Re: get_nohz_timer_target?

From	Thomas Gleixner <tglx@linutronix.de>
Newsgroups	linux.kernel
Subject	Re: get_nohz_timer_target?
Date	2016-07-08 19:00 +0200
Message-ID	<rSHi9-7nn-3@gated-at.bofh.it> (permalink)
References	<rphzd-6pz-25@gated-at.bofh.it> <rSzXj-2G5-15@gated-at.bofh.it> <rSCBQ-4i1-11@gated-at.bofh.it>
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On Fri, 8 Jul 2016, Frederic Weisbecker wrote:
> 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")

Good. Though that patch misses a stable tag.

Thanks,

	tglx

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Re: get_nohz_timer_target? Thomas Gleixner <tglx@linutronix.de> - 2016-07-08 11:10 +0200
  Re: get_nohz_timer_target? Frederic Weisbecker <fweisbec@gmail.com> - 2016-07-08 14:00 +0200
    Re: get_nohz_timer_target? Thomas Gleixner <tglx@linutronix.de> - 2016-07-08 19:00 +0200

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