Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753217AbXJVVsU (ORCPT ); Mon, 22 Oct 2007 17:48:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751562AbXJVVsK (ORCPT ); Mon, 22 Oct 2007 17:48:10 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:39054 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751249AbXJVVsH (ORCPT ); Mon, 22 Oct 2007 17:48:07 -0400 Date: Mon, 22 Oct 2007 14:47:38 -0700 (PDT) From: Linus Torvalds To: Alan Cox cc: Geert Uytterhoeven , Jens Axboe , Linux Kernel Development , mingo@elte.hu, Linux/m68k Subject: Re: [PATCH 09/10] Change table chaining layout In-Reply-To: <20071022224343.4abf3c96@the-village.bc.nu> Message-ID: References: <1193076664-13652-1-git-send-email-jens.axboe@oracle.com> <1193076664-13652-10-git-send-email-jens.axboe@oracle.com> <20071022211617.31f5c63d@the-village.bc.nu> <20071022224343.4abf3c96@the-village.bc.nu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1087 Lines: 27 On Mon, 22 Oct 2007, Alan Cox wrote: > For structures, not array elements or stack objects. Does gcc now get > aligned correct as an attribute on a stack object ? I think m68k stack layout still guarantees 4-byte-alignment, no? > Still doesn't answer the rather more important question - why not just > stick a NULL on the end instead of all the nutty hacks ? You still do need one bit for the discontiguous case, so it's not like you can avoid the hacks anyway (unless you just blow up the structure entirely) and make it a separate member). So once you have that bit+pointer, using a separate NULL entry isn't exactly prettier. Especially as we actally want to see the difference between "end-of-allocation" and "not yet filled in", so you shouldn't use NULL anyway, you should probably use something like "all-ones". Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/