From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030203AbWI0MEY (ORCPT ); Wed, 27 Sep 2006 08:04:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030204AbWI0MEY (ORCPT ); Wed, 27 Sep 2006 08:04:24 -0400 Received: from cantor.suse.de ([195.135.220.2]:51107 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1030203AbWI0MEX (ORCPT ); Wed, 27 Sep 2006 08:04:23 -0400 From: Andi Kleen To: Heiko Carstens Subject: Re: [PATCH] x86: Add portable getcpu call Date: Wed, 27 Sep 2006 14:04:09 +0200 User-Agent: KMail/1.9.3 Cc: Linux Kernel Mailing List , Martin Schwidefsky References: <200609262300.k8QN06dD013707@hera.kernel.org> <20060927113739.GB6872@osiris.boeblingen.de.ibm.com> In-Reply-To: <20060927113739.GB6872@osiris.boeblingen.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200609271404.09621.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > So this means that the contents of getcpu_cache will look completely > different if a process runs in 32bit mode or 64bit mode. Even if you're > saying "user programs should not..." this looks odd to me. > Is this really on purpose and do you really think that no user space > application will ever rely on the format of getcpu_cache? The vsyscalls do, but if anything else does it deserves breaking. In the user headers it will also be just a array blob. I was considering to xor it with a random value to bring the point across more strongly, but then didn't do it. Do you think I should? -Andi