From owner-freebsd-arm@FreeBSD.ORG Thu Feb 18 10:03:20 2010 Return-Path: Delivered-To: freebsd-arm@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AD2BD1065700 for ; Thu, 18 Feb 2010 10:03:20 +0000 (UTC) (envelope-from gjb@semihalf.com) Received: from smtp.semihalf.com (smtp.semihalf.com [213.17.239.109]) by mx1.freebsd.org (Postfix) with ESMTP id 5545F8FC15 for ; Thu, 18 Feb 2010 10:03:19 +0000 (UTC) Received: from localhost (unknown [213.17.239.109]) by smtp.semihalf.com (Postfix) with ESMTP id 4B43FC42D5; Thu, 18 Feb 2010 10:55:24 +0100 (CET) X-Virus-Scanned: by amavisd-new at semihalf.com Received: from smtp.semihalf.com ([213.17.239.109]) by localhost (smtp.semihalf.com [213.17.239.109]) (amavisd-new, port 10024) with ESMTP id z9RpXCi12fr8; Thu, 18 Feb 2010 10:55:23 +0100 (CET) Received: from [10.0.0.75] (unknown [213.17.239.108]) by smtp.semihalf.com (Postfix) with ESMTPA id 66FE6C42D4; Thu, 18 Feb 2010 10:55:23 +0100 (CET) Message-ID: <4B7D0E02.6020708@semihalf.com> Date: Thu, 18 Feb 2010 10:53:06 +0100 From: Grzegorz Bernacki User-Agent: Thunderbird 2.0.0.16 (X11/20090618) MIME-Version: 1.0 To: Rafal Jaworowski References: <20100217151607.GU43625@cicely7.cicely.de> <20100217151941.GV43625@cicely7.cicely.de> <20100217152900.GX43625@cicely7.cicely.de> <20100217.100004.321689434032786752.imp@bsdimp.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: rpaulo@gmail.com, freebsd-arm@FreeBSD.org, ticso@cicely7.cicely.de, ticso@cicely.de Subject: Re: kdump on ARM X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the StrongARM Processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Feb 2010 10:03:20 -0000 Rafal Jaworowski wrote: > On 2010-02-17, at 18:00, M. Warner Losh wrote: > >> In message: <20100217152900.GX43625@cicely7.cicely.de> >> Bernd Walter writes: >> : On Wed, Feb 17, 2010 at 04:19:41PM +0100, Bernd Walter wrote: >> : > On Wed, Feb 17, 2010 at 04:16:07PM +0100, Bernd Walter wrote: >> : > > On Wed, Feb 17, 2010 at 02:54:05PM +0000, Rui Paulo wrote: >> : > > > On 17 Feb 2010, at 14:18, Grzegorz Bernacki wrote: >> : > > > I wonder if this can't be made non arm conditional? >> : > >> : > Ups - I'd just recovered from Mr. Sandman's work. >> : > So we all agree about. >> : > Nevertheless it should be verified if this is just a faulty struct >> : > definition. >> : > On the other hand I think it is not because someone else wrote it is >> : > a brokem on mips as well. >> : >> : I'm really still sleeping - noone mentioned mips at all. >> : > > Either this struct is properly aligned or not. >> : > > So why should this be made conditional? >> : > > Non strict alignment architecturs also have problems with this, but >> : > > it is usualy just speed penalties. >> : > > There is one ARM sepcific struct missalignment problem. >> : > > In this case we usually add __packed macro to structure definition. >> : > > For most structures this usually means no change on other >> : > > archtitectures and we only declare the struct to forcibly be what the >> : > > programmer already expected. >> : > > Only a few programmers are aware that they expect something from >> : > > structures, which is not garantied. >> >> This code is clearly nutso when it comes to alignment. I've come up >> with a slightly better patch. I'd though about doing the structure >> assignment that I suggested in a prior note, but the compiler is free >> to assume alignment when copying the structures, which may end badly. >> There's no way we can add __packed or __aligned easily to this code >> (although the ktrstat and ktrsockaddr routines should be able to have >> that annotation, a quick test suggests that the annotations I tried >> didn't take right). >> >> I don't have a good ARM setup at the moment to actually test these >> changes. Can others test them? They seem to work for me on x86, but >> that isn't saying much. > > Thanks, this looks better. We'll test this in our set-up and verify, but only tomorrow I guess... > > Rafal > Yes, this patch is much better. I've tested it on ARM and it works fine. grzesiek