Re: [parisc-linux] sched_clock implementation

[Carlos O'Donell <carlos@baldric.uwo.ca>]

On Fri, Sep 19, 2003 at 03:32:41PM +0000, Joel Soete wrote:
> Matthew Wilcox wrote:
> 
> >Anyone want to do better than the lame implementation?  ;-)
> >
> >----- Forwarded message from Andrew Morton <akpm@osdl.org> -----
> >
> >I'll be merging Ingo & Con's CPOU scheduler changes into Linus's tree soon.
> >
> >It does require that the architecture provides a new timing function:
> >
> >A lame implementation is:
> >
> >/*
> >* Returns nanoseconds
> >*/
> > 
> >
> Hi Willy,
> 
> (Certainly yet another stupid question but) to reach such accuracy we 
> would need to have access to some 'time device' with an accuracy better 
> then the nanosec (iirc 10^-9) (because it doesn't seems to me possible 
> to get enough accuracy with cpu clock < 10^9 ie 1Ghz: the most case for 
> parisc systems). Does it exist such device and where to start to read 
> some doc?

We could use cr16 to get better accuracy. See list discussions about
fast gettimeofday.

c.