Re: [PATCH] sched/fair: Only apply cpufreq pressure where frequency is invariant

[K Prateek Nayak]

Hello Hongyan,

On 9/9/2026 9:39 AM, Hongyan Xia wrote:
>> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
>> index b898b6544069..97f4a3ba5107 100644
>> --- a/drivers/cpufreq/cpufreq.c
>> +++ b/drivers/cpufreq/cpufreq.c
>> @@ -2586,8 +2586,11 @@ static void cpufreq_update_pressure(struct cpufreq_policy *policy)
>>   
>>   	cpu = cpumask_first(policy->related_cpus);
>>   	max_freq = arch_scale_freq_ref(cpu);
>> -	if (!max_freq)
>> -		max_freq = policy->cpuinfo.max_freq;
>> +	if (!max_freq) {
>> +		max_freq = __resolve_freq(policy, policy->cpuinfo.max_freq,
>> +					  policy->cpuinfo.min_freq, policy->cpuinfo.max_freq,
>> +					  CPUFREQ_RELATION_H);
>> +	}
>>   
>>   	capped_freq = policy->max;
>>   
> 
> LGTM.

Thanks a ton for taking a look at the suggestion.

> 
> NIT: I do wonder if we need a full __resolve_freq() each time. We could 
> cache the highest achievable OPP on max_freq updates, but that's future 
> optimization.

Sure! We can cache it in the policy object during
cpufreq_policy_online().

Jianyong Wu would like to take a stab at it? If not, I can send it out
early next week.

-- 
Thanks and Regards,
Prateek

Disclaimer: Hygon emails are routed differently in our organization.
Response might be slightly delayed until my NNTP rule finds the email.
Sorry for any inconvenience.