7 files changed, 29 insertions, 41 deletions

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;