From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934309Ab1ESS2I (ORCPT ); Thu, 19 May 2011 14:28:08 -0400 Received: from out2.smtp.messagingengine.com ([66.111.4.26]:48164 "EHLO out2.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933941Ab1ESSZy (ORCPT ); Thu, 19 May 2011 14:25:54 -0400 X-Sasl-enc: StP7qbNI7eDMHrklwaU7fOEYXlBXx4Nf/3hwMNK04z+W 1305829553 X-Mailbox-Line: From gregkh@clark.kroah.org Thu May 19 11:24:37 2011 Message-Id: <20110519182437.773080895@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Thu, 19 May 2011 11:23:45 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, John Stultz , Thomas Gleixner Subject: [15/21] clocksource: Install completely before selecting In-Reply-To: <20110519182446.GA23751@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: john stultz commit e05b2efb82596905ebfe88e8612ee81dec9b6592 upstream. Christian Hoffmann reported that the command line clocksource override with acpi_pm timer fails: Kernel command line: clocksource=acpi_pm hpet clockevent registered Switching to clocksource hpet Override clocksource acpi_pm is not HRT compatible. Cannot switch while in HRT/NOHZ mode. The watchdog code is what enables CLOCK_SOURCE_VALID_FOR_HRES, but we actually end up selecting the clocksource before we enqueue it into the watchdog list, so that's why we see the warning and fail to switch to acpi_pm timer as requested. That's particularly bad when we want to debug timekeeping related problems in early boot. Put the selection call last. Reported-by: Christian Hoffmann Signed-off-by: John Stultz Link: http://lkml.kernel.org/r/%3C1304558210.2943.24.camel%40work-vm%3E Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- kernel/time/clocksource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -561,8 +561,8 @@ int clocksource_register(struct clocksou mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); - clocksource_select(); clocksource_enqueue_watchdog(cs); + clocksource_select(); mutex_unlock(&clocksource_mutex); return 0; }