From 6bcfd7f8c28887a4298bc4386b02cb90c9fa0c13 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 8 Oct 2015 11:16:48 -0700 Subject: [PATCH] tcp: fix RFS vs lockless listeners Before recent TCP listener patches, we were updating listener sk->sk_rxhash before the cloning of master socket. children sk_rxhash was therefore correct after the normal 3WHS. But with lockless listener, we no longer dirty/change listener sk_rxhash as it would be racy. We need to correctly update the child sk_rxhash, otherwise first data packet wont hit correct cpu if RFS is used. Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet Reported-by: Willem de Bruijn Cc: Tom Herbert Acked-by: Tom Herbert Signed-off-by: David S. Miller --- net/ipv4/syncookies.c | 1 + net/ipv4/tcp_minisocks.c | 1 + 2 files changed, 2 insertions(+) diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 8113c30ccf96..2dbb11331f6c 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -225,6 +225,7 @@ struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, child = icsk->icsk_af_ops->syn_recv_sock(sk, skb, req, dst); if (child) { atomic_set(&req->rsk_refcnt, 1); + sock_rps_save_rxhash(child, skb); inet_csk_reqsk_queue_add(sk, req, child); } else { reqsk_free(req); diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 9adf1e2c3170..1079e6ad77fe 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -768,6 +768,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, if (!child) goto listen_overflow; + sock_rps_save_rxhash(child, skb); tcp_synack_rtt_meas(child, req); inet_csk_reqsk_queue_drop(sk, req); inet_csk_reqsk_queue_add(sk, req, child);