Messages in this thread |  | | Date | Tue, 3 Jun 2003 17:17:04 +0200 (CEST) | From | venom@sns ... | Subject | Re: system clock speed too high? |
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I reported this same problem for kernel 2.5.69/70 on pentiumIII with chipset i810, but it seems the reports has been unnoticed.
I replicated your tests with 2.5.70 without acpi, same results here.
On Tue, 3 Jun 2003, Andreas Haumer wrote:
> Date: Tue, 03 Jun 2003 11:54:26 +0200 > From: Andreas Haumer <andreas@xss.co.at> > To: Alan Cox <alan@lxorguk.ukuu.org.uk> > Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org> > Subject: Re: system clock speed too high? > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Hi, > > Alan Cox wrote: > > On Llu, 2003-06-02 at 20:40, Andreas Haumer wrote: > > > >>-----BEGIN PGP SIGNED MESSAGE----- > >>Hash: SHA1 > >> > >>Hi! > >> > >>(I've already reported this previously as post scriptum > >>to a different bugreport, so it might have slipped through > >>unnoticed...) > > > > > > Does this occur if you boot with "notsc" or if you run a non ACPI kernel > > ? > > > I did some more tests on this machine, with the following > results: > > 1.) Kernel 2.4.21-rc6-ac1 (ACPI compiled as module) > a) no special kernel commandline option > -> System doesn't boot, fusion MPT driver doesn't find > the hardware listed on the PCI bus (problem already > reported in a previous mail) > > b) boot with "acpi=off" > -> System does boot, fusion MTP driver finds the controller > -> time runs 2.5 times too fast > > c) boot with "acpi=off notsc" > -> same as 1b) > > 2.) Kernel 2.4.21-rc4 (ACPI compiled as module) > a) no special kernel commandline option > -> System does boot, fusion MTP driver finds the controller > -> time runs 2.5 times too fast > > b) boot with "acpi=off" > -> Same as 2a) > > c) boot with "acpi=off notsc" > -> Same as 2a) > > 3.) Kernel 2.4.21-rc2-ac2 (ACPI compiled as module) > a) no special kernel commandline option > -> System doesn't boot, fusion MPT driver doesn't find > the hardware listed on the PCI bus > > b) boot with "acpi=off" > -> System does boot, fusion MTP driver finds the controller > -> time runs 2.5 times too fast > > c) boot with "acpi=off notsc" > -> same as 3b) > > > 4.) Kernel 2.4.21-rc6-ac1 (without ACPI) > a) no special kernel commandline option > -> System does boot, fusion MTP driver finds the controller > -> time runs 2.5 times too fast > > b) boot with "notsc" > -> Same as 4a) > > 5.) Kernel 2.4.21-rc4 (ACPI compiled as module) > floppy-minisystem, booting into initrd only > modules loaded: unix.o. ext2.o, floppy.o > -> time runs 2.5 times too fast > > > Time "acceleration" always seems to be by a factor of exactly 2.5 > Proof: > root@setup:~ {502} $ ntpdate ntp.xss.co.at; sleep 300; ntpdate ntp.xss.co.at > 3 Jun 11:31:52 ntpdate[1185]: step time server 194.152.162.17 offset -895.898772 sec > 3 Jun 11:33:52 ntpdate[1187]: step time server 194.152.162.17 offset -180.088187 sec > > (I first sync the system clock with our NTP timeserver, then sleep > 300 seconds, and then again sync against our NTP server) > > Sleeping 300 "system seconds" takes 120 "wall clock seconds" and > brings the system clock ahead of 180 seconds, which gives a speed > up factor of 2.5. Does this number ring any bell? > > Additional info: I'm booting with LILO and have set LILO timeout > to 10 seconds. This works fine: "LILO time" is the same as wall > clock time. So this speed up must be triggered somewhere inside > the kernel, it seems... > > Any idea someone? > > - - andreas > > - -- > Andreas Haumer | mailto:andreas@xss.co.at > *x Software + Systeme | http://www.xss.co.at/ > Karmarschgasse 51/2/20 | Tel: +43-1-6060114-0 > A-1100 Vienna, Austria | Fax: +43-1-6060114-71 > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.2.1 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iD8DBQE+3HBPxJmyeGcXPhERAplBAKCYqTbno0EnP9WqKwtzXyUjBCUosgCfT7qw > vfPbba5yqYD0qUI9BDJBD40= > =i+JF > -----END PGP SIGNATURE----- > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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