From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967788AbWLILho (ORCPT ); Sat, 9 Dec 2006 06:37:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S967799AbWLILho (ORCPT ); Sat, 9 Dec 2006 06:37:44 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:46471 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967788AbWLILhn (ORCPT ); Sat, 9 Dec 2006 06:37:43 -0500 Date: Sat, 9 Dec 2006 12:36:32 +0100 From: Ingo Molnar To: Andrew Morton Cc: Thomas Gleixner , linux-kernel@vger.kernel.org Subject: [patch] high-res timers: next_event calculation fix Message-ID: <20061209113632.GA31648@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -5.9 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-5.9 required=5.9 tests=ALL_TRUSTED,BAYES_00 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Subject: [patch] high-res timers: next_event calculation fix From: Ingo Molnar do not set expires_next to KTIME_MAX if a too short timeout is being set - this can result in the clock events device being shut down completely. found via a stresstest on a C3-lapic-plagued laptop that did very short sleeps. This bug could explain the 'Synaptics hang' that was reported. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/time/clockevents.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) Index: linux/kernel/time/clockevents.c =================================================================== --- linux.orig/kernel/time/clockevents.c +++ linux/kernel/time/clockevents.c @@ -510,10 +510,8 @@ int clockevents_set_next_event(ktime_t e struct clock_event_device *nextevt = devices->nextevt; int64_t delta = ktime_to_ns(ktime_sub(expires, ktime_get())); - if (delta <= 0 && !force) { - devices->expires_next.tv64 = KTIME_MAX; + if (delta <= 0 && !force) return -ETIME; - } devices->expires_next = expires;