[v1] locking: Some locking code cleanups

[PATCH 2/4] locking/mutex: Clean up mutex.h

Posted by Waiman Long 1 year, 12 months ago

CONFIG_DEBUG_MUTEXES and CONFIG_PREEMPT_RT are mutually exclusive. They
can't be both set at the same time.  Move down the mutex_destroy()
function declaration to the bottom of mutex.h to eliminate duplicated
mutex_destroy() declaration.

Also remove the duplicated mutex_trylock() function declaration in the
CONFIG_PREEMPT_RT section.

Signed-off-by: Waiman Long <longman@redhat.com>
---
 include/linux/mutex.h | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index 7e208d46ba5b..bad383713db2 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -35,18 +35,10 @@
 #ifndef CONFIG_PREEMPT_RT
 
 #ifdef CONFIG_DEBUG_MUTEXES
-
-#define __DEBUG_MUTEX_INITIALIZER(lockname)				\
+# define __DEBUG_MUTEX_INITIALIZER(lockname)				\
 	, .magic = &lockname
-
-extern void mutex_destroy(struct mutex *lock);
-
 #else
-
 # define __DEBUG_MUTEX_INITIALIZER(lockname)
-
-static inline void mutex_destroy(struct mutex *lock) {}
-
 #endif
 
 /**
@@ -101,9 +93,6 @@ extern bool mutex_is_locked(struct mutex *lock);
 
 extern void __mutex_rt_init(struct mutex *lock, const char *name,
 			    struct lock_class_key *key);
-extern int mutex_trylock(struct mutex *lock);
-
-static inline void mutex_destroy(struct mutex *lock) { }
 
 #define mutex_is_locked(l)	rt_mutex_base_is_locked(&(l)->rtmutex)
 
@@ -170,6 +159,16 @@ extern void mutex_unlock(struct mutex *lock);
 
 extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
 
+#ifdef CONFIG_DEBUG_MUTEXES
+
+extern void mutex_destroy(struct mutex *lock);
+
+#else
+
+static inline void mutex_destroy(struct mutex *lock) {}
+
+#endif
+
 DEFINE_GUARD(mutex, struct mutex *, mutex_lock(_T), mutex_unlock(_T))
 DEFINE_GUARD_COND(mutex, _try, mutex_trylock(_T))
 DEFINE_GUARD_COND(mutex, _intr, mutex_lock_interruptible(_T) == 0)
-- 
2.39.3

Re: [PATCH 2/4] locking/mutex: Clean up mutex.h

Posted by Boqun Feng 1 year, 11 months ago

On Mon, Feb 12, 2024 at 10:16:54PM -0500, Waiman Long wrote:
> CONFIG_DEBUG_MUTEXES and CONFIG_PREEMPT_RT are mutually exclusive. They
> can't be both set at the same time.  Move down the mutex_destroy()
> function declaration to the bottom of mutex.h to eliminate duplicated
> mutex_destroy() declaration.
> 
> Also remove the duplicated mutex_trylock() function declaration in the
> CONFIG_PREEMPT_RT section.
> 
> Signed-off-by: Waiman Long <longman@redhat.com>

Reviewed-by: Boqun Feng <boqun.feng@gmail.com>

Although, can you move the first "#ifdef CONFIG_DEBUG_MUTEXES" out of
the "#ifndef CONFIG_PREEMPT_RT" and combine it with the second one, i.e.

	#ifdef CONFIG_DEBUG_MUTEXES
	# define __DEBUG_MUTEX_INITIALIZER(lockname) ...
	extern void mutex_destroy(struct mutex *lock);
	#else
	# define __DEBUG_MUTEX_INITIALIZER(lockname) ..
	static inline void mutex_destroy(struct mutex *lock) {}
	#endif

	#ifndef CONFIG_PREEMPT_RT
	...

Thoughts?

Regards,
Boqun

> ---
>  include/linux/mutex.h | 23 +++++++++++------------
>  1 file changed, 11 insertions(+), 12 deletions(-)
> 
> diff --git a/include/linux/mutex.h b/include/linux/mutex.h
> index 7e208d46ba5b..bad383713db2 100644
> --- a/include/linux/mutex.h
> +++ b/include/linux/mutex.h
> @@ -35,18 +35,10 @@
>  #ifndef CONFIG_PREEMPT_RT
>  
>  #ifdef CONFIG_DEBUG_MUTEXES
> -
> -#define __DEBUG_MUTEX_INITIALIZER(lockname)				\
> +# define __DEBUG_MUTEX_INITIALIZER(lockname)				\
>  	, .magic = &lockname
> -
> -extern void mutex_destroy(struct mutex *lock);
> -
>  #else
> -
>  # define __DEBUG_MUTEX_INITIALIZER(lockname)
> -
> -static inline void mutex_destroy(struct mutex *lock) {}
> -
>  #endif
>  
>  /**
> @@ -101,9 +93,6 @@ extern bool mutex_is_locked(struct mutex *lock);
>  
>  extern void __mutex_rt_init(struct mutex *lock, const char *name,
>  			    struct lock_class_key *key);
> -extern int mutex_trylock(struct mutex *lock);
> -
> -static inline void mutex_destroy(struct mutex *lock) { }
>  
>  #define mutex_is_locked(l)	rt_mutex_base_is_locked(&(l)->rtmutex)
>  
> @@ -170,6 +159,16 @@ extern void mutex_unlock(struct mutex *lock);
>  
>  extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
>  
> +#ifdef CONFIG_DEBUG_MUTEXES
> +
> +extern void mutex_destroy(struct mutex *lock);
> +
> +#else
> +
> +static inline void mutex_destroy(struct mutex *lock) {}
> +
> +#endif
> +
>  DEFINE_GUARD(mutex, struct mutex *, mutex_lock(_T), mutex_unlock(_T))
>  DEFINE_GUARD_COND(mutex, _try, mutex_trylock(_T))
>  DEFINE_GUARD_COND(mutex, _intr, mutex_lock_interruptible(_T) == 0)
> -- 
> 2.39.3
>

Re: [PATCH 2/4] locking/mutex: Clean up mutex.h

Posted by Waiman Long 1 year, 11 months ago

On 2/21/24 23:33, Boqun Feng wrote:
> On Mon, Feb 12, 2024 at 10:16:54PM -0500, Waiman Long wrote:
>> CONFIG_DEBUG_MUTEXES and CONFIG_PREEMPT_RT are mutually exclusive. They
>> can't be both set at the same time.  Move down the mutex_destroy()
>> function declaration to the bottom of mutex.h to eliminate duplicated
>> mutex_destroy() declaration.
>>
>> Also remove the duplicated mutex_trylock() function declaration in the
>> CONFIG_PREEMPT_RT section.
>>
>> Signed-off-by: Waiman Long <longman@redhat.com>
> Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
>
> Although, can you move the first "#ifdef CONFIG_DEBUG_MUTEXES" out of
> the "#ifndef CONFIG_PREEMPT_RT" and combine it with the second one, i.e.
>
> 	#ifdef CONFIG_DEBUG_MUTEXES
> 	# define __DEBUG_MUTEX_INITIALIZER(lockname) ...
> 	extern void mutex_destroy(struct mutex *lock);
> 	#else
> 	# define __DEBUG_MUTEX_INITIALIZER(lockname) ..
> 	static inline void mutex_destroy(struct mutex *lock) {}
> 	#endif
>
> 	#ifndef CONFIG_PREEMPT_RT
> 	...
>
> Thoughts?

Sure. I can move it up and combine the two pieces.

Thanks for the review.

Cheers,
Longman

>
> Regards,
> Boqun
>
>> ---
>>   include/linux/mutex.h | 23 +++++++++++------------
>>   1 file changed, 11 insertions(+), 12 deletions(-)
>>
>> diff --git a/include/linux/mutex.h b/include/linux/mutex.h
>> index 7e208d46ba5b..bad383713db2 100644
>> --- a/include/linux/mutex.h
>> +++ b/include/linux/mutex.h
>> @@ -35,18 +35,10 @@
>>   #ifndef CONFIG_PREEMPT_RT
>>   
>>   #ifdef CONFIG_DEBUG_MUTEXES
>> -
>> -#define __DEBUG_MUTEX_INITIALIZER(lockname)				\
>> +# define __DEBUG_MUTEX_INITIALIZER(lockname)				\
>>   	, .magic = &lockname
>> -
>> -extern void mutex_destroy(struct mutex *lock);
>> -
>>   #else
>> -
>>   # define __DEBUG_MUTEX_INITIALIZER(lockname)
>> -
>> -static inline void mutex_destroy(struct mutex *lock) {}
>> -
>>   #endif
>>   
>>   /**
>> @@ -101,9 +93,6 @@ extern bool mutex_is_locked(struct mutex *lock);
>>   
>>   extern void __mutex_rt_init(struct mutex *lock, const char *name,
>>   			    struct lock_class_key *key);
>> -extern int mutex_trylock(struct mutex *lock);
>> -
>> -static inline void mutex_destroy(struct mutex *lock) { }
>>   
>>   #define mutex_is_locked(l)	rt_mutex_base_is_locked(&(l)->rtmutex)
>>   
>> @@ -170,6 +159,16 @@ extern void mutex_unlock(struct mutex *lock);
>>   
>>   extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
>>   
>> +#ifdef CONFIG_DEBUG_MUTEXES
>> +
>> +extern void mutex_destroy(struct mutex *lock);
>> +
>> +#else
>> +
>> +static inline void mutex_destroy(struct mutex *lock) {}
>> +
>> +#endif
>> +
>>   DEFINE_GUARD(mutex, struct mutex *, mutex_lock(_T), mutex_unlock(_T))
>>   DEFINE_GUARD_COND(mutex, _try, mutex_trylock(_T))
>>   DEFINE_GUARD_COND(mutex, _intr, mutex_lock_interruptible(_T) == 0)
>> -- 
>> 2.39.3
>>