Messages in this thread | | | Date | Mon, 17 Mar 2008 16:46:39 +0100 | From | Pavel Machek <> | Subject | Re: Timer interrupt stops, causes soft lockup |
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Hi!
> Of course when time stops progessing forward at a steady pace all > sorts of Bad Things happen. > > The clock loop is caused by jiffies not incrementing. It seems that wall > time updates itself and then resync's with jiffies every ~4s. > > We verified that all spinlocks ( xtime_lock in particular ) were not > being held, and that the kernel had no reason not to update jiffies. > Other interrupts continue to fire, so we're not stuck in the timer > handler. > > So, we went on to look at the PIC. We threw together a little kernel > module to get some debug info.
Nice debugging.
> We have over 10 systems demonstrating the problem, many in customer > sites.
Does nosmp help?
Does noapic/nolapic help?
You may want to try testing with HZ=4000... to show the problem faster. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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