Kernel crash with acpi_processor, cpu_idle and intel_idle =y

[Mark van Dijk <lists+xen@internecto.net>]

Hi everyone,

When I set CONFIG_ACPI_PROCESSOR, CONFIG_CPU_IDLE and CONFIG_INTEL_IDLE
to y then I cannot boot Xen; there is a crash. If I turn
CONFIG_INTEL_IDLE off then the boot goes well and, after dom0 has
booted, xenpm works and gives some sane output, see below. I have
tested this with kernels 3.2 to 3.4.6. 

Is it impossible to use INTEL_IDLE with Xen? If this is a known issue
then maybe someone can add info to the INTEL_IDLE help text in the
kernel configuration...

I am using this on a dual CPU motherboard, it has two Xeon W3530 CPUs
(i.e. family 6, model 26, stepping 5). I have also tested this with a
single-CPU Core2 Quad Q6600 and the same situation occurs here, but the
below output is of the W3530 Xeon system.

While I'm not that familiar with CPUidle, one thing that seems to be
not right is that the maximum idle state here is C3 while the processor
should be able to reach as far as C7.

Here is the snipped output of two commands:

# xenpm get-cpufreq-states
cpu id               : 0
total P-states       : 11
usable P-states      : 11
current frequency    : 1600 MHz
P0         [2801 MHz]: transition [                  11]
                       residency  [                 866 ms]
P1         [2800 MHz]: transition [                   1]
                       residency  [                   0 ms]
P2         [2667 MHz]: transition [                   0]
                       residency  [                   0 ms]
P3         [2533 MHz]: transition [                   1]
                       residency  [                   1 ms]
P4         [2400 MHz]: transition [                   0]
                       residency  [                   0 ms]
P5         [2267 MHz]: transition [                   2]
                       residency  [                  36 ms]
P6         [2133 MHz]: transition [                   1]
                       residency  [                   0 ms]
P7         [2000 MHz]: transition [                   0]
                       residency  [                   0 ms]
P8         [1867 MHz]: transition [                   0]
                       residency  [                   0 ms]
P9         [1733 MHz]: transition [                   2]
                       residency  [                   0 ms]
*P10       [1600 MHz]: transition [                   9]
                       residency  [                 960 ms]


# xenpm get-cpuidle-states           
Max possible C-state: C7

cpu id               : 0
total C-states       : 4
idle time(ms)        : 240266
C0                   : transition [               39457]
                       residency  [               10534 ms]
C1                   : transition [                3965]
                       residency  [                2274 ms]
C2                   : transition [                 371]
                       residency  [                 495 ms]
C3                   : transition [               35121]
                       residency  [              230822 ms]
pc2                  : [                   0 ms]
pc3                  : [                   0 ms]
pc6                  : [                   0 ms]
pc7                  : [                   0 ms]
cc3                  : [                   0 ms]
cc6                  : [                   0 ms]
cc7                  : [                   0 ms]

# xenpm get-cpufreq-para             
cpu id               : 0
affected_cpus        : 0
cpuinfo frequency    : max [2801000] min [1600000] cur [1600000]
scaling_driver       : acpi-cpufreq
scaling_avail_gov    : userspace performance powersave ondemand
current_governor     : ondemand
  ondemand specific  :
    sampling_rate    : max [10000000] min [10000] cur [20000]
    up_threshold     : 80
scaling_avail_freq   : 2801000 2800000 2667000 2533000 2400000 2267000
2133000 2000000 1867000 1733000 *1600000 scaling frequency    : max
[2801000] min [1600000] cur [1600000] turbo mode           : enabled

Kind regards,
Mark van Dijk

PS I am not receiving xen-devel messages but this message does
probably belong there so I'm posting it there too.



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