linux-kernel - [tip:timers/nohz] nohz: Include local CPU in full dynticks global kick

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Message-ID: <tip-c2e7fcf53c3cb02b4ada1c66a9bc8a4d97d58aba@git.kernel.org>
Date:	Fri, 16 Aug 2013 11:46:56 -0700
From:	tip-bot for Frederic Weisbecker <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...nel.org,
	peterz@...radead.org, efault@....de, bp@...en8.de,
	paulmck@...ux.vnet.ibm.com, zhong@...ux.vnet.ibm.com,
	fweisbec@...il.com, rostedt@...dmis.org, khilman@...aro.org,
	tglx@...utronix.de
Subject: [tip:timers/nohz] nohz:
  Include local CPU in full dynticks global kick

Commit-ID:  c2e7fcf53c3cb02b4ada1c66a9bc8a4d97d58aba
Gitweb:     http://git.kernel.org/tip/c2e7fcf53c3cb02b4ada1c66a9bc8a4d97d58aba
Author:     Frederic Weisbecker <fweisbec@...il.com>
AuthorDate: Fri, 2 Aug 2013 18:29:56 +0200
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Fri, 16 Aug 2013 17:55:33 +0200

nohz: Include local CPU in full dynticks global kick

tick_nohz_full_kick_all() is useful to notify all full dynticks
CPUs that there is a system state change to checkout before
re-evaluating the need for the tick.

Unfortunately this is implemented using smp_call_function_many()
that ignores the local CPU. This CPU also needs to re-evaluate
the tick.

on_each_cpu_mask() is not useful either because we don't want to
re-evaluate the tick state in place but asynchronously from an IPI
to avoid messing up with any random locking scenario.

So lets call tick_nohz_full_kick() from tick_nohz_full_kick_all()
so that the usual irq work takes care of it.

Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
Cc: Steven Rostedt <rostedt@...dmis.org>
Cc: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Li Zhong <zhong@...ux.vnet.ibm.com>
Cc: Mike Galbraith <efault@....de>
Cc: Kevin Hilman <khilman@...aro.org>
Signed-off-by: Peter Zijlstra <peterz@...radead.org>
Link: http://lkml.kernel.org/r/1375460996-16329-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 kernel/time/tick-sched.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index adea6fc3..3612fc7 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -246,6 +246,7 @@ void tick_nohz_full_kick_all(void)
 	preempt_disable();
 	smp_call_function_many(tick_nohz_full_mask,
 			       nohz_full_kick_ipi, NULL, false);
+	tick_nohz_full_kick();
 	preempt_enable();
 }
 
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