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From: "George Spelvin" <linux@horizon.com>
To: johnstul@us.ibm.com, linux@horizon.com
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
	ulrich.windl@rz.uni-regensburg.de, williams@redhat.com,
	zippel@linux-m68k.org
Subject: Re: [RFC][PATCH] Adjust SHIFT_PLL to improve NTP convergence.
Date: 7 May 2009 02:07:41 -0400	[thread overview]
Message-ID: <20090507060741.26571.qmail@science.horizon.com> (raw)
In-Reply-To: <1241624640.9110.3.camel@jstultz-laptop>

> Yea. The TSC calibration issue has been around for awhile. Although the
> code has been tweaked recently, I'm not seeing that much improved
> consistency from reboot to reboot.
> 
> Its a hard trade off for folks who need very quick boot time, vs folks
> that want very stable and accurate clocks across reboots.
> 
> I'll be looking into the calibration code to see how much is needed to
> bring the error rate down.

The fast estimate is very good.  Would it be possible to do a fine
calibration in parallel with the rest of the boot sequence?  Maybe until
the first adjtimex call?  Or is it essential that the numbers not
change?

  reply	other threads:[~2009-05-07  6:07 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-04 21:03 [RFC][PATCH] Adjust SHIFT_PLL to improve NTP convergence john stultz
2009-05-05  0:27 ` Rik van Riel
2009-05-06 14:46 ` George Spelvin
2009-05-06 15:44   ` John Stultz
2009-05-07  6:07     ` George Spelvin [this message]
2009-05-07  9:14   ` Ulrich Windl
2009-05-07 18:07     ` George Spelvin
2009-05-07 19:37       ` john stultz

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