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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
Date: Tue, 24 Sep 2013 09:34:56 +0200	[thread overview]
Message-ID: <20130924073456.GE28538@gmail.com> (raw)
In-Reply-To: <000001414c3d064a-ebe0610b-6951-4a74-bd33-8480e3e1e364-000000@email.amazonses.com>


* 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

  parent reply	other threads:[~2013-09-24  7:35 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20130923191256.584672290@linux.com>
2013-09-23 19:12 ` [pchecks v1 2/4] Use raw cpu ops for calls that would trigger with checks Christoph Lameter
2013-09-24  7:28   ` Ingo Molnar
2013-09-24  7:32   ` Ingo Molnar
2013-09-24 12:45     ` Eric Dumazet
2013-09-24  7:34   ` Ingo Molnar [this message]
2013-09-23 19:12 ` [pchecks v1 1/4] Subject; percpu: Add raw_cpu_ops Christoph Lameter
2013-09-23 19:24 ` [pchecks v1 4/4] percpu: Add preemption checks to __this_cpu ops Christoph Lameter
2013-09-24  8:03   ` Ingo Molnar
2013-09-24 14:24     ` Christoph Lameter
2013-09-24 15:18       ` Ingo Molnar
2013-09-24 15:35         ` Christoph Lameter
2013-09-24 17:26           ` Ingo Molnar
2013-09-25 16:46             ` Christoph Lameter
2013-09-25 18:26               ` Ingo Molnar
2013-09-27 14:36                 ` Christoph Lameter
2013-09-28  8:52                   ` Ingo Molnar
2013-09-23 19:24 ` [pchecks v1 3/4] Use raw_cpu_ops for refresh_cpu_vm_stats() Christoph Lameter
2013-09-24  7:43   ` Ingo Molnar

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