From patchwork Tue Nov 25 20:25:55 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 10746 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 310BDDDDEF for ; Wed, 26 Nov 2008 07:26:07 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751928AbYKYU0B (ORCPT ); Tue, 25 Nov 2008 15:26:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751193AbYKYU0B (ORCPT ); Tue, 25 Nov 2008 15:26:01 -0500 Received: from gw1.cosmosbay.com ([86.65.150.130]:36556 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119AbYKYU0A (ORCPT ); Tue, 25 Nov 2008 15:26:00 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) by gw1.cosmosbay.com (8.13.7/8.13.7) with ESMTP id mAPKPum0029297; Tue, 25 Nov 2008 21:25:56 +0100 Message-ID: <492C5F53.2090901@cosmosbay.com> Date: Tue, 25 Nov 2008 21:25:55 +0100 From: Eric Dumazet User-Agent: Thunderbird 2.0.0.18 (Windows/20081105) MIME-Version: 1.0 To: "David S. Miller" CC: Linux Netdev List Subject: [PATCH] net: udp_unhash() can test if sk is hashed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.6 (gw1.cosmosbay.com [0.0.0.0]); Tue, 25 Nov 2008 21:25:56 +0100 (CET) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Impact: Optimization Like done in inet_unhash(), we can avoid taking a chain lock if socket is not hashed in udp_unhash() Triggered by close(socket(AF_INET, SOCK_DGRAM, 0)); Signed-off-by: Eric Dumazet --- net/ipv4/udp.c | 18 ++++++++++-------- 1 files changed, 10 insertions(+), 8 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index da869ce..e2ab258 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -970,16 +970,18 @@ int udp_disconnect(struct sock *sk, int flags) void udp_lib_unhash(struct sock *sk) { - struct udp_table *udptable = sk->sk_prot->h.udp_table; - unsigned int hash = udp_hashfn(sock_net(sk), sk->sk_hash); - struct udp_hslot *hslot = &udptable->hash[hash]; + if (sk_hashed(sk)) { + struct udp_table *udptable = sk->sk_prot->h.udp_table; + unsigned int hash = udp_hashfn(sock_net(sk), sk->sk_hash); + struct udp_hslot *hslot = &udptable->hash[hash]; - spin_lock_bh(&hslot->lock); - if (sk_nulls_del_node_init_rcu(sk)) { - inet_sk(sk)->num = 0; - sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + spin_lock_bh(&hslot->lock); + if (sk_nulls_del_node_init_rcu(sk)) { + inet_sk(sk)->num = 0; + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + } + spin_unlock_bh(&hslot->lock); } - spin_unlock_bh(&hslot->lock); } EXPORT_SYMBOL(udp_lib_unhash);