Add power_profile, a script that changes the ACPI CPU Cx idle state and/or

the throttling state in response to line transitions.  Future plans
include adding support for CPU frequency changes.

Add a devd.conf entry for calling this script.

The default values for this are:
performance_cx_lowest="HIGH"       # Use HLT (C0) online
performance_throttle_state="HIGH"  # 100% (no throttling)
economy_cx_lowest="LOW"            # Use the lowest Cx state possible
economy_throttle_state="HIGH"      # 100% (no throttling)

etc/defaults/rc.conf

@@ -441,6 +441,10 @@ watchdogd_enable="NO"	# Start the software watchdog daemon
 devfs_rulesets="/etc/defaults/devfs.rules /etc/devfs.rules" # Files containing
 							    # devfs(8) rules.
 devfs_system_ruleset=""	# The name of a ruleset to apply to /dev
+performance_cx_lowest="HIGH"		# Online CPU idle state
+performance_throttle_state="HIGH"	# Online throttling state
+economy_cx_lowest="LOW"			# Offline CPU idle state
+economy_throttle_state="HIGH"		# Offline throttling state
 
 ##############################################################
 ### Jail Configuration #######################################

etc/devd.conf

@@ -70,6 +70,13 @@ nomatch 0 {
 #	action "logger Unknown device: $pnpinfo $location $bus";
 };
 
+# Switch power profiles when the AC line state changes
+notify 10 {
+	match "system"		"ACPI";
+	match "subsystem"	"ACAD";
+	action			"/etc/rc.d/power_profile $notify";
+};
+
 /* EXAMPLES TO END OF FILE
 
 # The following might be an example of something that a vendor might

etc/rc.d/Makefile

@@ -26,7 +26,7 @@ FILES=	DAEMON LOGIN NETWORKING SERVERS \
 	network_ipv6 nfsclient nfsd \
 	nfslocking nfsserver nisdomain ntpd ntpdate \
 	othermta \
-	pccard pcvt ppp-user pppoed pwcheck \
+	pccard pcvt power_profile ppp-user pppoed pwcheck \
 	quota \
 	random rarpd rcconf.sh root \
 	route6d routed routing rpcbind rtadvd rwho \

etc/rc.d/power_profile

@@ -0,0 +1,86 @@
+#!/bin/sh
+#
+# Modify the power profile based on AC line state.  This script is
+# usually called from devd(8).
+#
+# Arguments: 0x00 (AC offline, economy) or 0x01 (AC online, performance)
+#
+# $FreeBSD$
+#
+
+# PROVIDE: power_profile
+# KEYWORD: FreeBSD nostart
+
+. /etc/rc.subr
+
+name="power_profile"
+LOGGER="logger -t power_profile -p daemon.notice"
+
+# Set a given sysctl node to a value.
+#
+# Variables:
+# $node: sysctl node to set with the new value
+# $value: HIGH for the highest performance value, LOW for the best
+#	  economy value, or the value itself.
+# $highest_value: maximum value for this sysctl, when $value is "HIGH"
+# $lowest_value: minimum value for this sysctl, when $value is "LOW"
+#
+sysctl_set ()
+{
+	# Check if the node exists
+	if [ -z "$(sysctl -n ${node} 2> /dev/null)" ]; then
+		return
+	fi
+
+	# Get the new value, checking for special types HIGH or LOW
+	case ${value} in
+	[Hh][Ii][Gg][Hh])
+		value=${highest_value}
+		;;
+	[Ll][Oo][Ww])
+		value=${lowest_value}
+		;;
+	*)
+		;;
+	esac
+
+	# Set the desired value
+	[ -n "${value}" ] && sysctl ${node}=${value}
+}
+
+if [ $# -ne 1 ]; then
+	err 1 "Usage: $0 [0x00|0x01]"
+fi
+load_rc_config $name
+
+# Find the next state (performance or economy).
+state=$1
+case ${state} in
+0x01 | '')
+	${LOGGER} "changed to 'performance'"
+	profile="performance"
+	;;
+0x00)
+	${LOGGER} "changed to 'economy'"
+	profile="economy"
+	;;
+*)
+	echo "Usage: $0 [0x00|0x01]"
+	exit 1
+esac
+
+# Set the various sysctls based on the profile's values.
+node="hw.acpi.cpu.cx_lowest"
+highest_value=0
+lowest_value="$(sysctl -n hw.acpi.cpu.cx_supported | \
+	awk '{ print split($0, a) - 1 }' - 2> /dev/null)"
+eval value=\$${profile}_cx_lowest
+sysctl_set
+
+node="hw.acpi.cpu.throttle_state"
+highest_value="$(sysctl -n hw.acpi.cpu.throttle_max 2> /dev/null)"
+lowest_value="1"
+eval value=\$${profile}_throttle_state
+sysctl_set
+
+exit 0