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Date: Mon, 4 Jan 2016 17:52:20 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Gilad Ben Yossef <giladb@ezchip.com>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Rik van Riel" <riel@redhat.com>, Tejun Heo <tj@kernel.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Christoph Lameter <cl@linux.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Andy Lutomirski <luto@amacapital.net>, <linux-doc@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v9 06/13] task_isolation: add debug boot flag
Message-ID: <20160104175220.310be95c@gandalf.local.home>
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On Mon, 4 Jan 2016 14:34:44 -0500
Chris Metcalf <cmetcalf@ezchip.com> wrote:


> +#ifdef CONFIG_TASK_ISOLATION
> +void task_isolation_debug(int cpu)
> +{
> +	struct task_struct *p;
> +
> +	if (!task_isolation_possible(cpu))
> +		return;
> +
> +	rcu_read_lock();

What's the rcu_read_lock() for? I don't see what is being protected by
rcu here?

-- Steve

> +	p = cpu_curr(cpu);
> +	get_task_struct(p);
> +	rcu_read_unlock();
> +	task_isolation_debug_task(cpu, p);
> +	put_task_struct(p);
> +}
> +#endif
> +