I don't see the patch below in Linus's tree. If it's there, what is the git commit id?
thanks, greg k-h On Thu, Jun 25, 2009 at 04:01:24PM +0200, Thomas Renninger wrote: > Comment from Venkatesh: > ... > This mutex is just serializing the changes to those variables. I could't > think of any functionality issues of not having the lock as such. > > -> rip it out. > > CC: Venkatesh Pallipadi <[email protected]> > Signed-off-by: Thomas Renninger <[email protected]> > --- > drivers/cpufreq/cpufreq_conservative.c | 61 > +++----------------------------- > drivers/cpufreq/cpufreq_ondemand.c | 48 +++---------------------- > 2 files changed, 10 insertions(+), 99 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq_conservative.c > b/drivers/cpufreq/cpufreq_conservative.c > index 7a74d17..6303379 100644 > --- a/drivers/cpufreq/cpufreq_conservative.c > +++ b/drivers/cpufreq/cpufreq_conservative.c > @@ -18,7 +18,6 @@ > #include <linux/cpu.h> > #include <linux/jiffies.h> > #include <linux/kernel_stat.h> > -#include <linux/mutex.h> > #include <linux/hrtimer.h> > #include <linux/tick.h> > #include <linux/ktime.h> > @@ -84,19 +83,6 @@ static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); > > static unsigned int dbs_enable; /* number of CPUs using this policy */ > > -/* > - * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug > - * lock and dbs_mutex. cpu_hotplug lock should always be held before > - * dbs_mutex. If any function that can potentially take cpu_hotplug lock > - * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, > then > - * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock > - * is recursive for the same process. -Venki > - * DEADLOCK ALERT! (2) : do_dbs_timer() must not take the dbs_mutex, because > it > - * would deadlock with cancel_delayed_work_sync(), which is needed for proper > - * raceless workqueue teardown. > - */ > -static DEFINE_MUTEX(dbs_mutex); > - > static struct workqueue_struct *kconservative_wq; > > static struct dbs_tuners { > @@ -236,10 +222,7 @@ static ssize_t store_sampling_down_factor(struct > cpufreq_policy *unused, > if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) > return -EINVAL; > > - mutex_lock(&dbs_mutex); > dbs_tuners_ins.sampling_down_factor = input; > - mutex_unlock(&dbs_mutex); > - > return count; > } > > @@ -253,10 +236,7 @@ static ssize_t store_sampling_rate(struct cpufreq_policy > *unused, > if (ret != 1) > return -EINVAL; > > - mutex_lock(&dbs_mutex); > dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate()); > - mutex_unlock(&dbs_mutex); > - > return count; > } > > @@ -267,16 +247,11 @@ static ssize_t store_up_threshold(struct cpufreq_policy > *unused, > int ret; > ret = sscanf(buf, "%u", &input); > > - mutex_lock(&dbs_mutex); > if (ret != 1 || input > 100 || > - input <= dbs_tuners_ins.down_threshold) { > - mutex_unlock(&dbs_mutex); > + input <= dbs_tuners_ins.down_threshold) > return -EINVAL; > - } > > dbs_tuners_ins.up_threshold = input; > - mutex_unlock(&dbs_mutex); > - > return count; > } > > @@ -287,17 +262,12 @@ static ssize_t store_down_threshold(struct > cpufreq_policy *unused, > int ret; > ret = sscanf(buf, "%u", &input); > > - mutex_lock(&dbs_mutex); > /* cannot be lower than 11 otherwise freq will not fall */ > if (ret != 1 || input < 11 || input > 100 || > - input >= dbs_tuners_ins.up_threshold) { > - mutex_unlock(&dbs_mutex); > + input >= dbs_tuners_ins.up_threshold) > return -EINVAL; > - } > > dbs_tuners_ins.down_threshold = input; > - mutex_unlock(&dbs_mutex); > - > return count; > } > > @@ -316,11 +286,9 @@ static ssize_t store_ignore_nice_load(struct > cpufreq_policy *policy, > if (input > 1) > input = 1; > > - mutex_lock(&dbs_mutex); > - if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ > - mutex_unlock(&dbs_mutex); > + if (input == dbs_tuners_ins.ignore_nice) /* nothing to do */ > return count; > - } > + > dbs_tuners_ins.ignore_nice = input; > > /* we need to re-evaluate prev_cpu_idle */ > @@ -332,8 +300,6 @@ static ssize_t store_ignore_nice_load(struct > cpufreq_policy *policy, > if (dbs_tuners_ins.ignore_nice) > dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; > } > - mutex_unlock(&dbs_mutex); > - > return count; > } > > @@ -352,10 +318,7 @@ static ssize_t store_freq_step(struct cpufreq_policy > *policy, > > /* no need to test here if freq_step is zero as the user might actually > * want this, they would be crazy though :) */ > - mutex_lock(&dbs_mutex); > dbs_tuners_ins.freq_step = input; > - mutex_unlock(&dbs_mutex); > - > return count; > } > > @@ -566,13 +529,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy > *policy, > if (this_dbs_info->enable) /* Already enabled */ > break; > > - mutex_lock(&dbs_mutex); > - > rc = sysfs_create_group(&policy->kobj, &dbs_attr_group); > - if (rc) { > - mutex_unlock(&dbs_mutex); > + if (rc) > return rc; > - } > > for_each_cpu(j, policy->cpus) { > struct cpu_dbs_info_s *j_dbs_info; > @@ -612,13 +571,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy > *policy, > CPUFREQ_TRANSITION_NOTIFIER); > } > dbs_timer_init(this_dbs_info); > - > - mutex_unlock(&dbs_mutex); > - > break; > > case CPUFREQ_GOV_STOP: > - mutex_lock(&dbs_mutex); > dbs_timer_exit(this_dbs_info); > sysfs_remove_group(&policy->kobj, &dbs_attr_group); > dbs_enable--; > @@ -631,13 +586,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy > *policy, > cpufreq_unregister_notifier( > &dbs_cpufreq_notifier_block, > CPUFREQ_TRANSITION_NOTIFIER); > - > - mutex_unlock(&dbs_mutex); > - > break; > > case CPUFREQ_GOV_LIMITS: > - mutex_lock(&dbs_mutex); > if (policy->max < this_dbs_info->cur_policy->cur) > __cpufreq_driver_target( > this_dbs_info->cur_policy, > @@ -646,8 +597,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy > *policy, > __cpufreq_driver_target( > this_dbs_info->cur_policy, > policy->min, CPUFREQ_RELATION_L); > - mutex_unlock(&dbs_mutex); > - > break; > } > return 0; > diff --git a/drivers/cpufreq/cpufreq_ondemand.c > b/drivers/cpufreq/cpufreq_ondemand.c > index e741c33..d080a48 100644 > --- a/drivers/cpufreq/cpufreq_ondemand.c > +++ b/drivers/cpufreq/cpufreq_ondemand.c > @@ -17,7 +17,6 @@ > #include <linux/cpu.h> > #include <linux/jiffies.h> > #include <linux/kernel_stat.h> > -#include <linux/mutex.h> > #include <linux/hrtimer.h> > #include <linux/tick.h> > #include <linux/ktime.h> > @@ -91,19 +90,6 @@ static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); > > static unsigned int dbs_enable; /* number of CPUs using this policy */ > > -/* > - * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug > - * lock and dbs_mutex. cpu_hotplug lock should always be held before > - * dbs_mutex. If any function that can potentially take cpu_hotplug lock > - * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, > then > - * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock > - * is recursive for the same process. -Venki > - * DEADLOCK ALERT! (2) : do_dbs_timer() must not take the dbs_mutex, because > it > - * would deadlock with cancel_delayed_work_sync(), which is needed for proper > - * raceless workqueue teardown. > - */ > -static DEFINE_MUTEX(dbs_mutex); > - > static struct workqueue_struct *kondemand_wq; > > static struct dbs_tuners { > @@ -269,14 +255,10 @@ static ssize_t store_sampling_rate(struct > cpufreq_policy *unused, > int ret; > ret = sscanf(buf, "%u", &input); > > - mutex_lock(&dbs_mutex); > - if (ret != 1) { > - mutex_unlock(&dbs_mutex); > + if (ret != 1) > return -EINVAL; > - } > - dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate()); > - mutex_unlock(&dbs_mutex); > > + dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate()); > return count; > } > > @@ -287,16 +269,11 @@ static ssize_t store_up_threshold(struct cpufreq_policy > *unused, > int ret; > ret = sscanf(buf, "%u", &input); > > - mutex_lock(&dbs_mutex); > if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || > - input < MIN_FREQUENCY_UP_THRESHOLD) { > - mutex_unlock(&dbs_mutex); > + input < MIN_FREQUENCY_UP_THRESHOLD) > return -EINVAL; > - } > > dbs_tuners_ins.up_threshold = input; > - mutex_unlock(&dbs_mutex); > - > return count; > } > > @@ -315,11 +292,9 @@ static ssize_t store_ignore_nice_load(struct > cpufreq_policy *policy, > if (input > 1) > input = 1; > > - mutex_lock(&dbs_mutex); > - if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ > - mutex_unlock(&dbs_mutex); > + if (input == dbs_tuners_ins.ignore_nice) /* nothing to do */ > return count; > - } > + > dbs_tuners_ins.ignore_nice = input; > > /* we need to re-evaluate prev_cpu_idle */ > @@ -332,8 +307,6 @@ static ssize_t store_ignore_nice_load(struct > cpufreq_policy *policy, > dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; > > } > - mutex_unlock(&dbs_mutex); > - > return count; > } > > @@ -350,10 +323,8 @@ static ssize_t store_powersave_bias(struct > cpufreq_policy *unused, > if (input > 1000) > input = 1000; > > - mutex_lock(&dbs_mutex); > dbs_tuners_ins.powersave_bias = input; > ondemand_powersave_bias_init(); > - mutex_unlock(&dbs_mutex); > > return count; > } > @@ -586,13 +557,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy > *policy, > if (this_dbs_info->enable) /* Already enabled */ > break; > > - mutex_lock(&dbs_mutex); > dbs_enable++; > > rc = sysfs_create_group(&policy->kobj, &dbs_attr_group); > if (rc) { > dbs_enable--; > - mutex_unlock(&dbs_mutex); > return rc; > } > > @@ -627,28 +596,21 @@ static int cpufreq_governor_dbs(struct cpufreq_policy > *policy, > dbs_tuners_ins.sampling_rate = def_sampling_rate; > } > dbs_timer_init(this_dbs_info); > - > - mutex_unlock(&dbs_mutex); > break; > > case CPUFREQ_GOV_STOP: > - mutex_lock(&dbs_mutex); > dbs_timer_exit(this_dbs_info); > sysfs_remove_group(&policy->kobj, &dbs_attr_group); > dbs_enable--; > - mutex_unlock(&dbs_mutex); > - > break; > > case CPUFREQ_GOV_LIMITS: > - mutex_lock(&dbs_mutex); > if (policy->max < this_dbs_info->cur_policy->cur) > __cpufreq_driver_target(this_dbs_info->cur_policy, > policy->max, CPUFREQ_RELATION_H); > else if (policy->min > this_dbs_info->cur_policy->cur) > __cpufreq_driver_target(this_dbs_info->cur_policy, > policy->min, CPUFREQ_RELATION_L); > - mutex_unlock(&dbs_mutex); > break; > } > return 0; > -- > 1.6.0.2 > > -- > To unsubscribe from this list: send the line "unsubscribe cpufreq" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > > _______________________________________________ > stable mailing list > [email protected] > http://linux.kernel.org/mailman/listinfo/stable -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
