From owner-freebsd-hackers@FreeBSD.ORG Thu Feb 23 15:18:21 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BAB131065670 for ; Thu, 23 Feb 2012 15:18:21 +0000 (UTC) (envelope-from dudu@dudu.ro) Received: from mail-gy0-f182.google.com (mail-gy0-f182.google.com [209.85.160.182]) by mx1.freebsd.org (Postfix) with ESMTP id 6AE268FC14 for ; Thu, 23 Feb 2012 15:18:21 +0000 (UTC) Received: by ghbg15 with SMTP id g15so723146ghb.13 for ; Thu, 23 Feb 2012 07:18:20 -0800 (PST) Received-SPF: pass (google.com: domain of dudu@dudu.ro designates 10.50.155.231 as permitted sender) client-ip=10.50.155.231; Authentication-Results: mr.google.com; spf=pass (google.com: domain of dudu@dudu.ro designates 10.50.155.231 as permitted sender) smtp.mail=dudu@dudu.ro; dkim=pass header.i=dudu@dudu.ro Received: from mr.google.com ([10.50.155.231]) by 10.50.155.231 with SMTP id vz7mr2315434igb.26.1330010300691 (num_hops = 1); Thu, 23 Feb 2012 07:18:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dudu.ro; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=ZCzEs60V/gUAmWEuwTYU8asbaOKuqBtRWhXHYxoATWk=; b=OSDgcWCCW7ndJUKzlBa2B2q1fTxK2wO9x4Yb0YaSSO3MAorWf+kQso83K3nIBgAY9g 3IVIufIMqsEJZWpR0trBV6EngWj1UhWNji9MJPlxVzMfHMAIPAAAeqcoGXBGgCD9Cpwy cP+BvqiZcBuR2duiMYpMBAGdgbJMBFdvykD1s= Received: by 10.50.155.231 with SMTP id vz7mr1790758igb.26.1330008404801; Thu, 23 Feb 2012 06:46:44 -0800 (PST) MIME-Version: 1.0 Received: by 10.42.223.69 with HTTP; Thu, 23 Feb 2012 06:46:04 -0800 (PST) In-Reply-To: <4F46500D.3070609@my.gd> References: <4F45AB76.5050201@FreeBSD.org> <201202230822.16304.jhb@freebsd.org> <4F46500D.3070609@my.gd> From: Vlad Galu Date: Thu, 23 Feb 2012 14:46:04 +0000 Message-ID: To: Damien Fleuriot X-Gm-Message-State: ALoCoQnLm1764jvPl6ISwhPO+q7NrlByTskxjtS75ugjLSTR7vcWqQcWvXFkCEX3HgS7I7f7uROQ Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-hackers@freebsd.org Subject: Re: PostgreSQL benchmarks (now with Linux numbers) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Feb 2012 15:18:21 -0000 On Thu, Feb 23, 2012 at 2:41 PM, Damien Fleuriot wrote: > > > On 2/23/12 2:22 PM, John Baldwin wrote: > > On Wednesday, February 22, 2012 9:59:02 pm Doug Barton wrote: > >> On 02/22/2012 01:42, Ivan Voras wrote: > >>> The Dragonfly team has recently liberated their VM from the giant lock > and there are some interesting benchmarks comparing it to FreeBSD 9 and a > > derivative of RedHat Enterprise Linux: > >>> > >>> http://leaf.dragonflybsd.org/mailarchive/kernel/2011-11/msg00008.html > >>> > >>> Other developments are described in their release notes: > http://www.dragonflybsd.org/release30/ > >> > >> The 4.5 times improvement by enabling kern.ipc.shm_use_phys is pretty > >> notable, what prevents us from enabling that by default? > > > > It makes all your SYSV SHMs wired. That's fine if you are running a > dedicated > > server using SYSV SHMs where you want that process to use all the RAM in > the > > machine (e.g. a pgqsl server). It's not so great for a general purpose > load > > where you would like an otherwise-idle process using SYSV SHMs to have > the SHMs > > paged out to swap if other processes on the machine need memory and the > box is > > under memory pressure. > > > > John, any chance we can get that in layman's terms ? > > I'm totally no coder, but I'd really like if we could do this at my work > place to increase our firewalls' performances. > Hi Damien, The above setting prevents the SYSV shared memory from being swapped by the pager. It is useful in a database context, where you want the pages to be available imediately, without having to wait until they are loaded back from disk (in a memory constrained environment). I won't help your firewall at all. -- Good, fast & cheap. Pick any two.