2021-11-22 08:49:54

by Yajun Deng

Subject: [PATCH net-next] neighbor: Remove redundant if statement

The if statement already exists in the __neigh_event_send() function,
remove redundant if statement.

Signed-off-by: Yajun Deng <[email protected]>
---
include/net/neighbour.h | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 38a0c1d24570..667129827816 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -452,9 +452,7 @@ static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)

if (READ_ONCE(neigh->used) != now)
WRITE_ONCE(neigh->used, now);
- if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
- return __neigh_event_send(neigh, skb);
- return 0;
+ return __neigh_event_send(neigh, skb);
}

#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
--
2.32.0

2021-11-22 09:17:00

by Joe Perches

Subject: Re: [PATCH net-next] neighbor: Remove redundant if statement

On Mon, 2021-11-22 at 16:49 +0800, Yajun Deng wrote:
> The if statement already exists in the __neigh_event_send() function,
> remove redundant if statement.
[]
> diff --git a/include/net/neighbour.h b/include/net/neighbour.h
[]
> @@ -452,9 +452,7 @@ static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
>
> if (READ_ONCE(neigh->used) != now)
> WRITE_ONCE(neigh->used, now);
> - if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
> - return __neigh_event_send(neigh, skb);
> - return 0;
> + return __neigh_event_send(neigh, skb);
> }

Perhaps this is an optimization to avoid the lock/unlock in __neigh_event_send?
If so a comment could be useful.

And also perhaps this code would be clearer with the test reversed:

if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
return 0;

return __neigh_event_send(neigh, skb);