[LinuxPPS] ntp-dev-4.2.5p237-RC does sync with PPS for me

[William S. Brasher]

On Wed, 28 Oct 2009, clemens at dwf.com wrote:

> 
> Other than the ppstest (which is good) and the ntpq which shows that you are
> not syncing to the PPS source (even tho it has lower jitter) Im not sure 
> what you are seeing dynamically.
> 
> In 2.6.31.x (and perhaps earlier) the variable 
> 
> 	#define SHIFT_PLL  4 has been set to 2
> 
> there was also an implication in some of the postings that with this change
> you should be able to run with Hz = 1000.
> 
> When I have tried this, my ntp wandered all over the place.  It could start 
> with
> an offset of 10ms and after a while be at 15s, all the time being the CHOSEN
> device.  Mumph.
> 
> As an additional experiment, could you check what HZ you have set in your 
> kernel,
> and set it back to 100 if it is not already there.  This will require a 
> mrproper
> recompile of the kernel since Hz is used everywhere.
> 
> Im not too sure if this is going to solve your problem, but it caused me a lot
> of grief.
> 
> -- 
>                                         Reg.Clemens
>                                         reg at dwf.com
> 
> 
> 



The kernel as compiled works with ntp-4.2.4p7 with no problems.  I also 
checked the HZ, and it was 1000 on this box, a 64 bit box, while the 32 
bit boxes are all set to HZ=100.  So, I'll recompile the 64 bit kernel 
with HZ=100 and add the latest linux-2.6.31 patch to the kernels on the 32 
bit machines, and test the lot.

An afternoon of building kernels, it would seem.