diff mbox

[v3,05/12] locking/ww_mutex: Remove the __ww_mutex_lock inline wrappers

Message ID 1482346000-9927-6-git-send-email-nhaehnle@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Nicolai Hähnle Dec. 21, 2016, 6:46 p.m. UTC 
From: Nicolai Hähnle <Nicolai.Haehnle@amd.com>

Keep the documentation in the header file since there is no good
place for it in mutex.c: there are two rather different
implementations with different EXPORT_SYMBOLs for each function.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Maarten Lankhorst <dev@mblankhorst.nl>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
---
 include/linux/ww_mutex.h | 18 ++++--------------
 kernel/locking/mutex.c   | 16 ++++++++--------
 2 files changed, 12 insertions(+), 22 deletions(-)

Comments

Peter Zijlstra Dec. 23, 2016, 10:48 a.m. UTC | #1 
On Wed, Dec 21, 2016 at 07:46:33PM +0100, Nicolai Hähnle wrote:
> diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h
> index a5960e5..b2eaaab 100644
> --- a/include/linux/ww_mutex.h
> +++ b/include/linux/ww_mutex.h
> @@ -186,11 +186,6 @@ static inline void ww_acquire_fini(struct ww_acquire_ctx *ctx)
>  #endif
>  }
>  
> -extern int __must_check __ww_mutex_lock(struct ww_mutex *lock,
> -					struct ww_acquire_ctx *ctx);
> -extern int __must_check __ww_mutex_lock_interruptible(struct ww_mutex *lock,
> -						      struct ww_acquire_ctx *ctx);
> -
>  /**
>   * ww_mutex_lock - acquire the w/w mutex
>   * @lock: the mutex to be acquired
> @@ -220,10 +215,8 @@ extern int __must_check __ww_mutex_lock_interruptible(struct ww_mutex *lock,
>   *
>   * A mutex acquired with this function must be released with ww_mutex_unlock.
>   */
> -static inline int ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
> -{
> -	return __ww_mutex_lock(lock, ctx);
> -}
> +extern int __must_check ww_mutex_lock(struct ww_mutex *lock,
> +				      struct ww_acquire_ctx *ctx);
>  
>  /**
>   * ww_mutex_lock_interruptible - acquire the w/w mutex, interruptible
> @@ -255,11 +248,8 @@ static inline int ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ct
>   *
>   * A mutex acquired with this function must be released with ww_mutex_unlock.
>   */
> -static inline int __must_check ww_mutex_lock_interruptible(struct ww_mutex *lock,
> -							   struct ww_acquire_ctx *ctx)
> -{
> -	return __ww_mutex_lock_interruptible(lock, ctx);
> -}
> +extern int __must_check ww_mutex_lock_interruptible(struct ww_mutex *lock,
> +						    struct ww_acquire_ctx *ctx);
>  
>  /**
>   * ww_mutex_lock_slow - slowpath acquiring of the w/w mutex
> diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
> index a41bec2..282c6de 100644

For some reason this patch appears to make lib/locking-selftest.c really
unhappy.

I get endless streams of:

../lib/locking-selftest.c: In function ‘ww_test_fail_acquire’:
../lib/locking-selftest.c:1141:6: error: void value not ignored as it ought to be
  ret = WWL(&o, &t);
      ^

Apparently GCC gets confused about __much_check on inline functions or
something, or I got the patch wrong.
Nicolai Hähnle Dec. 23, 2016, 11:16 a.m. UTC | #2 
On 23.12.2016 11:48, Peter Zijlstra wrote:
> On Wed, Dec 21, 2016 at 07:46:33PM +0100, Nicolai Hähnle wrote:
>> diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h
>> index a5960e5..b2eaaab 100644
>> --- a/include/linux/ww_mutex.h
>> +++ b/include/linux/ww_mutex.h
>> @@ -186,11 +186,6 @@ static inline void ww_acquire_fini(struct ww_acquire_ctx *ctx)
>>  #endif
>>  }
>>
>> -extern int __must_check __ww_mutex_lock(struct ww_mutex *lock,
>> -					struct ww_acquire_ctx *ctx);
>> -extern int __must_check __ww_mutex_lock_interruptible(struct ww_mutex *lock,
>> -						      struct ww_acquire_ctx *ctx);
>> -
>>  /**
>>   * ww_mutex_lock - acquire the w/w mutex
>>   * @lock: the mutex to be acquired
>> @@ -220,10 +215,8 @@ extern int __must_check __ww_mutex_lock_interruptible(struct ww_mutex *lock,
>>   *
>>   * A mutex acquired with this function must be released with ww_mutex_unlock.
>>   */
>> -static inline int ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
>> -{
>> -	return __ww_mutex_lock(lock, ctx);
>> -}
>> +extern int __must_check ww_mutex_lock(struct ww_mutex *lock,
>> +				      struct ww_acquire_ctx *ctx);
>>
>>  /**
>>   * ww_mutex_lock_interruptible - acquire the w/w mutex, interruptible
>> @@ -255,11 +248,8 @@ static inline int ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ct
>>   *
>>   * A mutex acquired with this function must be released with ww_mutex_unlock.
>>   */
>> -static inline int __must_check ww_mutex_lock_interruptible(struct ww_mutex *lock,
>> -							   struct ww_acquire_ctx *ctx)
>> -{
>> -	return __ww_mutex_lock_interruptible(lock, ctx);
>> -}
>> +extern int __must_check ww_mutex_lock_interruptible(struct ww_mutex *lock,
>> +						    struct ww_acquire_ctx *ctx);
>>
>>  /**
>>   * ww_mutex_lock_slow - slowpath acquiring of the w/w mutex
>> diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
>> index a41bec2..282c6de 100644
>
> For some reason this patch appears to make lib/locking-selftest.c really
> unhappy.
>
> I get endless streams of:
>
> ../lib/locking-selftest.c: In function ‘ww_test_fail_acquire’:
> ../lib/locking-selftest.c:1141:6: error: void value not ignored as it ought to be
>   ret = WWL(&o, &t);
>       ^
>
> Apparently GCC gets confused about __much_check on inline functions or
> something, or I got the patch wrong.

Weird, I'm not getting that, and it makes no sense either from a quick 
glimpse of the code. Is there anything beside 
CONFIG_DEBUG_LOCKING_API_SELFTESTS I would have to enable to trigger 
this? FWIW:

$ gcc --version
gcc (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609

>
>
Peter Zijlstra Dec. 23, 2016, 12:13 p.m. UTC | #3 
On Fri, Dec 23, 2016 at 12:16:03PM +0100, Nicolai Hähnle wrote:

> >For some reason this patch appears to make lib/locking-selftest.c really
> >unhappy.
> >
> >I get endless streams of:
> >
> >../lib/locking-selftest.c: In function ‘ww_test_fail_acquire’:
> >../lib/locking-selftest.c:1141:6: error: void value not ignored as it ought to be
> >  ret = WWL(&o, &t);
> >      ^
> >
> >Apparently GCC gets confused about __much_check on inline functions or
> >something, or I got the patch wrong.
> 
> Weird, I'm not getting that, and it makes no sense either from a quick
> glimpse of the code. Is there anything beside
> CONFIG_DEBUG_LOCKING_API_SELFTESTS I would have to enable to trigger this?

Not entirely sure, I'm building an allmodconfig.

> FWIW:
> 
> $ gcc --version
> gcc (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609

gcc (Debian 6.2.1-5) 6.2.1 20161124
diff mbox

Patch

diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h
index a5960e5..b2eaaab 100644
--- a/include/linux/ww_mutex.h
+++ b/include/linux/ww_mutex.h
@@ -186,11 +186,6 @@  static inline void ww_acquire_fini(struct ww_acquire_ctx *ctx)
 #endif
 }
 
-extern int __must_check __ww_mutex_lock(struct ww_mutex *lock,
-					struct ww_acquire_ctx *ctx);
-extern int __must_check __ww_mutex_lock_interruptible(struct ww_mutex *lock,
-						      struct ww_acquire_ctx *ctx);
-
 /**
  * ww_mutex_lock - acquire the w/w mutex
  * @lock: the mutex to be acquired
@@ -220,10 +215,8 @@  extern int __must_check __ww_mutex_lock_interruptible(struct ww_mutex *lock,
  *
  * A mutex acquired with this function must be released with ww_mutex_unlock.
  */
-static inline int ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
-{
-	return __ww_mutex_lock(lock, ctx);
-}
+extern int __must_check ww_mutex_lock(struct ww_mutex *lock,
+				      struct ww_acquire_ctx *ctx);
 
 /**
  * ww_mutex_lock_interruptible - acquire the w/w mutex, interruptible
@@ -255,11 +248,8 @@  static inline int ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ct
  *
  * A mutex acquired with this function must be released with ww_mutex_unlock.
  */
-static inline int __must_check ww_mutex_lock_interruptible(struct ww_mutex *lock,
-							   struct ww_acquire_ctx *ctx)
-{
-	return __ww_mutex_lock_interruptible(lock, ctx);
-}
+extern int __must_check ww_mutex_lock_interruptible(struct ww_mutex *lock,
+						    struct ww_acquire_ctx *ctx);
 
 /**
  * ww_mutex_lock_slow - slowpath acquiring of the w/w mutex
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index a41bec2..282c6de 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -818,7 +818,7 @@  ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 }
 
 int __sched
-__ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
 	int ret;
 
@@ -831,10 +831,10 @@  __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(__ww_mutex_lock);
+EXPORT_SYMBOL_GPL(ww_mutex_lock);
 
 int __sched
-__ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
 	int ret;
 
@@ -848,7 +848,7 @@  __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(__ww_mutex_lock_interruptible);
+EXPORT_SYMBOL_GPL(ww_mutex_lock_interruptible);
 
 #endif
 
@@ -1025,7 +1025,7 @@  EXPORT_SYMBOL(mutex_trylock);
 
 #ifndef CONFIG_DEBUG_LOCK_ALLOC
 int __sched
-__ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
 	might_sleep();
 
@@ -1037,10 +1037,10 @@  __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 
 	return __ww_mutex_lock_slowpath(lock, ctx);
 }
-EXPORT_SYMBOL(__ww_mutex_lock);
+EXPORT_SYMBOL(ww_mutex_lock);
 
 int __sched
-__ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
 	might_sleep();
 
@@ -1052,7 +1052,7 @@  __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 
 	return __ww_mutex_lock_interruptible_slowpath(lock, ctx);
 }
-EXPORT_SYMBOL(__ww_mutex_lock_interruptible);
+EXPORT_SYMBOL(ww_mutex_lock_interruptible);
 
 #endif