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Date:   Tue, 8 Dec 2020 07:03:09 -0800
From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Marco Elver <elver@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>,
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        Ingo Molnar <mingo@kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        Will Deacon <will@kernel.org>,
        Naresh Kamboju <naresh.kamboju@linaro.org>,
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        syzbot+56078ac0b9071335a745@syzkaller.appspotmail.com,
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Subject: Re: [patch 3/3] tick: Annotate tick_do_timer_cpu data races
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On Tue, Dec 08, 2020 at 09:11:29AM +0100, Peter Zijlstra wrote:
> On Mon, Dec 07, 2020 at 11:44:06AM -0800, Paul E. McKenney wrote:
> 
> > Also, in this particular case, why data_race() rather than READ_ONCE()?
> > Do we really expect the compiler to be able to optimize this case
> > significantly without READ_ONCE()?
> 
> It's about intent and how the code reads. READ_ONCE() is something
> completely different from data_race(). data_race() is correct here.

Why?

							Thanx, Paul