From owner-svn-src-head@freebsd.org Tue Feb 2 20:23:28 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 9EB17A982D8; Tue, 2 Feb 2016 20:23:28 +0000 (UTC) (envelope-from delphij@gmail.com) Received: from mail-io0-x234.google.com (mail-io0-x234.google.com [IPv6:2607:f8b0:4001:c06::234]) (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 6CB811C33; Tue, 2 Feb 2016 20:23:28 +0000 (UTC) (envelope-from delphij@gmail.com) Received: by mail-io0-x234.google.com with SMTP id 9so31186474iom.1; Tue, 02 Feb 2016 12:23:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=umMK6C0gQDbkTdRUn83fAjme+B/UipsggqUIJFDiSfo=; b=tjhJTqC+Gd0UaQyYVDzlo+nA57XdRDHrd0+j10j6yuhmnBlt6VW1LH0FiwiwOL00Pp oogGBOSYHKKGchT8INmecMqBHmuBHTHOh89wJ7q22awfKCwNvD3w0+NDKHBoeBShRsem XzXojB/nm4XdciA5V0UWS4beaRIeo1BrguDV5Pdv4A1HwaMnjKXPZd0DiWG3PdgU5Bj2 /FJUC9nhw2dkkGr8gN4LMAQUe8n280SxO4BDPhDcw+Q6iQUXi17cAqzcXVz68NIizy84 m4Kk5OX4WLP+ALOUNsdnCbUZUTuGkWznkEJl0GfT9zZGSvtkOaxhv7qQVwHxb3O9hi3x ttVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=umMK6C0gQDbkTdRUn83fAjme+B/UipsggqUIJFDiSfo=; b=ZQxJc6IiegOvFS13zD2KG8v164D1c+ut5negKvnrJm6fYCNXGchJHiyn8kpbfwxTx7 5tzJE1fQnXd1RrFvYSNMIHNshbbnIsQrJVCSB70tvWoFqDhTJXoGWClzIGhmMat44qJL X7Xp/nrPfuFxNbhj4ygOdiG+AawCMUMK1jKEEoDG5CpoY0a5BpIC6/Lcubqgxk7kqxM5 ebxOOJfF6gPDUuvT/08d0hrPyjeiBg/IggnHM94WdRK7cmP7fN6rbRY7aVMRJXXVtjRN l7HnGVQK13vJaUtMDy+FXFwrscrd0n3ZpjQzfRoCVObyxxK+ZelxHYluD1Z4XP3APFIK n7Nw== X-Gm-Message-State: AG10YOS3zSbarr/I8AxZZjK4rmHrDEQlHNDsxhXk5AcLHWD2YYnu8V8gW28ZEDhRn6jsIuXxvqpBwBO36rqlPA== MIME-Version: 1.0 X-Received: by 10.107.9.220 with SMTP id 89mr16396895ioj.6.1454444607666; Tue, 02 Feb 2016 12:23:27 -0800 (PST) Received: by 10.36.54.207 with HTTP; Tue, 2 Feb 2016 12:23:27 -0800 (PST) In-Reply-To: <56B10D67.4050602@freebsd.org> References: <201602020557.u125vxCP084718@repo.freebsd.org> <36439709.poT7RgRunK@ralph.baldwin.cx> <56B10D67.4050602@freebsd.org> Date: Tue, 2 Feb 2016 12:23:27 -0800 Message-ID: Subject: Re: svn commit: r295136 - in head: sys/kern sys/netinet sys/sys usr.bin/netstat From: Xin LI To: Alfred Perlstein Cc: John Baldwin , "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.20 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: Tue, 02 Feb 2016 20:23:28 -0000 On Tuesday, February 2, 2016, Alfred Perlstein wrote: > > > On 2/2/16 11:39 AM, John Baldwin wrote: > >> On Tuesday, February 02, 2016 05:57:59 AM Alfred Perlstein wrote: >> >>> Author: alfred >>> Date: Tue Feb 2 05:57:59 2016 >>> New Revision: 295136 >>> URL: https://svnweb.freebsd.org/changeset/base/295136 >>> >>> Log: >>> Increase max allowed backlog for listen sockets >>> from short to int. >>> PR: 203922 >>> Submitted by: White Knight >>> MFC After: 4 weeks >>> >> You do realize that this breaks the ABI of the sysctls used to fetch >> connection lists (and so will break existing binaries like ucd-snmpd, >> etc.) >> and thus can't be MFC'd right? >> > OK, I will not MFC it. > > Is it worthwhile to extend the xsocket to have padding so that in 11.x and > beyond we can allow for some changes in the structure? > > Another idea I had was to include a version number with the sysctl request > so that we can send back versioned structures, let me know what you think > about that. > > The first idea will take not more than a few days for me to accomplish, > the second (versioning the sysctl) probably a few more days than that. We have similar construction (versioned ioctl) in FreeBSD ZFS but the main goal is to keep system bootable, not to support all functionalities. Do we change the structure often and is it important enough to warrant the complexity? I think kmem interface have a simple size check to guard against world/kernel inconsistency. I would second John's comment on the necessity of the change though, if one already have 32K of *backlogged* connections, it's probably not very useful to allow more coming in. It sounds like the application itself is seriously broken, and unless expanding the field have some performance benefit, I don't think it should stay. -- Xin LI https://www.delphij.net/ FreeBSD - The Power to Serve! Live free or die