From owner-svn-src-head@freebsd.org Sun Sep 27 14:58:52 2015 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 253F7A0AA0D; Sun, 27 Sep 2015 14:58:52 +0000 (UTC) (envelope-from melifaro@ipfw.ru) Received: from forward19p.cmail.yandex.net (forward19p.cmail.yandex.net [IPv6:2a02:6b8:0:1465::aa]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "forwards.mail.yandex.net", Issuer "Certum Level IV CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D023D5FA; Sun, 27 Sep 2015 14:58:51 +0000 (UTC) (envelope-from melifaro@ipfw.ru) Received: from web20g.yandex.ru (web20g.yandex.ru [IPv6:2a02:6b8:0:1402::30]) by forward19p.cmail.yandex.net (Yandex) with ESMTP id F1A2220B42; Sun, 27 Sep 2015 17:58:36 +0300 (MSK) Received: from 127.0.0.1 (localhost [127.0.0.1]) by web20g.yandex.ru (Yandex) with ESMTP id 133456AC132B; Sun, 27 Sep 2015 17:58:35 +0300 (MSK) Received: by web20g.yandex.ru with HTTP; Sun, 27 Sep 2015 17:58:35 +0300 From: Alexander V. Chernikov Envelope-From: melifaro@ipfw.ru To: Bjoern A. Zeeb , George Neville-Neil Cc: "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" In-Reply-To: References: <201509270529.t8R5TYRf095540@repo.freebsd.org> Subject: Re: svn commit: r288301 - in head/sys: net netinet netinet6 MIME-Version: 1.0 Message-Id: <2804821443365915@web20g.yandex.ru> X-Mailer: Yamail [ http://yandex.ru ] 5.0 Date: Sun, 27 Sep 2015 17:58:35 +0300 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=koi8-r X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.20 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: Sun, 27 Sep 2015 14:58:52 -0000 27.09.2015, 15:26, "Bjoern A. Zeeb" : > On Sun, 27 Sep 2015, Alexander V. Chernikov wrote: > >> šAuthor: melifaro >> šDate: Sun Sep 27 05:29:34 2015 >> šNew Revision: 288301 >> šURL: https://svnweb.freebsd.org/changeset/base/288301 >> >> šLog: >> ššEliminate nd6_nud_hint() and its TCP bindings. >> >> ššInitially function was introduced in r53541 (KAME initial commit) to >> šššš"provide hints from upper layer protocols that indicate a connection >> ššššis making "forward progress"" (quote from RFC 2461 7.3.1 Reachability >> ššššConfirmation). >> ššHowever, it was converted to do nothing (e.g. just return) in r122922 >> šššš(tcp_hostcache implementation) back in 2003. Some defines were moved >> ššššto tcp_var.h in r169541. Then, it was broken (for non-corner cases) >> ššššby r186119 (L2<>L3 split) in 2008 (NULL ifp in nd6_lookup). So, >> ššššright now this code is broken and has no "real" base users. >> >> ššDifferential Revision: https://reviews.freebsd.org/D3699 > > PR: 165692 > > It would be nice to have the feature back though it would be very > expensive locking wise if it'd remain a per-packet operation. It looks like there are options to implement this without significant overhead (like, on proper TCP session teardown, or on delayed-ack timer, or/and with some sort of sampling + special "no-gw" flag). I'd prefer not to shift my focus from projects/routing now, but I can cooperate with someone from TCP side and resurrect/test nd6_nud_hint() > > -- > Bjoern A. Zeeb "Come on. Learn, goddamn it.", WarGames, 1983