Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754645Ab3GDKW6 (ORCPT ); Thu, 4 Jul 2013 06:22:58 -0400 Received: from mga11.intel.com ([192.55.52.93]:17777 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750769Ab3GDKW5 (ORCPT ); Thu, 4 Jul 2013 06:22:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,994,1363158000"; d="scan'208";a="365228313" Message-ID: <51D54CBD.1010400@intel.com> Date: Thu, 04 Jul 2013 18:21:49 +0800 From: Alex Shi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: Thomas Gleixner CC: hpa@linux.intel.com, tim.c.chen@linux.intel.com, linux-kernel@vger.kernel.org, andi.kleen@intel.com, a.p.zijlstra@chello.nl, mingo@elte.hu Subject: Re: [PATCH 1/3] clocksource: clean up clocksource_select References: <1372916056-24301-1-git-send-email-alex.shi@intel.com> <1372916056-24301-2-git-send-email-alex.shi@intel.com> In-Reply-To: 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 Content-Length: 965 Lines: 32 > We need this check and it is completely unrelated to the problem > you're trying to solve. > > Assume the following: > > System boots with clocksource A and switches into highres mode. > Now clocksource B gets registered and B is not highres capable. > > clocksource_find_best() selects again A, but we have > clocksource=B on the kernel command line to override the kernel > decision. > > By removing the check, you install he non highres capable clocksource > B and kill the machine. > You'r right. my bad, Sorry! BTW, why we allow user override a second best clocksource? I mean user can override the tsc with hpet. because undetected unstable tsc? -- Thanks Alex -- 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/