Re: [PATCH] highres: Do not run the TIMER_SOFTIRQ after switching to highres mode

[Ingo Molnar]

* Andres Salomon <dilinger@xxxxxxxxxx> wrote:

> Thomas Gleixner wrote:
> >>> The question is, how the tick timer gets enqueued in the softirq queue.
> >>> Can you isolate the codepath, where this happens ?
> > 
> > The TIMER_SOFTIRQ runs the hrtimers during bootup until a usable
> > clocksource and clock event sources are registered. The switch to high
> > resolution mode happens inside of the TIMER_SOFTIRQ, but runs the
> > softirq afterwards. That way the tick emulation timer, which was set up
> > in the switch to highres might be executed in the softirq context, which
> > is a BUG. The rbtree has not to be touched by the softirq after the
> > highres switch.
> > 
> 
> And an additional request, just to make it explicit that we should not 
> have any NO_SOFTIRQ callbacks in the tree; BUG out if we encounter 
> such a thing.

please change it to WARN_ON_ONCE()...

'bug out' might mean: 'dead box'/'no resume'/'no bootup'.

	Ingo
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