Re: NMI watchdog + NOHZ question

[David Miller <davem@davemloft.net>]

From: Andi Kleen <andi@firstfloor.org>
Date: Wed, 24 Jun 2009 09:15:55 +0200

> On Wed, Jun 24, 2009 at 12:08:11AM -0700, David Miller wrote:
>> From: Andi Kleen <andi@firstfloor.org>
>> Date: Wed, 24 Jun 2009 09:03:15 +0200
>> 
>> >> I'm not exactly sure what to do about this.
>> > 
>> > Ack the timer interrupt earlier (and also give it a high priority?)
>> 
>> It has a higher priority, but all interrupts get re-enabled right
>> before we process software interrupts.  So the flood of qla2xxx
>> interrupts can come in before we can run the timer softirq and
>> thus schedule the next timer interrupt.
> 
> Ah you have a one shot timer and it gets rescheduled in the softirq?
> If yes why not in doing that directly in the hardirq handler?

Then what's the point of the generic timer code supporting one-shot
clock sources? :-)