From owner-freebsd-hackers@FreeBSD.ORG Thu Feb 12 17:06:54 2009 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 8AD761065673 for ; Thu, 12 Feb 2009 17:06:54 +0000 (UTC) (envelope-from jhs@berklix.org) Received: from flat.berklix.org (flat.berklix.org [83.236.223.115]) by mx1.freebsd.org (Postfix) with ESMTP id 0C6ED8FC1F for ; Thu, 12 Feb 2009 17:06:53 +0000 (UTC) (envelope-from jhs@berklix.org) Received: from js.berklix.net (p549A771B.dip.t-dialin.net [84.154.119.27]) (authenticated bits=0) by flat.berklix.org (8.13.8/8.13.8) with ESMTP id n1CH6nm5046032; Thu, 12 Feb 2009 18:06:52 +0100 (CET) (envelope-from jhs@berklix.org) Received: from fire.js.berklix.net (fire.js.berklix.net [192.168.91.41]) by js.berklix.net (8.13.8/8.13.8) with ESMTP id n1CH6bVH032358; Thu, 12 Feb 2009 18:06:37 +0100 (CET) (envelope-from jhs@berklix.org) Received: from fire.js.berklix.net (localhost [127.0.0.1]) by fire.js.berklix.net (8.14.3/8.14.3) with ESMTP id n1CH75XW003391; Thu, 12 Feb 2009 18:07:10 +0100 (CET) (envelope-from jhs@fire.js.berklix.net) Message-Id: <200902121707.n1CH75XW003391@fire.js.berklix.net> To: Jille Timmermans From: "Julian Stacey" Organization: http://berklix.com BSD Unix Linux Consultancy, Munich Germany User-agent: EXMH on FreeBSD http://berklix.com/free/ X-URL: http://berklix.com In-reply-to: Your message "Thu, 12 Feb 2009 17:34:23 +0100." <49944F8F.5080104@quis.cx> Date: Thu, 12 Feb 2009 18:07:05 +0100 Sender: jhs@berklix.org Cc: freebsd-hackers@freebsd.org, Andrew Brampton Subject: Re: pahole - Finding holes in kernel structs 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, 12 Feb 2009 17:06:54 -0000 Hi, Reference: > From: Jille Timmermans > Date: Thu, 12 Feb 2009 17:34:23 +0100 > Message-id: <49944F8F.5080104@quis.cx> Jille Timmermans wrote: > Julian Stacey schreef: > >> 1) Is it worth my time trying to rearrange structs? > > > > I wondered whether as a sensitivity test, some version of gcc (or > > its competitor ?) might have capability to automatically re-order > > variables ? but found nothing in man gcc "Optimization Options". > There is a __packed attribute, I don't know what it exactly does and > whether it is an improvement. Ah: gcc -fpack-struct Cheers, Julian -- Julian Stacey: BSDUnixLinux C Prog Admin SysEng Consult Munich www.berklix.com Mail plain ASCII text. HTML & Base64 text are spam. www.asciiribbon.org