Messages in this thread | | | Date | Wed, 13 Dec 2006 21:40:34 +0100 (CET) | From | Roman Zippel <> | Subject | Re: [RFC] HZ free ntp |
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Hi,
On Wed, 13 Dec 2006, john stultz wrote:
> > The largest possible interval is freq cycles (or 1 second without > > adjustments). That is the base interval and without redesigning NTP we > > can't change that. This base interval can be subdivided into smaller > > intervals for incremental updates. > > Indeed, larger then 1 second intervals would require the second_overflow > code to be reworked too.
There isn't much to rework without a complete redesign.
> > You cannot choose arbitrary intervals otherwise you get other problems, > > e.g. with your patch time_offset handling is broken. > > I'm not seeing this yet. Any more details?
time_offset is scaled to HZ in do_adjtimex, which needs to be changed as well.
> > You don't have to introduce anything new, it's tick_length that changes > > and HZ that becomes a variable in this function. > > So, forgive me for rehashing this, but it seems we're cross talking > again. The context here is the dynticks code. Where HZ doesn't change, > but we get interrupts at much reduced rates.
I know and all you have to change in the ntp and some related code is to replace HZ there with a variable, thus make it changable, so you can increase the update interval (i.e. it becomes 1s/hz instead of 1s/HZ).
> However, in doing so we have to > work w/ the ntp.c code which (as Ingo earlier mentioned) has a number of > HZ based assumptions.
Repeating Ingo's nonsense doesn't make it any more true. :-(
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