Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756332AbaFXQlY (ORCPT ); Tue, 24 Jun 2014 12:41:24 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:32768 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755612AbaFXPw5 (ORCPT ); Tue, 24 Jun 2014 11:52:57 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Hocko , Borislav Petkov , Thomas Gleixner , Rui Xiang Subject: [PATCH 3.10 44/52] nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off Date: Tue, 24 Jun 2014 11:50:59 -0400 Message-Id: <20140624154716.124452652@linuxfoundation.org> X-Mailer: git-send-email 2.0.0 In-Reply-To: <20140624154713.428945460@linuxfoundation.org> References: <20140624154713.428945460@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 0e576acbc1d9600cf2d9b4a141a2554639959d50 upstream. If CONFIG_NO_HZ=n tick_nohz_get_sleep_length() returns NSEC_PER_SEC/HZ. If CONFIG_NO_HZ=y and the nohz functionality is disabled via the command line option "nohz=off" or not enabled due to missing hardware support, then tick_nohz_get_sleep_length() returns 0. That happens because ts->sleep_length is never set in that case. Set it to NSEC_PER_SEC/HZ when the NOHZ mode is inactive. Reported-by: Michal Hocko Reported-by: Borislav Petkov Signed-off-by: Thomas Gleixner Cc: Rui Xiang Signed-off-by: Greg Kroah-Hartman --- kernel/time/tick-sched.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -720,8 +720,10 @@ static bool can_stop_idle_tick(int cpu, return false; } - if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) + if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) { + ts->sleep_length = (ktime_t) { .tv64 = NSEC_PER_SEC/HZ }; return false; + } if (need_resched()) return false; -- 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/