Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270358AbUJUEre (ORCPT ); Thu, 21 Oct 2004 00:47:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270430AbUJUErZ (ORCPT ); Thu, 21 Oct 2004 00:47:25 -0400 Received: from fw.osdl.org ([65.172.181.6]:4069 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S270358AbUJUEn0 (ORCPT ); Thu, 21 Oct 2004 00:43:26 -0400 Date: Wed, 20 Oct 2004 21:36:22 -0700 From: Andrew Morton To: Nick Piggin Cc: andrea@novell.com, linux-kernel@vger.kernel.org Subject: Re: ZONE_PADDING wastes 4 bytes of the new cacheline Message-Id: <20041020213622.77afdd4a.akpm@osdl.org> In-Reply-To: <417728B0.3070006@yahoo.com.au> References: <20041021011714.GQ24619@dualathlon.random> <417728B0.3070006@yahoo.com.au> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 707 Lines: 30 Nick Piggin wrote: > > > #if defined(CONFIG_SMP) > > struct zone_padding { > > - int x; > > } ____cacheline_maxaligned_in_smp; > > #define ZONE_PADDING(name) struct zone_padding name; > > #else > > Perhaps to keep old compilers working? Not sure. gcc-2.95 is OK with it. Stock 2.6.9: sizeof(struct zone) = 1920 With Andrea's patch: sizeof(struct zone) = 1536 With ZONE_PADDING removed: sizeof(struct zone) = 1408 - 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/