From owner-freebsd-net@freebsd.org Sun Apr 15 14:28:10 2018 Return-Path: Delivered-To: freebsd-net@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 87887F970F5 for ; Sun, 15 Apr 2018 14:28:10 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [78.47.246.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 0844276A93 for ; Sun, 15 Apr 2018 14:28:09 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (root@eg.sd.rdtc.ru [62.231.161.221] (may be forged)) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id w3FES1Jx036783 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 15 Apr 2018 16:28:02 +0200 (CEST) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: freebsd-rwg@pdx.rh.CN85.dnsmgr.net Received: from [10.58.0.4] ([10.58.0.4]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id w3FERsKN067782 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Sun, 15 Apr 2018 21:27:54 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: High rate of NFS cache misses after upgrading from 10.3-prerelease to 11.1-release To: "Rodney W. Grimes" References: <201804151419.w3FEJVi4046362@pdx.rh.CN85.dnsmgr.net> Cc: Rick Macklem , Niels Kobschaetzki , "freebsd-net@freebsd.org" From: Eugene Grosbein Message-ID: <5AD36164.4000406@grosbein.net> Date: Sun, 15 Apr 2018 21:27:48 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <201804151419.w3FEJVi4046362@pdx.rh.CN85.dnsmgr.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=2.2 required=5.0 tests=BAYES_00, LOCAL_FROM, RDNS_NONE autolearn=no autolearn_force=no version=3.4.1 X-Spam-Report: * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 2.6 LOCAL_FROM From my domains * 1.9 RDNS_NONE Delivered to internal network by a host with no rDNS X-Spam-Level: ** X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on hz.grosbein.net X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 15 Apr 2018 14:28:10 -0000 15.04.2018 21:19, Rodney W. Grimes wrote: >>>> It is a website with quite some traffic handles by three webservers behind a pair >of loadbalancers. >>>> We see a loss of 20% in speed(TTFB reduced by 100ms; sounds not a lot but >Google et al doesn?t like it at all) after upgrading to 11.1 with a combined upgrade >to php7.1. On another server without NFS that upgrade improved performance >considerably (I was told ca 30% by the front end-dev) >>> One thing you could try is booting the 11.1 kernel on an 10.3 system. Newer >>> FreeBSD kernels should work with older userland. >> >> Though one should remember that some important system utilities >> may and probably will not work with newer kernel, like /sbin/ipfw, route, >> ifconfig, netstat etc. > > I thought that as long as the newer kernel has the right > COMPAT_FREEBSD10 compiled in that all this stuff should work. > Am I miss understanding this kernel option? COMPAT_FREEBSD10 does not cover all cases (in-kernel structures etc.) and bugs can happen, too. You won't be happy if you discover similar case in /sbin/ipfw or ifconfig as this combination (old ipfw+new kernel) is not something we test thoroughly.