diff options
Diffstat (limited to 'Documentation/cpuidle/sysfs.txt')
| -rw-r--r-- | Documentation/cpuidle/sysfs.txt | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/Documentation/cpuidle/sysfs.txt b/Documentation/cpuidle/sysfs.txt new file mode 100644 index 00000000000..50d7b164275 --- /dev/null +++ b/Documentation/cpuidle/sysfs.txt @@ -0,0 +1,79 @@ + + + Supporting multiple CPU idle levels in kernel + + cpuidle sysfs + +System global cpuidle related information and tunables are under +/sys/devices/system/cpu/cpuidle + +The current interfaces in this directory has self-explanatory names: +* current_driver +* current_governor_ro + +With cpuidle_sysfs_switch boot option (meant for developer testing) +following objects are visible instead. +* current_driver +* available_governors +* current_governor +In this case users can switch the governor at run time by writing +to current_governor. + + +Per logical CPU specific cpuidle information are under +/sys/devices/system/cpu/cpuX/cpuidle +for each online cpu X + +-------------------------------------------------------------------------------- +# ls -lR /sys/devices/system/cpu/cpu0/cpuidle/ +/sys/devices/system/cpu/cpu0/cpuidle/: +total 0 +drwxr-xr-x 2 root root 0 Feb 8 10:42 state0 +drwxr-xr-x 2 root root 0 Feb 8 10:42 state1 +drwxr-xr-x 2 root root 0 Feb 8 10:42 state2 +drwxr-xr-x 2 root root 0 Feb 8 10:42 state3 + +/sys/devices/system/cpu/cpu0/cpuidle/state0: +total 0 +-r--r--r-- 1 root root 4096 Feb 8 10:42 desc +-r--r--r-- 1 root root 4096 Feb 8 10:42 latency +-r--r--r-- 1 root root 4096 Feb 8 10:42 name +-r--r--r-- 1 root root 4096 Feb 8 10:42 power +-r--r--r-- 1 root root 4096 Feb 8 10:42 time +-r--r--r-- 1 root root 4096 Feb 8 10:42 usage + +/sys/devices/system/cpu/cpu0/cpuidle/state1: +total 0 +-r--r--r-- 1 root root 4096 Feb 8 10:42 desc +-r--r--r-- 1 root root 4096 Feb 8 10:42 latency +-r--r--r-- 1 root root 4096 Feb 8 10:42 name +-r--r--r-- 1 root root 4096 Feb 8 10:42 power +-r--r--r-- 1 root root 4096 Feb 8 10:42 time +-r--r--r-- 1 root root 4096 Feb 8 10:42 usage + +/sys/devices/system/cpu/cpu0/cpuidle/state2: +total 0 +-r--r--r-- 1 root root 4096 Feb 8 10:42 desc +-r--r--r-- 1 root root 4096 Feb 8 10:42 latency +-r--r--r-- 1 root root 4096 Feb 8 10:42 name +-r--r--r-- 1 root root 4096 Feb 8 10:42 power +-r--r--r-- 1 root root 4096 Feb 8 10:42 time +-r--r--r-- 1 root root 4096 Feb 8 10:42 usage + +/sys/devices/system/cpu/cpu0/cpuidle/state3: +total 0 +-r--r--r-- 1 root root 4096 Feb 8 10:42 desc +-r--r--r-- 1 root root 4096 Feb 8 10:42 latency +-r--r--r-- 1 root root 4096 Feb 8 10:42 name +-r--r--r-- 1 root root 4096 Feb 8 10:42 power +-r--r--r-- 1 root root 4096 Feb 8 10:42 time +-r--r--r-- 1 root root 4096 Feb 8 10:42 usage +-------------------------------------------------------------------------------- + + +* desc : Small description about the idle state (string) +* latency : Latency to exit out of this idle state (in microseconds) +* name : Name of the idle state (string) +* power : Power consumed while in this idle state (in milliwatts) +* time : Total time spent in this idle state (in microseconds) +* usage : Number of times this state was entered (count) |