Re: [PATCH V8 02/13] ntp: add ADJ_SETOFFSET mode bit

[john stultz <johnstul@us.ibm.com>]

On Tue, 2011-01-11 at 05:47 +0900, Kuwahara,T. wrote:
> On Mon, Jan 10, 2011 at 4:17 PM, Richard Cochran
> <richardcochran@gmail.com> wrote:
> > the PTP Hardware Clocks for which this whole patch
> > set was created in the first place will keep their time as TAI.
> 
> Are you sure of that?  I don't have the standard handy (it's non-free,
> right?) but it seems that the Annex B states differently.  But that's
> not the point anyway.  My concern is that your patch not only adds the
> useless (and broken) feature to the existing syscall but also makes a
> permanent change to the public interface for your own use.  That's
> what I'm against.  So if you stop touching the struct timex, I won't
> complain anymore.

You still haven't explained *why* you're so protective of the timex and
adjtimex interfaces.  While I do want to keep compatible the
functionality where possible, I don't see why Linux should be limited by
what other OSes do.

Injecting an offset to the system time seems like a reasonable thing for
adjtimex to do (rather then adding a new syscall). Further utilizing a
new mode bit for this functionality seems reasonable and cleaner then
your suggestions for utilizing existing mode bits in combined with other
magic bits. If there is a compelling reason why not to do this, do
please let us know! We might just agree with you after hearing it. :)

thanks
-john