Debian12
#
Power states
State
Description
1
RUN
Working
CPU is in running state
2
STANDBY
WFI
CPU enters WFI, clock is in gating state
3
OFF
Poweroff
CPU is in off state, no clock and power
dete cpu-idle-states in cpuX node:
CPU0: cpu0@0 {
…
cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
};
disable cpuidle: cpuidle.off=1
enable cpuidle: cpuidle.off=0 or delete it
#/sys/devices/system/cpu/cpuX/cpuidle/stateX
root@cix-localhost:/sys/devices/system/cpu/cpu0/cpuidle/state0# ls
above default_status disable name rejected time
below desc latency power residency usage
- name, name;
- desc, more detailed description;
- disable, reading and setting of cpuidle enable state;
- latency, the time required to exit this state, in us;
- power, power consumption in this state, in mW;
- time, total time spent in this state, in us
- usage, number of times this state was entered.
#/sys/devices/system/cpu/cpuidle# ls
available_governors current_driver current_governor current_governor_ro
1 Like
avaf
January 6, 2026, 1:04pm
2
hong.guo:
@hong.guo Do you mean enable ? Can you clarify this?
I have some dumb questions:
cpu10 and cpu11 never gets idle state ?
/sys/devices/system/cpu/cpu0/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu1/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu2/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu3/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu4/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu5/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu6/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu7/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu8/cpuidle/:
driver state0 state1 state2
/sys/devices/system/cpu/cpu9/cpuidle/:
driver state0 state1 state2
DTS
cpu0@0 {
compatible = "arm,armv8";
reg = <0x00 0x00>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x02>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x0f 0x10>;
capacity-dmips-mhz = <0x193>;
phandle = <0x02>;
};
cpu1@100 {
compatible = "arm,armv8";
reg = <0x00 0x100>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x02>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x0f 0x10>;
capacity-dmips-mhz = <0x193>;
phandle = <0x03>;
};
cpu2@200 {
compatible = "arm,armv8";
reg = <0x00 0x200>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x02>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x0f 0x10>;
capacity-dmips-mhz = <0x193>;
phandle = <0x04>;
};
cpu3@300 {
compatible = "arm,armv8";
reg = <0x00 0x300>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x02>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x0f 0x10>;
capacity-dmips-mhz = <0x193>;
phandle = <0x05>;
};
cpu4@400 {
compatible = "arm,armv8";
reg = <0x00 0x400>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x05>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x11 0x10>;
capacity-dmips-mhz = <0x400>;
phandle = <0x06>;
};
cpu5@500 {
compatible = "arm,armv8";
reg = <0x00 0x500>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x05>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x11 0x10>;
capacity-dmips-mhz = <0x400>;
phandle = <0x07>;
};
cpu6@600 {
compatible = "arm,armv8";
reg = <0x00 0x600>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x06>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x11 0x10>;
capacity-dmips-mhz = <0x400>;
phandle = <0x08>;
};
cpu7@700 {
compatible = "arm,armv8";
reg = <0x00 0x700>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x06>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x11 0x10>;
capacity-dmips-mhz = <0x400>;
phandle = <0x09>;
};
cpu8@800 {
compatible = "arm,armv8";
reg = <0x00 0x800>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x03>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x11 0x10>;
capacity-dmips-mhz = <0x400>;
phandle = <0x0a>;
};
cpu9@900 {
compatible = "arm,armv8";
reg = <0x00 0x900>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x03>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x11 0x10>;
capacity-dmips-mhz = <0x400>;
phandle = <0x0b>;
};
cpu10@a00 {
compatible = "arm,armv8";
reg = <0x00 0xa00>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x04>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x11 0x10>;
capacity-dmips-mhz = <0x400>;
phandle = <0x0c>;
};
cpu11@b00 {
compatible = "arm,armv8";
reg = <0x00 0xb00>;
device_type = "cpu";
enable-method = "psci";
clocks = <0x0e 0x04>;
#cooling-cells = <0x02>;
cpu-idle-states = <0x11 0x10>;
capacity-dmips-mhz = <0x400>;
phandle = <0x0d>;
};
};
I want to write a small cpufreq + cpu temp monitor , so a little understanding would be helpful.
/# cat /sys/devices/system/cpu/online
/sys/devices/system/cpu/cpu10/cpuidle:
/sys/devices/system/cpu/cpu11/cpuidle:
/sys/devices/system/cpu/cpu1/cpuidle:
/sys/devices/system/cpu/cpu2/cpuidle:
/sys/devices/system/cpu/cpu3/cpuidle:
/sys/devices/system/cpu/cpu4/cpuidle:
/sys/devices/system/cpu/cpu5/cpuidle:
/sys/devices/system/cpu/cpu6/cpuidle:
/sys/devices/system/cpu/cpu7/cpuidle:
/sys/devices/system/cpu/cpu8/cpuidle:
/sys/devices/system/cpu/cpu9/cpuidle:
