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From: erik quanstrom <quanstro@quanstro.net>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] timesync doubletime
Date: Mon,  7 Aug 2006 20:39:50 -0500	[thread overview]
Message-ID: <ccf4955b5919e6cba29821d400d10735@quanstro.net> (raw)
In-Reply-To: <20060808004253.GA51122@kris.home>

since /dev/rtc is verified working and since i am not running timesync at all,
it seems to me that the problem must be in the kernel and sleep (thus the
kernel's fastticks) must be running too fast.

in 60s sleep (same pace as date output), the rtc advances only 32 or 33sec
(6:44-6:11, 09:06-08:34, 09:51-09:19).

doing things the other way gives 60 rtc sec = 110 system sec.

; fn rtcmin { s = `{cat /dev/rtc} ; end = `{echo $s + 60 | hoc} ; while (! ~ `{cat /dev/rtc} $end) usleep 4}
; date ; rtcmin ; date
Mon Aug  7 20:33:25 CDT 2006
Mon Aug  7 20:35:15 CDT 2006

- erik

On Mon Aug  7 19:43:27 CDT 2006, bsdaemon@comcast.net wrote:
> On Mon, Aug 07, 2006 at 07:12:41PM -0500, erik quanstrom wrote:
> >; cat /dev/rtc > /dev/time ; sleep 60 ; date ; date `{cat /dev/rtc}
> >Mon Aug  7 19:07:11 CDT 2006
> >Mon Aug  7 19:06:44 CDT 2006
> >; ; cat /dev/rtc > /dev/time ; sleep 60 ; date ; date `{cat /dev/rtc}
> >Mon Aug  7 19:09:34 CDT 2006
> >Mon Aug  7 19:09:06 CDT 2006
> >; ; ; cat /dev/rtc > /dev/time ; sleep 60 ; date ; date `{cat /dev/rtc}
> >Mon Aug  7 19:10:19 CDT 2006
> >Mon Aug  7 19:09:51 CDT 2006
> 
> That output isn't very useful. This would be more useful:
> fn dates { date; date `{cat /dev/rtc} }
> dates; cat /dev/rtc>/dev/time; dates; sleep 60; dates; sleep 60; dates
> 
> I suspect that the issue is that your clock is being synchronized to an ntp 
> server which has a different time from your real time clock.
> 
> -- 
> Kris Maglione
> 
> If it would be cheaper to buy a new unit, the company
> will insist upon repairing the old one.


  reply	other threads:[~2006-08-08  1:39 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-08-08  0:12 erik quanstrom
2006-08-08  0:42 ` Kris Maglione
2006-08-08  1:39   ` erik quanstrom [this message]
2006-08-08  1:46     ` andrey mirtchovski
2006-08-08  2:37       ` erik quanstrom
2006-08-08  1:59         ` andrey mirtchovski
2006-08-08  3:10           ` erik quanstrom
2006-08-08  6:09             ` Steve Simon
2006-08-08  6:15               ` andrey mirtchovski
2006-08-08  6:21                 ` andrey mirtchovski
2006-08-08 15:00               ` John Floren
2006-08-08  2:09     ` geoff
2006-08-08  3:40       ` erik quanstrom
2006-08-08  3:09         ` Kris Maglione
2006-08-08 14:53 ` Russ Cox
2006-08-08 20:07   ` erik quanstrom

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