[LinuxPPS] PLL sensitivity

[Cirilo Bernardo]

On Wed, Nov 19, 2008 at 3:04 AM, Udo van den Heuvel <udovdh at xs4all.nl> wrote:
> So: anybody?
> What info do we need before we can start to (pseudo) code the function?
>

For kcbind, I imagine just read the RFC for PPS.

If I'm not mistaken, an earlier implementation of PPS had a kcbind
patch for Linux and there were even some remnants in the kernel
headers; there is no sign of any actual implementation in the kernel
source though.

Although 'kcbind' may look simple to implement, a thorough
understanding of the kernel timer system is needed first.  I had a
look over a year ago and then walked away; there were so many changes
(high-resolution timer in development, 'HPET' timer was implemented
but was being removed because it did not work, tickless timer work,
etc).  So whoever implements kcbind has to make sure there is no
unwanted side-effect on the kernel.  I imagine whoever looks into
kcbind may also have to fix up other issues like the scheduler
interrupt frequency and its effect on NTP.

- Cirilo