xref: /freebsd/usr.sbin/powerd/powerd.8 (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
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25.\" $FreeBSD$
26.\"
27.Dd July 4, 2013
28.Dt POWERD 8
29.Os
30.Sh NAME
31.Nm powerd
32.Nd "system power control utility"
33.Sh SYNOPSIS
34.Nm
35.Op Fl a Ar mode
36.Op Fl b Ar mode
37.Op Fl i Ar percent
38.Op Fl m Ar freq
39.Op Fl M Ar freq
40.Op Fl n Ar mode
41.Op Fl p Ar ival
42.Op Fl P Ar pidfile
43.Op Fl r Ar percent
44.Op Fl v
45.Sh DESCRIPTION
46The
47.Nm
48utility monitors the system state and sets various power control options
49accordingly.
50It offers power-saving modes that can be
51individually selected for operation on AC power or batteries.
52.Bl -tag -width ".Ar hiadaptive"
53.It Ar maximum
54Choose the highest performance values.
55May be abbreviated as
56.Ar max .
57.It Ar minimum
58Choose the lowest performance values to get the most power savings.
59May be abbreviated as
60.Ar min .
61.It Ar adaptive
62Attempt to strike a balance by degrading performance when the system
63appears idle and increasing it when the system is busy.
64It offers a good balance between a small performance loss for greatly
65increased power savings.
66May be abbreviated as
67.Ar adp .
68.It Ar hiadaptive
69Like
70.Ar adaptive
71mode, but tuned for systems where performance and interactivity are
72more important than power consumption.
73It increases frequency faster, reduces frequency less aggressively, and
74will maintain full frequency for longer.
75May be abbreviated as
76.Ar hadp .
77.El
78.Pp
79The default mode is
80.Ar adaptive
81for battery power and
82.Ar hiadaptive
83for the rest.
84.Pp
85.Nm
86recognizes these runtime options:
87.Bl -tag -width ".Fl r Ar percent"
88.It Fl a Ar mode
89Selects the
90.Ar mode
91to use while on AC power.
92.It Fl b Ar mode
93Selects the
94.Ar mode
95to use while on battery power.
96.It Fl i Ar percent
97Specifies the CPU load percent level when adaptive
98mode should begin to degrade performance to save power.
99The default is 50% or lower.
100.It Fl m Ar freq
101Specifies the minimum frequency to throttle down to.
102.It Fl M Ar freq
103Specifies the maximum frequency to throttle up to.
104.It Fl n Ar mode
105Selects the
106.Ar mode
107to use normally when the AC line state is unknown.
108.It Fl p Ar ival
109Specifies a different polling interval (in milliseconds) for AC line state
110and system idle levels.
111The default is 250 ms.
112.It Fl P Ar pidfile
113Specifies an alternative file in which the process ID should be stored.
114The default is
115.Pa /var/run/powerd.pid .
116.It Fl r Ar percent
117Specifies the CPU load percent level where adaptive
118mode should consider the CPU running and increase performance.
119The default is 75% or higher.
120.It Fl v
121Verbose mode.
122Messages about power changes will be printed to stdout and
123.Nm
124will operate in the foreground.
125.El
126.Sh SEE ALSO
127.Xr acpi 4 ,
128.Xr apm 4 ,
129.Xr cpufreq 4
130.Sh HISTORY
131The
132.Nm
133utility first appeared in
134.Fx 6.0 .
135.Sh AUTHORS
136.An -nosplit
137.An Colin Percival
138first wrote
139.Nm estctrl ,
140the utility that
141.Nm
142is based on.
143.An Nate Lawson
144then updated it for
145.Xr cpufreq 4 ,
146added features, and wrote this manual page.
147.Sh BUGS
148The
149.Nm
150utility should also power down idle disks and other components besides the CPU.
151.Pp
152If
153.Nm
154is used with
155.Pa power_profile ,
156they may override each other.
157.Pp
158The
159.Nm
160utility
161should probably use the
162.Xr devctl 4
163interface instead of polling for AC line state.
164