From owner-freebsd-hackers@freebsd.org Fri Mar 16 18:07:15 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 43937F624AF for ; Fri, 16 Mar 2018 18:07:15 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from pmta2.delivery6.ore.mailhop.org (pmta2.delivery6.ore.mailhop.org [54.200.129.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id BB6876C9F1 for ; Fri, 16 Mar 2018 18:07:14 +0000 (UTC) (envelope-from ian@freebsd.org) X-MHO-User: b45caf0b-2944-11e8-b951-f99fef315fd9 X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Originating-IP: 67.177.211.60 X-Mail-Handler: DuoCircle Outbound SMTP Received: from ilsoft.org (unknown [67.177.211.60]) by outbound2.ore.mailhop.org (Halon) with ESMTPSA id b45caf0b-2944-11e8-b951-f99fef315fd9; Fri, 16 Mar 2018 18:06:10 +0000 (UTC) Received: from rev (rev [172.22.42.240]) by ilsoft.org (8.15.2/8.15.2) with ESMTP id w2GI75fR029310; Fri, 16 Mar 2018 12:07:05 -0600 (MDT) (envelope-from ian@freebsd.org) Message-ID: <1521223625.99081.61.camel@freebsd.org> Subject: Re: option TCP_RFC7413 is not in GENERIC From: Ian Lepore To: Patrick Kelsey , freebsd-hackers@freebsd.org Date: Fri, 16 Mar 2018 12:07:05 -0600 In-Reply-To: References: <1521062028.2511351.1303413736.6960BF4F@webmail.messagingengine.com> <20180314233811.GA35025@mail.bsd4all.net> <1521216713.99081.55.camel@freebsd.org> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.18.5.1 FreeBSD GNOME Team Port Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Mar 2018 18:07:15 -0000 On Fri, 2018-03-16 at 16:42 +0000, Patrick Kelsey wrote: > On Fri, Mar 16, 2018 at 12:12 PM Ian Lepore wrote: > > > > > On Fri, 2018-03-16 at 16:04 +0000, Patrick Kelsey wrote: > > > > > > The current thinking is that users who care > > > about such performance differences are dealing with extreme workloads > > that > > > > > > already motivate them to compile their own kernels, or are working with > > > very resource-constrained platforms, so the way forward is to keep the > > > TCP_RFC7413 kernel option around and enable it by default for the > > > server-class platforms (armd64 and arm64). > > I have no idea what TCP_RFC7413 even is, but I know I was forced to add > > it to my kernel config when I installed the bind911 package during a > > recent upgrade.  This is on a tiny NUC for which saturating even one of > > its gbe interfaces would count as "extreme workload". :) > > > > > RFC7413 is TCP Fast Open (TFO), which is a way to short-circuit TCP > handshakes if conditions are met.  I'm curious as to why you were > forced to add the option to your kernel config when you installed bind911. > Maybe that version of bind was assuming something like 'if the TCP_FASTOPEN > sockopt is defined in a header, then all setsockopt(TCP_FASTOPEN) should > succeed or else die'?  That would be a very weird assumption, as the MacOS, > Linux, and FreeBSD implementations all have a sysctl that can be used to > disable the feature system-wide at any point in time. > > -Patrick Oh, then I assume it's because TCP_FASTOPEN is in the default options when the package gets built. -- Ian