diff mbox series

[net-next,3/9] net: avoid dirtying sk->sk_napi_id

Message ID 20211021162253.333616-6-eric.dumazet@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series tcp: receive path optimizations | expand

Checks

Context Check Description
netdev/apply fail Patch does not apply to net-next
netdev/tree_selection success Clearly marked for net-next

Commit Message

Eric Dumazet Oct. 21, 2021, 4:22 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

sk_napi_id is located in a cache line that can be kept read mostly.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/net/busy_poll.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 40296ed976a9778ceb239b99ad783cb99b8b92ef..4202c609bb0b09345c0f1c5105adf409a3a89f74 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -130,7 +130,8 @@  static inline void skb_mark_napi_id(struct sk_buff *skb,
 static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
 {
 #ifdef CONFIG_NET_RX_BUSY_POLL
-	WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
+	if (unlikely(READ_ONCE(sk->sk_napi_id) != skb->napi_id))
+		WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
 #endif
 	sk_rx_queue_set(sk, skb);
 }