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From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] hardlockup: detect hard lockups without NMIs using secondary cpus
Date: Thu, 10 Jan 2013 12:38:33 -0800	[thread overview]
Message-ID: <20130110203833.GE14149@atomide.com> (raw)
In-Reply-To: <1357783059-13923-1-git-send-email-ccross@android.com>

* Colin Cross <ccross@android.com> [130109 18:05]:
> +static void watchdog_check_hardlockup_other_cpu(void)
> +{
> +	int cpu;
> +	cpumask_t cpus = watchdog_cpus;
> +
> +	/*
> +	 * Test for hardlockups every 3 samples.  The sample period is
> +	 *  watchdog_thresh * 2 / 5, so 3 samples gets us back to slightly over
> +	 *  watchdog_thresh (over by 20%).
> +	 */
> +	if (__this_cpu_read(hrtimer_interrupts) % 3 != 0)
> +		return;
> +
> +	/* check for a hardlockup on the next cpu */
> +	cpu = cpumask_next(smp_processor_id(), &cpus);

Hmm don't you want to check cpu_oneline_mask here and
return if the other CPU is offline?

> +	if (cpu >= nr_cpu_ids)
> +		cpu = cpumask_first(&cpus);
> +	if (cpu == smp_processor_id())
> +		return;

Regards,

Tony

WARNING: multiple messages have this Message-ID (diff)
From: Tony Lindgren <tony@atomide.com>
To: Colin Cross <ccross@android.com>
Cc: linux-kernel@vger.kernel.org, Don Zickus <dzickus@redhat.com>,
	Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	liu chuansheng <chuansheng.liu@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] hardlockup: detect hard lockups without NMIs using secondary cpus
Date: Thu, 10 Jan 2013 12:38:33 -0800	[thread overview]
Message-ID: <20130110203833.GE14149@atomide.com> (raw)
In-Reply-To: <1357783059-13923-1-git-send-email-ccross@android.com>

* Colin Cross <ccross@android.com> [130109 18:05]:
> +static void watchdog_check_hardlockup_other_cpu(void)
> +{
> +	int cpu;
> +	cpumask_t cpus = watchdog_cpus;
> +
> +	/*
> +	 * Test for hardlockups every 3 samples.  The sample period is
> +	 *  watchdog_thresh * 2 / 5, so 3 samples gets us back to slightly over
> +	 *  watchdog_thresh (over by 20%).
> +	 */
> +	if (__this_cpu_read(hrtimer_interrupts) % 3 != 0)
> +		return;
> +
> +	/* check for a hardlockup on the next cpu */
> +	cpu = cpumask_next(smp_processor_id(), &cpus);

Hmm don't you want to check cpu_oneline_mask here and
return if the other CPU is offline?

> +	if (cpu >= nr_cpu_ids)
> +		cpu = cpumask_first(&cpus);
> +	if (cpu == smp_processor_id())
> +		return;

Regards,

Tony

  parent reply	other threads:[~2013-01-10 20:38 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-10  1:57 [PATCH] hardlockup: detect hard lockups without NMIs using secondary cpus Colin Cross
2013-01-10  1:57 ` Colin Cross
2013-01-10 14:02 ` Don Zickus
2013-01-10 14:02   ` Don Zickus
2013-01-10 14:22   ` Russell King - ARM Linux
2013-01-10 14:22     ` Russell King - ARM Linux
2013-01-10 16:18     ` Frederic Weisbecker
2013-01-10 16:18       ` Frederic Weisbecker
2013-01-10 17:00       ` Russell King - ARM Linux
2013-01-10 17:00         ` Russell King - ARM Linux
2013-01-10 17:27   ` Colin Cross
2013-01-10 17:27     ` Colin Cross
2013-01-10 18:17     ` Don Zickus
2013-01-10 18:17       ` Don Zickus
2013-01-10 20:38 ` Tony Lindgren [this message]
2013-01-10 20:38   ` Tony Lindgren
2013-01-10 22:34   ` Colin Cross
2013-01-10 22:34     ` Colin Cross
2013-01-10 23:42     ` Tony Lindgren
2013-01-10 23:42       ` Tony Lindgren
2013-01-11  1:39 ` Liu, Chuansheng
2013-01-11  1:39   ` Liu, Chuansheng
2013-01-11  5:34   ` Colin Cross
2013-01-11  5:34     ` Colin Cross
2013-01-11  5:57     ` Liu, Chuansheng
2013-01-11  5:57       ` Liu, Chuansheng
2013-01-11  6:17       ` Colin Cross
2013-01-11  6:17         ` Colin Cross
2013-01-11  6:27         ` Liu, Chuansheng
2013-01-11  6:27           ` Liu, Chuansheng

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