From owner-svn-src-head@freebsd.org Fri Jan 5 17:38:43 2018 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 0FCA6EB60E7 for ; Fri, 5 Jan 2018 17:38:43 +0000 (UTC) (envelope-from steven@multiplay.co.uk) Received: from mail-wm0-x22b.google.com (mail-wm0-x22b.google.com [IPv6:2a00:1450:400c:c09::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 8F9A374514 for ; Fri, 5 Jan 2018 17:38:42 +0000 (UTC) (envelope-from steven@multiplay.co.uk) Received: by mail-wm0-x22b.google.com with SMTP id i11so3791764wmf.4 for ; Fri, 05 Jan 2018 09:38:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=multiplay-co-uk.20150623.gappssmtp.com; s=20150623; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language; bh=mXbSfU4JzPIfZQXL8I5iOBEBkj6jpQiQaU5i2UzkFxs=; b=FaG5up3FDmmH0/bvA6lMkH8g4M8KbSaIbAiPFkdum4G1GFZe3zhC4DF6HtnbTpPgzB /pdCqajpr82NJdQgDHUu0V7QL1bOdRNCIiEKmjgJOfdtAi+yUA8fb9tCI1X2Ke+G2yZJ 3BxyZGYDwHmK678X9cgDG7kj81/ujBYXovXCckPV8Z9l0fuZ/C5jX1Q28iRn/J6M6wJw JFQuZUSVbAW3gUEY+vwyfdjGZLxLdTRoy2JH/LiLlJ/Hfgtn/pj+S7ViKQ1OIc87++x3 v7MAgPTZMP+gSE78wH7hYSarufSsshJLP/MZutufA/GTbDqIwfXkPWyBHskgHKVTRQFe Qq7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language; bh=mXbSfU4JzPIfZQXL8I5iOBEBkj6jpQiQaU5i2UzkFxs=; b=T/qFOHIHQpnvghgjtHtewmCKg5lwLTP73jaQxH/BL/XbABxRFEZetGlfvEfauLAesm z86mjcvKC5zIOPoKPHfDXzQdbzNkDuIPcEvs9s+Ix3FQWRmnYMNiNWhG6FCze0uZmRse ah/3N/JuN0a0KBA1kc5xdzjjjd9le2uNhYiFp3uqZ9PAQ1M7ZnY8vwZYLM3qXgtLtI+6 dereaDgAEnMiWX4N3JV/E+OS6uIi3yFT3t4RH38Vz5Sv3u+WYni4nqiVSYIgZ2pUoEry tZjzcmEc9V4vTr0fKacSzjqMfBsozGLmNByGQHRKFZ03cXtIe774KQRbN0r3baNXUc56 wcIw== X-Gm-Message-State: AKGB3mK/NgTth5Lw+OQ7Tc7/iyUaELZqHBbEkun1tmp6r3pKOcY/urZG kISDybuwym7pJqn5HQWpbOwJ9m1EdJU= X-Google-Smtp-Source: ACJfBovq2v7TIbwiFy52FYgjiemScpYYGJfKyqDkydAwfGwvnhRE4RefUTSorgBlSRUdaZqDZfDJfQ== X-Received: by 10.80.134.37 with SMTP id o34mr5173727edo.37.1515173920424; Fri, 05 Jan 2018 09:38:40 -0800 (PST) Received: from [10.10.1.111] ([185.97.61.1]) by smtp.gmail.com with ESMTPSA id e46sm4760128edb.93.2018.01.05.09.38.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 05 Jan 2018 09:38:39 -0800 (PST) Subject: Re: svn commit: r327559 - in head: . sys/net To: Eugene Grosbein , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <201801042005.w04K5liB049411@repo.freebsd.org> <5A4E9397.9000308@grosbein.net> <5A4EDC62.50508@grosbein.net> <5A4F824C.1060405@grosbein.net> <97d173fb-4f47-609d-8319-07282a283473@multiplay.co.uk> <5A4FB2E0.4010603@grosbein.net> From: Steven Hartland Message-ID: <4e72bc1d-e535-d3e2-eba3-3d9bd575ba4f@multiplay.co.uk> Date: Fri, 5 Jan 2018 17:38:40 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <5A4FB2E0.4010603@grosbein.net> Content-Language: en-US Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Jan 2018 17:38:43 -0000 On 05/01/2018 17:16, Eugene Grosbein wrote: > >>> That is, there is no guarantee of persistance of flowid of incoming packets >>> as they can be received with distinct ports of lagg being distinct hardware >>> computing flowid differently. Some ports may not support RSS at all. >>> We should not use incoming hardware flowid for anything by default in case of TCP. >> I don't believe your statement about persistence of flowid due to the use of variant ports is correct >> as LACP states that packets from the same flow "should" under normal conditions (no failure) be received on the same port. > It still does not guarantee that and you miss opportunity of network failures that can easily change flowid of incoming packets. Correct, but that's not the normal behavior so the chances of seeing any impact of out of order packets is very small. > >> In the case where the HW doesn't support RSS, then flowid should either always be unset or be set by OS to consistent value hence that should function as expected. >> >> That said I don't disagree that all hostA -> hostB should use Manual hash, as I can't see anyway to use to HW hash, >> however the ports in your example are wrong > Yes, I stand corrected (just copied your example and adjusted it incompletly). > >>> Why do you mix flowid of incoming stream with flowid of outgoing stream? >>> >> I expect this was done so we don't have the overhead of calculating a packet hash for every outgoing packet >> i.e. its an optimization, however I believe this is only possible for the destination host which always >> has a valid flowid, and not for the source host. > How do you know that flowid of incoming packet is preserved on outgoing path? It should not. https://github.com/freebsd/freebsd/blob/master/sys/netinet/ip_output.c#L234     Regards     Steve