From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760868Ab2J2UoX (ORCPT ); Mon, 29 Oct 2012 16:44:23 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:18478 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757235Ab2J2Uix (ORCPT ); Mon, 29 Oct 2012 16:38:53 -0400 X-Authority-Analysis: v=2.0 cv=KcBQQHkD c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=fRE2Z7D5Rc8A:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=_I1haf9WbHAA:10 a=pGLkceISAAAA:8 a=VwQbUJbxAAAA:8 a=Z4Rwk6OoAAAA:8 a=20KFwNOVAAAA:8 a=9AzMRrQhAAAA:8 a=NufY4J3AAAAA:8 a=KKAkSRfTAAAA:8 a=JfrnYn6hAAAA:8 a=ftUzEednAAAA:8 a=sozttTNsAAAA:8 a=EUspDBNiAAAA:8 a=VnNF1IyMAAAA:8 a=fh4mg5NFAAAA:8 a=yuHW65_V7381hc6k-hIA:9 a=MSl-tDqOz04A:10 a=LI9Vle30uBYA:10 a=jbrJJM5MRmoA:10 a=jEp0ucaQiEUA:10 a=SxxB86fLhQ4A:10 a=re9sYKne76oA:10 a=WwgC8nHKvroA:10 a=3Rfx1nUSh_UA:10 a=QwxQZocgbLcA:10 a=x2szoZtqnggA:10 a=IG2fH9E8heMA:10 a=Im-eZXwrtqoA:10 a=jeBq3FmKZ4MA:10 a=Zh68SRI7RUMA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-Id: <20121029203850.023551882@goodmis.org> User-Agent: quilt/0.60-1 Date: Mon, 29 Oct 2012 16:27:34 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Thomas Gleixner , Peter Zijlstra , Clark Williams , Frederic Weisbecker , Li Zefan , Ingo Molnar , "Paul E. McKenney" , Mike Galbraith , Alessio Igor Bogani , Avi Kivity , Chris Metcalf , Christoph Lameter , Daniel Lezcano , Geoff Levand , Gilad Ben Yossef , Hakan Akkan , Kevin Hilman , Max Krasnyansky , Stephen Hemminger , Sven-Thorsten Dietrich Subject: [PATCH 23/32] sched: Update rq clock on nohz CPU before migrating tasks References: <20121029202711.062749374@goodmis.org> Content-Disposition: inline; filename=0023-sched-Update-rq-clock-on-nohz-CPU-before-migrating-t.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Frederic Weisbecker Because the sched_class::put_prev_task() callback of rt and fair classes are referring to the rq clock to update their runtime statistics. A CPU running in tickless mode may carry a stale value. We need to update it there. Signed-off-by: Frederic Weisbecker Cc: Alessio Igor Bogani Cc: Andrew Morton Cc: Avi Kivity Cc: Chris Metcalf Cc: Christoph Lameter Cc: Daniel Lezcano Cc: Geoff Levand Cc: Gilad Ben Yossef Cc: Hakan Akkan Cc: Ingo Molnar Cc: Kevin Hilman Cc: Max Krasnyansky Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Stephen Hemminger Cc: Steven Rostedt Cc: Sven-Thorsten Dietrich Cc: Thomas Gleixner --- kernel/sched/core.c | 6 ++++++ kernel/sched/sched.h | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 783d5e4..f0fa54d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4851,6 +4851,12 @@ static void migrate_tasks(unsigned int dead_cpu) */ rq->stop = NULL; + /* + * ->put_prev_task() need to have an up-to-date value + * of rq->clock[_task] + */ + update_nohz_rq_clock(rq); + for ( ; ; ) { /* * There's this thread running, bail when that's the only diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index c6cd9ec..1956494 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -948,6 +948,12 @@ static inline void dec_nr_running(struct rq *rq) extern void update_rq_clock(struct rq *rq); +static inline void update_nohz_rq_clock(struct rq *rq) +{ + if (cpuset_cpu_adaptive_nohz(cpu_of(rq))) + update_rq_clock(rq); +} + extern void activate_task(struct rq *rq, struct task_struct *p, int flags); extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); -- 1.7.10.4