linux-kernel - Re: [PATCH v4 03/10] cpufreq: intel_pstate: Use scope-based cleanup helper

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Message-ID: <20250905104743.00004177@huawei.com>
Date: Fri, 5 Sep 2025 10:47:43 +0100
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: Zihuan Zhang <zhangzihuan@...inos.cn>
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Subject: Re: [PATCH v4 03/10] cpufreq: intel_pstate: Use scope-based cleanup
 helper

On Wed,  3 Sep 2025 21:17:26 +0800
Zihuan Zhang <zhangzihuan@...inos.cn> wrote:

> Replace the manual cpufreq_cpu_put() with __free(put_cpufreq_policy)
> annotation for policy references. This reduces the risk of reference
> counting mistakes and aligns the code with the latest kernel style.
> 
> No functional change intended.
> 
> Signed-off-by: Zihuan Zhang <zhangzihuan@...inos.cn>

One trivial comment inline.  This LGTM
Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>

> ---
>  drivers/cpufreq/intel_pstate.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index f366d35c5840..925efb1e65be 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -1209,6 +1209,17 @@ static bool hybrid_clear_max_perf_cpu(void)
>  	return ret;
>  }
>  
> +static struct freq_qos_request *intel_pstate_cpufreq_get_req(int cpu)
> +{
> +	struct cpufreq_policy *policy __free(put_cpufreq_policy) =
> +		cpufreq_cpu_get(cpu);
> +
> +	if (!policy)
> +		return NULL;
> +
> +	return policy->driver_data;
> +}
> +
>  static void __intel_pstate_get_hwp_cap(struct cpudata *cpu)
>  {
>  	u64 cap;
> @@ -1698,19 +1709,13 @@ static ssize_t store_no_turbo(struct kobject *a, struct kobj_attribute *b,
>  static void update_qos_request(enum freq_qos_req_type type)
>  {
>  	struct freq_qos_request *req;
> -	struct cpufreq_policy *policy;
>  	int i;
>  
>  	for_each_possible_cpu(i) {
>  		struct cpudata *cpu = all_cpu_data[i];
>  		unsigned int freq, perf_pct;
>  
> -		policy = cpufreq_cpu_get(i);
> -		if (!policy)
> -			continue;
> -
> -		req = policy->driver_data;
> -		cpufreq_cpu_put(policy);
> +		req = intel_pstate_cpufreq_get_req(i);
>  

I'd drop this blank line as it'll keep the setting or req and checking it
closely coupled.  Previously the put inbetween stopped that but now
we can improve the formatting!

>  		if (!req)
>  			continue;