Re: [PATCH V7 1/8] ntp: add ADJ_SETOFFSET mode bit

[Richard Cochran]

On Sat, Dec 18, 2010 at 05:16:52AM +0900, Kuwahara,T. wrote:
> On 12/17/10, Richard Cochran <richardcochran@xxxxxxxxx> wrote:
> > This patch adds a new mode bit into the timex structure. When set, the bit
> > instructs the kernel to add the given time value to the current time.
> >
> 
> The proposed new control mode, ADJ_SETOFFSET, is logically the same as
> ADJ_OFFSET with timex.constant == -INFINITY.  So it is possible to do
> the same thing without risking forward compatibility.  (I mean by "risking
> forward compatibility" that the mode bit 0x0040 may be defined differently
> by the upstream maintainer anytime in the future.)

Can you please elaborate?

I don't see any way to use timex.constant with ADJ_OFFSET in order to
correct a time offset. The 'time_constant' in kernel/time/ntp.c is
restricted to the interval [0..MAXTC], and MAXTC is 10 in timex.h.

Richard
--
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/