diff mbox

[1/3] cpufreq: move call to __find_governor() to cpufreq_init_policy()

Message ID 9f9546137135103556c69815c72b81ed93cc1ca2.1393318100.git.viresh.kumar@linaro.org
State New
Headers show

Commit Message

Viresh Kumar Feb. 25, 2014, 8:50 a.m. UTC
We call __find_governor() during addition of first CPU of every policy to find
the last governor used for this CPU before it was hotplugged-out.

After that we call cpufreq_parse_governor() in cpufreq_init_policy() either with
this governor or default governor. And right after that policy->governor is set
to NULL.

So, instead of doing this move the relevant parts to cpufreq_init_policy()
policy only and initialize policy->governor to NULL at the beginning.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---

Hi Saravana,

I hope only the first two patches would fix things for you but probably you can
test all three.

@Rafael: We might need to get these in next rc only as these are more or less
fixes.

 drivers/cpufreq/cpufreq.c | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

Comments

Rafael J. Wysocki March 1, 2014, 1 a.m. UTC | #1
On Tuesday, February 25, 2014 02:20:09 PM Viresh Kumar wrote:
> We call __find_governor() during addition of first CPU of every policy to find
> the last governor used for this CPU before it was hotplugged-out.
> 
> After that we call cpufreq_parse_governor() in cpufreq_init_policy() either with
> this governor or default governor. And right after that policy->governor is set
> to NULL.

This is a problem, right?  So care to write *why* it is a problem here?

> So, instead of doing this move the relevant parts to cpufreq_init_policy()
> policy only and initialize policy->governor to NULL at the beginning.

And this change is supposed to fix that problem, right?  You're not moving
stuff around just for the fun of it?

> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>
> ---
> 
> Hi Saravana,
> 
> I hope only the first two patches would fix things for you but probably you can
> test all three.
> 
> @Rafael: We might need to get these in next rc only as these are more or less
> fixes.
> 
>  drivers/cpufreq/cpufreq.c | 34 ++++++++++++++++------------------
>  1 file changed, 16 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index c755b5f..cc4f244 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -879,18 +879,27 @@ err_out_kobj_put:
>  
>  static void cpufreq_init_policy(struct cpufreq_policy *policy)
>  {
> +	struct cpufreq_governor *gov = NULL;
>  	struct cpufreq_policy new_policy;
>  	int ret = 0;
>  
>  	memcpy(&new_policy, policy, sizeof(*policy));
>  
> +	/* Update governor of new_policy to the governor used before hotplug */
> +#ifdef CONFIG_HOTPLUG_CPU
> +	gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu));
> +#endif
> +	if (gov)
> +		pr_debug("Restoring governor %s for cpu %d\n",
> +				policy->governor->name, policy->cpu);
> +	else
> +		gov = CPUFREQ_DEFAULT_GOVERNOR;
> +
> +	new_policy.governor = gov;
> +
>  	/* Use the default policy if its valid. */
>  	if (cpufreq_driver->setpolicy)
> -		cpufreq_parse_governor(policy->governor->name,
> -					&new_policy.policy, NULL);
> -
> -	/* assure that the starting sequence is run in cpufreq_set_policy */
> -	policy->governor = NULL;
> +		cpufreq_parse_governor(gov->name, &new_policy.policy, NULL);
>  
>  	/* set default policy */
>  	ret = cpufreq_set_policy(policy, &new_policy);
> @@ -944,11 +953,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
>  	unsigned long flags;
>  
>  	read_lock_irqsave(&cpufreq_driver_lock, flags);
> -
>  	policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
> -
>  	read_unlock_irqrestore(&cpufreq_driver_lock, flags);
>  
> +	policy->governor = NULL;
> +
>  	return policy;
>  }
>  
> @@ -1036,7 +1045,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
>  	unsigned long flags;
>  #ifdef CONFIG_HOTPLUG_CPU
>  	struct cpufreq_policy *tpolicy;
> -	struct cpufreq_governor *gov;
>  #endif
>  
>  	if (cpu_is_offline(cpu))
> @@ -1094,7 +1102,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
>  	else
>  		policy->cpu = cpu;
>  
> -	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
>  	cpumask_copy(policy->cpus, cpumask_of(cpu));
>  
>  	init_completion(&policy->kobj_unregister);
> @@ -1179,15 +1186,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
>  	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
>  				     CPUFREQ_START, policy);
>  
> -#ifdef CONFIG_HOTPLUG_CPU
> -	gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
> -	if (gov) {
> -		policy->governor = gov;
> -		pr_debug("Restoring governor %s for cpu %d\n",
> -		       policy->governor->name, cpu);
> -	}
> -#endif
> -
>  	if (!frozen) {
>  		ret = cpufreq_add_dev_interface(policy, dev);
>  		if (ret)
>
Rafael J. Wysocki March 1, 2014, 1:09 a.m. UTC | #2
On Tuesday, February 25, 2014 02:20:09 PM Viresh Kumar wrote:
> We call __find_governor() during addition of first CPU of every policy to find
> the last governor used for this CPU before it was hotplugged-out.
> 
> After that we call cpufreq_parse_governor() in cpufreq_init_policy() either with
> this governor or default governor. And right after that policy->governor is set
> to NULL.
> 
> So, instead of doing this move the relevant parts to cpufreq_init_policy()
> policy only and initialize policy->governor to NULL at the beginning.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> 
> Hi Saravana,
> 
> I hope only the first two patches would fix things for you but probably you can
> test all three.
> 
> @Rafael: We might need to get these in next rc only as these are more or less
> fixes.
> 
>  drivers/cpufreq/cpufreq.c | 34 ++++++++++++++++------------------
>  1 file changed, 16 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index c755b5f..cc4f244 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -879,18 +879,27 @@ err_out_kobj_put:
>  
>  static void cpufreq_init_policy(struct cpufreq_policy *policy)
>  {
> +	struct cpufreq_governor *gov = NULL;
>  	struct cpufreq_policy new_policy;
>  	int ret = 0;
>  
>  	memcpy(&new_policy, policy, sizeof(*policy));
>  

And while I'm at it, can we *please* avoid adding new #ifdef blocks into
function bodies?

Please introduce a wrapper around __find_governor() returning NULL for
CONFIG_HOTPLUG_CPU unset.

> +	/* Update governor of new_policy to the governor used before hotplug */
> +#ifdef CONFIG_HOTPLUG_CPU
> +	gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu));
> +#endif
> +	if (gov)
> +		pr_debug("Restoring governor %s for cpu %d\n",
> +				policy->governor->name, policy->cpu);
> +	else
> +		gov = CPUFREQ_DEFAULT_GOVERNOR;
> +
> +	new_policy.governor = gov;
> +
>  	/* Use the default policy if its valid. */
>  	if (cpufreq_driver->setpolicy)
> -		cpufreq_parse_governor(policy->governor->name,
> -					&new_policy.policy, NULL);
> -
> -	/* assure that the starting sequence is run in cpufreq_set_policy */
> -	policy->governor = NULL;
> +		cpufreq_parse_governor(gov->name, &new_policy.policy, NULL);
>  
>  	/* set default policy */
>  	ret = cpufreq_set_policy(policy, &new_policy);
> @@ -944,11 +953,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
>  	unsigned long flags;
>  
>  	read_lock_irqsave(&cpufreq_driver_lock, flags);
> -
>  	policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
> -

Why do these whitespace changes belong to this patch?

>  	read_unlock_irqrestore(&cpufreq_driver_lock, flags);
>  
> +	policy->governor = NULL;
> +
>  	return policy;
>  }
>  
> @@ -1036,7 +1045,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
>  	unsigned long flags;
>  #ifdef CONFIG_HOTPLUG_CPU
>  	struct cpufreq_policy *tpolicy;
> -	struct cpufreq_governor *gov;
>  #endif
>  
>  	if (cpu_is_offline(cpu))
> @@ -1094,7 +1102,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
>  	else
>  		policy->cpu = cpu;
>  
> -	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
>  	cpumask_copy(policy->cpus, cpumask_of(cpu));
>  
>  	init_completion(&policy->kobj_unregister);
> @@ -1179,15 +1186,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
>  	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
>  				     CPUFREQ_START, policy);
>  
> -#ifdef CONFIG_HOTPLUG_CPU
> -	gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
> -	if (gov) {
> -		policy->governor = gov;
> -		pr_debug("Restoring governor %s for cpu %d\n",
> -		       policy->governor->name, cpu);
> -	}
> -#endif
> -
>  	if (!frozen) {
>  		ret = cpufreq_add_dev_interface(policy, dev);
>  		if (ret)
>
Viresh Kumar March 4, 2014, 3:43 a.m. UTC | #3
On 1 March 2014 06:39, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
> And while I'm at it, can we *please* avoid adding new #ifdef blocks into
> function bodies?
>
> Please introduce a wrapper around __find_governor() returning NULL for
> CONFIG_HOTPLUG_CPU unset.

I have tried fixing all the suggestions you gave for this series. Please have a
look at V2 set and let me know if I am still missing anything.
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diff mbox

Patch

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index c755b5f..cc4f244 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -879,18 +879,27 @@  err_out_kobj_put:
 
 static void cpufreq_init_policy(struct cpufreq_policy *policy)
 {
+	struct cpufreq_governor *gov = NULL;
 	struct cpufreq_policy new_policy;
 	int ret = 0;
 
 	memcpy(&new_policy, policy, sizeof(*policy));
 
+	/* Update governor of new_policy to the governor used before hotplug */
+#ifdef CONFIG_HOTPLUG_CPU
+	gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu));
+#endif
+	if (gov)
+		pr_debug("Restoring governor %s for cpu %d\n",
+				policy->governor->name, policy->cpu);
+	else
+		gov = CPUFREQ_DEFAULT_GOVERNOR;
+
+	new_policy.governor = gov;
+
 	/* Use the default policy if its valid. */
 	if (cpufreq_driver->setpolicy)
-		cpufreq_parse_governor(policy->governor->name,
-					&new_policy.policy, NULL);
-
-	/* assure that the starting sequence is run in cpufreq_set_policy */
-	policy->governor = NULL;
+		cpufreq_parse_governor(gov->name, &new_policy.policy, NULL);
 
 	/* set default policy */
 	ret = cpufreq_set_policy(policy, &new_policy);
@@ -944,11 +953,11 @@  static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
 	unsigned long flags;
 
 	read_lock_irqsave(&cpufreq_driver_lock, flags);
-
 	policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
-
 	read_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
+	policy->governor = NULL;
+
 	return policy;
 }
 
@@ -1036,7 +1045,6 @@  static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 	unsigned long flags;
 #ifdef CONFIG_HOTPLUG_CPU
 	struct cpufreq_policy *tpolicy;
-	struct cpufreq_governor *gov;
 #endif
 
 	if (cpu_is_offline(cpu))
@@ -1094,7 +1102,6 @@  static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 	else
 		policy->cpu = cpu;
 
-	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 	cpumask_copy(policy->cpus, cpumask_of(cpu));
 
 	init_completion(&policy->kobj_unregister);
@@ -1179,15 +1186,6 @@  static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 				     CPUFREQ_START, policy);
 
-#ifdef CONFIG_HOTPLUG_CPU
-	gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
-	if (gov) {
-		policy->governor = gov;
-		pr_debug("Restoring governor %s for cpu %d\n",
-		       policy->governor->name, cpu);
-	}
-#endif
-
 	if (!frozen) {
 		ret = cpufreq_add_dev_interface(policy, dev);
 		if (ret)