[LinuxPPS] Re: Measuring interrupt latency with NTP

[Rodolfo Giometti]

On Sun, Aug 13, 2006 at 03:36:52PM -0400, linux at horizon.com wrote:
> I just rebooted with 2.6.18-rc4 + linuxpps, and have configured my NTP
> 4.2.2 server with both the palisade (127.127.29.0) and ATOM (127.127.22.0)
> drivers.  (The latter took some hacking to eliminate "handle == 0" and
> "#ifdef PPS_API_VERS_1" tests.)

Can you please send us the patches for the NTPD drivers that you used?

> First, a bug report: /proc/pps/00/assert appears to have 100 Hz granularity:
> 
> 1155490053.23000 #11215
> 1155490054.23000 #11216
> 1155490055.25000 #11217
> 1155490056.23000 #11218
> 1155490057.24000 #11219
> 1155490058.24000 #11220
> 
> A quick look in linuxpps_procfs_assert_read shows that it should be printing
> a few leading zeros:
> 
> -	len += sprintf(page+len, "%ld.%ld #%ld\n",
> +	len += sprintf(page+len, "%ld.%09ld #%ld\n",
>                          linuxpps_source[id].assert_tu.tspec.tv_sec,
>                          linuxpps_source[id].assert_tu.tspec.tv_nsec,
>                          linuxpps_source[id].assert_sequence);

Fixed.

Ciao,

Rodolfo

-- 

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