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Subject: Re: [patch] clockevents_notify() need to be called with irq's
 enabled
From: Suresh Siddha <suresh.b.siddha@intel.com>
Reply-To: suresh.b.siddha@intel.com
To: Thomas Gleixner <tglx@linutronix.de>
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       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>,
       "Brown, Len" <len.brown@intel.com>
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Organization: Intel Corp
Date: Fri, 14 Aug 2009 00:26:18 -0700
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On Thu, 2009-08-13 at 23:05 -0700, Thomas Gleixner wrote:
> On Thu, 13 Aug 2009, Suresh Siddha wrote:
> 
> > From: Suresh Siddha <suresh.b.siddha@intel.com>
> > Subject: clockevents_notify() need to be called with irq's enabled
> > 
> > Currently clockevents_notify() is called with interrupts enabled at some
> > places and interrupts disabled at some other places.
> 
> The only place I can see which calls clockevents_notify with
> interrupts enabled is the hrtimer cpu hotplug code.
> 
> I'm a bit wary to enable interrupts all over the place in sensitive
> corners like ACPI idle code ...
> 
> Why don't we just do the obvious and take clockevents_lock irqsave ?

We didn't go that route because of the smp_call_function() in the cpu
hotplug code. So we can't disable interrupts in that path.

ACPI idle code changes were ok'd by Venki. We did 4 or so hours testing
with our patch. Will do more testing in the coming days.

thanks,
suresh