Re: Timekeeping hosed by factor 3, high lapic[01] interrupt rates

From: Doug White <dwhite_at_gumbysoft.com>
Date: Thu, 26 May 2005 10:30:16 -0700 (PDT)
On Mon, 23 May 2005, Jens Schweikhardt wrote:

> ...
> # # 3. Backout rev 1.218 of src/sys/i386/isa/clock.c so the irq0 interrupt
> # # handler is reactivated and the RTC fiddled.
> #
> # Will do so next. I've nailed the change between March 6 and March 30.
> # 1.218 is from 2005/03/24 21:34:16, which would fit.
>
> We have a winner. Backing out 1.218 from a 2005/03/24 system does the trick,
> as well as a CURRENT without 1.218 (but 1.219-220 in there) bring back irq0
> and time dilation is gone. All clocks work correctly.

Hm ... not sure what part of that commit is the bad part.  You might try
changing

if (!using_lapic_timer) {

to

if(1) {

in the most recent rev of clock.c to register irq0 again.  If that doesn't
chang ethe dialation then something else in the system must be depending
on the RTC periodic interrupt.

> Now the question is: what is so special in my system so that I appear
> to be the only one to notice the problem?

Good question. What CPUs do you have in that machine again? Copy out the
'CPU' and related lines from dmesg.

--
Doug White                    |  FreeBSD: The Power to Serve
dwhite_at_gumbysoft.com          |  www.FreeBSD.org
Received on Thu May 26 2005 - 15:30:16 UTC

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