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>

1 files changed, 23 insertions, 0 deletions

diff --git a/Documentation/cpuidle/core.txt b/Documentation/cpuidle/core.txt
new file mode 100644
index 000000000000..63ecc5dc9d8a
--- /dev/null
+++ b/Documentation/cpuidle/core.txt
@@ -0,0 +1,23 @@
+
+                Supporting multiple CPU idle levels in kernel
+
+                                cpuidle
+
+General Information:
+
+Various CPUs today support multiple idle levels that are differentiated
+by varying exit latencies and power consumption during idle.
+cpuidle is a generic in-kernel infrastructure that separates
+idle policy (governor) from idle mechanism (driver) and provides a
+standardized infrastructure to support independent development of
+governors and drivers.
+
+cpuidle resides under drivers/cpuidle.
+
+Boot options:
+"cpuidle_sysfs_switch"
+enables current_governor interface in /sys/devices/system/cpu/cpuidle/,
+which can be used to switch governors at run time. This boot option
+is meant for developer testing only. In normal usage, kernel picks the
+best governor based on governor ratings.
+SEE ALSO: sysfs.txt in this directory.