linux-kernel - Re: [PATCH v4 04/10] cpufreq: powernv: Use scope-based cleanup helper

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Message-ID: <20250905104952.00002f58@huawei.com>
Date: Fri, 5 Sep 2025 10:49:52 +0100
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: Zihuan Zhang <zhangzihuan@...inos.cn>
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Subject: Re: [PATCH v4 04/10] cpufreq: powernv: Use scope-based cleanup
 helper

On Wed,  3 Sep 2025 21:17:27 +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>
This one is a little more weak wrt to justification.  Kernel style
isn't to use __free() where there isn't a significant benefit.

Up to maintainer of the driver on this one so I'll not offer
a tag.

> ---
>  drivers/cpufreq/powernv-cpufreq.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index 7d9a5f656de8..811fdbf398fa 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -892,15 +892,15 @@ static int powernv_cpufreq_reboot_notifier(struct notifier_block *nb,
>  				unsigned long action, void *unused)
>  {
>  	int cpu;
> -	struct cpufreq_policy *cpu_policy;
>  
>  	rebooting = true;
>  	for_each_online_cpu(cpu) {
> -		cpu_policy = cpufreq_cpu_get(cpu);
> +		struct cpufreq_policy *cpu_policy __free(put_cpufreq_policy) =
> +			cpufreq_cpu_get(cpu);
> +
>  		if (!cpu_policy)
>  			continue;
>  		powernv_cpufreq_target_index(cpu_policy, get_nominal_index());
> -		cpufreq_cpu_put(cpu_policy);
>  	}
>  
>  	return NOTIFY_DONE;
> @@ -913,7 +913,6 @@ static struct notifier_block powernv_cpufreq_reboot_nb = {
>  static void powernv_cpufreq_work_fn(struct work_struct *work)
>  {
>  	struct chip *chip = container_of(work, struct chip, throttle);
> -	struct cpufreq_policy *policy;
>  	unsigned int cpu;
>  	cpumask_t mask;
>  
> @@ -928,14 +927,14 @@ static void powernv_cpufreq_work_fn(struct work_struct *work)
>  	chip->restore = false;
>  	for_each_cpu(cpu, &mask) {
>  		int index;
> +		struct cpufreq_policy *policy __free(put_cpufreq_policy) =
> +			cpufreq_cpu_get(cpu);
>  
> -		policy = cpufreq_cpu_get(cpu);
>  		if (!policy)
>  			continue;
>  		index = cpufreq_table_find_index_c(policy, policy->cur, false);
>  		powernv_cpufreq_target_index(policy, index);
>  		cpumask_andnot(&mask, &mask, policy->cpus);
> -		cpufreq_cpu_put(policy);
>  	}
>  out:
>  	cpus_read_unlock();