Messages in this thread | | | Date | Tue, 4 May 2004 18:50:22 +0200 (CEST) | From | Tim Schmielau <> | Subject | Re: /proc or ps tools bug? 2.6.3, time is off |
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On Tue, 4 May 2004, john stultz wrote:
> On Mon, 2004-05-03 at 23:12, Tim Schmielau wrote: > > > > I wonder whether it's conceptually correct to use jiffies for accurate > > long-time measurements at all. ntpd is there for a reason. Using both > > corrected, accurate and freely running clocks IMHO is calling for trouble. > > This might be something to think about for 2.7. > > Indeed. Moving away from jiffies as a time counter and more of an > interrupt counter is important. That allows for implementations of > variable HZ and other things the high-res timer folks want without > affecting the time keeping code. > > Roughly, I'd like to see the time code for all arches in 2.7 to look > like:
[simple, well thought-out proposal snipped]
> time_interrupt_hook(): > updates system_time.
> Of course, with this approach, we actually have to be able to trust the > hardware 100%. With the current state of i386 hw having serious problems > w/ reliable timesources, this may be difficult.
Well, with some configurable plausibility checks in time_interrupt_hook() it shouldn't be worse than what we have now...
> I've got a bigger proposal (with proper credits to Keith Mannthey and > George Anzinger for reviews and corrections) that I wrote up awhile > back, and I'll likely send it out if this sketch gathers any interest.
Yes, that sounds interesting. It's just that I won't have any spare time to spend in the next two weeks.
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