From owner-freebsd-hackers@FreeBSD.ORG Fri Oct 31 02:16:57 2008 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 4B7E01065672; Fri, 31 Oct 2008 02:16:57 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.delphij.net (delphij-pt.tunnel.tserv2.fmt.ipv6.he.net [IPv6:2001:470:1f03:2c9::2]) by mx1.freebsd.org (Postfix) with ESMTP id E6F728FC08; Fri, 31 Oct 2008 02:16:56 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.geekcn.org (tarsier.geekcn.org [211.166.10.233]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by tarsier.delphij.net (Postfix) with ESMTPS id D767428449; Fri, 31 Oct 2008 10:16:55 +0800 (CST) Received: from localhost (tarsier.geekcn.org [211.166.10.233]) by tarsier.geekcn.org (Postfix) with ESMTP id 7C31DEB9E54; Fri, 31 Oct 2008 10:16:55 +0800 (CST) X-Virus-Scanned: amavisd-new at geekcn.org Received: from tarsier.geekcn.org ([211.166.10.233]) by localhost (mail.geekcn.org [211.166.10.233]) (amavisd-new, port 10024) with ESMTP id 7YTczj-ml35t; Fri, 31 Oct 2008 10:16:50 +0800 (CST) Received: from charlie.delphij.net (adsl-76-237-33-62.dsl.pltn13.sbcglobal.net [76.237.33.62]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by tarsier.geekcn.org (Postfix) with ESMTPSA id 66A9CEB99EF; Fri, 31 Oct 2008 10:16:47 +0800 (CST) DomainKey-Signature: a=rsa-sha1; s=default; d=delphij.net; c=nofws; q=dns; h=message-id:date:from:reply-to:organization:user-agent: mime-version:to:cc:subject:references:in-reply-to: x-enigmail-version:openpgp:content-type:content-transfer-encoding; b=xKVoX4K1aXbB7DEOqUWSw+4ZvD8KbSQQA0eT497RXdHL5+hqCk647oR6qaYlBT03S UEIaRD3PRzbxZHYH6lsdw== Message-ID: <490A6A8A.7080504@delphij.net> Date: Thu, 30 Oct 2008 19:16:42 -0700 From: Xin LI Organization: The FreeBSD Project User-Agent: Thunderbird 2.0.0.17 (X11/20080928) MIME-Version: 1.0 To: Jeremy Chadwick References: <20081030154711.GA8416@icarus.home.lan> In-Reply-To: <20081030154711.GA8416@icarus.home.lan> X-Enigmail-Version: 0.95.7 OpenPGP: id=18EDEBA0; url=http://www.delphij.net/delphij.asc Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org Subject: Re: open(2) and O_NOATIME X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: d@delphij.net List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Oct 2008 02:16:57 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Jeremy Chadwick wrote: > I've recently been reading about Linux's O_NOATIME flag to open(2), and > I'm curious why we haven't implemented this. There seem to be a lot of > good reasons to implement such a thing. > > Chances are it's due to lack of time/interest, which is expected, but I > was wondering if there were other reasons. > > I realise mount's noatime trumps this, but there are lots of scenarios > where atime is desired as a default, but disabled in specific cases. Em... Allowing administrators to disable NOATIME would be a good thing, but wouldn't allowing arbitrary program to decide whether atime should be changed, be a serious security disaster? Disclaimer: I'm not a big atime fan myself, actually I disable atime on a lot of my servers for performance reasons :) Cheers, - -- Xin LI http://www.delphij.net/ FreeBSD - The Power to Serve! -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkkKaooACgkQi+vbBBjt66CImQCgj51GGHXFaGhsFk4fAAWhmfV5 +s4An2Hn2TCVhqXEpzEL3xNwxy6YE84M =n7f/ -----END PGP SIGNATURE-----