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Linux下动态电源管理(Dynamic Power Management)的用户守护进程

1. Overview

dpmd is a user daemon to change the CPU clock according to the rules
setting in the configuration file (dpmd.conf).

dpmd is based on the DPM (Dynamic Power Management) supported by the
Linux kernel. You should first configure the kernel to select the
CONFIG_DPM. Then compile and run your kernel.

Type "make clean" and "make" to build the daemon.


2. DPM Initialization

Before running dpmd, you must create different operating points and 
policies for the system.

The command format to create a operating point is:

CMD_CREATE_OPT="create_opt <opt_name> <Voltage> <NF> <NR> <NO> <ICLK_DIV> 
<SCLK_DIV> <MCLK_DIV> <PCLK_DIV>"

Then echo this command to "/proc/driver/dpm/cmd", like this:

echo $CMD_CREATE_OPT > /proc/driver/dpm/cmd

After create the operating points, you need to create the classes and
policies, like this:

CMD_CREATE_CLASS="create_class <cls_name> <opt_name>"

Then echo this command to "/proc/driver/dpm/cmd", like this:

echo $CMD_CREATE_CLASS > /proc/driver/dpm/cmd

The command format to create a policy is:

CMD_CREATE_POLICY="create_policy <policy_name>
		<cls_name> <cls_name> <cls_name> <cls_name>
		<cls_name> <cls_name> <cls_name> <cls_name>
		<cls_name>
		<cls_name> <cls_name> <cls_name> <cls_name>"

Then echo this command to "/proc/driver/dpm/cmd", like this:

echo $CMD_CREATE_POLICY > /proc/driver/dpm/cmd

Next is an example:

#!/bin/sh

echo create_opt opt_350 0  190  2  1  1  3  3  3  > /proc/driver/dpm/cmd
echo create_opt opt_58  0  190  2  1  6  12 12 12  > /proc/driver/dpm/cmd

echo create_class cls_350 opt_350 > /proc/driver/dpm/cmd
echo create_class cls_58  opt_58  > /proc/driver/dpm/cmd

echo "create_policy 350 cls_350 cls_350 cls_350 cls_350" \
                        "cls_350 cls_350 cls_350 cls_350" \
			"cls_350" \
			"cls_350 cls_350 cls_350 cls_350" > /proc/driver/dpm/cmd
echo "create_policy 58 cls_58 cls_58 cls_58 cls_58" \
                        "cls_58 cls_58 cls_58 cls_58" \
			"cls_58" \
			"cls_58 cls_58 cls_58 cls_58" > /proc/driver/dpm/cmd


3. dpmd Configuration (dpmd.conf)

dpmd works depending on the configuration.

General information:

[POLICY_HIGH]: the name of the high policy that will be set.
[POLICY_LOW]: the name of the low policy that will be set.
[POLL_INTERVAL]: the polling interval in second.

Rules:

[CPU_INTERVAL]: the cpu interval that working on POLICY_LOW.
[PROGRAMS]: the programs that working on POLICY_HIGH.
[SUSPEND_INTERVAL]: the idle time in second that will suspend the system.