delay loop calibration failed for 2.6.32 guest kernels on Intel Atom CPU 330

[Ralph Schmieder]

Going from CentOS5 to CentOS6 and the kernel change from 2.6.18 to 2.6.32 breaks the timer calibration and makes the system almost totally unusable (also on other 2.6.32 or newer based distros).

There's no VT-x on the Atom so HPET is turned off. However, I can observe the effect also on a Mac Mini w/ VirtualBox 4. The impact is not as dramatic as the Core2Duo on the Mac provides more performance to begin with. But the delay loop calibration on the Mac is also off (and not showing the value 2.6.18 shows).

I'm running VirtualBox 4.1.4 on a 64-Bit Ubuntu 10.04 w/ ~4G of DRAM and an Intel Atom 330 Dual Core CPU w/ HT

Please see the additional log files with cpuinfo etc on the virtual and the physical systems.

On 2.6.32 for the guest:

Fast TSC calibration failed
TSC: Unable to calibrate against PIT
TSC: HPET/PMTIMER calibration failed.
Marking TSC unstable due to could not calculate TSC khz
Calibrating delay loop... 293.88 BogoMIPS (lpj=146944)
Initializing cgroup subsys cpuacctmce: CPU supports 0 MCE banks
Performance Events: unsupported p6 CPU model 28 no PMU driver, software events only.
weird, boot CPU (#0) not listed by the BIOS.
APIC calibration not consistent with PM-Timer: 247ms instead of 100ms
APIC delta adjusted to PM-Timer: 6254153 (15508853)
Total of 1 processors activated (293.88 BogoMIPS).
Switching to clocksource jiffies
Switching to clocksource acpi_pm
hrtimer: interrupt took 3406704 ns

On 2.6.18 for the guest:

Calibrating delay loop (skipped), value calculated using timer frequency.. 3200.05 BogoMIPS (lpj=1600025)
Intel machine check reporting enabled on CPU#0.
CPU0: Intel(R) Atom(TM) CPU  330   @ 1.60GHz stepping 02
Using local APIC timer interrupts.
WARNING calibrate_APIC_clock: the APIC timer calibration may be wrong.
Brought up 1 CPUs
ACPI: (supports S0 S1 S4 S5<6>Time: acpi_pm clocksource has been installed.

Thanks for looking into this! -ralph

[Ralph Schmieder]

VBox.log, configuration of VM (2.6.32), log files of virtual hosts and physical hosts