[PATCH net-next 4/9] net: avoid dirtying sk->sk_rx_queue_mapping
From: Eric Dumazet <hidden>
Date: 2021-10-21 16:23:18
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
From: Eric Dumazet <edumazet@google.com> sk_rx_queue_mapping is located in a cache line that should be kept read mostly. Signed-off-by: Eric Dumazet <edumazet@google.com> --- include/net/sock.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index 99c4194cb61add848e3a35db0f952c4193f5ea1f..b4d3744b188ad869b4ec55f78e04236b710898de 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h@@ -1916,10 +1916,8 @@ static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb) if (skb_rx_queue_recorded(skb)) { u16 rx_queue = skb_get_rx_queue(skb); - if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING)) - return; - - sk->sk_rx_queue_mapping = rx_queue; + if (unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue)) + WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue); } #endif }
--
2.33.0.1079.g6e70778dc9-goog