From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: "pavel@ucw.cz" <pavel@ucw.cz>, "lee@kernel.org" <lee@kernel.org>,
"vadimp@nvidia.com" <vadimp@nvidia.com>,
"mpe@ellerman.id.au" <mpe@ellerman.id.au>,
"npiggin@gmail.com" <npiggin@gmail.com>,
"hdegoede@redhat.com" <hdegoede@redhat.com>,
"mazziesaccount@gmail.com" <mazziesaccount@gmail.com>,
"peterz@infradead.org" <peterz@infradead.org>,
"mingo@redhat.com" <mingo@redhat.com>,
"will@kernel.org" <will@kernel.org>,
"longman@redhat.com" <longman@redhat.com>,
"boqun.feng@gmail.com" <boqun.feng@gmail.com>,
"nikitos.tr@gmail.com" <nikitos.tr@gmail.com>,
George Stark <gnstark@salutedevices.com>,
"kernel@salutedevices.com" <kernel@salutedevices.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-leds@vger.kernel.org" <linux-leds@vger.kernel.org>
Subject: Re: [PATCH RFC v4-bis] locking: introduce devm_mutex_init
Date: Fri, 15 Dec 2023 17:51:37 +0000 [thread overview]
Message-ID: <8688dfe9-4a94-44af-a12c-7c238ab9dcad@csgroup.eu> (raw)
In-Reply-To: <CAHp75VfBcmTBXXtU6o1x0Ea24wG-_Qb46opkS0EXKQ1Ynh0Mcw@mail.gmail.com>
Le 15/12/2023 à 16:58, Andy Shevchenko a écrit :
> On Fri, Dec 15, 2023 at 8:23 AM Christophe Leroy
> <christophe.leroy@csgroup.eu> wrote:
>>
>> From: George Stark <gnstark@salutedevices.com>
>>
>> Using of devm API leads to a certain order of releasing resources.
>> So all dependent resources which are not devm-wrapped should be deleted
>> with respect to devm-release order. Mutex is one of such objects that
>> often is bound to other resources and has no own devm wrapping.
>> Since mutex_destroy() actually does nothing in non-debug builds
>> frequently calling mutex_destroy() is just ignored which is safe for now
>> but wrong formally and can lead to a problem if mutex_destroy() will be
>> extended so introduce devm_mutex_init()
>
> Missing period.
>
> ...
>
>> } while (0)
>> #endif /* CONFIG_PREEMPT_RT */
>
> ^^^ (1)
>
>> +struct device;
>> +
>> +/*
>> + * devm_mutex_init() registers a function that calls mutex_destroy()
>> + * when the ressource is released.
>> + *
>> + * When mutex_destroy() is a not, there is no need to register that
>> + * function.
>> + */
>> +#ifdef CONFIG_DEBUG_MUTEXES
>
> Shouldn't this be
>
> #if defined(CONFIG_DEBUG_MUTEXES) && !defined(CONFIG_PREEMPT_RT)
>
> (see (1) as well)?
Isn't needed, handled by Kconfig:
config DEBUG_MUTEXES
bool "Mutex debugging: basic checks"
depends on DEBUG_KERNEL && !PREEMPT_RT
>
>> +void mutex_destroy(struct mutex *lock);
>> +int devm_mutex_init(struct device *dev, struct mutex *lock);
>> +#else
>> +static inline void mutex_destroy(struct mutex *lock) {}
>> +
>> +static inline int devm_mutex_init(struct device *dev, struct mutex *lock)
>> +{
>> + mutex_init(lock);
>> + return 0;
>> +}
>> +#endif
>
next prev parent reply other threads:[~2023-12-15 17:51 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-14 17:36 [PATCH v4 00/10] devm_led_classdev_register() usage problem George Stark
2023-12-14 17:36 ` [PATCH v4 01/10] leds: aw2013: unlock mutex before destroying it George Stark
2024-02-23 15:07 ` (subset) " Lee Jones
2023-12-14 17:36 ` [PATCH v4 02/10] locking: introduce devm_mutex_init George Stark
2023-12-14 18:48 ` Waiman Long
2023-12-14 19:53 ` Christophe Leroy
2023-12-14 21:48 ` Waiman Long
2023-12-15 5:46 ` Christophe Leroy
2023-12-17 1:05 ` George Stark
2023-12-17 9:31 ` Christophe Leroy
2023-12-18 13:26 ` George Stark
2023-12-14 19:47 ` Christophe Leroy
2023-12-15 6:22 ` [PATCH RFC v4-bis] " Christophe Leroy
2023-12-15 15:58 ` Andy Shevchenko
2023-12-15 17:51 ` Christophe Leroy [this message]
2023-12-16 1:30 ` Waiman Long
2023-12-14 17:36 ` [PATCH v4 03/10] leds: aw2013: use devm API to cleanup module's resources George Stark
2023-12-14 17:36 ` [PATCH v4 04/10] leds: aw200xx: " George Stark
2023-12-14 17:36 ` [PATCH v4 05/10] leds: lp3952: " George Stark
2023-12-14 17:36 ` [PATCH v4 06/10] leds: lm3532: " George Stark
2023-12-14 17:36 ` [PATCH v4 07/10] leds: nic78bx: " George Stark
2023-12-14 17:36 ` [PATCH v4 08/10] leds: mlxreg: use devm_mutex_init for mutex initializtion George Stark
2023-12-14 17:36 ` [PATCH v4 09/10] leds: an30259a: use devm_mutext_init for mutext initialization George Stark
2023-12-14 17:36 ` [PATCH v4 10/10] leds: powernv: use LED_RETAIN_AT_SHUTDOWN flag for leds George Stark
2023-12-21 15:11 ` [PATCH v4 00/10] devm_led_classdev_register() usage problem Lee Jones
2024-02-09 17:11 ` Andy Shevchenko
2024-02-11 23:52 ` [DMARC error][SPF error] " George Stark
2024-02-12 9:53 ` Andy Shevchenko
2024-02-13 0:14 ` George Stark
2024-02-13 10:55 ` Andy Shevchenko
2024-02-13 23:56 ` George Stark
2024-02-09 17:17 ` Andy Shevchenko
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