Messages in this thread | | | Date | Tue, 14 Apr 2009 15:23:19 +0200 | From | Ingo Molnar <> | Subject | Re: 2.6.30-rc1 - nmi_watchdog broken? |
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* Ed Tomlinson <edt@aei.ca> wrote:
> On Tuesday 14 April 2009 04:42:32 Ingo Molnar wrote: > > > > * Ed Tomlinson <edt@aei.ca> wrote: > > > > > Hi, > > > > > > I've been having fun finding bugs in 30-rc1. One of them is a > > > hard freeze. I've not seen this type of problem on this hardware > > > before 30-rc1 - so I doubt if its hardware. The best way I know > > > to debug a hard hang is with the nmi_watchdog. I just cannot get > > > it to work. > > > > [ Btw., have you tried CONFIG_PROVE_LOCKING=y - does it produce > > anything before or at the hard lockup point? ] > > > > > The system is a 3 core amd cpu on a 790gx chipset. > > > > > > If I boot the nmi_watchdog=1 it complains that lapci is not > > > available and the boot stops. Same problem if I change the > > > clocksource to tsc, If I disable highres timers it panics. If I > > > use nmi_watchdog=2 it panics. Am I doing something wrong or have I > > > hit a bug? > > > > > > Logs of boots with and without highres timers inlined below. > > > > hm, nmi_watchdog=1 acting funny is not unheard of. But > > nmi_watchdog=2 should really work. How does it panic, do > > you have a capture of that? > > I had not tried nmi_watchdog=2 highres=off. This works. Looks > like there is a conflict between highres timers and nmi_watchdog > here.
yes. Both use a limited resource of the lapic so we get one or the other.
( Might be fixable once we migrate the NMI watchdog code over to perfcounters. )
Ingo
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