From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932181Ab2GBQ4k (ORCPT ); Mon, 2 Jul 2012 12:56:40 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:57427 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754050Ab2GBQ4j (ORCPT ); Mon, 2 Jul 2012 12:56:39 -0400 Date: Mon, 2 Jul 2012 09:56:33 -0700 From: Tejun Heo To: "H. Peter Anvin" Cc: "Eric W. Biederman" , hacklu , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] x86, boot: Optimize the elf header handling. Message-ID: <20120702165633.GA555@google.com> References: <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> <4FF098E2.3040307@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4FF098E2.3040307@zytor.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, guys. On Sun, Jul 01, 2012 at 11:37:22AM -0700, H. Peter Anvin wrote: > 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? I don't think the .data..percpu section needs 2M alignment. The percpu data section is only used as init template and actual percpu addresses always go through offsetting against __per_cpu_offset[] - no matter what the vaddrs in the vmlinux are, they get offsetted into 2M aligned linear address if necessary. I think the only alignment .data..percpu needs is cacheline alignment for separating its subsections. Thanks. -- tejun