question on update_wall_time_one_tick()

question on update_wall_time_one_tick()

[Chris Friesen]

If we call update_wall_time_one_tick(), with a mode of ADJ_OFFSET_SINGLESHOT, 
the offset can be up to +/-512000 usec.

However, in update_wall_time_one_tick(), the offset adjustment each tick is 
limited to the range of -tickadj < x < tickadj.  On many current systems, 
tickadj is 1.  Thus, a large adjustment takes a *long* time.

While we are doing this offset change, if someone else requests another offset, 
it will totally overwrite any unapplied portion of the offset from the previous 
call:

	/* Changes by adjtime() do not take effect till next tick. */
	if (time_next_adjust != 0) {
		time_adjust = time_next_adjust;
		time_next_adjust = 0;
	}

Thus, doing an offset of +512000, immediately followed by an offset of -512000, 
will leave you with a significant negative offset.

Is this the desired behaviour?

Chris

Re: question on update_wall_time_one_tick() -- doh!

[Chris Friesen]

Friesen, Christopher [CAR:VC21:EXCH] wrote:

> Thus, doing an offset of +512000, immediately followed by an offset of 
> -512000, will leave you with a significant negative offset.
> 
> Is this the desired behaviour?

Just realized this was the old adjtime() behaviour.  Wasn't clear from the 
adjtimex() man page.

Chris