Re: IA64 implementation of timesource for new time of day subsystem

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

On Mon, 2005-05-16 at 12:29 -0700, David Mosberger wrote: 
> >>>>> On Mon, 16 May 2005 12:24:08 -0700 (PDT), Christoph Lameter <clameter@engr.sgi.com> said:
> 
>   Christoph> Other IA64 vendors will see that their timer performance
>   Christoph> drops significantly after the new timer subsystem is
>   Christoph> in. IBM no longer has IA64 systems that rely on ITC?
> 
> Would that somehow make it ok to break existing and working code?

No. I intend to preserve the existing functionality (and performance) of
the current code. The current timeofday core should allow for this (as I
described in my last mail), so really its just a matter of either me or
someone else getting around to properly converting that arch with the
help of the arch maintainer. Until the arch is really ready to use the
new timeofday core, no changes are necessary.

Christoph's patch is just a step in the right direction. That is, a much
appreciated step, I haven't yet had the time to implement or test the
ia64 timesources. Any notable regressions introduced will need to be
resolved before the arch specific patch is finally submitted.

What I'm trying to shake out, with Christoph's help, is any major
limitations in the core timeofday code that would keep an arch from
being able to use it.  I feel Christoph's concerns have been addressed,
but please let me know if you disagree.

thanks
-john