsem);
 	switch (list) {
 	case CPUFREQ_TRANSITION_NOTIFIER:
-		ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb);
+		ret = blocking_notifier_chain_register(
+				&cpufreq_transition_notifier_list, nb);
 		break;
 	case CPUFREQ_POLICY_NOTIFIER:
-		ret = notifier_chain_register(&cpufreq_policy_notifier_list, nb);
+		ret = blocking_notifier_chain_register(
+				&cpufreq_policy_notifier_list, nb);
 		break;
 	default:
 		ret = -EINVAL;
 	}
-	up_write(&cpufreq_notifier_rwsem);
 
 	return ret;
 }
@@ -1157,24 +1154,24 @@ EXPORT_SYMBOL(cpufreq_register_notifier);
  *	Remove a driver from the CPU frequency notifier list.
  *
  *	This function may sleep, and has the same return conditions as
- *	notifier_chain_unregister.
+ *	blocking_notifier_chain_unregister.
  */
 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
 {
 	int ret;
 
-	down_write(&cpufreq_notifier_rwsem);
 	switch (list) {
 	case CPUFREQ_TRANSITION_NOTIFIER:
-		ret = notifier_chain_unregister(&cpufreq_transition_notifier_list, nb);
+		ret = blocking_notifier_chain_unregister(
+				&cpufreq_transition_notifier_list, nb);
 		break;
 	case CPUFREQ_POLICY_NOTIFIER:
-		ret = notifier_chain_unregister(&cpufreq_policy_notifier_list, nb);
+		ret = blocking_notifier_chain_unregister(
+				&cpufreq_policy_notifier_list, nb);
 		break;
 	default:
 		ret = -EINVAL;
 	}
-	up_write(&cpufreq_notifier_rwsem);
 
 	return ret;
 }
@@ -1346,29 +1343,23 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_poli
 	if (ret)
 		goto error_out;
 
-	down_read(&cpufreq_notifier_rwsem);
-
 	/* adjust if necessary - all reasons */
-	notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST,
-			    policy);
+	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+			CPUFREQ_ADJUST, policy);
 
 	/* adjust if necessary - hardware incompatibility*/
-	notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_INCOMPATIBLE,
-			    policy);
+	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+			CPUFREQ_INCOMPATIBLE, policy);
 
 	/* verify the cpu speed can be set within this limit,
 	   which might be different to the first one */
 	ret = cpufreq_driver->verify(policy);
-	if (ret) {
-		up_read(&cpufreq_notifier_rwsem);
+	if (ret)
 		goto error_out;
-	}
 
 	/* notification of the new policy */
-	notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_NOTIFY,
-			    policy);
-
-	up_read(&cpufreq_notifier_rwsem);
+	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+			CPUFREQ_NOTIFY, policy);
 
 	data->min = policy->min;
 	data->max = policy->max;
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index ac38766..037f6bf 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -35,12 +35,7 @@
  */
 
 #define DEF_FREQUENCY_UP_THRESHOLD		(80)
-#define MIN_FREQUENCY_UP_THRESHOLD		(0)
-#define MAX_FREQUENCY_UP_THRESHOLD		(100)
-
 #define DEF_FREQUENCY_DOWN_THRESHOLD		(20)
-#define MIN_FREQUENCY_DOWN_THRESHOLD		(0)
-#define MAX_FREQUENCY_DOWN_THRESHOLD		(100)
 
 /* 
  * The polling frequency of this governor depends on the capability of 
@@ -53,10 +48,14 @@
  * All times here are in uS.
  */
 static unsigned int 				def_sampling_rate;
-#define MIN_SAMPLING_RATE			(def_sampling_rate / 2)
+#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))
+#define MIN_SAMPLING_RATE			(def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
 #define MAX_SAMPLING_RATE			(500 * def_sampling_rate)
-#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER	(100000)
-#define DEF_SAMPLING_DOWN_FACTOR		(5)
+#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER	(1000)
+#define DEF_SAMPLING_DOWN_FACTOR		(1)
+#define MAX_SAMPLING_DOWN_FACTOR		(10)
 #define TRANSITION_LATENCY_LIMIT		(10 * 1000)
 
 static void do_dbs_timer(void *data);
@@ -66,6 +65,8 @@ struct cpu_dbs_info_s {
 	unsigned int 		prev_cpu_idle_up;
 	unsigned int 		prev_cpu_idle_down;
 	unsigned int 		enable;
+	unsigned int		down_skip;
+	unsigned int		requested_freq;
 };
 static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
 
@@ -87,6 +88,8 @@ static struct dbs_tuners dbs_tuners_ins = {
 	.up_threshold 		= DEF_FREQUENCY_UP_THRESHOLD,
 	.down_threshold 	= DEF_FREQUENCY_DOWN_THRESHOLD,
 	.sampling_down_factor 	= DEF_SAMPLING_DOWN_FACTOR,
+	.ignore_nice		= 0,
+	.freq_step		= 5,
 };
 
 static inline unsigned int get_cpu_idle_time(unsigned int cpu)
@@ -136,7 +139,7 @@ static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
 	unsigned int input;
 	int ret;
 	ret = sscanf (buf, "%u", &input);
-	if (ret != 1 )
+	if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
 		return -EINVAL;
 
 	mutex_lock(&dbs_mutex);
@@ -173,8 +176,7 @@ 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 || 
-			input < MIN_FREQUENCY_UP_THRESHOLD ||
+	if (ret != 1 || input > 100 || input < 0 ||
 			input <= dbs_tuners_ins.down_threshold) {
 		mutex_unlock(&dbs_mutex);
 		return -EINVAL;
@@ -194,8 +196,7 @@ static ssize_t store_down_threshold(struct cpufreq_policy *unused,
 	ret = sscanf (buf, "%u", &input);
 
 	mutex_lock(&dbs_mutex);
-	if (ret != 1 || input > MAX_FREQUENCY_DOWN_THRESHOLD || 
-			input < MIN_FREQUENCY_DOWN_THRESHOLD ||
+	if (ret != 1 || input > 100 || input < 0 ||
 			input >= dbs_tuners_ins.up_threshold) {
 		mutex_unlock(&dbs_mutex);
 		return -EINVAL;
@@ -297,31 +298,17 @@ static struct attribute_group dbs_attr_group = {
 static void dbs_check_cpu(int cpu)
 {
 	unsigned int idle_ticks, up_idle_ticks, down_idle_ticks;
+	unsigned int tmp_idle_ticks, total_idle_ticks;
 	unsigned int freq_step;
 	unsigned int freq_down_sampling_rate;
-	static int down_skip[NR_CPUS];
-	static int requested_freq[NR_CPUS];
-	static unsigned short init_flag = 0;
-	struct cpu_dbs_info_s *this_dbs_info;
-	struct cpu_dbs_info_s *dbs_info;
-
+	struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
 	struct cpufreq_policy *policy;
-	unsigned int j;
 
-	this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
 	if (!this_dbs_info->enable)
 		return;
 
 	policy = this_dbs_info->cur_policy;
 
-	if ( init_flag == 0 ) {
-		for_each_online_cpu(j) {
-			dbs_info = &per_cpu(cpu_dbs_info, j);
-			requested_freq[j] = dbs_info->cur_policy->cur;
-		}
-		init_flag = 1;
-	}
-	
 	/* 
 	 * The default safe range is 20% to 80% 
 	 * Every sampling_rate, we check
@@ -337,39 +324,29 @@ static void dbs_check_cpu(int cpu)
 	 */
 
 	/* Check for frequency increase */
-
 	idle_ticks = UINT_MAX;
-	for_each_cpu_mask(j, policy->cpus) {
-		unsigned int tmp_idle_ticks, total_idle_ticks;
-		struct cpu_dbs_info_s *j_dbs_info;
 
-		j_dbs_info = &per_cpu(cpu_dbs_info, j);
-		/* Check for frequency increase */
-		total_idle_ticks = get_cpu_idle_time(j);
-		tmp_idle_ticks = total_idle_ticks -
-			j_dbs_info->prev_cpu_idle_up;
-		j_dbs_info->prev_cpu_idle_up = total_idle_ticks;
-
-		if (tmp_idle_ticks < idle_ticks)
-			idle_ticks = tmp_idle_ticks;
-	}
+	/* Check for frequency increase */
+	total_idle_ticks = get_cpu_idle_time(cpu);
+	tmp_idle_ticks = total_idle_ticks -
+		this_dbs_info->prev_cpu_idle_up;
+	this_dbs_info->prev_cpu_idle_up = total_idle_ticks;
+
+	if (tmp_idle_ticks < idle_ticks)
+		idle_ticks = tmp_idle_ticks;
 
 	/* Scale idle ticks by 100 and compare with up and down ticks */
 	idle_ticks *= 100;
 	up_idle_ticks = (100 - dbs_tuners_ins.up_threshold) *
-		usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
+			usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
 
 	if (idle_ticks < up_idle_ticks) {
-		down_skip[cpu] = 0;
-		for_each_cpu_mask(j, policy->cpus) {
-			struct cpu_dbs_info_s *j_dbs_info;
+		this_dbs_info->down_skip = 0;
+		this_dbs_info->prev_cpu_idle_down =
+			this_dbs_info->prev_cpu_idle_up;
 
-			j_dbs_info = &per_cpu(cpu_dbs_info, j);
-			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 (requested_freq[cpu] == policy->max)
+		if (this_dbs_info->requested_freq == policy->max)
 			return;
 		
 		freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100;
@@ -378,49 +355,45 @@ static void dbs_check_cpu(int cpu)
 		if (unlikely(freq_step == 0))
 			freq_step = 5;
 		
-		requested_freq[cpu] += freq_step;
-		if (requested_freq[cpu] > policy->max)
-			requested_freq[cpu] = policy->max;
+		this_dbs_info->requested_freq += freq_step;
+		if (this_dbs_info->requested_freq > policy->max)
+			this_dbs_info->requested_freq = policy->max;
 
-		__cpufreq_driver_target(policy, requested_freq[cpu], 
+		__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
 			CPUFREQ_RELATION_H);
 		return;
 	}
 
 	/* Check for frequency decrease */
-	down_skip[cpu]++;
-	if (down_skip[cpu] < dbs_tuners_ins.sampling_down_factor)
+	this_dbs_info->down_skip++;
+	if (this_dbs_info->down_skip < dbs_tuners_ins.sampling_down_factor)
 		return;
 
-	idle_ticks = UINT_MAX;
-	for_each_cpu_mask(j, policy->cpus) {
-		unsigned int tmp_idle_ticks, total_idle_ticks;
-		struct cpu_dbs_info_s *j_dbs_info;
+	/* Check for frequency decrease */
+	total_idle_ticks = this_dbs_info->prev_cpu_idle_up;
+	tmp_idle_ticks = total_idle_ticks -
+		this_dbs_info->prev_cpu_idle_down;
+	this_dbs_info->prev_cpu_idle_down = total_idle_ticks;
 
-		j_dbs_info = &per_cpu(cpu_dbs_info, j);
-		total_idle_ticks = j_dbs_info->prev_cpu_idle_up;
-		tmp_idle_ticks = total_idle_ticks -
-			j_dbs_info->prev_cpu_idle_down;
-		j_dbs_info->prev_cpu_idle_down = total_idle_ticks;
-
-		if (tmp_idle_ticks < idle_ticks)
-			idle_ticks = tmp_idle_ticks;
-	}
+	if (tmp_idle_ticks < idle_ticks)
+		idle_ticks = tmp_idle_ticks;
 
 	/* Scale idle ticks by 100 and compare with up and down ticks */
 	idle_ticks *= 100;
-	down_skip[cpu] = 0;
+	this_dbs_info->down_skip = 0;
 
 	freq_down_sampling_rate = dbs_tuners_ins.sampling_rate *
 		dbs_tuners_ins.sampling_down_factor;
 	down_idle_ticks = (100 - dbs_tuners_ins.down_threshold) *
-			usecs_to_jiffies(freq_down_sampling_rate);
+		usecs_to_jiffies(freq_down_sampling_rate);
 
 	if (idle_ticks > down_idle_ticks) {
-		/* if we are already at the lowest speed then break out early
+		/*
+		 * if we are already at the lowest speed then break out early
 		 * or if we 'cannot' reduce the speed as the user might want
-		 * freq_step to be zero */
-		if (requested_freq[cpu] == policy->min
+		 * freq_step to be zero
+		 */
+		if (this_dbs_info->requested_freq == policy->min
 				|| dbs_tuners_ins.freq_step == 0)
 			return;
 
@@ -430,13 +403,12 @@ static void dbs_check_cpu(int cpu)
 		if (unlikely(freq_step == 0))
 			freq_step = 5;
 
-		requested_freq[cpu] -= freq_step;
-		if (requested_freq[cpu] < policy->min)
-			requested_freq[cpu] = policy->min;
+		this_dbs_info->requested_freq -= freq_step;
+		if (this_dbs_info->requested_freq < policy->min)
+			this_dbs_info->requested_freq = policy->min;
 
-		__cpufreq_driver_target(policy,
-			requested_freq[cpu],
-			CPUFREQ_RELATION_H);
+		__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
+				CPUFREQ_RELATION_H);
 		return;
 	}
 }
@@ -493,11 +465,13 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 			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_up = get_cpu_idle_time(cpu);
 			j_dbs_info->prev_cpu_idle_down
 				= j_dbs_info->prev_cpu_idle_up;
 		}
 		this_dbs_info->enable = 1;
+		this_dbs_info->down_skip = 0;
+		this_dbs_info->requested_freq = policy->cur;
 		sysfs_create_group(&policy->kobj, &dbs_attr_group);
 		dbs_enable++;
 		/*
@@ -507,16 +481,17 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		if (dbs_enable == 1) {
 			unsigned int latency;
 			/* policy latency is in nS. Convert it to uS first */
+			latency = policy->cpuinfo.transition_latency / 1000;
+			if (latency == 0)
+				latency = 1;
 
-			latency = policy->cpuinfo.transition_latency;
-			if (latency < 1000)
-				latency = 1000;
-
-			def_sampling_rate = (latency / 1000) *
+			def_sampling_rate = 10 * latency *
 					DEF_SAMPLING_RATE_LATENCY_MULTIPLIER;
+
+			if (def_sampling_rate < MIN_STAT_SAMPLING_RATE)
+				def_sampling_rate = MIN_STAT_SAMPLING_RATE;
+
 			dbs_tuners_ins.sampling_rate = def_sampling_rate;
-			dbs_tuners_ins.ignore_nice = 0;
-			dbs_tuners_ins.freq_step = 5;
 
 			dbs_timer_init();
 		}
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 69aa1db..956d121 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -84,6 +84,7 @@ struct dbs_tuners {
 static struct dbs_tuners dbs_tuners_ins = {
 	.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)
@@ -350,6 +351,9 @@ static void dbs_check_cpu(int cpu)
 	freq_next = (freq_next * policy->cur) /
 			(dbs_tuners_ins.up_threshold - 10);
 
+	if (freq_next < policy->min)
+		freq_next = policy->min;
+
 	if (freq_next <= ((policy->cur * 95) / 100))
 		__cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_L);
 }
@@ -395,8 +399,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 			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;
 
@@ -431,8 +438,6 @@ 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();
 		}