Re: [PATCH] fix BUG using smp_processor_id() in touch_nmi_watchdog and touch_softlockup_watchdog

[Frederic Weisbecker <fweisbec@gmail.com>]

On Mon, Aug 16, 2010 at 05:08:29PM +0300, Sergey Senozhatsky wrote:
>  void touch_softlockup_watchdog(void)
>  {
> -	__get_cpu_var(watchdog_touch_ts) = 0;
> +	int this_cpu = get_cpu();
> +	per_cpu(watchdog_touch_ts, this_cpu) = 0;
> +	put_cpu();
>  }



If preemption is disabled and you deal with the current cpu,
then please use __get_cpu_var, it makes the code more
readable:


void touch_softlockup_watchdog(void)
{
	preempt_disable();
	__get_cpu_var(watchdog_touch_ts) = 0;
	preempt_enable();
}


Same below.

Thanks.


>  EXPORT_SYMBOL(touch_softlockup_watchdog);
>  
> @@ -142,7 +143,9 @@ void touch_all_softlockup_watchdogs(void)
>  #ifdef CONFIG_HARDLOCKUP_DETECTOR
>  void touch_nmi_watchdog(void)
>  {
> -	__get_cpu_var(watchdog_nmi_touch) = true;
> +	int this_cpu = get_cpu();
> +	per_cpu(watchdog_nmi_touch, this_cpu) = true;
> +	put_cpu();
>  	touch_softlockup_watchdog();
>  }
>  EXPORT_SYMBOL(touch_nmi_watchdog);
> 
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