1 .\" (c) Copyright 2010 by Matthew Dillon and Dima Ruban. Permission to
2 .\" use and distribute based on the DragonFly copyright.
9 .Nd simple ACPI based CPU/power control
13 .Op Fl p Ar hysteresis
14 .Op Fl u Ar trigger_up
16 .Op Fl T Ar sample_time
20 daemon monitors the CPU load and automatically adjusts the CPU
23 All CPUs will be set to their maximum frequency when the 1 second
24 machine load exceeds 25% of one CPU.
25 All CPUs will be set to their
26 minimum frequency when the 10 second machine load drops below 12% of
29 The options are as follows:
30 .Bl -tag -width ".Fl p Ar hysteresis"
35 to not go to the background and prints some debug output to
37 .It Fl p Ar hysteresis
38 Percent of the upper limit to subtract as an hysteresis value to scale
39 down to the min frequency.
40 The default is 10 (meaning 10%).
43 Disables switching to turbo mode as maximum frequency completely.
44 Switching to turbo mode as maximum frequency is enabled by default,
45 if the CPU supports it.
46 .It Fl u Ar trigger_up
47 Per CPU load limit in percent to force maximum frequency.
48 The default is 25 (meaning an instantanious load of 0.25 on a
49 single cpu). The load is calculated over 3 polls.
50 It is suggested that this value not be made lower than
53 Polling time in seconds. Default is 1.0.
54 Setting this value lower will poll for load changes faster.
55 For example, a workstation might want to use 0.2 or 0.4.
56 .Nm can become unstable if you make this value too small.
57 .It Fl T Ar sample_time
58 Total sample interval in seconds. Default is 8.0.
59 This effects how quickly powerd ratchets down the frequency
60 and cpus on an idle machine. Longer times will ratchet down
62 For example, a workstation might want to use a value of 30.0.
65 The defaults work well for servers but a workstation user might want
66 to use something like the following in their
68 to ratchet up the machine more quickly in response to spike loads
69 (such as when you are browsing).
71 .Li powerd_enable="YES"
73 .Li powerd_flags="-u 7 -r 0.2 -T 60"
77 utility will exit with a non-zero code if the required sysctls are not
86 command first appeared in
89 I'm shocked I tell you, shocked that there might be bugs in this program!