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

From: john stultz
Date: Wed Aug 24 2005 - 13:00:47 EST


On Wed, 2005-08-24 at 01:54 +0200, Roman Zippel wrote:
> Hi,
>
> On Tue, 23 Aug 2005, john stultz wrote:
>
> > I'm assuming gettimeofday()/clock_gettime() looks something like:
> > xtime + (get_cycles()-last_update)*(mult+ntp_adj)>>shift
>
> Where did you get the ntp_adj from? It's not in my example.
> gettimeofday() was in the previous mail: "xtime + (cycle_offset * mult +
> error) >> shift". The difference between system time and reference
> time is really important. gettimeofday() returns the system time, NTP
> controls the reference time and these two are synchronized regularly.
> I didn't see that anywhere in your example.

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

?

thanks
-john

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/