Re: [RFC - 0/9] Generic timekeeping subsystem (v. B5)

From: john stultz
Date: Wed Aug 24 2005 - 14:16:32 EST


On Wed, 2005-08-24 at 20:48 +0200, Roman Zippel wrote:
> Hi,
>
> On Wed, 24 Aug 2005, john stultz wrote:
>
> > Ok, so then to clarify the above (as you mention gettimeofday uses
> > system_time), would your gettimeofday look something like:
> >
> > gettiemofday():
> > return (system_time + (cycle_offset * mult) + error)>> shift
> >
> > ?
>
> No.
>
> reference_time = xtime;
> system_time = xtime + error >> shift;
> gettimeofday = system_time + (cycle_offset * mult) >> shift;

Eh? In your example code from before you look to be keeping the
system_time and error values in shifted nsec units.

from your example:
> // at init: system_update = update_cycles * mult;
> system_time += system_update;

and:
> error = system_time - (xtime.tv_nsec << shift);

This doesn't seem to make sense with the above. Could you clarify?

thanks
-john

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