[PATCH net-next 3/9] net: avoid dirtying sk->sk_napi_id
From: Eric Dumazet <hidden>
Date: 2021-10-21 16:23:16
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 --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); }
--
2.33.0.1079.g6e70778dc9-goog