On Fri, 2010-05-28 at 02:33 +0200, Bernhard Schmidt wrote: > On 28.05.2010 02:00, john stultz wrote: > > Looking at the diff: > > --- dmesg-lenny 2010-05-27 16:45:33.000000000 -0700 > > +++ dmesg-squeeze 2010-05-27 16:46:14.000000000 -0700 > > @@ -132,8 +132,8 @@ > > console [ttyS1] enabled > > hpet clockevent registered > > Fast TSC calibration using PIT > > -Detected 2660.398 MHz processor. > > -Calibrating delay loop (skipped), value calculated using timer frequency.. 5320.79 BogoMIPS (lpj=10641592) > > +Detected 2613.324 MHz processor. > > +Calibrating delay loop (skipped), value calculated using timer frequency.. 5226.64 BogoMIPS (lpj=10453296) > > Security Framework initialized > > Dentry cache hash table entries: 524288 (order: 10, 4194304 bytes) > > Inode-cache hash table entries: 262144 (order: 9, 2097152 bytes) > > @@ -160,7 +160,7 @@ > > CPU0: Intel(R) Xeon(R) CPU 3075 @ 2.66GHz stepping 0b > > Booting Node 0, Processors #1 > > Brought up 2 CPUs > > -Total of 2 processors activated (10640.79 BogoMIPS). > > +Total of 2 processors activated (10546.63 BogoMIPS). > > NET: Registered protocol family 16 > > ACPI: bus type pci registered > > PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0xe0000000-0xefffffff] (base 0xe0000000) > > > > So you can see in the above the during the second boot the TSC > > calibration was badly mis-calculated. This was the cause of the skew. > > > > Not sure how that might be linked to the distro upgrade. It could have > > been something like SMI damage during the calibration time, but I > > thought the calibration loop watched for that. > > > > Bernhard: I expect with all those vms, this machine isn't rebooted > > frequently. So could you look at the logs to see how much the "Detected > > xxxx.yyy MHz processor." line varies by across a few other boots (if > > they still exist?). > > Correct, the box isn't rebooted often, but I do have a few dmesg outputs > laying around. lpj was always almost the same until the very last boot > which screwed up the clock. > > dmesg:[ 0.000000] Linux version 2.6.33 (root@svr02) (gcc version > 4.3.2 (Debian 4.3.2-1.1) ) #1 SMP Sun Mar 7 23:01:45 CET 2010 > dmesg:[ 0.008005] Calibrating delay loop (skipped), value calculated > using timer frequency.. 5226.64 BogoMIPS (lpj=10453296) > dmesg:[ 0.288002] Total of 2 processors activated (10546.63 BogoMIPS). Yea. The bogomips/loops per jiffies are actually calculated with a different chunk of code (although its interesting it miscalculated in both cases). Could you send the "Detected xxxx.yyy MHz processor." lines as well? thanks -john -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
