From owner-freebsd-arch@FreeBSD.ORG Tue Nov 1 18:19:12 2011 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 95E1D1065692 for ; Tue, 1 Nov 2011 18:19:12 +0000 (UTC) (envelope-from peter@wemm.org) Received: from mail-vx0-f182.google.com (mail-vx0-f182.google.com [209.85.220.182]) by mx1.freebsd.org (Postfix) with ESMTP id 4F0308FC15 for ; Tue, 1 Nov 2011 18:19:12 +0000 (UTC) Received: by vcbfk26 with SMTP id fk26so3236707vcb.13 for ; Tue, 01 Nov 2011 11:19:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wemm.org; s=google; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=j1GguU4cXwVbRUAhaVjetobPx/oDGg8wk0xSOIZJEa0=; b=CWO9aXOoDTElZziJNF0+GjZ7gmWd9apobsZx5WGTvlt9+OOwi3Lfh6R2ZD/hTIxeBu 6pvE3XkZga2t1EJKkiD9aCpp4nuU3UUs2/9NbpzKNuUNpn2siHxpmpnkbKoj7WNk5nZP BxxU0f3MXmLPkVG/4LwC8FBlVwTFF6RaP2wWA= MIME-Version: 1.0 Received: by 10.220.7.72 with SMTP id c8mr38290vcc.149.1320169652686; Tue, 01 Nov 2011 10:47:32 -0700 (PDT) Received: by 10.221.13.130 with HTTP; Tue, 1 Nov 2011 10:47:32 -0700 (PDT) In-Reply-To: <20111101141937.GV2258@hoeg.nl> References: <201110281426.00013.jhb@freebsd.org> <201110311717.53476.jhb@freebsd.org> <20111031221627.GR2258@hoeg.nl> <201111011001.42775.jhb@freebsd.org> <20111101141937.GV2258@hoeg.nl> Date: Tue, 1 Nov 2011 10:47:32 -0700 Message-ID: From: Peter Wemm To: Ed Schouten Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: arch@freebsd.org, Jilles Tjoelker Subject: Re: [PATCH] fadvise(2) system call 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: Tue, 01 Nov 2011 18:19:12 -0000 On Tue, Nov 1, 2011 at 7:19 AM, Ed Schouten wrote: > Hi John, > > * John Baldwin , 20111101 15:01: >> Hmmm, there is an fadvise(2) manpage. =A0I had presumed from that it was >> a public interface. > > That's interesting. What kind of distro/version are you using? I'm using > libc6-2.13-20ubuntu5 from Ubuntu 11.10 (amd64). Don't forget that the Linux kernel syscalls are not automatically published to userland like ours are. glibc is (usually) very deliberate about what symbols it publishes, what macros it defines in its #include mess, and so on. Just because a syscall is called "fadvise" in the kernel doesn't mean the userland part is fadvise as well, if it even exists. Heck, even glibc might not assume the syscall exists in the kernel. eg: mrename() and so on. eg: lseek vs llseek and all the syscall64 variants. Bottom line(s): 1) Is this a standardized symbol? 2) Is it used in other OS's? 3) Do the implementations vary? If it exists in a widely used linux, it counts a lot as a "defacto" standardized defintion. Also, does autoconf/automake have stubs to check for it? and so on. --=20 Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com; KI6FJV "All of this is for nothing if we don't go to the stars" - JMS/B5 "If Java had true garbage collection, most programs would delete themselves upon execution." -- Robert Sewell