Re: [PATCH v4 2/6] cpufreq: Add boost_freq_req QoS request

[Pierre Gondois <pierre.gondois@arm.com>]

On 2/25/26 03:33, zhenglifeng (A) wrote:
> On 2/25/2026 1:08 AM, 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 | 41 ++++++++++++++++++++++++++++++++++-----
>>   include/linux/cpufreq.h   |  1 +
>>   2 files changed, 37 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
>> index db414c052658b..52efa4805afee 100644
>> --- a/drivers/cpufreq/cpufreq.c
>> +++ b/drivers/cpufreq/cpufreq.c
>> @@ -1359,17 +1359,25 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
>>   	/* Cancel any pending policy->update work before freeing the policy. */
>>   	cancel_work_sync(&policy->update);
>>   
>> -	if (policy->max_freq_req) {
>> +	if (policy->max_freq_req || policy->boost_freq_req) {
>>   		/*
>> -		 * Remove max_freq_req after sending CPUFREQ_REMOVE_POLICY
>> -		 * notification, since CPUFREQ_CREATE_POLICY notification was
>> -		 * sent after adding max_freq_req earlier.
>> +		 * Remove max/boost _freq_req after sending CPUFREQ_REMOVE_POLICY
>> +		 * notification, since CPUFREQ_CREATE_POLICY notification was sent
>> +		 * after adding max/boost _freq_req earlier.
>>   		 */
>>   		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
>>   					     CPUFREQ_REMOVE_POLICY, policy);
>> -		freq_qos_remove_request(policy->max_freq_req);
>>   	}
>>   
>> +	if ((policy->max_freq_req && !policy->boost_supported) ||
>> +	    policy->boost_freq_req) {
> Is this if statement written in the wrong place?

Yes right ...

I also forgot to remove the below if conditions as you suggessted


>
>> +		freq_qos_remove_request(policy->boost_freq_req);
>> +		kfree(policy->boost_freq_req);
>> +	}
>> +
>> +	if (policy->max_freq_req)
>> +		freq_qos_remove_request(policy->max_freq_req);
>> +
>>   	freq_qos_remove_request(policy->min_freq_req);
>>   	kfree(policy->min_freq_req);
>>   
>