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Date: Fri, 8 Jul 2016 13:49:39 +0200
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>, vatikaharlalka@gmail.com,
        Preeti U Murthy <preeti@linux.vnet.ibm.com>,
        Ingo Molnar <mingo@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: get_nohz_timer_target?
Message-ID: <20160708114937.GB30200@lerouge>
References: <20160418133709.GA10358@localhost.localdomain>
 <alpine.DEB.2.11.1607081105260.4083@nanos>
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On Fri, Jul 08, 2016 at 11:05:58AM +0200, Thomas Gleixner wrote:
> On Mon, 18 Apr 2016, Richard Cochran wrote:
> > Looking at kernel/sched/core.c:get_nohz_timer_target(), I don't
> > understand the change made in:
> > 
> >     commit 9642d18eee2cd169b60c6ac0f20bda745b5a3d1e
> >     Author: Vatika Harlalka <vatikaharlalka@gmail.com>
> >     Date:   Tue Sep 1 16:50:59 2015 +0200
> >     nohz: Affine unpinned timers to housekeepers
> > 
> > After that change, the code now reads like this:
> > 
> > 	int i, cpu = smp_processor_id();
> > 	struct sched_domain *sd;
> > 
> > 	if (!idle_cpu(cpu) && is_housekeeping_cpu(cpu))
> > 		return cpu;
> > 
> > 	rcu_read_lock();
> > 	for_each_domain(cpu, sd) {
> > 		for_each_cpu(i, sched_domain_span(sd)) {
> > 			if (!idle_cpu(i) && is_housekeeping_cpu(cpu)) {
> > --------------------------------------------------------------- ^^^
> > Was this supposed to be 'i' instead?
> 
> Yes. Care to send a patch?

Ah this got fixed already: 444969223c81c7d0a95136b7b4cfdcfbc96ac5bd
("sched/nohz: Fix affine unpinned timers mess")

Thanks.

> 
> Thanks,
> 
> 	tglx