linux-kernel - Re: [PATCH] thermal: cpu_cooling: Remove usage of devm functions

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Date:	Thu, 27 Aug 2015 07:27:08 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Vaishali Thakkar <vthakkar1994@...il.com>,
	Javi Merino <javi.merino@....com>
Cc:	Zhang Rui <rui.zhang@...el.com>,
	Eduardo Valentin <edubezval@...il.com>,
	Linux PM list <linux-pm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] thermal: cpu_cooling: Remove usage of devm functions

On Wed, Aug 19, 2015 at 11:52 AM, Vaishali Thakkar
<vthakkar1994@...il.com> wrote:
> In the function cpufreq_get_requested_power, the memory allocated
> for load_cpu is live within the function only. And after the
> allocation it is immediately freed with devm_kfree. There is no
> need to allocate memory for load_cpu with devm function so replace
> devm_kcalloc with kcalloc and devm_kfree with kfree.
>
> Signed-off-by: Vaishali Thakkar <vthakkar1994@...il.com>
> ---
> This patch is having one checkpatch.pl warning which suggests that
> kfree(NULL) is safe. But I think leaving code with if is nice
> because it reflects the fact that kcalloc was under an if. So, I
> have ignored checkpatch. If maintainer wants me to go for changing
> things, I am fine with it too.
> ---
>  drivers/thermal/cpu_cooling.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
> index 620dcd4..babf8b3 100644
> --- a/drivers/thermal/cpu_cooling.c
> +++ b/drivers/thermal/cpu_cooling.c
> @@ -584,8 +584,7 @@ static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev,
>         if (trace_thermal_power_cpu_get_power_enabled()) {
>                 u32 ncpus = cpumask_weight(&cpufreq_device->allowed_cpus);
>
> -               load_cpu = devm_kcalloc(&cdev->device, ncpus, sizeof(*load_cpu),
> -                                       GFP_KERNEL);
> +               load_cpu = kcalloc(ncpus, sizeof(*load_cpu), GFP_KERNEL);
>         }
>
>         for_each_cpu(cpu, &cpufreq_device->allowed_cpus) {
> @@ -609,7 +608,7 @@ static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev,
>         ret = get_static_power(cpufreq_device, tz, freq, &static_power);
>         if (ret) {
>                 if (load_cpu)
> -                       devm_kfree(&cdev->device, load_cpu);
> +                       kfree(load_cpu);
>                 return ret;
>         }
>
> @@ -618,7 +617,7 @@ static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev,
>                         &cpufreq_device->allowed_cpus,
>                         freq, load_cpu, i, dynamic_power, static_power);
>
> -               devm_kfree(&cdev->device, load_cpu);
> +               kfree(load_cpu);
>         }
>
>         *power = static_power + dynamic_power;

Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

@Eduardo: Ignore V2 and apply this one :)
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