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Date: Mon, 14 Nov 2016 16:01:19 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        Zhang Rui <rui.zhang@intel.com>,
        Rafael Wysocki <rafael.j.wysocki@intel.com>,
        "Chen, Yu C" <yu.c.chen@intel.com>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Petr Mladek <pmladek@suse.com>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Arjan van de Ven <arjan@linux.intel.com>
Subject: Re: [PATCH 1/3] idle: add support for tasks that inject idle
Message-ID: <20161114150119.GG3142@twins.programming.kicks-ass.net>
References: <1478718312-12847-1-git-send-email-jacob.jun.pan@linux.intel.com>
 <1478718312-12847-2-git-send-email-jacob.jun.pan@linux.intel.com>
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On Wed, Nov 09, 2016 at 11:05:10AM -0800, Jacob Pan wrote:
> +void play_idle()
> +{
> +	/*
> +	 * Only FIFO tasks can disable the tick since they don't need the forced
> +	 * preemption.
> +	 */
> +	WARN_ON_ONCE(current->policy != SCHED_FIFO);
> +	WARN_ON_ONCE(current->nr_cpus_allowed != 1);
> +	WARN_ON_ONCE(!(current->flags & PF_KTHREAD));
> +	WARN_ON_ONCE(!(current->flags & PF_NO_SETAFFINITY));
> +	rcu_sleep_check();
> +
> +	preempt_disable();
> +	current->flags |= PF_IDLE;
> +	do_idle();
> +	current->flags &= ~PF_IDLE;
> +
> +	preempt_fold_need_resched();
> +	preempt_enable();
> +}
> +EXPORT_SYMBOL_GPL(play_idle);

Hurm.. didn't this initially also include the setup of the timer and
take an timeout argument?