Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264872AbTFCJvR (ORCPT ); Tue, 3 Jun 2003 05:51:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264884AbTFCJvR (ORCPT ); Tue, 3 Jun 2003 05:51:17 -0400 Received: from camus.xss.co.at ([194.152.162.19]:17934 "EHLO camus.xss.co.at") by vger.kernel.org with ESMTP id S264872AbTFCJvN (ORCPT ); Tue, 3 Jun 2003 05:51:13 -0400 Message-ID: <3EDC72B3.9040109@xss.co.at> Date: Tue, 03 Jun 2003 12:04:35 +0200 From: Andreas Haumer Organization: xS+S User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3) Gecko/20030312 X-Accept-Language: en-us, en MIME-Version: 1.0 To: george anzinger CC: linux-kernel@vger.kernel.org Subject: Re: system clock speed too high? References: <3EDBA83B.5050406@xss.co.at> <3EDBB4B0.6070601@mvista.com> In-Reply-To: <3EDBB4B0.6070601@mvista.com> X-Enigmail-Version: 0.74.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3487 Lines: 114 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi! george anzinger wrote: > Andreas Haumer wrote: > [...] >> I have a quite strange phenomenon here: I see a ~2.5 times >> speed up of system time on a Asus AP1700-S5 server with >> Linux-2.4.21-rc6-ac1. >> Simple proof: a "sleep 300" command terminates after exactly >> 120 seconds of wall clock time. > > > Just as a wild shot in the dark, what speed does the kernel think the > cpu is running at and does this match what the BIOS thinks? > > It sounds like the CLOCK_TICK_RATE is wrong. This would show up as the > kernel thinking the cpu was fast also. > Hm, I don't think this is the case. BIOS reports (correctly) a single, hyperthreaded Xeon CPU with 2.4GHz Kernel reports the same: root@setup:~ {503} $ uname -a Linux setup 2.4.21-rc6-ac1 #2 SMP Tue Jun 3 09:45:13 CEST 2003 i686 unknown root@setup:~ {504} $ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 2 model name : Intel(R) Xeon(TM) CPU 2.40GHz stepping : 7 cpu MHz : 2392.065 cache size : 512 KB physical id : 0 siblings : 2 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm bogomips : 4771.02 processor : 1 vendor_id : GenuineIntel cpu family : 15 model : 2 model name : Intel(R) Xeon(TM) CPU 2.40GHz stepping : 7 cpu MHz : 2392.065 cache size : 512 KB physical id : 0 siblings : 2 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm bogomips : 4771.02 root@setup:~ {505} $ ntpdate ntp.xss.co.at; sleep 500; ntpdate ntp.xss.co.at 3 Jun 11:58:16 ntpdate[1118]: step time server 194.152.162.17 offset -177.268071 sec 3 Jun 12:01:36 ntpdate[1120]: step time server 194.152.162.17 offset -300.106769 sec (Sleeping 500 "system seconds" takes 200 "wall clock seconds") > You pin this to a particular kernel version. Do other kernel versions > do a better job? > So far I tried with: 2.4.21-rc2-ac2 (ACPI compiled as module) 2.4.21-rc4 (ACPI compiled as module) 2.4.21-rc6-ac1 (ACPI compiled as module) 2.4.21-rc6-ac1 (no ACPI comiled at all) Time acceleration is the same for all kernels. I'll try it with some older kernels, too. - - 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+3HKxxJmyeGcXPhERAkZ/AJ9tjgI6K2HtM/tL15nKDFIKzdcvQgCfYOGY i96/o6Nyxlem5yOp1A2Q//s= =plFh -----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/