| Message ID | 0a6620ff5a330126b21d00244d4fad62cff4f230.1653565641.git.viresh.kumar@linaro.org |
|---|---|
| State | Accepted |
| Commit | 9ab9b9d3fb9231cdcfda8e0fb3d9c24a2f95ed26 |
| Headers | show |
| Series | cpufreq: Minor cleanups | expand |
On Thu, May 26, 2022 at 1:51 PM Viresh Kumar <viresh.kumar@linaro.org> wrote: > > This change was introduced long back by: > > commit 4f750c930822 ("cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug") > > Since then, both cpufreq and hotplug core have been reworked and have > much better locking in place. The race mentioned in commit 4f750c930822 > isn't possible anymore. > > Drop the unnecessary locking. > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > drivers/cpufreq/cpufreq.c | 19 ++++--------------- > 1 file changed, 4 insertions(+), 15 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 53d163a84e06..bb237d1ce5e7 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -973,21 +973,10 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, > if (!fattr->store) > return -EIO; > > - /* > - * cpus_read_trylock() is used here to work around a circular lock > - * dependency problem with respect to the cpufreq_register_driver(). > - */ > - if (!cpus_read_trylock()) > - return -EBUSY; > - > - if (cpu_online(policy->cpu)) { > - down_write(&policy->rwsem); > - if (likely(!policy_is_inactive(policy))) > - ret = fattr->store(policy, buf, count); > - up_write(&policy->rwsem); > - } > - > - cpus_read_unlock(); > + down_write(&policy->rwsem); > + if (likely(!policy_is_inactive(policy))) > + ret = fattr->store(policy, buf, count); > + up_write(&policy->rwsem); > > return ret; > } > -- Applied along with the [1/3] as 5.20 material, thanks!
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 53d163a84e06..bb237d1ce5e7 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -973,21 +973,10 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, if (!fattr->store) return -EIO; - /* - * cpus_read_trylock() is used here to work around a circular lock - * dependency problem with respect to the cpufreq_register_driver(). - */ - if (!cpus_read_trylock()) - return -EBUSY; - - if (cpu_online(policy->cpu)) { - down_write(&policy->rwsem); - if (likely(!policy_is_inactive(policy))) - ret = fattr->store(policy, buf, count); - up_write(&policy->rwsem); - } - - cpus_read_unlock(); + down_write(&policy->rwsem); + if (likely(!policy_is_inactive(policy))) + ret = fattr->store(policy, buf, count); + up_write(&policy->rwsem); return ret; }
This change was introduced long back by: commit 4f750c930822 ("cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug") Since then, both cpufreq and hotplug core have been reworked and have much better locking in place. The race mentioned in commit 4f750c930822 isn't possible anymore. Drop the unnecessary locking. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/cpufreq/cpufreq.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-)