From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:46558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932240AbeEHINm (ORCPT ); Tue, 8 May 2018 04:13:42 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Peter Zijlstra (Intel)" , Thomas Gleixner , "Rafael J. Wysocki" , len.brown@intel.com, rjw@rjwysocki.net, diego.viola@gmail.com, rui.zhang@intel.com Subject: [PATCH 4.16 51/52] clocksource: Consistent de-rate when marking unstable Date: Tue, 8 May 2018 10:10:49 +0200 Message-Id: <20180508073935.333431008@linuxfoundation.org> In-Reply-To: <20180508073928.058320984@linuxfoundation.org> References: <20180508073928.058320984@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Zijlstra commit cd2af07d823e5287cd6c91d54337348c2a873462 upstream. When a registered clocksource gets marked unstable the watchdog_kthread will de-rate and re-select the clocksource. Ensure it also de-rates when getting called on an unregistered clocksource. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Reviewed-by: Rafael J. Wysocki Cc: len.brown@intel.com Cc: rjw@rjwysocki.net Cc: diego.viola@gmail.com Cc: rui.zhang@intel.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180430100344.594904898@infradead.org Signed-off-by: Greg Kroah-Hartman --- kernel/time/clocksource.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -152,12 +152,19 @@ static void __clocksource_unstable(struc cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); cs->flags |= CLOCK_SOURCE_UNSTABLE; - if (list_empty(&cs->list)) + /* + * If the clocksource is registered clocksource_watchdog_kthread() will + * re-rate and re-select. + */ + if (list_empty(&cs->list)) { + cs->rating = 0; return; + } if (cs->mark_unstable) cs->mark_unstable(cs); + /* kick clocksource_watchdog_kthread() */ if (finished_booting) schedule_work(&watchdog_work); }