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Date: Tue, 8 Apr 2014 21:29:29 +0700
From: Alexey Dokuchaev <danfe@nsu.ru>
To: John Baldwin <john@baldwin.cx>
Subject: Re: System clock falls behind quickly on Mac mini G4
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On Mon, Apr 07, 2014 at 05:04:58PM -0400, John Baldwin wrote:
> Also, if the frequency is calibrated incorrectly during boot for some reason,
> your time-of-day clock will drift constantly.  I've seen this on x86 boxes

Yes, I remember a thread (x86ish) some time ago about bogus TSC calibration,
but...

> where the TSC was calibrated incorrectly due to an interaction with SMM
> interrupts for legacy USB emulation.  In that case, adjusting machdep.tsc_freq
> to match the frequency from the CPU's brand string "fixed" the drift.

... sysctl -a does not show machdep.tsc_freq for me on this G4 box for
some reason (GENERIC kernel).

./danfe