Based on kernel version 2.6.26. Page generated on 2008-07-16 21:12 EST.
1 2 3 Supporting multiple CPU idle levels in kernel 4 5 cpuidle sysfs 6 7 System global cpuidle related information and tunables are under 8 /sys/devices/system/cpu/cpuidle 9 10 The current interfaces in this directory has self-explanatory names: 11 * current_driver 12 * current_governor_ro 13 14 With cpuidle_sysfs_switch boot option (meant for developer testing) 15 following objects are visible instead. 16 * current_driver 17 * available_governors 18 * current_governor 19 In this case users can switch the governor at run time by writing 20 to current_governor. 21 22 23 Per logical CPU specific cpuidle information are under 24 /sys/devices/system/cpu/cpuX/cpuidle 25 for each online cpu X 26 27 -------------------------------------------------------------------------------- 28 # ls -lR /sys/devices/system/cpu/cpu0/cpuidle/ 29 /sys/devices/system/cpu/cpu0/cpuidle/: 30 total 0 31 drwxr-xr-x 2 root root 0 Feb 8 10:42 state0 32 drwxr-xr-x 2 root root 0 Feb 8 10:42 state1 33 drwxr-xr-x 2 root root 0 Feb 8 10:42 state2 34 drwxr-xr-x 2 root root 0 Feb 8 10:42 state3 35 36 /sys/devices/system/cpu/cpu0/cpuidle/state0: 37 total 0 38 -r--r--r-- 1 root root 4096 Feb 8 10:42 desc 39 -r--r--r-- 1 root root 4096 Feb 8 10:42 latency 40 -r--r--r-- 1 root root 4096 Feb 8 10:42 name 41 -r--r--r-- 1 root root 4096 Feb 8 10:42 power 42 -r--r--r-- 1 root root 4096 Feb 8 10:42 time 43 -r--r--r-- 1 root root 4096 Feb 8 10:42 usage 44 45 /sys/devices/system/cpu/cpu0/cpuidle/state1: 46 total 0 47 -r--r--r-- 1 root root 4096 Feb 8 10:42 desc 48 -r--r--r-- 1 root root 4096 Feb 8 10:42 latency 49 -r--r--r-- 1 root root 4096 Feb 8 10:42 name 50 -r--r--r-- 1 root root 4096 Feb 8 10:42 power 51 -r--r--r-- 1 root root 4096 Feb 8 10:42 time 52 -r--r--r-- 1 root root 4096 Feb 8 10:42 usage 53 54 /sys/devices/system/cpu/cpu0/cpuidle/state2: 55 total 0 56 -r--r--r-- 1 root root 4096 Feb 8 10:42 desc 57 -r--r--r-- 1 root root 4096 Feb 8 10:42 latency 58 -r--r--r-- 1 root root 4096 Feb 8 10:42 name 59 -r--r--r-- 1 root root 4096 Feb 8 10:42 power 60 -r--r--r-- 1 root root 4096 Feb 8 10:42 time 61 -r--r--r-- 1 root root 4096 Feb 8 10:42 usage 62 63 /sys/devices/system/cpu/cpu0/cpuidle/state3: 64 total 0 65 -r--r--r-- 1 root root 4096 Feb 8 10:42 desc 66 -r--r--r-- 1 root root 4096 Feb 8 10:42 latency 67 -r--r--r-- 1 root root 4096 Feb 8 10:42 name 68 -r--r--r-- 1 root root 4096 Feb 8 10:42 power 69 -r--r--r-- 1 root root 4096 Feb 8 10:42 time 70 -r--r--r-- 1 root root 4096 Feb 8 10:42 usage 71 -------------------------------------------------------------------------------- 72 73 74 * desc : Small description about the idle state (string) 75 * latency : Latency to exit out of this idle state (in microseconds) 76 * name : Name of the idle state (string) 77 * power : Power consumed while in this idle state (in milliwatts) 78 * time : Total time spent in this idle state (in microseconds) 79 * usage : Number of times this state was entered (count)