From patchwork Wed Mar 30 05:16:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Yingliang X-Patchwork-Id: 603234 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 [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3qZbVg0b36z9sBc for ; Wed, 30 Mar 2016 16:17:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751958AbcC3FRM (ORCPT ); Wed, 30 Mar 2016 01:17:12 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:40199 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751342AbcC3FRM (ORCPT ); Wed, 30 Mar 2016 01:17:12 -0400 Received: from 172.24.1.48 (EHLO SZXEML429-HUB.china.huawei.com) ([172.24.1.48]) by szxrg01-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DHV22990; Wed, 30 Mar 2016 13:17:03 +0800 (CST) Received: from localhost (10.177.19.219) by SZXEML429-HUB.china.huawei.com (10.82.67.184) with Microsoft SMTP Server id 14.3.235.1; Wed, 30 Mar 2016 13:16:59 +0800 From: Yang Yingliang To: CC: , Subject: [PATCH RFC] net: decrease the length of backlog queue immediately after it's detached from sk Date: Wed, 30 Mar 2016 13:16:41 +0800 Message-ID: <1459315001-3448-1-git-send-email-yangyingliang@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.1 MIME-Version: 1.0 X-Originating-IP: [10.177.19.219] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090203.56FB6151.003A, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 66fe8eef2adedfe020e5d6ea8e491238 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When task A hold the sk owned in tcp_sendmsg, if lots of packets arrive and the packets will be added to backlog queue. The packets will be handled in release_sock called from tcp_sendmsg. When the sk_backlog is removed from sk, the length will not decrease until all the packets in backlog queue are handled. This may leads to the new packets be dropped because the lenth is too big. So set the lenth to 0 immediately after it's detached from sk. Signed-off-by: Yang Yingliang --- net/core/sock.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/core/sock.c b/net/core/sock.c index 47fc8bb..108be05 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1933,6 +1933,7 @@ static void __release_sock(struct sock *sk) do { sk->sk_backlog.head = sk->sk_backlog.tail = NULL; + sk->sk_backlog.len = 0; bh_unlock_sock(sk); do {