From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755606Ab2ETNz6 (ORCPT ); Sun, 20 May 2012 09:55:58 -0400 Received: from orion.tchmachines.com ([208.76.84.200]:59757 "EHLO orion.tchmachines.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755458Ab2ETNz4 (ORCPT ); Sun, 20 May 2012 09:55:56 -0400 Message-ID: <4FB8F7E9.4020005@scalemp.com> Date: Sun, 20 May 2012 16:55:53 +0300 From: Vlad Reply-To: vlad@scalemp.com Organization: ScaleMP User-Agent: Mozilla/5.0 (X11; Linux i686; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Ingo Molnar CC: linux-kernel , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Shai Fultheim (Shai@ScaleMP.com)" Subject: Re: [PATCH v2 2/2] x86: Added read_mostly declaration/definition to vars from smp.h References: <201205151831.57871.vlad@scalemp.com> <20120518081416.GA20872@gmail.com> In-Reply-To: <20120518081416.GA20872@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - orion.tchmachines.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - scalemp.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/18/2012 11:14 AM, Ingo Molnar wrote: > * Vlad Zolotarov wrote: > >> Added a "read-mostly" qualifier to the following variables in smp.h: >> - cpu_sibling_map >> - cpu_core_map >> - cpu_llc_shared_map >> - cpu_llc_id >> - cpu_number >> - x86_cpu_to_apicid >> - x86_bios_cpu_apicid >> - x86_cpu_to_logical_apicid >> >> As long as all the variables above are only written during the initialization, >> this change is meant to prevent the false sharing and improve the >> performance on large multiprocessor systems. >> >> Signed-off-by: Vlad Zolotarov >> Signed-off-by: Shai Fultheim >> --- >> arch/x86/include/asm/apic.h | 2 +- >> arch/x86/include/asm/smp.h | 16 ++++++++-------- >> arch/x86/kernel/apic/apic.c | 6 +++--- >> arch/x86/kernel/setup_percpu.c | 2 +- >> arch/x86/kernel/smpboot.c | 8 ++++---- >> 5 files changed, 17 insertions(+), 17 deletions(-) > > This does not build on !SMP kernels that has APIC enabled. Oops... :) My bad. I'll rebase and respin. Thanks, vlad > > Thanks, > > Ingo > -- > 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/ >