Re: printk timestamps jumping back and forth in 2.6.25-rc.

Ingo Molnar
2008-02-29T19:45:29Z

* David Miller <davem@davemloft.net> wrote:

> From: Paul Mackerras <paulus@samba.org>
> Date: Fri, 29 Feb 2008 22:11:26 +1100
>
> > On powerpc we use the timebase register, which is synchronized across
> > CPUs, so if this will add unnecessary overhead, we will want to way to
> > turn it off on powerpc (assuming this ends up going upstream).
>
> Similarly on sparc64, all of our TSCs are fully synchronized so this
> complexity is completely unnecessary.

i suspect for them the easiest way is to expose time_sync_thresh and let
them set it to ULONG_MAX - which skips all synchronization overhead and
complexity.

Ingo