Re: time interpolation hooks

[David Mosberger <davidm@napali.hpl.hp.com>]

>>>>> On Mon, 19 May 2003 17:42:03 +0000, Arjan van de Ven <arjanv@redhat.com> said:

  Arjan> On Mon, May 19, 2003 at 10:34:43AM -0700, David Mosberger wrote:

  >> struct time_interpolator {
  >> void (*update_wall_time) (long delta_nsec);
  >> void (*reset_wall_time) (long delta_nsec);
  >> unsigned long frequency;	/* frequency in counts/second */
  >> unsigned long drift;		/* drift in parts-per-million (?) */
  >> };

  Arjan> probably also a "get interpolated value" kind of thing ?

Yes, of course.  Not a good idea to write an email in a hurry.

  Arjan> other than that it seems to match what I had in mind.
  Arjan> For the score we may need something creative; I'm not sure all timers
  Arjan> have a defined drift, otoh parts-per-million seems to be the
  Arjan> standard mechanism of reporting this.

What could you possibly do about a timer with an unknown drift?
Perhaps give preference to higher frequency, even if the drift is
unknown?  In any case, I suppose we can fine-tune the policy
afterwards.

Andrew, I assume it's OK with you if I update the ia64 code to the
proposed interface and then send you an updated patch?

	--david