search for: invariant_tsc

...e OS may use the TSC for wall clock timer services (instead of ACPI or HPET timers). TSC reads are much more efficient and do not incur the overhead associated with a ring transition or access to a platform resource." So the first question "is a constant_tsc the same as Intel''s invariant_tsc or is an invariant_tsc the xen combination of both constant_tsc + nonstop_tsc?" Based on the examination of the code, it appears to me that it is the latter. Is this true? I have a laptop with the Intel Centrino chipset, Intel Core 2 Duo, P8400, 2.26GHz and the CPUID(0x80000007) is returni...

...ACPI-safe.frequency: 3579545 kern.timecounter.tc.ACPI-safe.quality: 850 kern.timecounter.tc.TSC-low.mask: 4294967295 kern.timecounter.tc.TSC-low.counter: 2854866610 kern.timecounter.tc.TSC-low.frequency: 10937740 kern.timecounter.tc.TSC-low.quality: 1000 kern.timecounter.smp_tsc: 1 kern.timecounter.invariant_tsc: 1 $ sysctl kern.eventtimer kern.eventtimer.choice: LAPIC(400) i8254(100) RTC(0) kern.eventtimer.et.LAPIC.flags: 15 kern.eventtimer.et.LAPIC.frequency: 100002217 kern.eventtimer.et.LAPIC.quality: 400 kern.eventtimer.et.i8254.flags: 1 kern.eventtimer.et.i8254.frequency: 1193182 kern.eventtimer.et.i8...

I've now seen this on two different VMs on two different ESXi servers (Xeon based hosts but different hardware otherwise and at different facilities): Everything runs fine for weeks then (seemingly) suddenly/randomly the clock STOPS. In the first case I saw a jump backwards of about 15 minutes (and then a 'freeze' of the clock). The second time just 'time standing