From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759378AbcAUCzP (ORCPT ); Wed, 20 Jan 2016 21:55:15 -0500 Received: from mail-pa0-f43.google.com ([209.85.220.43]:33744 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759239AbcAUCyi (ORCPT ); Wed, 20 Jan 2016 21:54:38 -0500 From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: Thomas Gleixner Cc: Peter Zijlstra , Frederic Weisbecker , linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH] nohz: fix jiffies warp while switch to low-res nohz mode Date: Thu, 21 Jan 2016 10:54:19 +0800 Message-Id: <1453344859-5235-1-git-send-email-wanpeng.li@hotmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org After commit 0ff53d096422 ("tick: sched: Force tick interrupt and get rid of softirq magic"), next expire time is overwritten by last_jiffies_update while switch to low-res nohz mode which leads to jiffies warp. This patch fix it by programming ce device the expire time in the future. Signed-off-by: Wanpeng Li --- kernel/time/tick-sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 9cc20af..cea6a0e 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -993,9 +993,9 @@ static void tick_nohz_switch_to_nohz(void) /* Get the next period */ next = tick_init_jiffy_update(); - hrtimer_forward_now(&ts->sched_timer, tick_period); hrtimer_set_expires(&ts->sched_timer, next); - tick_program_event(next, 1); + hrtimer_forward_now(&ts->sched_timer, tick_period); + tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1); tick_nohz_activate(ts, NOHZ_MODE_LOWRES); } -- 1.9.1