Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754996AbYBQGW3 (ORCPT ); Sun, 17 Feb 2008 01:22:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752556AbYBQGWU (ORCPT ); Sun, 17 Feb 2008 01:22:20 -0500 Received: from rv-out-0910.google.com ([209.85.198.190]:22574 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752479AbYBQGWT (ORCPT ); Sun, 17 Feb 2008 01:22:19 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=EcbF0R34S+axsjXOm5JxCvFpY+cstw1uX8Bd4zcVfjGQqLpkZSsDNVzPM4OSsWl4ePRi8b7O36Uab75P2lh1A/bnoavpTBTxA63o+C6kW+o9G2yuZ82r5a5qscfMsyqltRNvJTRi6LE3eDaUKszJl9d55AleouAqoa2FmQ8BDkc= Message-ID: <86802c440802162222k47f5bebbhf42fef0f11ce3243@mail.gmail.com> Date: Sat, 16 Feb 2008 22:22:17 -0800 From: "Yinghai Lu" To: "Ingo Molnar" Subject: Re: [PATCH 3/4] x86_64: Fold pda into per cpu area Cc: travis@sgi.com, "Andrew Morton" , "Andi Kleen" , "Thomas Gleixner" , "Jeremy Fitzhardinge" , "Christoph Lameter" , "Jack Steiner" , linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: <20080215201640.GA6200@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080201191414.961558000@sgi.com> <20080201191415.450555000@sgi.com> <20080215201640.GA6200@elte.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1748 Lines: 56 On Feb 15, 2008 12:16 PM, Ingo Molnar wrote: > > * travis@sgi.com wrote: > > > include/asm-generic/vmlinux.lds.h | 2 + > > include/linux/percpu.h | 9 ++++- > > couldnt these two generic bits be done separately (perhaps a preparatory > but otherwise NOP patch pushed upstream straight away) to make > subsequent patches only touch x86 architecture files? this patch need to apply to mainline asap. or you need revert to the patch about include/asm-x86/percpu.h +#ifdef CONFIG_X86_64 +#include + +/* Same as asm-generic/percpu.h, except that we store the per cpu offset + in the PDA. Longer term the PDA and every per cpu variable + should be just put into a single section and referenced directly + from %gs */ + +#ifdef CONFIG_SMP +#include + +#define __per_cpu_offset(cpu) (cpu_pda(cpu)->data_offset) +#define __my_cpu_offset read_pda(data_offset) + +#define per_cpu_offset(x) (__per_cpu_offset(x)) + #endif +#include + +DECLARE_PER_CPU(struct x8664_pda, pda); + +#else /* CONFIG_X86_64 */ because current tree in setup_per_cpu_areas will have cpu_pda(i)->data_offset = ptr - __per_cpu_start; but at that time all APs will use cpu_pda for boot cpu...,and APs will get their pda in do_boot_cpu() the result is all cpu will have same data_offset, there will share one per_cpu_data..that is totally wrong!! that could explain a lot of strange panic ....recently about NUMA... YH -- 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/