From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Subject: Re: [RFC/RFT][PATCH v2 1/6] time: tick-sched: Reorganize idle tick management code
Date: Thu, 08 Mar 2018 10:22:26 +0100
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References: <2067762.1uWBf5RSRc@aspire.rjw.lan> <4136227.b9g9WnMbNJ@aspire.rjw.lan> <20180307231827.GA9367@lerouge>
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To: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>, Linux PM <linux-pm@vger.kernel.org>, Thomas Gleixner <tglx@linutronix.de>, Frederic Weisbecker <fweisbec@gmail.com>, Paul McKenney <paulmck@linux.vnet.ibm.com>, Thomas Ilsche <thomas.ilsche@tu-dresden.de>, Doug Smythies <dsmythies@telus.net>, Rik van Riel <riel@surriel.com>, Aubrey Li <aubrey.li@linux.intel.com>, Mike Galbraith <mgalbraith@suse.de>, LKML <linux-kernel@vger.kernel.org>
List-Id: linux-pm@vger.kernel.org

On Thursday, March 8, 2018 12:18:29 AM CET Frederic Weisbecker wrote:
> On Tue, Mar 06, 2018 at 10:02:01AM +0100, Rafael J. Wysocki wrote:
> > Index: linux-pm/kernel/time/tick-sched.c
> > ===================================================================
> > --- linux-pm.orig/kernel/time/tick-sched.c
> > +++ linux-pm/kernel/time/tick-sched.c
> > +
> > +/**
> > + * tick_nohz_idle_prepare - prepare for entering idle on the current CPU.
> > + *
> > + * Called when we start the idle loop.
> > + */
> > +void tick_nohz_idle_prepare(void)
> > +{
> > +	struct tick_sched *ts;
> > +
> > +	__tick_nohz_idle_prepare();
> > +
> > +	local_irq_disable();
> > +
> > +	ts = this_cpu_ptr(&tick_cpu_sched);
> > +	ts->inidle = 1;
> > +
> > +	local_irq_enable();
> > +}
> 
> Why not calling tick_nohz_start_idle() from there? This is going to
> simplify the rest, you won't need to call tick_nohz_idle_go_idle()
> from places that don't want to stop the tick and you can then remove
> the stop_tick argument.

So I guess I would then use ts->idle_entrytime as "now" in the
tick_nohz_get_sleep_length() computation, right?