Date: Fri, 17 Jun 2005 14:50:42 -0400 From: John Baldwin <jhb@FreeBSD.org> To: freebsd-current@freebsd.org Cc: Jens Schweikhardt <schweikh@schweikhardt.net> Subject: Re: Timekeeping hosed by factor 3, high lapic[01] interrupt rates Message-ID: <200506171450.44146.jhb@FreeBSD.org> In-Reply-To: <20050608190147.GA917@schweikhardt.net> References: <20050516113420.GA786@schweikhardt.net> <20050526205831.GA958@schweikhardt.net> <20050608190147.GA917@schweikhardt.net>
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On Wednesday 08 June 2005 03:01 pm, Jens Schweikhardt wrote:
> On Thu, May 26, 2005 at 10:58:31PM +0200, Jens Schweikhardt wrote:
> # On Thu, May 26, 2005 at 10:30:16AM -0700, Doug White wrote:
> # # 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.
> #
> # It does make time dilation go away.
>
> Any chance this gets backed out, or worked around, e.g. with a
> sysctl, device hint, or some other knob?
Is this the patch you are running with?
>Index: clock.c
===================================================================
RCS file: /usr/cvs/src/sys/i386/isa/clock.c,v
retrieving revision 1.220
diff -u -r1.220 clock.c
--- clock.c 14 May 2005 09:10:01 -0000 1.220
+++ clock.c 27 May 2005 19:42:54 -0000
@@ -784,7 +784,7 @@
* clocks, setup the interrupt handler for the 8254 timer 0 so
* that it can drive hardclock().
*/
- if (!using_lapic_timer) {
+ if (!using_lapic_timer || 1) {
intr_add_handler("clk", 0, (driver_intr_t *)clkintr, NULL,
INTR_TYPE_CLK | INTR_FAST, NULL);
i8254_intsrc = intr_lookup_source(0);
Also, can you get the output of 'sysctl kern.clockrate' for both cases?
--
John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve" = http://www.FreeBSD.org
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