Re: [RFC PATCH] Add timer-source of walltime for ftrace

Steven Rostedt
2009-08-18T18:58:39Z

On Wed, 19 Aug 2009, KOSAKI Motohiro wrote:

> > +u64 notrace trace_clock_walltime(void)
> > +{
> > + u32 remainder;
> > + return base_walltime.tv_sec + div_u64_rem(
> > + trace_clock() + base_walltime.tv_nsec,
> > + NSEC_PER_SEC, &remainder);
> > +}
>
> Why do we need calculate walltime at ring-buffer recordng phase?
> IOW, Why can't we calculate this at displaing time?

Right! We should have something like this:

return (u64)base_walltime.tv_sec * NSEC_PER_SEC +
trace_clock() + base_walltime.tv_nsec;

And then we could divide it out later.

And then we could even show more fields in the output and not limit
ourselves to seconds.

-- Steve