From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754959Ab3AHCQ6 (ORCPT ); Mon, 7 Jan 2013 21:16:58 -0500 Received: from mail-we0-f170.google.com ([74.125.82.170]:63360 "EHLO mail-we0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755430Ab3AHCJL (ORCPT ); Mon, 7 Jan 2013 21:09:11 -0500 From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Alessio Igor Bogani , Andrew Morton , Chris Metcalf , Christoph Lameter , Geoff Levand , Gilad Ben Yossef , Hakan Akkan , Ingo Molnar , Li Zhong , Namhyung Kim , "Paul E. McKenney" , Paul Gortmaker , Peter Zijlstra , Steven Rostedt , Thomas Gleixner Subject: [PATCH 12/33] sched: Comment on rq->clock correctness in ttwu_do_wakeup() in nohz Date: Tue, 8 Jan 2013 03:08:12 +0100 Message-Id: <1357610913-1080-13-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1357610913-1080-1-git-send-email-fweisbec@gmail.com> References: <1357610913-1080-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Just to avoid confusion. Signed-off-by: Frederic Weisbecker Cc: Alessio Igor Bogani Cc: Andrew Morton Cc: Chris Metcalf Cc: Christoph Lameter Cc: Geoff Levand Cc: Gilad Ben Yossef Cc: Hakan Akkan Cc: Ingo Molnar Cc: Li Zhong Cc: Namhyung Kim Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner --- kernel/sched/core.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 63b25e2..bfac40f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1302,6 +1302,12 @@ ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) if (p->sched_class->task_woken) p->sched_class->task_woken(rq, p); + /* + * For adaptive nohz case: We called ttwu_activate() + * which just updated the rq clock. There is an + * exception with p->on_rq != 0 but in this case + * we are not idle and rq->idle_stamp == 0 + */ if (rq->idle_stamp) { u64 delta = rq->clock - rq->idle_stamp; u64 max = 2*sysctl_sched_migration_cost; -- 1.7.5.4