Re: [PATCH v2 1/2] completion: Add support for initializing completion with lockdep_map

[Byungchul Park <byungchul.park@lge.com>]

On Fri, Sep 08, 2017 at 05:46:24PM +0900, Byungchul Park wrote:
> To peter,
> 
> Does it work?
> 
> Chagnes from v1
>  - Add a completion initialization function with a lockdep map
>  - Enhance readability of the workqueue code

Again, this does not introduce any new things but only does what it
should be done, now that wait_for_completion() includes its lockdep_map.

For 'might' things I introduced, please take a look at another mail
thread where I want to discuss it.

> ----->8-----
> >From e148617e20ebc9c9eefe7bb222b9bba07cb963bc Mon Sep 17 00:00:00 2001
> From: Byungchul Park <byungchul.park@lge.com>
> Date: Fri, 8 Sep 2017 17:39:48 +0900
> Subject: [PATCH v2 1/2] completion: Add support for initializing completion
>  with lockdep_map
> 
> Sometimes, we want to initialize completions with sparate lockdep maps
> to assign lock classes under control. For example, the workqueue code
> manages lockdep maps, as it can classify lockdep maps properly.
> Provided a function for that purpose.
> 
> Signed-off-by: Byungchul Park <byungchul.park@lge.com>
> ---
>  include/linux/completion.h | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/include/linux/completion.h b/include/linux/completion.h
> index cae5400..182d56e 100644
> --- a/include/linux/completion.h
> +++ b/include/linux/completion.h
> @@ -49,6 +49,13 @@ static inline void complete_release_commit(struct completion *x)
>  	lock_commit_crosslock((struct lockdep_map *)&x->map);
>  }
>  
> +#define init_completion_with_map(x, m)					\
> +do {									\
> +	lockdep_init_map_crosslock((struct lockdep_map *)&(x)->map,	\
> +			(m)->name, (m)->key, 0);				\
> +	__init_completion(x);						\
> +} while (0)
> +
>  #define init_completion(x)						\
>  do {									\
>  	static struct lock_class_key __key;				\
> @@ -58,6 +65,7 @@ static inline void complete_release_commit(struct completion *x)
>  	__init_completion(x);						\
>  } while (0)
>  #else
> +#define init_completion_with_map(x, m) __init_completion(x)
>  #define init_completion(x) __init_completion(x)
>  static inline void complete_acquire(struct completion *x) {}
>  static inline void complete_release(struct completion *x) {}
> -- 
> 1.9.1