Re: Getting current time
Re: Getting current time
- Subject: Re: Getting current time
- From: Sean Peisert <email@hidden>
- Date: Sat, 8 Jan 2005 08:58:18 -0800
On Sat, 8 Jan 2005 00:59:17 -0500, Karl Magdsick <email@hidden> wrote:
> If you want to get a clock error estimate from within the kernel, what
> do you want to use as your reference clock?
I have a CDMA clock plugged into a third-party of my XServe, that I
have confirmed accuracy on. I also have a number of other stratum 1
NTP clocks that ntpd is peering with.
> The NTP error estimate is based on clock skew, which requires two
> clocks. It would appear that this would require porting an NTP (or
> other protocol to query remote clocks) client into kernel space or
> else writing some user-space code to implement/utilize an NTP client
> and pass the information to the kernel. Jitter between the CPU clock
> and the BIOS clock is not sufficient for this purpose.
Ah, so this comes back to really just needing the ntp_adjtime() call
to work, because whatever I implement will need to talk to ntpd?
Do you have any advice to massaging the kern_ntptime.c and timex.h
files from FreeBSD into something that will function properly on
Darwin?
Thanks,
Sean
>
>
> -Karl
>
> On Fri, 7 Jan 2005 13:26:31 -0800, Sean Peisert <email@hidden> wrote:
> > > >> I was wondering if there is a way to get the current time of the day
> > > >> it is on the system from
> > > >> within a kernel extension I am writing.
> > > >
> > > > You can follow the code for gettimeofday() and just call
> >
> > Is there an equivalent to this for getting the error estimate that
> > ntp_adjtime() gives?
> >
> > --
> > Sean Peisert
> > http://www.sdsc.edu/~peisert/
>
--
Sean Peisert (858) 822-3685 (voice)
email@hidden (858) 822-5443 (fax)
http://www.sdsc.edu/~peisert/
Fellow,
San Diego Supercomputer Center
University of California, San Diego
9500 Gilman Drive, MC 0505
La Jolla, CA 92093-0505
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