summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq
diff options
context:
space:
mode:
authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>2006-06-28 13:51:19 -0700
committerDave Jones <davej@redhat.com>2006-06-30 01:33:31 -0400
commit2f8a835c705794f71726eb12c06fb0f24fe07ed3 (patch)
treec16b1a4bf85df6822b9bcedc608f1db9ddf6e571 /drivers/cpufreq
parent7a6bc1cdd506cf81f856f0fef4e56a2ba0c5a26d (diff)
downloadop-kernel-dev-2f8a835c705794f71726eb12c06fb0f24fe07ed3.zip
op-kernel-dev-2f8a835c705794f71726eb12c06fb0f24fe07ed3.tar.gz
[CPUFREQ] Make ondemand sampling per CPU and remove the mutex usage in sampling path.
Make ondemand sampling per CPU and remove the mutex usage in sampling path. Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq_ondemand.c72
1 files changed, 32 insertions, 40 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index a2add11e..18b016e 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -64,6 +64,7 @@ struct cpu_dbs_info_s {
cputime64_t prev_cpu_idle;
cputime64_t prev_cpu_wall;
struct cpufreq_policy *cur_policy;
+ struct work_struct work;
unsigned int enable;
};
static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
@@ -81,7 +82,7 @@ static unsigned int dbs_enable; /* number of CPUs using this policy */
static DEFINE_MUTEX (dbs_mutex);
static DECLARE_WORK (dbs_work, do_dbs_timer, NULL);
-static struct workqueue_struct *dbs_workq;
+static struct workqueue_struct *kondemand_wq;
struct dbs_tuners {
unsigned int sampling_rate;
@@ -233,17 +234,15 @@ static struct attribute_group dbs_attr_group = {
/************************** sysfs end ************************/
-static void dbs_check_cpu(int cpu)
+static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
{
unsigned int idle_ticks, total_ticks;
unsigned int load;
- struct cpu_dbs_info_s *this_dbs_info;
cputime64_t cur_jiffies;
struct cpufreq_policy *policy;
unsigned int j;
- this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
if (!this_dbs_info->enable)
return;
@@ -314,35 +313,29 @@ static void dbs_check_cpu(int cpu)
static void do_dbs_timer(void *data)
{
- int i;
- lock_cpu_hotplug();
- mutex_lock(&dbs_mutex);
- for_each_online_cpu(i)
- dbs_check_cpu(i);
- queue_delayed_work(dbs_workq, &dbs_work,
- usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
- mutex_unlock(&dbs_mutex);
- unlock_cpu_hotplug();
+ unsigned int cpu = smp_processor_id();
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
+
+ dbs_check_cpu(dbs_info);
+ queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work,
+ usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
}
-static inline void dbs_timer_init(void)
+static inline void dbs_timer_init(unsigned int cpu)
{
- INIT_WORK(&dbs_work, do_dbs_timer, NULL);
- if (!dbs_workq)
- dbs_workq = create_singlethread_workqueue("ondemand");
- if (!dbs_workq) {
- printk(KERN_ERR "ondemand: Cannot initialize kernel thread\n");
- return;
- }
- queue_delayed_work(dbs_workq, &dbs_work,
- usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
+
+ INIT_WORK(&dbs_info->work, do_dbs_timer, 0);
+ queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work,
+ usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
return;
}
-static inline void dbs_timer_exit(void)
+static inline void dbs_timer_exit(unsigned int cpu)
{
- if (dbs_workq)
- cancel_rearming_delayed_workqueue(dbs_workq, &dbs_work);
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
+
+ cancel_rearming_delayed_workqueue(kondemand_wq, &dbs_info->work);
}
static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
@@ -370,6 +363,16 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
break;
mutex_lock(&dbs_mutex);
+ dbs_enable++;
+ if (dbs_enable == 1) {
+ kondemand_wq = create_workqueue("kondemand");
+ if (!kondemand_wq) {
+ printk(KERN_ERR "Creation of kondemand failed\n");
+ dbs_enable--;
+ mutex_unlock(&dbs_mutex);
+ return -ENOSPC;
+ }
+ }
for_each_cpu_mask(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(cpu_dbs_info, j);
@@ -380,7 +383,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
}
this_dbs_info->enable = 1;
sysfs_create_group(&policy->kobj, &dbs_attr_group);
- dbs_enable++;
/*
* Start the timerschedule work, when this governor
* is used for first time
@@ -399,23 +401,20 @@ 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_timer_init();
}
+ dbs_timer_init(policy->cpu);
mutex_unlock(&dbs_mutex);
break;
case CPUFREQ_GOV_STOP:
mutex_lock(&dbs_mutex);
+ dbs_timer_exit(policy->cpu);
this_dbs_info->enable = 0;
sysfs_remove_group(&policy->kobj, &dbs_attr_group);
dbs_enable--;
- /*
- * Stop the timerschedule work, when this governor
- * is used for first time
- */
if (dbs_enable == 0)
- dbs_timer_exit();
+ destroy_workqueue(kondemand_wq);
mutex_unlock(&dbs_mutex);
@@ -452,13 +451,6 @@ static int __init cpufreq_gov_dbs_init(void)
static void __exit cpufreq_gov_dbs_exit(void)
{
- /* Make sure that the scheduled work is indeed not running.
- Assumes the timer has been cancelled first. */
- if (dbs_workq) {
- flush_workqueue(dbs_workq);
- destroy_workqueue(dbs_workq);
- }
-
cpufreq_unregister_governor(&cpufreq_gov_dbs);
}
OpenPOWER on IntegriCloud