Subject: Re: Linux 2.6.21-rc1
From: Daniel Walker <dwalker@mvista.com>
To: tglx@linutronix.de
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, mingo@elte.hu
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Date: Wed, 21 Feb 2007 09:19:00 -0800
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On Wed, 2007-02-21 at 18:07 +0100, Thomas Gleixner wrote:
> On Wed, 2007-02-21 at 08:24 -0800, Daniel Walker wrote:
> > > The most interesting core change may be the dyntick/nohz one, where timer 
> > > ticks will only happen when needed. It's been brewing for a _loong_ time, 
> > > but it's in the standard kernel now as an option. 
> > 
> > On i386 I get the following,
> > 
> > TCP cubic registered                                                            
> > NET: Registered protocol family 1                                               
> > NET: Registered protocol family 17                                              
> > Testing NMI watchdog ... CPU#0: NMI appears to be stuck (24->24)!               
> > CPU#1: NMI appears to be stuck (0->0)!                                          
> > CPU#2: NMI appears to be stuck (0->0)!                                          
> > CPU#3: NMI appears to be stuck (0->0)!              
> > 
> > when I add nmi_watchdog=1 to my boot args which worked on prior kernels.
> > On closer inspection it looks like arch/i386/kernel/io_apic.c :
> > check_timer() --> timer_irq_works() depends on IRQ0 incrementing jiffies
> > which is no longer the case AFAIK.
> 
> At this point the PIT / HPET _is_ active and incrementing jiffies. The
> switch to local apic timers happens afterwards. 

Could be the switch over then which confuses the NMI . 

> > I'm not sure exactly how that relates to the NMI, but the check_timer()
> > function disabled the NMI through the io-apic if it can't get the
> > "timer" working through the io-apic.
> 
> Boot log please.
> 
> 	tglx
> 

.config is in there too .

ftp://source.mvista.com/pub/dwalker/tglx/

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