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* [PATCH net-next] net: rtnetlink: convert rcu_assign_pointer to RCU_INIT_POINTER
@ 2021-09-18  6:36 Yajun Deng
  2021-09-19 12:00 ` patchwork-bot+netdevbpf
  2021-09-23 17:09 ` Eric Dumazet
  0 siblings, 2 replies; 3+ messages in thread
From: Yajun Deng @ 2021-09-18  6:36 UTC (permalink / raw)
  To: davem, kuba; +Cc: netdev, linux-kernel, Yajun Deng

It no need barrier when assigning a NULL value to an RCU protected
pointer. So use RCU_INIT_POINTER() instead for more fast.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
 net/core/rtnetlink.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 972c8cb303a5..327ca6bc6e6d 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -301,7 +301,7 @@ int rtnl_unregister(int protocol, int msgtype)
 	}
 
 	link = rtnl_dereference(tab[msgindex]);
-	rcu_assign_pointer(tab[msgindex], NULL);
+	RCU_INIT_POINTER(tab[msgindex], NULL);
 	rtnl_unlock();
 
 	kfree_rcu(link, rcu);
@@ -337,7 +337,7 @@ void rtnl_unregister_all(int protocol)
 		if (!link)
 			continue;
 
-		rcu_assign_pointer(tab[msgindex], NULL);
+		RCU_INIT_POINTER(tab[msgindex], NULL);
 		kfree_rcu(link, rcu);
 	}
 	rtnl_unlock();
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH net-next] net: rtnetlink: convert rcu_assign_pointer to RCU_INIT_POINTER
  2021-09-18  6:36 [PATCH net-next] net: rtnetlink: convert rcu_assign_pointer to RCU_INIT_POINTER Yajun Deng
@ 2021-09-19 12:00 ` patchwork-bot+netdevbpf
  2021-09-23 17:09 ` Eric Dumazet
  1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-09-19 12:00 UTC (permalink / raw)
  To: Yajun Deng; +Cc: davem, kuba, netdev, linux-kernel

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Sat, 18 Sep 2021 14:36:07 +0800 you wrote:
> It no need barrier when assigning a NULL value to an RCU protected
> pointer. So use RCU_INIT_POINTER() instead for more fast.
> 
> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
> ---
>  net/core/rtnetlink.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Here is the summary with links:
  - [net-next] net: rtnetlink: convert rcu_assign_pointer to RCU_INIT_POINTER
    https://git.kernel.org/netdev/net-next/c/4fc29989835a

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH net-next] net: rtnetlink: convert rcu_assign_pointer to RCU_INIT_POINTER
  2021-09-18  6:36 [PATCH net-next] net: rtnetlink: convert rcu_assign_pointer to RCU_INIT_POINTER Yajun Deng
  2021-09-19 12:00 ` patchwork-bot+netdevbpf
@ 2021-09-23 17:09 ` Eric Dumazet
  1 sibling, 0 replies; 3+ messages in thread
From: Eric Dumazet @ 2021-09-23 17:09 UTC (permalink / raw)
  To: Yajun Deng, davem, kuba; +Cc: netdev, linux-kernel



On 9/17/21 11:36 PM, Yajun Deng wrote:
> It no need barrier when assigning a NULL value to an RCU protected
> pointer. So use RCU_INIT_POINTER() instead for more fast.
> 
> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
> ---
>  net/core/rtnetlink.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index 972c8cb303a5..327ca6bc6e6d 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -301,7 +301,7 @@ int rtnl_unregister(int protocol, int msgtype)
>  	}
>  
>  	link = rtnl_dereference(tab[msgindex]);
> -	rcu_assign_pointer(tab[msgindex], NULL);
> +	RCU_INIT_POINTER(tab[msgindex], NULL);
>  	rtnl_unlock();
>  
>  	kfree_rcu(link, rcu);
> @@ -337,7 +337,7 @@ void rtnl_unregister_all(int protocol)
>  		if (!link)
>  			continue;
>  
> -		rcu_assign_pointer(tab[msgindex], NULL);
> +		RCU_INIT_POINTER(tab[msgindex], NULL);
>  		kfree_rcu(link, rcu);
>  	}
>  	rtnl_unlock();
> 

FYI, there is no memory barrier involved in 

rcu_assign_pointer(tab[msgindex], NULL);

This has been the case for the last 5 years.

Your patch was not needed really.

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-09-23 17:09 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-09-18  6:36 [PATCH net-next] net: rtnetlink: convert rcu_assign_pointer to RCU_INIT_POINTER Yajun Deng
2021-09-19 12:00 ` patchwork-bot+netdevbpf
2021-09-23 17:09 ` Eric Dumazet

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