From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/Documentation/cpuidle/core.txt | 23 ++++++++ kernel/Documentation/cpuidle/driver.txt | 37 +++++++++++++ kernel/Documentation/cpuidle/governor.txt | 28 ++++++++++ kernel/Documentation/cpuidle/sysfs.txt | 92 +++++++++++++++++++++++++++++++ 4 files changed, 180 insertions(+) create mode 100644 kernel/Documentation/cpuidle/core.txt create mode 100644 kernel/Documentation/cpuidle/driver.txt create mode 100644 kernel/Documentation/cpuidle/governor.txt create mode 100644 kernel/Documentation/cpuidle/sysfs.txt (limited to 'kernel/Documentation/cpuidle') diff --git a/kernel/Documentation/cpuidle/core.txt b/kernel/Documentation/cpuidle/core.txt new file mode 100644 index 000000000..63ecc5dc9 --- /dev/null +++ b/kernel/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. diff --git a/kernel/Documentation/cpuidle/driver.txt b/kernel/Documentation/cpuidle/driver.txt new file mode 100644 index 000000000..1b0d81d92 --- /dev/null +++ b/kernel/Documentation/cpuidle/driver.txt @@ -0,0 +1,37 @@ + + + Supporting multiple CPU idle levels in kernel + + cpuidle drivers + + + + +cpuidle driver hooks into the cpuidle infrastructure and handles the +architecture/platform dependent part of CPU idle states. Driver +provides the platform idle state detection capability and also +has mechanisms in place to support actual entry-exit into CPU idle states. + +cpuidle driver initializes the cpuidle_device structure for each CPU device +and registers with cpuidle using cpuidle_register_device. + +If all the idle states are the same, the wrapper function cpuidle_register +could be used instead. + +It can also support the dynamic changes (like battery <-> AC), by using +cpuidle_pause_and_lock, cpuidle_disable_device and cpuidle_enable_device, +cpuidle_resume_and_unlock. + +Interfaces: +extern int cpuidle_register(struct cpuidle_driver *drv, + const struct cpumask *const coupled_cpus); +extern int cpuidle_unregister(struct cpuidle_driver *drv); +extern int cpuidle_register_driver(struct cpuidle_driver *drv); +extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); +extern int cpuidle_register_device(struct cpuidle_device *dev); +extern void cpuidle_unregister_device(struct cpuidle_device *dev); + +extern void cpuidle_pause_and_lock(void); +extern void cpuidle_resume_and_unlock(void); +extern int cpuidle_enable_device(struct cpuidle_device *dev); +extern void cpuidle_disable_device(struct cpuidle_device *dev); diff --git a/kernel/Documentation/cpuidle/governor.txt b/kernel/Documentation/cpuidle/governor.txt new file mode 100644 index 000000000..d9020f5e8 --- /dev/null +++ b/kernel/Documentation/cpuidle/governor.txt @@ -0,0 +1,28 @@ + + + + Supporting multiple CPU idle levels in kernel + + cpuidle governors + + + + +cpuidle governor is policy routine that decides what idle state to enter at +any given time. cpuidle core uses different callbacks to the governor. + +* enable() to enable governor for a particular device +* disable() to disable governor for a particular device +* select() to select an idle state to enter +* reflect() called after returning from the idle state, which can be used + by the governor for some record keeping. + +More than one governor can be registered at the same time and +users can switch between drivers using /sysfs interface (when enabled). +More than one governor part is supported for developers to easily experiment +with different governors. By default, most optimal governor based on your +kernel configuration and platform will be selected by cpuidle. + +Interfaces: +extern int cpuidle_register_governor(struct cpuidle_governor *gov); +struct cpuidle_governor diff --git a/kernel/Documentation/cpuidle/sysfs.txt b/kernel/Documentation/cpuidle/sysfs.txt new file mode 100644 index 000000000..b6f44f490 --- /dev/null +++ b/kernel/Documentation/cpuidle/sysfs.txt @@ -0,0 +1,92 @@ + + + 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 +-rw-r--r-- 1 root root 4096 Feb 8 10:42 disable +-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 +-rw-r--r-- 1 root root 4096 Feb 8 10:42 disable +-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 +-rw-r--r-- 1 root root 4096 Feb 8 10:42 disable +-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 +-rw-r--r-- 1 root root 4096 Feb 8 10:42 disable +-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) +* disable : Option to disable this idle state (bool) -> see note below +* 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) + +Note: +The behavior and the effect of the disable variable depends on the +implementation of a particular governor. In the ladder governor, for +example, it is not coherent, i.e. if one is disabling a light state, +then all deeper states are disabled as well, but the disable variable +does not reflect it. Likewise, if one enables a deep state but a lighter +state still is disabled, then this has no effect. -- cgit 1.2.3-korg