Re: dynamic-hz

From: Pavel Machek
Date: Mon Dec 13 2004 - 15:58:28 EST


Hi!

> > > > But that does not matter, right? Yes, one-shot timer will not fire
> > > > exactly at right place, but as long as you are reading TSC and basing
> > > > next shot on current time, error should not accumulate.
> > >
> > > As said in the rest of the message, the error (or some other error)
> > > accumulates heavily today in the tick-loss compensation/adjustment
> > > algorithm in arch/i386/kernel/timers/timer_tsc.c, so I'm sceptical
> > > about
> >
> > I do not see how it should accumulate. Lets have working TSC. You want
> > to emulate fixed-period timer with single-shot timer.
>
> Its caused by the fact that we don't use the the TSC to accumulate time.
> We are instead interpolating between timer ticks and the TSC, where

Yes, it was supposed to be simple, so that Andrea understands that
there's nothing inherently broken with single-shot timers.

Pavel
--
People were complaining that M$ turns users into beta-testers...
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