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Date: Mon, 26 May 2014 18:50:41 +0200
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Ingo Molnar <mingo@kernel.org>, Kevin Hilman <khilman@linaro.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Viresh Kumar <viresh.kumar@linaro.org>
Subject: Re: [PATCH 3/5] irq_work: Implement remote queueing
Message-ID: <20140526165039.GE2066@localhost.localdomain>
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On Mon, May 26, 2014 at 06:02:24PM +0200, Peter Zijlstra wrote:
> On Sun, May 25, 2014 at 04:29:49PM +0200, Frederic Weisbecker wrote:
> > +bool irq_work_queue_on(struct irq_work *work, int cpu)
> > +{
> > +	/* Only queue if not already pending */
> > +	if (!irq_work_claim(work))
> > +		return false;
> > +
> > +	/* All work should have been flushed before going offline */
> > +	WARN_ON_ONCE(cpu_is_offline(cpu));
> 	WARN_ON_ONCE(in_nmi());

But it's actually NMI safe, isn't it?

> 
> 
> Also, I would do both these checks before the claim thing.

Right, I'll move the check.

> 
> > +
> > +	if (llist_add(&work->llnode, &per_cpu(raised_list, cpu)))
> > +		native_send_call_func_single_ipi(cpu);
> > +
> > +	return true;
> > +}
> > +EXPORT_SYMBOL_GPL(irq_work_queue_on);
> 
>