linux-kernel - Re: [PATCH v8 01/10] time: tick-sched: Reorganize idle tick management code

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Date:   Sun, 1 Apr 2018 03:50:28 +0200
From:   Frederic Weisbecker <frederic@...nel.org>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     Linux PM <linux-pm@...r.kernel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Frederic Weisbecker <fweisbec@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Paul McKenney <paulmck@...ux.vnet.ibm.com>,
        Thomas Ilsche <thomas.ilsche@...dresden.de>,
        Doug Smythies <dsmythies@...us.net>,
        Rik van Riel <riel@...riel.com>,
        Aubrey Li <aubrey.li@...ux.intel.com>,
        Mike Galbraith <mgalbraith@...e.de>,
        LKML <linux-kernel@...r.kernel.org>,
        Len Brown <len.brown@...el.com>
Subject: Re: [PATCH v8 01/10] time: tick-sched: Reorganize idle tick
 management code

On Thu, Mar 29, 2018 at 02:00:01PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> Prepare the scheduler tick code for reworking the idle loop to
> avoid stopping the tick in some cases.
> 
> The idea is to split the nohz idle entry call to decouple the idle
> time stats accounting and preparatory work from the actual tick stop
> code, in order to later be able to delay the tick stop once we reach
> more power-knowledgeable callers.
> 
> Move away the tick_nohz_start_idle() invocation from
> __tick_nohz_idle_enter(), rename the latter to
> __tick_nohz_idle_stop_tick() and define tick_nohz_idle_stop_tick()
> as a wrapper around it for calling it from the outside.
> 
> Make tick_nohz_idle_enter() only call tick_nohz_start_idle() instead
> of calling the entire __tick_nohz_idle_enter(), add another wrapper
> disabling and enabling interrupts around tick_nohz_idle_stop_tick()
> and make the current callers of tick_nohz_idle_enter() call it too
> to retain their current functionality.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Reviewed-by: Frederic Weisbecker <frederic@...nel.org>

Thanks!