From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1067FC5ACD6 for ; Wed, 18 Mar 2020 09:46:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5C0820674 for ; Wed, 18 Mar 2020 09:46:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727595AbgCRJqo (ORCPT ); Wed, 18 Mar 2020 05:46:44 -0400 Received: from smtp-rs2-vallila1.fe.helsinki.fi ([128.214.173.73]:53282 "EHLO smtp-rs2-vallila1.fe.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727569AbgCRJqn (ORCPT ); Wed, 18 Mar 2020 05:46:43 -0400 Received: from whs-18.cs.helsinki.fi (whs-18.cs.helsinki.fi [128.214.166.46]) by smtp-rs2.it.helsinki.fi (8.14.7/8.14.7) with ESMTP id 02I9cEcM006446; Wed, 18 Mar 2020 11:38:14 +0200 Received: by whs-18.cs.helsinki.fi (Postfix, from userid 1070048) id B39C7360F61; Wed, 18 Mar 2020 11:38:14 +0200 (EET) From: =?ISO-8859-1?Q?Ilpo_J=E4rvinen?= To: netdev@vger.kernel.org Cc: Yuchung Cheng , Neal Cardwell , Eric Dumazet , Olivier Tilmans Subject: [RFC PATCH 27/28] gro: flushing when CWR is set negatively affects AccECN Date: Wed, 18 Mar 2020 11:38:08 +0200 Message-Id: <1584524289-24187-27-git-send-email-ilpo.jarvinen@helsinki.fi> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1584524289-24187-2-git-send-email-ilpo.jarvinen@helsinki.fi> References: <1584524289-24187-2-git-send-email-ilpo.jarvinen@helsinki.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Ilpo Järvinen As AccECN may keep CWR bit asserted due to different interpretation of the bit, flushing with GRO because of CWR may effectively disable GRO until AccECN counter field changes such that CWR-bit becomes 0. There is no harm done from not immediately forwarding the CWR'ed segment with RFC3168 ECN. Signed-off-by: Ilpo Järvinen --- net/ipv4/tcp_offload.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index 58ce382c793e..555c9be84f10 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -240,7 +240,6 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) found: /* Include the IP ID check below from the inner most IP hdr */ flush = NAPI_GRO_CB(p)->flush; - flush |= (__force int)(flags & TCP_FLAG_CWR); flush |= (__force int)((flags ^ tcp_flag_word(th2)) & ~(TCP_FLAG_FIN | TCP_FLAG_PSH)); flush |= (__force int)(th->ack_seq ^ th2->ack_seq); -- 2.20.1