From owner-svn-src-head@freebsd.org Fri Mar 25 20:56:02 2016 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 8840DADE11D; Fri, 25 Mar 2016 20:56:02 +0000 (UTC) (envelope-from bz@FreeBSD.org) Received: from mx1.sbone.de (mx1.sbone.de [IPv6:2a01:4f8:130:3ffc::401:25]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client CN "mx1.sbone.de", Issuer "SBone.DE" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4CF6315DF; Fri, 25 Mar 2016 20:56:02 +0000 (UTC) (envelope-from bz@FreeBSD.org) Received: from mail.sbone.de (mail.sbone.de [IPv6:fde9:577b:c1a9:31::2013:587]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mx1.sbone.de (Postfix) with ESMTPS id A226E25D3899; Fri, 25 Mar 2016 20:55:58 +0000 (UTC) Received: from content-filter.sbone.de (content-filter.sbone.de [IPv6:fde9:577b:c1a9:31::2013:2742]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.sbone.de (Postfix) with ESMTPS id 67DA1C79D32; Fri, 25 Mar 2016 20:55:57 +0000 (UTC) X-Virus-Scanned: amavisd-new at sbone.de Received: from mail.sbone.de ([IPv6:fde9:577b:c1a9:31::2013:587]) by content-filter.sbone.de (content-filter.sbone.de [fde9:577b:c1a9:31::2013:2742]) (amavisd-new, port 10024) with ESMTP id 5Wg5sOw6FWfJ; Fri, 25 Mar 2016 20:55:55 +0000 (UTC) Received: from nv.sbone.de (nv.sbone.de [IPv6:fde9:577b:c1a9:31::2013:138]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.sbone.de (Postfix) with ESMTPSA id 322AFC77171; Fri, 25 Mar 2016 20:55:55 +0000 (UTC) Date: Fri, 25 Mar 2016 20:55:54 +0000 (UTC) From: "Bjoern A. Zeeb" To: Gleb Smirnoff cc: "George V. Neville-Neil" , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r297225 - in head/sys: net netinet netinet6 In-Reply-To: <20160324203117.GY2616@FreeBSD.org> Message-ID: References: <201603240754.u2O7suvM006925@repo.freebsd.org> <20160324203117.GY2616@FreeBSD.org> X-OpenPGP-Key-Id: 0x14003F198FEFA3E77207EE8D2B58B8F83CCF1842 MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.21 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, 25 Mar 2016 20:56:02 -0000 On Thu, 24 Mar 2016, Gleb Smirnoff wrote: > On Thu, Mar 24, 2016 at 07:54:56AM +0000, George V. Neville-Neil wrote: > G> Author: gnn > G> Date: Thu Mar 24 07:54:56 2016 > G> New Revision: 297225 > G> URL: https://svnweb.freebsd.org/changeset/base/297225 > G> > G> Log: > G> FreeBSD previously provided route caching for TCP (and UDP). Re-add > G> route caching for TCP, with some improvements. In particular, invalidate > G> the route cache if a new route is added, which might be a better match. > G> The cache is automatically invalidated if the old route is deleted. > G> > G> Submitted by: Mike Karels > G> Reviewed by: gnn > G> Differential Revision: https://reviews.freebsd.org/D4306 > > I'm quite surprised to see this checked in, taking into account that the > D4306 has strong disagreement from melifaro@. > > So, now we got two aids for poor routing: TCP route caching & flowtable. I am uncertain by what you mean when you say "routing". For as forwarding is concerned, this doesn't matter. For as local connections are concerned, this is the start to scale again. You are saving 1-2 route lookups per first packet and 2-3 route lookups for any subsequent packet. Worst case scenario your FIB changes for each packet still improves the situation as in the first packet situation. Every lookup I don't have to do I don't have optimize a system for as badly as I would otherwise have to. Flowtable in my view, once this is fully flashed out, has no real reason to be used anymore. Everything else I think my initial reply and gnn's reply has covered. /bz