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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Prasad Sodagudi <psodagud@codeaurora.org>, john.stultz@linaro.org,
        sboyd@kernel.org
Cc:     linux-kernel@vger.kernel.org, saravanak@google.com,
        tsoni@codeaurora.org, tj@kernel.org,
        Prasad Sodagudi <psodagud@codeaurora.org>
Subject: Re: [PATCH 2/2] sched: Add a check for cpu unbound deferrable timers
In-Reply-To: <1584326350-30275-3-git-send-email-psodagud@codeaurora.org>
References: <1584326350-30275-1-git-send-email-psodagud@codeaurora.org> <1584326350-30275-3-git-send-email-psodagud@codeaurora.org>
Date:   Mon, 16 Mar 2020 09:38:45 +0100
Message-ID: <874kuoelt6.fsf@nanos.tec.linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
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Prasad Sodagudi <psodagud@codeaurora.org> writes:
> @@ -948,6 +949,11 @@ static void __tick_nohz_idle_stop_tick(struct tick_sched *ts)
>  	ktime_t expires;
>  	int cpu = smp_processor_id();
>  
> +#ifdef CONFIG_SMP
> +	if (check_pending_deferrable_timers(cpu))
> +		raise_softirq_irqoff(TIMER_SOFTIRQ);
> +#endif

So if that raises the soft interrupt then the warning in 

can_stop_idle_tick()

	if (unlikely(local_softirq_pending())) {
		....
                pr_warn()

will trigger. Try again.

Thanks,

        tglx