From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755889Ab2GAShd (ORCPT ); Sun, 1 Jul 2012 14:37:33 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46234 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751436Ab2GAShc (ORCPT ); Sun, 1 Jul 2012 14:37:32 -0400 Message-ID: <4FF098E2.3040307@zytor.com> Date: Sun, 01 Jul 2012 11:37:22 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: "Eric W. Biederman" , Tejun Heo CC: hacklu , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] x86, boot: Optimize the elf header handling. References: <4FB492F7.8050401@gmail.com> <87ipf9gtsb.fsf@xmission.com> <4FCAD590.8000506@zytor.com> <87obp0bxdv.fsf@xmission.com> <4FCB602B.70907@zytor.com> <87fwacb0jq.fsf_-_@xmission.com> <877gvob0g4.fsf_-_@xmission.com> <4FF06701.6010004@zytor.com> <4FF06DF4.4000006@zytor.com> <87wr2nsbvi.fsf@xmission.com> <4FF0769F.8090105@zytor.com> <87sjdbsb0v.fsf@xmission.com> <4FF07E66.2020706@zytor.com> <87d34fs914.fsf@xmission.com> <4FF085B1.6070604@zytor.com> <87a9zj9w43.fsf@xmission.com> In-Reply-To: <87a9zj9w43.fsf@xmission.com> X-Enigmail-Version: 1.4.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/01/2012 11:25 AM, Eric W. Biederman wrote: > > Well I see what is going on now. > > In the vmlinux the paddrs and the poffsests stop tracking when they > come to the percpu PT_LOAD segment. > > It looks like we give the percpu segment a 4K alignment in memory > and a 2M alignment in the file. > > It looks like something is causing ld to compute an unfortunate physical > load address for the percpu section. > > At first glace I would say that is a bug. Either we need the alignment > or we don't. But if we need the alignment we certainly need it to > be respected for the real memory locations of the init symbols.. > If we don't need it, I think we can use -z max-page-size=4096, but we use the PMD alignment for percpu on x86-64; Tejun, does that apply to the .data..percpu section in the executable as well? -hpa