Re: [PATCH] rcu: Add lock annotations to RCU locking primitives

["Paul E. McKenney" <paulmck@us.ibm.com>]

On Thu, Jun 29, 2006 at 02:39:23PM -0700, Josh Triplett wrote:
> Add __acquire annotations to rcu_read_lock and rcu_read_lock_bh, and add
> __release annotations to rcu_read_unlock and rcu_read_unlock_bh.  This allows
> sparse to detect improperly paired calls to these functions.

I will take whatever automated help I can get!!!

Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
> Signed-off-by: Josh Triplett <josh@freedesktop.org>
> 
> ---
> 
>  include/linux/rcupdate.h |   24 ++++++++++++++++++++----
>  1 files changed, 20 insertions(+), 4 deletions(-)
> 
> 0a6ff66d5cf24cf6106c933e1f183687358ebc7e
> diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
> index 48dfe00..b4ca73d 100644
> --- a/include/linux/rcupdate.h
> +++ b/include/linux/rcupdate.h
> @@ -163,14 +163,22 @@ extern int rcu_needs_cpu(int cpu);
>   *
>   * It is illegal to block while in an RCU read-side critical section.
>   */
> -#define rcu_read_lock()		preempt_disable()
> +#define rcu_read_lock() \
> +	do { \
> +		preempt_disable(); \
> +		__acquire(RCU); \
> +	} while(0)
>  
>  /**
>   * rcu_read_unlock - marks the end of an RCU read-side critical section.
>   *
>   * See rcu_read_lock() for more information.
>   */
> -#define rcu_read_unlock()	preempt_enable()
> +#define rcu_read_unlock() \
> +	do { \
> +		__release(RCU); \
> +		preempt_enable(); \
> +	} while(0)
>  
>  /*
>   * So where is rcu_write_lock()?  It does not exist, as there is no
> @@ -193,14 +201,22 @@ #define rcu_read_unlock()	preempt_enable
>   * can use just rcu_read_lock().
>   *
>   */
> -#define rcu_read_lock_bh()	local_bh_disable()
> +#define rcu_read_lock_bh() \
> +	do { \
> +		local_bh_disable(); \
> +		__acquire(RCU_BH); \
> +	} while(0)
>  
>  /*
>   * rcu_read_unlock_bh - marks the end of a softirq-only RCU critical section
>   *
>   * See rcu_read_lock_bh() for more information.
>   */
> -#define rcu_read_unlock_bh()	local_bh_enable()
> +#define rcu_read_unlock_bh() \
> +	do { \
> +		__release(RCU_BH); \
> +		local_bh_enable(); \
> +	} while(0)
>  
>  /**
>   * rcu_dereference - fetch an RCU-protected pointer in an
> 
>