From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from moutng.kundenserver.de ([212.227.126.188]) by canuck.infradead.org with esmtp (Exim 4.63 #1 (Red Hat Linux)) id 1Huxs4-0006WC-0d for linux-mtd@lists.infradead.org; Sun, 03 Jun 2007 17:44:29 -0400 From: Arnd Bergmann To: =?utf-8?q?J=C3=B6rn_Engel?= Subject: Re: [Patch 04/18] include/linux/logfs.h Date: Sun, 3 Jun 2007 23:42:25 +0200 References: <20070603183845.GA8952@lazybastard.org> <20070603184205.GE8952@lazybastard.org> In-Reply-To: <20070603184205.GE8952@lazybastard.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200706032342.27252.arnd@arndb.de> Cc: akpm@osdl.org, David Weinehall , Dongjun Shin , Kyle Moffett , linux-mtd@lists.infradead.org, Pavel Machek , Sam Ravnborg , Ulisses Furquim , CaT , Evgeniy Polyakov , Roland Dreier , Jamie Lokier , Pekka Enberg , Jan Engelhardt , Thomas Gleixner , Bill Davidsen , Albert Cahalan , John Stoffel , linux-kernel@vger.kernel.org, Ondrej Zajicek , linux-fsdevel@vger.kernel.org, David Woodhouse , Willy Tarreau List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sunday 03 June 2007, J=C3=B6rn Engel wrote: > +struct logfs_je_spillout { > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0__be64=C2=A0=C2=A0so_segment[0= ]; > +}__packed; All the on-disk data structures you define in this file have naturally aligned members, so the __packed attribute is not needed. However, I think it causes gcc to generate larger and slower code on some architectures, because now it has to assume that the data structure itself has no more than byte alignment. I'd simply remove all instances of __packed therefore. In order to verify that you got it right in all cases, build with '-Wpadded -Wpacked'. Arnd <>< From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752004AbXFCVoW (ORCPT ); Sun, 3 Jun 2007 17:44:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751051AbXFCVoK (ORCPT ); Sun, 3 Jun 2007 17:44:10 -0400 Received: from moutng.kundenserver.de ([212.227.126.188]:59265 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750827AbXFCVoI convert rfc822-to-8bit (ORCPT ); Sun, 3 Jun 2007 17:44:08 -0400 From: Arnd Bergmann To: =?utf-8?q?J=C3=B6rn_Engel?= Subject: Re: [Patch 04/18] include/linux/logfs.h Date: Sun, 3 Jun 2007 23:42:25 +0200 User-Agent: KMail/1.9.6 Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, akpm@osdl.org, Sam Ravnborg , John Stoffel , David Woodhouse , Jamie Lokier , Artem Bityutskiy , CaT , Jan Engelhardt , Evgeniy Polyakov , David Weinehall , Willy Tarreau , Kyle Moffett , Dongjun Shin , Pavel Machek , Bill Davidsen , Thomas Gleixner , Albert Cahalan , Pekka Enberg , Roland Dreier , Ondrej Zajicek , Ulisses Furquim References: <20070603183845.GA8952@lazybastard.org> <20070603184205.GE8952@lazybastard.org> In-Reply-To: <20070603184205.GE8952@lazybastard.org> X-Face: >j"dOR3XO=^3iw?0`(E1wZ/&le9!.ok[JrI=S~VlsF~}"P\+jx.GT@=?utf-8?q?=0A=09-oaEG?=,9Ba>v;3>:kcw#yO5?B:l{(Ln.2)=?utf-8?q?=27=7Dfw07+4-=26=5E=7CScOpE=3F=5D=5EXdv=5B/zWkA7=60=25M!DxZ=0A=09?= =?utf-8?q?8MJ=2EU5?="hi+2yT(k`PF~Zt;tfT,i,JXf=x@eLP{7B:"GyA\=UnN) =?utf-8?q?=26=26qdaA=3A=7D-Y*=7D=3A3YvzV9=0A=09=7E=273a=7E7I=7CWQ=5D?=<50*%U-6Ewmxfzdn/CK_E/ouMU(r?FAQG/ev^JyuX.%(By`" =?utf-8?q?L=5F=0A=09H=3Dbj?=)"y7*XOqz|SS"mrZ$`Q_syCd MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200706032342.27252.arnd@arndb.de> X-Provags-ID: V01U2FsdGVkX18W/7c1hjcF2K/wDwOWw1B1aXWKflCjmPP+Fvn bqwUGOerX9EwbOtx8U4oU02Hpc4RIFaqRh7U7RyI92/LT9H6L4 jrx2XK+s7fWbhToJRWIuQ== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 03 June 2007, Jörn Engel wrote: > +struct logfs_je_spillout { > +       __be64  so_segment[0]; > +}__packed; All the on-disk data structures you define in this file have naturally aligned members, so the __packed attribute is not needed. However, I think it causes gcc to generate larger and slower code on some architectures, because now it has to assume that the data structure itself has no more than byte alignment. I'd simply remove all instances of __packed therefore. In order to verify that you got it right in all cases, build with '-Wpadded -Wpacked'. Arnd <>< From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [Patch 04/18] include/linux/logfs.h Date: Sun, 3 Jun 2007 23:42:25 +0200 Message-ID: <200706032342.27252.arnd@arndb.de> References: <20070603183845.GA8952@lazybastard.org> <20070603184205.GE8952@lazybastard.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, akpm@osdl.org, Sam Ravnborg , John Stoffel , David Woodhouse , Jamie Lokier , Artem Bityutskiy , CaT , Jan Engelhardt , Evgeniy Polyakov , David Weinehall , Willy Tarreau , Kyle Moffett , Dongjun Shin , Pavel Machek , Bill Davidsen , Thomas Gleixner , Albert Cahalan , Pekka Enberg , Roland Dreier , Ondrej Zajicek , Ulisses Furquim To: =?utf-8?q?J=C3=B6rn_Engel?= Return-path: Received: from moutng.kundenserver.de ([212.227.126.188]:59265 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750827AbXFCVoI convert rfc822-to-8bit (ORCPT ); Sun, 3 Jun 2007 17:44:08 -0400 In-Reply-To: <20070603184205.GE8952@lazybastard.org> Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sunday 03 June 2007, J=C3=B6rn Engel wrote: > +struct logfs_je_spillout { > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0__be64=C2=A0=C2=A0so_segme= nt[0]; > +}__packed; All the on-disk data structures you define in this file have naturally aligned members, so the __packed attribute is not needed. However, I think it causes gcc to generate larger and slower code on some architectures, because now it has to assume that the data structure itself has no more than byte alignment. I'd simply remove all instances of __packed therefore. In order to verify that you got it right in all cases, build with '-Wpadded -Wpacked'. Arnd <>< - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html