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Date: Tue, 19 Feb 2002 09:25:03 +0000
From: Pavel Machek <pavel@suse.cz>
To: Tyson D Sawyer <tyson@rwii.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Missed jiffies
Message-ID: <20020219092502.A37@toy.ucw.cz>
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Hi!

> My system looses about 8 seconds every 20 minutes.  This is reported
> by ntp and verified by comparing 'date' to 'hwclock --show' and a wall
> clock.
> 
> My system is a x86 Dell laptop with HZ=1024.
...
> Since I have defined HZ to be 1024, I miss lots of timer interrupts. 
> However, since the the processor spends 18ms at a time in SMM (System
> Mangement Mode), then even the stock 10ms timer tick will sometimes
> miss a tick.  Thus the problem applies to non-hacked kernels also.

Kernel cancompensate for one lost tick, AFAIR, so go back to HZ=100.
									Pavel
-- 
Philips Velo 1: 1"x4"x8", 300gram, 60, 12MB, 40bogomips, linux, mutt,
details at http://atrey.karlin.mff.cuni.cz/~pavel/velo/index.html.

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