Date: Sat, 16 Aug 2003 12:06:21 +0900 (JST) From: MATOBA Hirozumi <matoba@st.rim.or.jp> To: thorsten.greiner@web.de Cc: nate@root.org Subject: Re: clock works slowly when I change CPU speed Message-ID: <20030816.120621.846933691.matoba@st.rim.or.jp> In-Reply-To: <20030815205047.GA719@tybalt> <20030816.022701.730550600.matoba@st.rim.or.jp> <11229.1060970608@critter.freebsd.dk> References: <11229.1060970608@critter.freebsd.dk> <1060978640.603.11.camel@localhost> <20030815205047.GA719@tybalt>
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On Fri, 15 Aug 2003 22:50:47 +0200 Thorsten Greiner wrote:
| $ dmesg | grep counter
| Timecounter "i8254" frequency 1193182 Hz
| Timecounter "ACPI-fast" frequency 3579545 Hz
| Timecounter "TSC" frequency 1595302164 Hz
| $ sysctl -w kern.timecounter.hardware=i8254
| Fixes the problem for me. I suspect you should set this in
| /etc/sysctl.conf to enable it permanently.
Thank you for your advice.
I compared the behaviors of the 2 kernel in the quoted mail below (I wrote)
about Timecounter in dmesg and about value of kern.timecounter.hardware,
then I understood the mail
On Fri, 15 Aug 2003 20:03:28 +0200 "Poul-Henning Kamp" wrote:
>> You should not be using the TSC for timekeeping if you change the
>> frequency of it.
means.
On my ThinkPad A22e, 3 kind of Timecounters appear in dmesg.
Between 2 kernels, both of about appeaing order in dmesg
and about the default value of kern.timecounter.hardware differ.
On kernel with the previous revision of these 3 file:
$ dmesg | grep counter
Timecounter "i8254" frequency 1193182 Hz
Timecounter "TSC" frequency 797048080 Hz
Timecounter "ACPI-fast" frequency 3579545 Hz
Timecounters tick every 10.000 msec
$ sysctl kern.timecounter.hardware
kern.timecounter.hardware: ACPI-fast
On kernel with the latest (on Aug 13) revision of these 3 files:
$ dmesg | grep counter
Timecounter "i8254" frequency 1193182 Hz
Timecounter "ACPI-fast" frequency 3579545 Hz
Timecounter "TSC" frequency 797048048 Hz
Timecounters tick every 10.000 msec
$ sysctl kern.timecounter.hardware
kern.timecounter.hardware: TSC
So, on kernel with the latest (on Aug 13) revision of these 3 files,
after executing
sysctl -w kern.timecounter.hardware=ACPI-fast
the clock works normally for any CPU speed settings, successfully.
I will put it in /etc/sysctl.conf :-)
# Does kernel choose the Timecounter which detects recently
# as the default value of kern.timecounter.hardware?
On Sat, 16 Aug 2003 02:27:01 +0900 (JST) I wrote:
| I changed 3 files in quoted mail below (tsc.c clock.h clock.c)
| back to the previous revision,
| on my ThinkPad A22e (the last cvsup was on Aug 13),
| and recompiled kernel (the config file is almost the same as GENERIC),
| and compared behavior of the clock between 2 kernels as:
|
| kernel with the latest (on Aug 13) revision of these 3 files
| kernel with the previous revision of these 3 file
|
| | >> Message-Id: <200308061505.h76F5Sih048392@repoman.freebsd.org>
| | >> From: Poul-Henning Kamp <phk@FreeBSD.org>
| | >> Date: Wed, 6 Aug 2003 08:05:28 -0700 (PDT)
| | >> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org,
| | >> cvs-all@FreeBSD.org
| | >> X-FreeBSD-CVS-Branch: HEAD
| | >> Subject: cvs commit: src/sys/i386/i386 tsc.c src/sys/i386/include clock.h
| | >> src/sys/i386/isa clock.c
| | >>
| | >> phk 2003/08/06 08:05:28 PDT
| | >>
| | >> FreeBSD src repository
| | >>
| | >> Modified files:
| | >> sys/i386/i386 tsc.c
| | >> sys/i386/include clock.h
| | >> sys/i386/isa clock.c
| | >> Log:
| | >> Dont initialize a TSC timecounter until we know if it is broken or not.
| | >>
| | >> Revision Changes Path
| | >> 1.201 +6 -0 src/sys/i386/i386/tsc.c
| | >> 1.45 +1 -0 src/sys/i386/include/clock.h
| | >> 1.201 +1 -0 src/sys/i386/isa/clock.c
--
matoba@st.rim.or.jp
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