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Unix/Linux 网络时间协议版本3 Network Time Protocol Version 3 (NTP) distribution for Unix systems

Replied: Mon, 02 Feb 1998 20:18:18 -0500
Replied: "Marc Brett <[e-mail]> "
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From: Marc Brett <[e-mail]>
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Date: Mon, 2 Feb 1998 17:30:02 +0000
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Subject: Hack for AIX
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Harlan,

We run a large number of AIX hosts at this location, some with good clocks,
and some with bad.  It's about a 50/50 split.  All of the recent xntp
releases allow the frequency of the bad clocks to drift to (+ve or -ve)
389.284 ppm (using xntpdc -c loopinfo), which in turn causes the occasional
time step.  The following hack restores the PRESET_TICKADJ value which was
present in older versions of xntp, namely xntp3.3c (included with SP
systems), and xntp3.4y (shipped with AIX 4) which behave fine.  The
frequency drift values of all hosts (good & bad) seem to be reduced
by applying this hack.

I must confess I don't understand _why_ this hack works.  I'd been hoping
that someone with more knowledge could engineer a fix from first principles,
but alas this hasn't happened yet.  Hopefully this hack isn't too far wrong.

The patch is for xntp3-5.92-export/configure.in.  If you are not
rebuilding configure with autoconf, apply this patch to configure instead.


Regards,

Marc

-- 
Marc Brett  [phone]            Western Geophysical
[e-mail]                     455 London Road, Isleworth
FAX: [phone]                   Middlesex TW7 5AB    UK

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*** configure.in.orig	Tue Jan 20 01:34:46 1998
--- configure.in	Mon Feb  2 16:23:41 1998
***************
*** 2020,2028 ****
        ans=80
        ;;
     *-*-aix*)
!       case "$ac_cv_var_can_kmem" in
!        no) ans=1000 ;;
!       esac
        ;;
     *-*-domainos)	# Skippy: won't be found...
        case "$ac_cv_var_can_kmem" in
--- 2020,2026 ----
        ans=80
        ;;
     *-*-aix*)
!       ans=1000
        ;;
     *-*-domainos)	# Skippy: won't be found...
        case "$ac_cv_var_can_kmem" in

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