From owner-freebsd-hackers@FreeBSD.ORG Thu Feb 12 16:50:10 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 2E9DC106564A for ; Thu, 12 Feb 2009 16:50:10 +0000 (UTC) (envelope-from jille@quis.cx) Received: from mulgore.hexon-is.nl (mulgore.hexon-is.nl [82.94.237.14]) by mx1.freebsd.org (Postfix) with ESMTP id 5F7D58FC19 for ; Thu, 12 Feb 2009 16:50:09 +0000 (UTC) (envelope-from jille@quis.cx) Received: from [10.0.0.142] (gw.hexon-nijmegen.nl [82.93.241.107]) (authenticated bits=0) by mulgore.hexon-is.nl (8.14.1/8.13.8) with ESMTP id n1CGYMDV017094; Thu, 12 Feb 2009 17:34:23 +0100 Message-ID: <49944F8F.5080104@quis.cx> Date: Thu, 12 Feb 2009 17:34:23 +0100 From: Jille Timmermans User-Agent: Thunderbird 2.0.0.19 (Windows/20081209) MIME-Version: 1.0 To: Julian Stacey References: <200902121549.n1CFnLdt002361@fire.js.berklix.net> In-Reply-To: <200902121549.n1CFnLdt002361@fire.js.berklix.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Hexon-MailScanner-Information: Please contact the ISP for more information X-Hexon-MailScanner-ID: n1CGYMDV017094 X-Hexon-MailScanner: Found to be clean X-Hexon-MailScanner-From: jille@quis.cx X-Hexon-MailScanner-Watermark: 1235061266.61968@ppP5W5Ss1URf75CK2+cshQ 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 16:50:10 -0000 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. -- Jille > > Cheers, > Julian