Remove hotplug cpu crap from cpufreq.

From: Dave Jones
Date: Wed Nov 01 2006 - 18:00:26 EST

I've had it with this stuff. For months, we've had various warnings
popping up from this code (which was clearly half-baked at best when it
went in).

Until someone steps up who actually gives a damn about fixing it, can
we just rip this crap out so I stop getting mails from users who couldn't
care less about CPU hotplug anyway?

Dave

The hotplug CPU locking in cpufreq is hurrendous.
No-one seems to care enough to fix it, so just remove it
so that the 99.9% of the real world users of this code can
use cpufreq without being bothered by warnings.

Signed-off-by: Dave Jones <davej@xxxxxxxxxx>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 86e69b7..ce99804 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -400,12 +400,10 @@ (struct cpufreq_policy * policy, const c
if (ret != 1) \
return -EINVAL; \
\
- lock_cpu_hotplug(); \
mutex_lock(&policy->lock); \
ret = __cpufreq_set_policy(policy, &new_policy); \
policy->user_policy.object = policy->object; \
mutex_unlock(&policy->lock); \
- unlock_cpu_hotplug(); \
\
return ret ? ret : count; \
}
@@ -461,8 +459,6 @@ static ssize_t store_scaling_governor (s
if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor))
return -EINVAL;

- lock_cpu_hotplug();
-
/* Do not use cpufreq_set_policy here or the user_policy.max
will be wrongly overridden */
mutex_lock(&policy->lock);
@@ -472,8 +468,6 @@ static ssize_t store_scaling_governor (s
policy->user_policy.governor = policy->governor;
mutex_unlock(&policy->lock);

- unlock_cpu_hotplug();
-
return ret ? ret : count;
}

@@ -1235,7 +1229,6 @@ EXPORT_SYMBOL(cpufreq_unregister_notifie
*********************************************************************/


-/* Must be called with lock_cpu_hotplug held */
int __cpufreq_driver_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
@@ -1261,13 +1254,11 @@ int cpufreq_driver_target(struct cpufreq
if (!policy)
return -EINVAL;

- lock_cpu_hotplug();
mutex_lock(&policy->lock);

ret = __cpufreq_driver_target(policy, target_freq, relation);

mutex_unlock(&policy->lock);
- unlock_cpu_hotplug();

cpufreq_cpu_put(policy);
return ret;
@@ -1275,7 +1266,6 @@ int cpufreq_driver_target(struct cpufreq
EXPORT_SYMBOL_GPL(cpufreq_driver_target);

/*
- * Locking: Must be called with the lock_cpu_hotplug() lock held
* when "event" is CPUFREQ_GOV_LIMITS
*/

@@ -1364,9 +1354,6 @@ int cpufreq_get_policy(struct cpufreq_po
EXPORT_SYMBOL(cpufreq_get_policy);


-/*
- * Locking: Must be called with the lock_cpu_hotplug() lock held
- */
static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy)
{
int ret = 0;
@@ -1466,8 +1453,6 @@ int cpufreq_set_policy(struct cpufreq_po
if (!data)
return -EINVAL;

- lock_cpu_hotplug();
-
/* lock this CPU */
mutex_lock(&data->lock);

@@ -1479,7 +1464,6 @@ int cpufreq_set_policy(struct cpufreq_po

mutex_unlock(&data->lock);

- unlock_cpu_hotplug();
cpufreq_cpu_put(data);

return ret;
@@ -1503,7 +1487,6 @@ int cpufreq_update_policy(unsigned int c
if (!data)
return -ENODEV;

- lock_cpu_hotplug();
mutex_lock(&data->lock);

dprintk("updating policy for CPU %u\n", cpu);
@@ -1529,7 +1512,6 @@ int cpufreq_update_policy(unsigned int c
ret = __cpufreq_set_policy(data, &policy);

mutex_unlock(&data->lock);
- unlock_cpu_hotplug();
cpufreq_cpu_put(data);
return ret;
}
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index c4c578d..528d16e 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -423,14 +423,12 @@ 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);
schedule_delayed_work(&dbs_work,
usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
mutex_unlock(&dbs_mutex);
- unlock_cpu_hotplug();
}

static inline void dbs_timer_init(void)
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index bf8aa45..e3bc0b1 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -424,9 +424,7 @@ static void do_dbs_timer(void *data)
INIT_WORK(&dbs_info->work, do_dbs_timer, (void *)DBS_NORMAL_SAMPLE);
if (!dbs_tuners_ins.powersave_bias ||
(unsigned long) data == DBS_NORMAL_SAMPLE) {
- lock_cpu_hotplug();
dbs_check_cpu(dbs_info);
- unlock_cpu_hotplug();
if (dbs_info->freq_lo) {
/* Setup timer for SUB_SAMPLE */
INIT_WORK(&dbs_info->work, do_dbs_timer,
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index c2ecc59..9926997 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -366,12 +366,10 @@ __exit cpufreq_stats_exit(void)
cpufreq_unregister_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER);
unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
- lock_cpu_hotplug();
for_each_online_cpu(cpu) {
cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_DEAD,
(void *)(long)cpu);
}
- unlock_cpu_hotplug();
}

MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@xxxxxxxxx>");
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
index a06c204..29ada96 100644
--- a/drivers/cpufreq/cpufreq_userspace.c
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -71,7 +71,6 @@ static int cpufreq_set(unsigned int freq

dprintk("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);

- lock_cpu_hotplug();
mutex_lock(&userspace_mutex);
if (!cpu_is_managed[policy->cpu])
goto err;
@@ -94,7 +93,6 @@ static int cpufreq_set(unsigned int freq

err:
mutex_unlock(&userspace_mutex);
- unlock_cpu_hotplug();
return ret;
}

--
http://www.codemonkey.org.uk
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