diff options
author | Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | 2008-02-14 00:16:13 -0500 |
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committer | Len Brown <len.brown@intel.com> | 2008-02-14 00:16:13 -0500 |
commit | fe8e288a63f2f3c51c288500282d0eb5cd26a534 (patch) | |
tree | f2d0178448df4367ce3692e4b0a4ebb3f7dcbd4e /Documentation/cpuidle/sysfs.txt | |
parent | 4fcb2fcd4d0678b8ae103d257dcb28074cbfc7fa (diff) |
cpuidle: Add Documentation
Documentation for cpuidle infrastructure. (resend)
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Len Brown <len.brown@intel.com>
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 @@ | |||
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) | ||