From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753423Ab2L2QrH (ORCPT ); Sat, 29 Dec 2012 11:47:07 -0500 Received: from mail-wi0-f177.google.com ([209.85.212.177]:45928 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752772Ab2L2Qno (ORCPT ); Sat, 29 Dec 2012 11:43:44 -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 , "Paul E. McKenney" , Paul Gortmaker , Peter Zijlstra , Steven Rostedt , Thomas Gleixner Subject: [PATCH 13/27] sched: Update rq clock on nohz CPU before setting fair group shares Date: Sat, 29 Dec 2012 17:42:52 +0100 Message-Id: <1356799386-4212-14-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1356799386-4212-1-git-send-email-fweisbec@gmail.com> References: <1356799386-4212-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Because we may update the execution time (sched_group_set_shares()-> update_cfs_shares()->reweight_entity()->update_curr()) before reweighting the entity after updating the group shares and this requires an uptodate version of the runqueue clock. Let's update it on the target CPU if it runs tickless because scheduler_tick() is not there to maintain it. 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: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner --- kernel/sched/fair.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 5eea870..a96f0f2 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6068,6 +6068,11 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) se = tg->se[i]; /* Propagate contribution to hierarchy */ raw_spin_lock_irqsave(&rq->lock, flags); + /* + * We may call update_curr() which needs an up-to-date + * version of rq clock if the CPU runs tickless. + */ + update_nohz_rq_clock(rq); for_each_sched_entity(se) update_cfs_shares(group_cfs_rq(se)); raw_spin_unlock_irqrestore(&rq->lock, flags); -- 1.7.5.4