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Message-ID: <a821c56b-2153-4464-8323-66ba62348f59@wanadoo.fr>
Date: Fri, 5 Jan 2024 15:47:43 +0100
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Subject: Re: [PATCH] thermal: core: Save a few bytes of memory when
 registering a cooling device
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To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>,
 Zhang Rui <rui.zhang@intel.com>, Lukasz Luba <lukasz.luba@arm.com>,
 alexis.lothore@bootlin.com, linux-kernel@vger.kernel.org,
 kernel-janitors@vger.kernel.org, linux-pm@vger.kernel.org
References: <4a3658efad8f6247ed8c477717dc2820b72319d0.1704462287.git.christophe.jaillet@wanadoo.fr>
 <CAJZ5v0hqaJ79BUj_hWDmErCVvJdBJ8o9fcHxcZDyP4+C4iDVxQ@mail.gmail.com>
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
In-Reply-To: <CAJZ5v0hqaJ79BUj_hWDmErCVvJdBJ8o9fcHxcZDyP4+C4iDVxQ@mail.gmail.com>
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Le 05/01/2024 à 14:50, Rafael J. Wysocki a écrit :
> On Fri, Jan 5, 2024 at 2:45 PM Christophe JAILLET
> <christophe.jaillet@wanadoo.fr> wrote:
>>
>> Some *thermal_cooling_device_register() calls pass a string literal as the
>> 'type' parameter.
>>
>> So kstrdup_const() can be used instead of kfree() to avoid a memory
> 
> I guess you mean kstrdup()?

Sure.
Stupid cut'n'paste typo. Thx for catching it.

Should I resend, or can it be fixed if/when the patch is applied?

CJ

> 
>> allocation in such cases.
>>
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>>   drivers/thermal/thermal_core.c | 6 +++---
>>   include/linux/thermal.h        | 2 +-
>>   2 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
>> index fa88d8707241..d21225ddbf10 100644
>> --- a/drivers/thermal/thermal_core.c
>> +++ b/drivers/thermal/thermal_core.c
>> @@ -846,7 +846,7 @@ static void thermal_release(struct device *dev)
>>                              sizeof("cooling_device") - 1)) {
>>                  cdev = to_cooling_device(dev);
>>                  thermal_cooling_device_destroy_sysfs(cdev);
>> -               kfree(cdev->type);
>> +               kfree_const(cdev->type);
>>                  ida_free(&thermal_cdev_ida, cdev->id);
>>                  kfree(cdev);
>>          }
>> @@ -918,7 +918,7 @@ __thermal_cooling_device_register(struct device_node *np,
>>          cdev->id = ret;
>>          id = ret;
>>
>> -       cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
>> +       cdev->type = kstrdup_const(type ? type : "", GFP_KERNEL);
>>          if (!cdev->type) {
>>                  ret = -ENOMEM;
>>                  goto out_ida_remove;
>> @@ -969,7 +969,7 @@ __thermal_cooling_device_register(struct device_node *np,
>>   out_cooling_dev:
>>          thermal_cooling_device_destroy_sysfs(cdev);
>>   out_cdev_type:
>> -       kfree(cdev->type);
>> +       kfree_const(cdev->type);
>>   out_ida_remove:
>>          ida_free(&thermal_cdev_ida, id);
>>   out_kfree_cdev:
>> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
>> index bf84595a4e86..052c72c0fa17 100644
>> --- a/include/linux/thermal.h
>> +++ b/include/linux/thermal.h
>> @@ -102,7 +102,7 @@ struct thermal_cooling_device_ops {
>>
>>   struct thermal_cooling_device {
>>          int id;
>> -       char *type;
>> +       const char *type;
>>          unsigned long max_state;
>>          struct device device;
>>          struct device_node *np;
>> --
>> 2.34.1
>>
> 
>