[LinuxPPS] linuxPPS with 64 bits system

[Hal V. Engel]

On Thursday 20 August 2009 07:43:54 am William S. Brasher wrote:
> On Thu, 20 Aug 2009, christophe taffoureau wrote:
> > Hi,
> >
> > For our software, we patched the 32 bits kernel with PPSkit to manage
> > the synchronisation of our application.
> > We want to upgrade and improve our software with a 64 bits linux kernel
> > and switch the synchronisation management to LinuxPPS.
> >
> > Does LinuxPPS patch support 64 bits kernel ?
>
> A short answer is "Yes, it does."

I can confirm this.   I have never used LinuxPPS on anything other than a 64 
bit system.  I think it should work on any architecture that the kernel runs 
on.  On x86 and x86_64 architectures there is additional optimization by way 
of a low level interrupts capability that should give lower jitter when used.

>
> I installed LinuxPPS using 64 bit code in the same way as I installed it
> using 32 bit code, and I've had no problems running it on a 64 bit
> machine.
>
>
>
> This morning ntp reports:
>
> bill at spectre: $ ntpq -p
>      remote           refid      st t when poll reach   delay   offset 
> jitter
> 
===========================================================================
>=== +GPS_NMEA(0)     .GPS.            0 l    2   16  377    0.000    0.000  
> 0.000 oPPS(0)          .PPS.            0 l    5   16  377    0.000   
> 0.000   0.000
>
> bill at spectre: $ ntptime
> ntp_gettime() returns code 0 (OK)
>   time ce37c9cd.f7af63ac  Thu, Aug 20 2009  8:10:37.967, (.967520417),
>   maximum error 5995 us, estimated error 0 us
> ntp_adjtime() returns code 0 (OK)
>   modes 0x0 (),
>   offset -0.398 us, frequency -146.638 ppm, interval 1 s,
>   maximum error 5995 us, estimated error 0 us,
>   status 0x2001 (PLL,NANO),
>   time constant 4, precision 0.001 us, tolerance 500 ppm,
>
> bill at spectre: $ ntpq -c rv
> assID=0 status=21f4 leap_none, sync_atomic/PPS, 15 events,
> event_peer/strat_chg,
> version="ntpd 4.2.4p7 at 1.1607-o Fri Jul 31 01:23:48 UTC 2009 (1)",
> processor="x86_64", system="Linux/2.6.30.2", leap=00, stratum=1,
> precision=-22, rootdelay=0.000, rootdispersion=0.324, peer=30836,
> refid=PPS, reftime=ce37c9f4.a1fa0fec  Thu, Aug 20 2009  8:11:16.632,
> poll=4, clock=ce37c9fb.8c89a282  Thu, Aug 20 2009  8:11:23.548, state=4,
> offset=0.000, frequency=-146.639, jitter=0.000, noise=0.001,
> stability=0.000, hostname="spectre", signature="md5WithRSAEncryption",
> flags=0x80003, update=200908201020, leapsec=200808080000, tai=34,
> cert="spectre spectre 0x0", expire=201006271614
>
> _______________________________________________
> LinuxPPS mailing list
> LinuxPPS at ml.enneenne.com
> http://ml.enneenne.com/cgi-bin/mailman/listinfo/linuxpps
> Wiki: http://wiki.enneenne.com/index.php/LinuxPPS_support