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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 C5B17C432C0 for ; Tue, 3 Dec 2019 10:15:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 988D3206F0 for ; Tue, 3 Dec 2019 10:15:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bJK3+CxN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726564AbfLCKPt (ORCPT ); Tue, 3 Dec 2019 05:15:49 -0500 Received: from mail-pf1-f177.google.com ([209.85.210.177]:35707 "EHLO mail-pf1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726516AbfLCKPs (ORCPT ); Tue, 3 Dec 2019 05:15:48 -0500 Received: by mail-pf1-f177.google.com with SMTP id b19so1635816pfo.2 for ; Tue, 03 Dec 2019 02:15:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=DKk2IUBi3mdO+O2zHCOm2ZGyT/hvCUHZiFW5LUr1COg=; b=bJK3+CxNwD5oEFZ2wDA5SCudGLeHrZcOR4JCRWaKdV5gJ/kDJbCgmI0rNq19POQMzU PuVwPIc3HbMHTCT0jpYfQvz59R19h9zB5WW26pLOGCNQ3VQ4Ho80ZGRQavL6jEqGRWU7 VM1KdXFJWwq00lEaCb9GZFJy38du5QD8eEuqLoJ4+iGlodkwxgxDELZ48kZxb4gpDWH8 CSFyORptU7xPbH3rrwc2WNsRsMHen1+HXM67EoduTnrD+BVg4J8/k7ZtlRvPVesu6JhJ 1G1lGZqt2j6PaEeoMIkYNVk92HDezcSqrsCqSoPCqCTfvHq9ffUiaHVZ2aw0qTpXYeJf d4uA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=DKk2IUBi3mdO+O2zHCOm2ZGyT/hvCUHZiFW5LUr1COg=; b=pvqjdwky4kcsroKvKX8a2HxXY/2dHg03WEB6oT8o/s0a1yug1UJ4yoMu7BCyAOGY4O nLD3SkUzvlZjQ1OWSxgwNTdAMB0OFzGrRlDC+esaSmf8dsE+Ok0wMa9QHtvZs+6gUtD2 bUcgX5hSoHAUQAodHnYuM0l92S5e4Zd92Ix/3Pg8OzIPv4xTdnOL916e+Gd/fzGhUpyB Co3t19VnP+79VQr2F/btsrL0q9XVGokMjG7Fn5ev06KvKK0X5G5Gk9LzBbZmwqNDoab8 Nvxg0URH4HvJOr18myxwwKsi1k/bWqBXDlYlLRmoZP1oXGFLQpzznMj1ZCDwMlbjeQsi fcQw== X-Gm-Message-State: APjAAAUI5z0IWQvxgrMA/WVKnhxYhgPtXEp9zfmvZ+zazKOwfGHV7isd j0XNeRbRP9QRw12ewe/mZYc= X-Google-Smtp-Source: APXvYqyj/UVxn9BsMo4Nd92Kj6aMXiDUa/WJma0DRvhvAcKZn3qHkbbInZ3Mwuha/ojhDmMsEAPDgA== X-Received: by 2002:a63:190c:: with SMTP id z12mr4194402pgl.1.1575368147659; Tue, 03 Dec 2019 02:15:47 -0800 (PST) Received: from dhcp-12-139.nay.redhat.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id s22sm2340200pjr.5.2019.12.03.02.15.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Dec 2019 02:15:46 -0800 (PST) Date: Tue, 3 Dec 2019 18:15:37 +0800 From: Hangbin Liu To: David Miller Cc: netdev@vger.kernel.org, ja@ssi.bg, marcelo.leitner@gmail.com, dsahern@gmail.com, edumazet@google.com Subject: Re: [PATCHv2 net] ipv6/route: should not update neigh confirm time during PMTU update Message-ID: <20191203101536.GJ18865@dhcp-12-139.nay.redhat.com> References: <20191122061919.26157-1-liuhangbin@gmail.com> <20191203021137.26809-1-liuhangbin@gmail.com> <20191202.184704.723174427717421022.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191202.184704.723174427717421022.davem@davemloft.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Dec 02, 2019 at 06:47:04PM -0800, David Miller wrote: > From: Hangbin Liu > Date: Tue, 3 Dec 2019 10:11:37 +0800 > > > Fix it by removing the dst_confirm_neigh() in __ip6_rt_update_pmtu() as > > there is no two-way communication during PMTU update. > > > > v2: remove dst_confirm_neigh directly as David Miller pointed out. > > That's not what I said. > > I said that this interface is designed for situations where the neigh > update is appropriate, and that's what happens for most callers _except_ > these tunnel cases. > > The tunnel use is the exception and invoking the interface > inappropriately. > > It is important to keep the neigh reachability fresh for TCP flows so > you cannot remove this dst_confirm_neigh() call. > > Instead, make a new interface that the tunnel use cases can call into > to elide the neigh update. > > Yes, this means you will have too update all of the tunnel callers > into these calls chains but that's the price we have to pay in this > situation unfortunately. Oh, I got what you mean now. thanks for the explain. I will see how to do this. Thanks Hangbin