Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755837AbYBSPmA (ORCPT ); Tue, 19 Feb 2008 10:42:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752013AbYBSPlx (ORCPT ); Tue, 19 Feb 2008 10:41:53 -0500 Received: from mtagate4.uk.ibm.com ([195.212.29.137]:11306 "EHLO mtagate4.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751551AbYBSPlw (ORCPT ); Tue, 19 Feb 2008 10:41:52 -0500 Date: Tue, 19 Feb 2008 16:41:50 +0100 From: Heiko Carstens To: Bastian Blank , Martin Schwidefsky , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: Re: [patch 07/13] Initialize per cpu lowcores on cpu hotplug. Message-ID: <20080219154149.GB11599@osiris.boeblingen.de.ibm.com> References: <20080219144047.587547541@de.ibm.com> <20080219144504.392301782@de.ibm.com> <20080219151355.GA24547@wavehammer.waldi.eu.org> <20080219153855.GA11599@osiris.boeblingen.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080219153855.GA11599@osiris.boeblingen.de.ibm.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1208 Lines: 25 On Tue, Feb 19, 2008 at 04:38:56PM +0100, Heiko Carstens wrote: > On Tue, Feb 19, 2008 at 04:13:55PM +0100, Bastian Blank wrote: > > On Tue, Feb 19, 2008 at 03:40:54PM +0100, Martin Schwidefsky wrote: > > > + /* > > > + * Only need to copy the first 512 bytes from address 0. But since > > > + * the compiler emits a warning if src == NULL for memcpy use copy_page > > > + * instead. Copies more than needed but this code is not performance > > > + * critical. > > > + */ > > > + copy_page(lowcore, &S390_lowcore); > > > > Boah, workaround alert. Why do you not fix the compiler? > > We need to copy from address 0 (that's where the lowcore resides). But gcc > insists to complain if memcpy is used with src == NULL.. Now what? Erm sorry, misread your question. Usually it's a bug to use memcpy with src == NULL. In this case it's ok. So I think it's perfectly ok if gcc emits a warning. If you know of a better way to get around this please let me know. -- 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/