PM / Wakeup: remove useless synchronize_rcu() call

PM / Wakeup: remove useless synchronize_rcu() call

[Eric Dumazet]

wakeup_source_add() adds an item into wakeup_sources list.

There is no need to call synchronize_rcu() at this point.

Its only needed in wakeup_source_remove()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: David Miller <davem@davemloft.net>,
CC: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/base/power/wakeup.c |    1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index abbbd33..84f7c7d 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -110,7 +110,6 @@ void wakeup_source_add(struct wakeup_source *ws)
 	spin_lock_irq(&events_lock);
 	list_add_rcu(&ws->entry, &wakeup_sources);
 	spin_unlock_irq(&events_lock);
-	synchronize_rcu();
 }
 EXPORT_SYMBOL_GPL(wakeup_source_add);
 

Re: PM / Wakeup: remove useless synchronize_rcu() call

[Rafael J. Wysocki]

On Wednesday, May 11, 2011, Eric Dumazet wrote:
> wakeup_source_add() adds an item into wakeup_sources list.
> 
> There is no need to call synchronize_rcu() at this point.
> 
> Its only needed in wakeup_source_remove()
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
> CC: David Miller <davem@davemloft.net>,
> CC: Greg Kroah-Hartman <gregkh@suse.de>

Applied to suspend-2.6/linux-next.

Thanks,
Rafael


> ---
>  drivers/base/power/wakeup.c |    1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> index abbbd33..84f7c7d 100644
> --- a/drivers/base/power/wakeup.c
> +++ b/drivers/base/power/wakeup.c
> @@ -110,7 +110,6 @@ void wakeup_source_add(struct wakeup_source *ws)
>  	spin_lock_irq(&events_lock);
>  	list_add_rcu(&ws->entry, &wakeup_sources);
>  	spin_unlock_irq(&events_lock);
> -	synchronize_rcu();
>  }
>  EXPORT_SYMBOL_GPL(wakeup_source_add);
>  
> 
> 
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Re: PM / Wakeup: remove useless synchronize_rcu() call

[Paul E. McKenney]

On Wed, May 11, 2011 at 10:15:59PM +0200, Eric Dumazet wrote:
> wakeup_source_add() adds an item into wakeup_sources list.
> 
> There is no need to call synchronize_rcu() at this point.
> 
> Its only needed in wakeup_source_remove()
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

> CC: David Miller <davem@davemloft.net>,
> CC: Greg Kroah-Hartman <gregkh@suse.de>
> ---
>  drivers/base/power/wakeup.c |    1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> index abbbd33..84f7c7d 100644
> --- a/drivers/base/power/wakeup.c
> +++ b/drivers/base/power/wakeup.c
> @@ -110,7 +110,6 @@ void wakeup_source_add(struct wakeup_source *ws)
>  	spin_lock_irq(&events_lock);
>  	list_add_rcu(&ws->entry, &wakeup_sources);
>  	spin_unlock_irq(&events_lock);
> -	synchronize_rcu();
>  }
>  EXPORT_SYMBOL_GPL(wakeup_source_add);
> 
> 
>