diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
index caa9f7711343..871366b83b3f 100644
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -377,10 +377,9 @@ acpi_cpufreq_cpu_init (
         arg0.buffer.length = 12;
         arg0.buffer.pointer = (u8 *) arg0_buf;
 
-	data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
+	data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
 	if (!data)
 		return (-ENOMEM);
-	memset(data, 0, sizeof(struct cpufreq_acpi_io));
 
 	acpi_io_data[cpu] = data;
 
diff --git a/arch/i386/kernel/cpu/cpufreq/powernow-k7.c b/arch/i386/kernel/cpu/cpufreq/powernow-k7.c
index 73a5dc5b26b8..edcd626001da 100644
--- a/arch/i386/kernel/cpu/cpufreq/powernow-k7.c
+++ b/arch/i386/kernel/cpu/cpufreq/powernow-k7.c
@@ -171,10 +171,9 @@ static int get_ranges (unsigned char *pst)
 	unsigned int speed;
 	u8 fid, vid;
 
-	powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table) * (number_scales + 1)), GFP_KERNEL);
+	powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) * (number_scales + 1)), GFP_KERNEL);
 	if (!powernow_table)
 		return -ENOMEM;
-	memset(powernow_table, 0, (sizeof(struct cpufreq_frequency_table) * (number_scales + 1)));
 
 	for (j=0 ; j < number_scales; j++) {
 		fid = *pst++;
@@ -305,16 +304,13 @@ static int powernow_acpi_init(void)
 		goto err0;
 	}
 
-	acpi_processor_perf = kmalloc(sizeof(struct acpi_processor_performance),
+	acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
 				      GFP_KERNEL);
-
 	if (!acpi_processor_perf) {
 		retval = -ENOMEM;
 		goto err0;
 	}
 
-	memset(acpi_processor_perf, 0, sizeof(struct acpi_processor_performance));
-
 	if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
 		retval = -EIO;
 		goto err1;
@@ -337,14 +333,12 @@ static int powernow_acpi_init(void)
 		goto err2;
 	}
 
-	powernow_table = kmalloc((number_scales + 1) * (sizeof(struct cpufreq_frequency_table)), GFP_KERNEL);
+	powernow_table = kzalloc((number_scales + 1) * (sizeof(struct cpufreq_frequency_table)), GFP_KERNEL);
 	if (!powernow_table) {
 		retval = -ENOMEM;
 		goto err2;
 	}
 
-	memset(powernow_table, 0, ((number_scales + 1) * sizeof(struct cpufreq_frequency_table)));
-
 	pc.val = (unsigned long) acpi_processor_perf->states[0].control;
 	for (i = 0; i < number_scales; i++) {
 		u8 fid, vid;
diff --git a/arch/i386/kernel/cpu/cpufreq/powernow-k8.c b/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
index 2d5c9adba0cd..68a1fc87f4ca 100644
--- a/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
@@ -462,7 +462,6 @@ static int check_supported_cpu(unsigned int cpu)
 
 	oldmask = current->cpus_allowed;
 	set_cpus_allowed(current, cpumask_of_cpu(cpu));
-	schedule();
 
 	if (smp_processor_id() != cpu) {
 		printk(KERN_ERR "limiting to cpu %u failed\n", cpu);
@@ -497,9 +496,7 @@ static int check_supported_cpu(unsigned int cpu)
 
 out:
 	set_cpus_allowed(current, oldmask);
-	schedule();
 	return rc;
-
 }
 
 static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst, u8 maxvid)
@@ -913,7 +910,6 @@ static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsi
 	/* only run on specific CPU from here on */
 	oldmask = current->cpus_allowed;
 	set_cpus_allowed(current, cpumask_of_cpu(pol->cpu));
-	schedule();
 
 	if (smp_processor_id() != pol->cpu) {
 		printk(KERN_ERR "limiting to cpu %u failed\n", pol->cpu);
@@ -968,8 +964,6 @@ static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsi
 
 err_out:
 	set_cpus_allowed(current, oldmask);
-	schedule();
-
 	return ret;
 }
 
@@ -991,12 +985,11 @@ static int __init powernowk8_cpu_init(struct cpufreq_policy *pol)
 	if (!check_supported_cpu(pol->cpu))
 		return -ENODEV;
 
-	data = kmalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
+	data = kzalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
 	if (!data) {
 		printk(KERN_ERR PFX "unable to alloc powernow_k8_data");
 		return -ENOMEM;
 	}
-	memset(data,0,sizeof(struct powernow_k8_data));
 
 	data->cpu = pol->cpu;
 
@@ -1026,7 +1019,6 @@ static int __init powernowk8_cpu_init(struct cpufreq_policy *pol)
 	/* only run on specific CPU from here on */
 	oldmask = current->cpus_allowed;
 	set_cpus_allowed(current, cpumask_of_cpu(pol->cpu));
-	schedule();
 
 	if (smp_processor_id() != pol->cpu) {
 		printk(KERN_ERR "limiting to cpu %u failed\n", pol->cpu);
@@ -1045,7 +1037,6 @@ static int __init powernowk8_cpu_init(struct cpufreq_policy *pol)
 
 	/* run on any CPU again */
 	set_cpus_allowed(current, oldmask);
-	schedule();
 
 	pol->governor = CPUFREQ_DEFAULT_GOVERNOR;
 	pol->cpus = cpu_core_map[pol->cpu];
@@ -1080,7 +1071,6 @@ static int __init powernowk8_cpu_init(struct cpufreq_policy *pol)
 
 err_out:
 	set_cpus_allowed(current, oldmask);
-	schedule();
 	powernow_k8_cpu_exit_acpi(data);
 
 	kfree(data);
@@ -1116,17 +1106,14 @@ static unsigned int powernowk8_get (unsigned int cpu)
 		set_cpus_allowed(current, oldmask);
 		return 0;
 	}
-	preempt_disable();
-	
+
 	if (query_current_values_with_pending_wait(data))
 		goto out;
 
 	khz = find_khz_freq_from_fid(data->currfid);
 
- out:
-	preempt_enable_no_resched();
+out:
 	set_cpus_allowed(current, oldmask);
-
 	return khz;
 }
 
diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
index 0ea010a7afb1..edb9873e27e3 100644
--- a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
@@ -423,12 +423,11 @@ static int centrino_cpu_init_acpi(struct cpufreq_policy *policy)
 		}
 	}
 
-	centrino_model[cpu] = kmalloc(sizeof(struct cpu_model), GFP_KERNEL);
+	centrino_model[cpu] = kzalloc(sizeof(struct cpu_model), GFP_KERNEL);
 	if (!centrino_model[cpu]) {
 		result = -ENOMEM;
 		goto err_unreg;
 	}
-	memset(centrino_model[cpu], 0, sizeof(struct cpu_model));
 
 	centrino_model[cpu]->model_name=NULL;
 	centrino_model[cpu]->max_freq = p.states[0].core_frequency * 1000;
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 6c6121b85a54..25acf478c9e8 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -593,12 +593,11 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 		goto module_out;
 	}
 
-	policy = kmalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
+	policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
 	if (!policy) {
 		ret = -ENOMEM;
 		goto nomem_out;
 	}
-	memset(policy, 0, sizeof(struct cpufreq_policy));
 
 	policy->cpu = cpu;
 	policy->cpus = cpumask_of_cpu(cpu);
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index c1fc9c62bb51..17741111246b 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -48,7 +48,10 @@
  * 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	(1000)
 #define DEF_SAMPLING_DOWN_FACTOR		(1)
@@ -416,13 +419,16 @@ 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 = 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;
 
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 3597f25d5efa..0bddb8e694d9 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -193,11 +193,15 @@ cpufreq_stats_create_table (struct cpufreq_policy *policy,
 	unsigned int cpu = policy->cpu;
 	if (cpufreq_stats_table[cpu])
 		return -EBUSY;
-	if ((stat = kmalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
+	if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
 		return -ENOMEM;
-	memset(stat, 0, sizeof (struct cpufreq_stats));
 
 	data = cpufreq_cpu_get(cpu);
+	if (data == NULL) {
+		ret = -EINVAL;
+		goto error_get_fail;
+	}
+
 	if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
 		goto error_out;
 
@@ -217,12 +221,11 @@ cpufreq_stats_create_table (struct cpufreq_policy *policy,
 	alloc_size += count * count * sizeof(int);
 #endif
 	stat->max_state = count;
-	stat->time_in_state = kmalloc(alloc_size, GFP_KERNEL);
+	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
 	if (!stat->time_in_state) {
 		ret = -ENOMEM;
 		goto error_out;
 	}
-	memset(stat->time_in_state, 0, alloc_size);
 	stat->freq_table = (unsigned int *)(stat->time_in_state + count);
 
 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
@@ -245,6 +248,7 @@ cpufreq_stats_create_table (struct cpufreq_policy *policy,
 	return 0;
 error_out:
 	cpufreq_cpu_put(data);
+error_get_fail:
 	kfree(stat);
 	cpufreq_stats_table[cpu] = NULL;
 	return ret;