Messages in this thread | | | Subject | Re: Hang and Soft Lockup problems with generic time code | From | James Bottomley <> | Date | Sat, 08 Jul 2006 17:13:05 -0500 |
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On Sat, 2006-07-08 at 14:47 -0700, john stultz wrote: > > Well, what I was seeing was that > > > > clocksource_read(clock) - clock->cycle_last > > > > is returning a value about 200 x clock->cycle_interval > > That then would be ~200 ticks. Is this at HZ=1000 ?
no, 250.
> > According to the debugging printks I put into update_wall_time(). I was > > assuming this was caused by a jump in the TSC count, but I suppose it > > could also be cause by spurious alterations to cycle_last or other > > effects I haven't traced. > > Since this issue effected both the TSC and ACPI PM timer, I'd more > likely suspect something is holding off the timer interrupt. This could > be some kernel code like a driver, or it could be something like an SMI > from the BIOS.
The driver takes only ~10s to insert and these cycle jumps occur within that time frame, so it's not a real 200s. The timer system has somehow manufactured the cycle jump.
James
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