From owner-svn-src-head@freebsd.org Fri Jan 8 21:10:43 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 D82D7A68421; Fri, 8 Jan 2016 21:10:43 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from cell.glebi.us (glebi.us [96.95.210.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "cell.glebi.us", Issuer "cell.glebi.us" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id A9B3C101C; Fri, 8 Jan 2016 21:10:43 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from cell.glebi.us (localhost [127.0.0.1]) by cell.glebi.us (8.15.2/8.15.2) with ESMTPS id u08LAgeJ012076 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 8 Jan 2016 13:10:42 -0800 (PST) (envelope-from glebius@FreeBSD.org) Received: (from glebius@localhost) by cell.glebi.us (8.15.2/8.15.2/Submit) id u08LAf7Y012075; Fri, 8 Jan 2016 13:10:41 -0800 (PST) (envelope-from glebius@FreeBSD.org) X-Authentication-Warning: cell.glebi.us: glebius set sender to glebius@FreeBSD.org using -f Date: Fri, 8 Jan 2016 13:10:41 -0800 From: Gleb Smirnoff To: NGie Cooper Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r293439 - in head: lib/libc/sys sys/dev/ti sys/kern sys/sys usr.bin/netstat Message-ID: <20160108211041.GG1906@FreeBSD.org> References: <201601082034.u08KYvLv075281@repo.freebsd.org> <96B980EE-FD2F-490E-BA5E-4F23A67CEB18@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <96B980EE-FD2F-490E-BA5E-4F23A67CEB18@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) 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: Fri, 08 Jan 2016 21:10:43 -0000 On Fri, Jan 08, 2016 at 12:44:32PM -0800, NGie Cooper wrote: N> > Log: N> > New sendfile(2) syscall. A joint effort of NGINX and Netflix from 2013 and N> > up to now. N> > N> > The new sendfile is the code that Netflix uses to send their multiple tens N> > of gigabits of data per second. The new implementation features asynchronous N> > I/O, when I/O operations are launched, but not awaited to be complete. An N> > explanation of why such behavior is beneficial compared to old one is N> > going to be too long for a commit message, so we will skip it here. N> > N> > Additional features of new syscall are extra flags, which provide an N> > application more control over data sent. The SF_NOCACHE flag tells N> > kernel that data shouldn't be cached after it was sent. The SF_READAHEAD() N> > macro allows to specify readahead size in pages. N> > N> > The new syscalls is a drop in replacement. No modifications are required N> > to applications. One can take nginx binary for stable/10 and run it N> > successfully on head. Although SF_NODISKIO lost its original sense, as now N> > sendfile doesn't block, and now means something completely different (tm), N> > using the new sendfile the old way is absolutely safe. N> > N> > Celebrates: Netflix global launch! N> > Sponsored by: Nginx, Inc. N> > Sponsored by: Netflix N> > Relnotes: yes N> N> Did anyone review these changes and the other changes made recently to sys/kern and sys/net* ? 1) The review requests were sent continuosly to arch@ during last 1.5 years. https://lists.freebsd.org/pipermail/freebsd-arch/2014-May/015385.html 2) Team of engineers at Netflix has a lot of code build on top of that code, e.g. SSL_sendfile(). Of course, writing something on top assumes reviewing, so assume it reviewed thoroughly by rrs@. Actually, here is list of people who did some review of the code: emax@, rrs@, scottl@, gallatin@, imp@. 3) Do you have any particulars concerns with this change or those made recently to sys/kern and sys/net*? -- Totus tuus, Glebius.