Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757898AbaAJQCo (ORCPT ); Fri, 10 Jan 2014 11:02:44 -0500 Received: from mail-oa0-f43.google.com ([209.85.219.43]:54859 "EHLO mail-oa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751339AbaAJQCn (ORCPT ); Fri, 10 Jan 2014 11:02:43 -0500 MIME-Version: 1.0 In-Reply-To: <52C4C216.3070607@huawei.com> References: <52C2811C.4090907@huawei.com> <52C4C216.3070607@huawei.com> Date: Fri, 10 Jan 2014 17:02:42 +0100 Message-ID: Subject: Re: [PATCH] mm: add a new command-line kmemcheck value From: Vegard Nossum To: Xishi Qiu Cc: Ingo Molnar , "H. Peter Anvin" , Vegard Nossum , Pekka Enberg , Mel Gorman , wangnan0@huawei.com, "the arch/x86 maintainers" , LKML , Linux MM Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2 January 2014 02:34, Xishi Qiu wrote: > On 2013/12/31 18:12, Vegard Nossum wrote: >> On 31 December 2013 09:32, Xishi Qiu wrote: >>> Add a new command-line kmemcheck value: kmemcheck=3 (disable the feature), >>> this is the same effect as CONFIG_KMEMCHECK disabled. >>> After doing this, we can enable/disable kmemcheck feature in one vmlinux. >> >> Could you please explain what exactly the difference is between the >> existing kmemcheck=0 parameter and the new kmemcheck=3? > > kmemcheck=0: enable kmemcheck feature, but don't check the memory. > and the OS use only one cpu.(setup_max_cpus = 1) > kmemcheck=3: disable kmemcheck feature. > this is the same effect as CONFIG_KMEMCHECK disabled. > OS will use cpus as many as possible. > I see. In that case, I think it's better to allow all the CPUs to keep running while kmemcheck is disabled with kmemcheck=0 boot parameter, and offline them when/if kmemcheck is reenabled via /proc/sys/kernel/kmemcheck. Vegard -- 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/