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[PATCH v1 2/4] cpufreq: Add boost_freq_req QoS request

Pierre Gondois posted 4 patches 2 weeks, 1 day ago
There is a newer version of this series
[PATCH v1 2/4] cpufreq: Add boost_freq_req QoS request
Posted by Pierre Gondois 2 weeks, 1 day ago 
The Power Management Quality of Service (PM QoS) allows to
aggregate constraints from multiple entities. It is currently
used to manage the min/max frequency of a given policy.

Frequency constraints can come for instance from:
- Thermal framework: acpi_thermal_cpufreq_init()
- Firmware: _PPC objects: acpi_processor_ppc_init()
- User: by setting policyX/scaling_[min|max]_freq
The minimum of the max frequency constraints is used to compute
the resulting maximum allowed frequency.

When enabling boost frequencies, the same frequency request object
(policy->max_freq_req) as to handle requests from users is used.
As a result, when setting:
- scaling_max_freq
- boost
The last sysfs file used overwrites the request from the other
sysfs file.

To avoid this, create a per-policy boost_freq_req to save the boost
constraints instead of overwriting the last scaling_max_freq
constraint.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
 drivers/cpufreq/cpufreq.c | 35 +++++++++++++++++++++++++++++++++++
 include/linux/cpufreq.h   |  1 +
 2 files changed, 36 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 11b29c7dbea9e..23f64346b80f8 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1370,6 +1370,18 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
 		freq_qos_remove_request(policy->max_freq_req);
 	}
 
+	if (policy->boost_freq_req) {
+		/*
+		 * Remove boost_freq_req after sending CPUFREQ_REMOVE_POLICY
+		 * notification, since CPUFREQ_CREATE_POLICY notification was
+		 * sent after adding boost_freq_req earlier.
+		 */
+		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+					     CPUFREQ_REMOVE_POLICY, policy);
+		freq_qos_remove_request(policy->boost_freq_req);
+		kfree(policy->boost_freq_req);
+	}
+
 	freq_qos_remove_request(policy->min_freq_req);
 	kfree(policy->min_freq_req);
 
@@ -1476,6 +1488,29 @@ static int cpufreq_policy_online(struct cpufreq_policy *policy,
 			goto out_destroy_policy;
 		}
 
+		if (policy->boost_supported) {
+			policy->boost_freq_req = kzalloc(sizeof(*policy->boost_freq_req),
+				GFP_KERNEL);
+			if (!policy->boost_freq_req) {
+				ret = -ENOMEM;
+				goto out_destroy_policy;
+			}
+
+			ret = freq_qos_add_request(&policy->constraints,
+						   policy->boost_freq_req,
+						   FREQ_QOS_MAX,
+						   FREQ_QOS_MAX_DEFAULT_VALUE);
+			if (ret < 0) {
+				/*
+				 * So we don't call freq_qos_remove_request() for an
+				 * uninitialized request.
+				 */
+				kfree(policy->boost_freq_req);
+				policy->boost_freq_req = NULL;
+				goto out_destroy_policy;
+			}
+		}
+
 		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 				CPUFREQ_CREATE_POLICY, policy);
 	}
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 0465d1e6f72ac..c292a6a19e4f5 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -81,6 +81,7 @@ struct cpufreq_policy {
 	struct freq_constraints	constraints;
 	struct freq_qos_request	*min_freq_req;
 	struct freq_qos_request	*max_freq_req;
+	struct freq_qos_request *boost_freq_req;
 
 	struct cpufreq_frequency_table	*freq_table;
 	enum cpufreq_table_sorting freq_table_sorted;
-- 
2.43.0
Re: [PATCH v1 2/4] cpufreq: Add boost_freq_req QoS request
Posted by zhenglifeng (A) 2 weeks, 1 day ago 
On 2025/12/4 18:13, Pierre Gondois wrote:
> The Power Management Quality of Service (PM QoS) allows to
> aggregate constraints from multiple entities. It is currently
> used to manage the min/max frequency of a given policy.
> 
> Frequency constraints can come for instance from:
> - Thermal framework: acpi_thermal_cpufreq_init()
> - Firmware: _PPC objects: acpi_processor_ppc_init()
> - User: by setting policyX/scaling_[min|max]_freq
> The minimum of the max frequency constraints is used to compute
> the resulting maximum allowed frequency.
> 
> When enabling boost frequencies, the same frequency request object
> (policy->max_freq_req) as to handle requests from users is used.
> As a result, when setting:
> - scaling_max_freq
> - boost
> The last sysfs file used overwrites the request from the other
> sysfs file.
> 
> To avoid this, create a per-policy boost_freq_req to save the boost
> constraints instead of overwriting the last scaling_max_freq
> constraint.
> 
> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
> ---
>  drivers/cpufreq/cpufreq.c | 35 +++++++++++++++++++++++++++++++++++
>  include/linux/cpufreq.h   |  1 +
>  2 files changed, 36 insertions(+)
> 
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 11b29c7dbea9e..23f64346b80f8 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1370,6 +1370,18 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
>  		freq_qos_remove_request(policy->max_freq_req);
>  	}
>  
> +	if (policy->boost_freq_req) {
> +		/*
> +		 * Remove boost_freq_req after sending CPUFREQ_REMOVE_POLICY
> +		 * notification, since CPUFREQ_CREATE_POLICY notification was
> +		 * sent after adding boost_freq_req earlier.
> +		 */
> +		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
> +					     CPUFREQ_REMOVE_POLICY, policy);

The CPUFREQ_REMOVE_POLICY notification is sent before removing
max_freq_req, I don't think it should be sent again here.

> +		freq_qos_remove_request(policy->boost_freq_req);
> +		kfree(policy->boost_freq_req);
> +	}
> +

I think boost_freq_req should be removed before removing max_freq_req,
since it was added after adding max_freq_req as shown below.

>  	freq_qos_remove_request(policy->min_freq_req);
>  	kfree(policy->min_freq_req);
>  
> @@ -1476,6 +1488,29 @@ static int cpufreq_policy_online(struct cpufreq_policy *policy,
>  			goto out_destroy_policy;
>  		}
>  
> +		if (policy->boost_supported) {
> +			policy->boost_freq_req = kzalloc(sizeof(*policy->boost_freq_req),
> +				GFP_KERNEL);
> +			if (!policy->boost_freq_req) {
> +				ret = -ENOMEM;
> +				goto out_destroy_policy;
> +			}
> +
> +			ret = freq_qos_add_request(&policy->constraints,
> +						   policy->boost_freq_req,
> +						   FREQ_QOS_MAX,
> +						   FREQ_QOS_MAX_DEFAULT_VALUE);
> +			if (ret < 0) {
> +				/*
> +				 * So we don't call freq_qos_remove_request() for an
> +				 * uninitialized request.
> +				 */
> +				kfree(policy->boost_freq_req);
> +				policy->boost_freq_req = NULL;
> +				goto out_destroy_policy;
> +			}
> +		}
> +
>  		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
>  				CPUFREQ_CREATE_POLICY, policy);
>  	}
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index 0465d1e6f72ac..c292a6a19e4f5 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -81,6 +81,7 @@ struct cpufreq_policy {
>  	struct freq_constraints	constraints;
>  	struct freq_qos_request	*min_freq_req;
>  	struct freq_qos_request	*max_freq_req;
> +	struct freq_qos_request *boost_freq_req;
>  
>  	struct cpufreq_frequency_table	*freq_table;
>  	enum cpufreq_table_sorting freq_table_sorted;
Re: [PATCH v1 2/4] cpufreq: Add boost_freq_req QoS request
Posted by Pierre Gondois 1 week, 4 days ago 
On 12/4/25 12:50, zhenglifeng (A) wrote:
> On 2025/12/4 18:13, Pierre Gondois wrote:
>> The Power Management Quality of Service (PM QoS) allows to
>> aggregate constraints from multiple entities. It is currently
>> used to manage the min/max frequency of a given policy.
>>
>> Frequency constraints can come for instance from:
>> - Thermal framework: acpi_thermal_cpufreq_init()
>> - Firmware: _PPC objects: acpi_processor_ppc_init()
>> - User: by setting policyX/scaling_[min|max]_freq
>> The minimum of the max frequency constraints is used to compute
>> the resulting maximum allowed frequency.
>>
>> When enabling boost frequencies, the same frequency request object
>> (policy->max_freq_req) as to handle requests from users is used.
>> As a result, when setting:
>> - scaling_max_freq
>> - boost
>> The last sysfs file used overwrites the request from the other
>> sysfs file.
>>
>> To avoid this, create a per-policy boost_freq_req to save the boost
>> constraints instead of overwriting the last scaling_max_freq
>> constraint.
>>
>> Signed-off-by: Pierre Gondois<pierre.gondois@arm.com>
>> ---
>>   drivers/cpufreq/cpufreq.c | 35 +++++++++++++++++++++++++++++++++++
>>   include/linux/cpufreq.h   |  1 +
>>   2 files changed, 36 insertions(+)
>>
>> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
>> index 11b29c7dbea9e..23f64346b80f8 100644
>> --- a/drivers/cpufreq/cpufreq.c
>> +++ b/drivers/cpufreq/cpufreq.c
>> @@ -1370,6 +1370,18 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
>>   		freq_qos_remove_request(policy->max_freq_req);
>>   	}
>>   
>> +	if (policy->boost_freq_req) {
>> +		/*
>> +		 * Remove boost_freq_req after sending CPUFREQ_REMOVE_POLICY
>> +		 * notification, since CPUFREQ_CREATE_POLICY notification was
>> +		 * sent after adding boost_freq_req earlier.
>> +		 */
>> +		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
>> +					     CPUFREQ_REMOVE_POLICY, policy);
> The CPUFREQ_REMOVE_POLICY notification is sent before removing
> max_freq_req, I don't think it should be sent again here.
Yes indeed
>> +		freq_qos_remove_request(policy->boost_freq_req);
>> +		kfree(policy->boost_freq_req);
>> +	}
>> +
> I think boost_freq_req should be removed before removing max_freq_req,
> since it was added after adding max_freq_req as shown below.

Ok right

>>   	freq_qos_remove_request(policy->min_freq_req);
>>   	kfree(policy->min_freq_req);
>>   
>> @@ -1476,6 +1488,29 @@ static int cpufreq_policy_online(struct cpufreq_policy *policy,
>>   			goto out_destroy_policy;
>>   		}
>>   
>> +		if (policy->boost_supported) {
>> +			policy->boost_freq_req = kzalloc(sizeof(*policy->boost_freq_req),
>> +				GFP_KERNEL);
>> +			if (!policy->boost_freq_req) {
>> +				ret = -ENOMEM;
>> +				goto out_destroy_policy;
>> +			}
>> +
>> +			ret = freq_qos_add_request(&policy->constraints,
>> +						   policy->boost_freq_req,
>> +						   FREQ_QOS_MAX,
>> +						   FREQ_QOS_MAX_DEFAULT_VALUE);
>> +			if (ret < 0) {
>> +				/*
>> +				 * So we don't call freq_qos_remove_request() for an
>> +				 * uninitialized request.
>> +				 */
>> +				kfree(policy->boost_freq_req);
>> +				policy->boost_freq_req = NULL;
>> +				goto out_destroy_policy;
>> +			}
>> +		}
>> +
>>   		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
>>   				CPUFREQ_CREATE_POLICY, policy);
>>   	}
>> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
>> index 0465d1e6f72ac..c292a6a19e4f5 100644
>> --- a/include/linux/cpufreq.h
>> +++ b/include/linux/cpufreq.h
>> @@ -81,6 +81,7 @@ struct cpufreq_policy {
>>   	struct freq_constraints	constraints;
>>   	struct freq_qos_request	*min_freq_req;
>>   	struct freq_qos_request	*max_freq_req;
>> +	struct freq_qos_request *boost_freq_req;
>>   
>>   	struct cpufreq_frequency_table	*freq_table;
>>   	enum cpufreq_table_sorting freq_table_sorted;

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