From owner-freebsd-performance@FreeBSD.ORG Wed Mar 19 23:40:07 2014 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8158EC1 for ; Wed, 19 Mar 2014 23:40:07 +0000 (UTC) Received: from mail01.lax1.stackjet.com (mon01.lax1.stackjet.com [174.136.104.178]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 62CA1E1A for ; Wed, 19 Mar 2014 23:40:06 +0000 (UTC) Received: from [10.23.9.200] (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sean@chittenden.org) by mail01.lax1.stackjet.com (Postfix) with ESMTPSA id C54423E8EA4; Wed, 19 Mar 2014 16:33:13 -0700 (PDT) Received: from [10.23.9.200] ([173.228.12.189] helo=[10.23.9.200]) by nutscrape.filter with SMTPS(ECDHE-RSA-AES256-SHA) (2.4.2); 19 Mar 2014 16:33:10 -0700 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 7.2 \(1874\)) Subject: Re: FreeBSD 10 and PostgreSQL 9.3 scalability issues From: Sean Chittenden In-Reply-To: <532A192A.1070509@gmail.com> Date: Wed, 19 Mar 2014 16:33:10 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: References: <5327B9B7.3050103@gmail.com> <2610F490C952470C9D15999550F67068@multiplay.co.uk> <532A192A.1070509@gmail.com> To: Petr Janda X-Mailer: Apple Mail (2.1874) X-Assp-Version: 2.4.2(14058) on nutscrape.filter X-Assp-ID: nutscrape.filter m-71993-40633 X-Assp-Session: 850424720 (mail 1) X-Assp-Envelope-From: sean@chittenden.org X-Assp-Intended-For: janda.petr@gmail.com X-Assp-Intended-For: killing@multiplay.co.uk X-Assp-Intended-For: freebsd-performance@freebsd.org X-Assp-Client-TLS: yes X-Assp-Server-TLS: yes X-Assp-Whitelisted: Yes Cc: freebsd-performance@freebsd.org, Steven Hartland X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Mar 2014 23:40:07 -0000 > As far as I know, the test was done on both UFS2 and ZFS and the > difference was marginal. As Adrian pointed out, there is an mmap(2) mutex in the way. Starting in = PostgreSQL 9.3, shared buffers are allocated out of mmap(2) instead of = shm. shm is only used to notify the PostgreSQL postmaster that a child = process exited/crashed (when a pid detaches from a shm segment, there is = a kernel event, but there is no kernel event when detaching from an = mmap(2) region). -sc http://www.postgresql.org/docs/9.3/static/release-9-3.html#AEN115039 >>> Just want to share these pgbench results done by DragonFlyBSD, and = would >>> like some input on why these numbers look so bad and what can be = done to >>> improve (ie. kernel tunables etc) the performance. >>>=20 >>> = http://lists.dragonflybsd.org/pipermail/users/attachments/20140310/4250b96= 1/attachment-0001.pdf >>>=20 >>=20 >>=20 >> Do you have the ability to test with FreeBSD 8.x and 9.x to see if = this is >> regression? >>=20 >> Also you don't mention the FS used in each case, so I'm wondering if = you >> used a ZFS install of FreeBSD which could help to explain things. -- Sean Chittenden sean@chittenden.org