From owner-freebsd-arch@FreeBSD.ORG Sun Apr 13 16:04:35 2008 Return-Path: Delivered-To: arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 13766106566B for ; Sun, 13 Apr 2008 16:04:35 +0000 (UTC) (envelope-from bright@elvis.mu.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id 015738FC16 for ; Sun, 13 Apr 2008 16:04:34 +0000 (UTC) (envelope-from bright@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1192) id BE76D1A4D80; Sun, 13 Apr 2008 09:04:34 -0700 (PDT) Date: Sun, 13 Apr 2008 09:04:34 -0700 From: Alfred Perlstein To: Poul-Henning Kamp Message-ID: <20080413160434.GD95731@elvis.mu.org> References: <20080412221654.S959@desktop> <1309.1208100178@critter.freebsd.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1309.1208100178@critter.freebsd.dk> User-Agent: Mutt/1.4.2.3i Cc: arch@freebsd.org Subject: Re: f_offset X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 13 Apr 2008 16:04:35 -0000 * Poul-Henning Kamp [080413 08:23] wrote: > In message <20080412221654.S959@desktop>, Jeff Roberson writes: > > >> The non p-prefix versions should always be serialized, because there > >> is know way of knowing where they read/write if you don't. > > > >Well that's at odds with what the standard says and what others implement. > >I think there is a clear case for serializing writes. I don't see what > >advantage we get from serializing reads. The heavy cost of > >synchronization should be justified by actual need. > > If you don't serialize read(2) and readv(2), how do you know where > they read from ? You don't always care, if the file is a fixed record file or datagram socket then it does not matter. -- - Alfred Perlstein