From owner-svn-src-all@freebsd.org Fri Jan 5 16:11:36 2018 Return-Path: Delivered-To: svn-src-all@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 4420BEB1F2E for ; Fri, 5 Jan 2018 16:11:36 +0000 (UTC) (envelope-from steven@multiplay.co.uk) Received: from mail-wm0-x22f.google.com (mail-wm0-x22f.google.com [IPv6:2a00:1450:400c:c09::22f]) (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 BEA2F701CF for ; Fri, 5 Jan 2018 16:11:35 +0000 (UTC) (envelope-from steven@multiplay.co.uk) Received: by mail-wm0-x22f.google.com with SMTP id b141so3362028wme.1 for ; Fri, 05 Jan 2018 08:11:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=multiplay-co-uk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language; bh=NBIMcssRnMOA9GRWEd0BWuKeDNtuecZHJu0DYgjvis0=; b=MoDLuPVZpu9kJPyVyu57sN8YKDisK8zfk7/eaoZqOonyNhNe0kFTC8i+WXqPs9UWCe bJkUtS6W9buc06UA4Gma+Ps/mZEnCXl3hjIz2K/M2YTiY+0/VIlRiEOR0mQzap9oEq3S z9q+GHHTZII+kCClm9BpcVmV2xhR52vdURuCzHg6t+ionxole4VHWP6V+yL2E5YQUE0O JcPDUbHZa95JXmHYNRlq7xMePFh0fKcZy24vifU38gDF1jMV1JHsJkvwDSUyMds7Eq4a Fjd9BI2BkCPPJKW548LdKlI2ggUGO9gi3nZRAf9Qmmv0Q1n7mNWmexLzreZE42v8Nr9w EUzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language; bh=NBIMcssRnMOA9GRWEd0BWuKeDNtuecZHJu0DYgjvis0=; b=DU4iDMcsRrc+cOgQx1aDCZ6pRCwUYyiUTdSTbM/Xl7Afup0SJJaJTv6TX1TpduP350 kFU1AnqWf2JftHbXxodYpB8iSKm8B3G2haK7J8DoX7HqyGznLn8pNs5+V15QU+91kQmO lwYPIG6w5U9U+FUendifV4sS0rtU9kkrx2f/A6NyF2cvG6Ux1xElTo79rPD9jr3rff+7 BNiyGWjKDlOVRs2rnnvosZS8jx0YR+/7Gh/h7ttdJtg9AYOXik0jhq//a4BCs/etM8Uu q6nn+okyZ0B1ddlgGVPeWovkzLacQecW4pN6Zmzy1cgS+MrBL4+uX2VWcO57DVh5S+Jo kS/g== X-Gm-Message-State: AKGB3mKQg6VLY+0H3UkT5yww0pMTZa6f+y2u+BuwqZ/ZNTkfzaZia0C9 6U1I/k87RWeLU3OgDrtzEdFYNA== X-Google-Smtp-Source: ACJfBotzuh6GnKSWwHYfDICNzSbpNsDLl4Gk5m57h6pTQxCV5HYt2CddGTNDt2bKKIEe59+zxP9P8g== X-Received: by 10.80.167.101 with SMTP id h92mr4747198edc.202.1515168694110; Fri, 05 Jan 2018 08:11:34 -0800 (PST) Received: from [10.10.1.111] ([185.97.61.1]) by smtp.gmail.com with ESMTPSA id 4sm3751735edf.81.2018.01.05.08.11.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 05 Jan 2018 08:11:32 -0800 (PST) Subject: Re: svn commit: r327559 - in head: . sys/net To: hiren panchasara Cc: 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> <20180104224214.GD18879@strugglingcoder.info> <63c3c450-aeaf-bdd5-5e16-414146c9bb3a@multiplay.co.uk> <20180105094126.GE18879@strugglingcoder.info> From: Steven Hartland Message-ID: <1854b421-3c09-c040-ba86-738b9c621eae@multiplay.co.uk> Date: Fri, 5 Jan 2018 16:11:34 +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: <20180105094126.GE18879@strugglingcoder.info> Content-Language: en-US Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Jan 2018 16:11:36 -0000 On 05/01/2018 09:41, hiren panchasara wrote: > IIRC, with 'RSS' in kernconf, most NIC drivers and stack should do the > right thing. Look at drivers and also conn startup code in TCP as I > recall it doing the flowid mapping correctly when stream originated from > the other side and had flowid assigned to it by the NIC. > > I am mostly concerned about the overhead of manual calculation but my > knowledge is a bit rusty right now and lagg has always been special so > please try this out and see. > I've not been able to find any such option: head:src> grep -ri rss sys/amd64/conf/ head:src> Any other ideas on where it might be or is it just the default on HEAD? That said the more I think / talk about this the more I believe manual calculation is the right option for LACP. The reason I believe this is: * When configuring LACP in a network knowing the hash method is important, so using an unknown "flowid" based hash could produce unexpected results. * There's no easy way (possibly no way at all) to determine the flowid from the HW for the first packet of a new outbound connection * Having the hash algorithm vary for inbound and outbound connections increases the chance of unexpected results. * LCAP combines NIC's of even speed, however they can be different HW so there's no guarantee that the partaking ports use the same flowid calculation, again increasing the chance of a problem. So as mentioned in a previous reply the more I think about the more believe flowid can't be successfully used as a hash source for LACP or loadbalance. What do others think, am I missing something?     Regards     Steve