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Date: Tue, 24 Sep 2013 09:34:56 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Christoph Lameter <cl@linux.com>, Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>, akpm@linuxfoundation.org,
        Steven Rostedt <srostedt@redhat.com>, linux-kernel@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: [pchecks v1 2/4] Use raw cpu ops for calls that would trigger
 with checks
Message-ID: <20130924073456.GE28538@gmail.com>
References: <20130923191256.584672290@linux.com>
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* Christoph Lameter <cl@linux.com> wrote:

> Index: linux/kernel/hrtimer.c
> ===================================================================
> --- linux.orig/kernel/hrtimer.c	2013-09-12 13:26:29.216103951 -0500
> +++ linux/kernel/hrtimer.c	2013-09-12 13:26:29.212103994 -0500
> @@ -538,7 +538,7 @@ static inline int hrtimer_is_hres_enable
>   */
>  static inline int hrtimer_hres_active(void)
>  {
> -	return __this_cpu_read(hrtimer_bases.hres_active);
> +	return raw_cpu_read(hrtimer_bases.hres_active);
>  }

If cpu_read() is used, does this check trigger?

If yes, what makes ignoring the check safe? Per change explanation is 
necessary for such annotations.

Thanks,

	Ingo