Re: Missed jiffies

From: Pavel Machek (pavel@suse.cz)
Date: Tue Feb 19 2002 - 04:25:03 EST

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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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