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author | mav <mav@FreeBSD.org> | 2008-11-18 13:24:38 +0000 |
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committer | mav <mav@FreeBSD.org> | 2008-11-18 13:24:38 +0000 |
commit | faa047f97de7a6629550353a467bcefa5b41ee40 (patch) | |
tree | 5bcf7cb8f01ce6d93578d1bebece1e6f96a8d132 /usr.sbin/powerd/powerd.8 | |
parent | ca9ebe8c73e11bf42a22a75208dec3ec4576e279 (diff) | |
download | FreeBSD-src-faa047f97de7a6629550353a467bcefa5b41ee40.zip FreeBSD-src-faa047f97de7a6629550353a467bcefa5b41ee40.tar.gz |
Set of powerd enchancements:
1. Make it more SMP polite. Previous version uses average CPU load that
often leads to load underestimation. It make powerd with default
configuration unusable on systems with more then 2 CPUs. I propose to use
summary load instead of average one. IMO this is the best we can do without
specially tuned scheduler. Also as soon as measuring total load on SMP
systems is more useful then total idle, I have switched to it.
2. Make powerd's operation independent from number and size of frequency
levels. I have added internal frequency counter which translated into real
frequencies only on a last stage and only as good as gone. Some systems may
have only several power levels, while others - many of them, so adaptation
time with previous approach was completely different.
3. As part of previous I have changed adaptive mode to rise frequency on
demand up to 2 times and fall on 1/8 per time internal.
4. For desktop (AC-powered) systems I have added one more mode - "hiadaptive".
It rises frequency twice faster, drops it 4 times slower, prefers twice
lower CPU load and has additional delay before leaving the highest frequency
after the period of maximum load. This mode was specially made to improve
interactivity of the systems where operation capabilities are more
significant then power consumption, but keeping maximum frequency all the
time is not needed.
5. I have reduced default polling interval from 1/2 to 1/4 of second.
It is not so important for algorithm math now, but gives better system
interactivity.
Discussed on: mobile@
Diffstat (limited to 'usr.sbin/powerd/powerd.8')
-rw-r--r-- | usr.sbin/powerd/powerd.8 | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/usr.sbin/powerd/powerd.8 b/usr.sbin/powerd/powerd.8 index 8ca5e0c..b104383 100644 --- a/usr.sbin/powerd/powerd.8 +++ b/usr.sbin/powerd/powerd.8 @@ -47,7 +47,8 @@ utility monitors the system state and sets various power control options accordingly. It offers three modes (maximum, minimum, and adaptive) that can be individually selected while on AC power or batteries. -The modes maximum, minimum, and adaptive may be abbreviated max, min, adp. +The modes maximum, minimum, adaptive and hiadaptive may be abbreviated +max, min, adp, hadp. .Pp Maximum mode chooses the highest performance values. Minimum mode selects the lowest performance values to get the most power @@ -56,8 +57,10 @@ Adaptive mode attempts to strike a balance by degrading performance when the system appears idle and increasing it when the system is busy. It offers a good balance between a small performance loss for greatly increased power savings. -The default mode is -adaptive. +Hiadaptive mode is alike adaptive mode, but tuned for systems where +performance and interactivity are more important then power consumption. +It rises frequency faster, drops slower and keeps twice lower CPU load. +The default mode is adaptive for battery power and hiadaptive for the rest. .Pp The .Nm @@ -72,10 +75,9 @@ Selects the .Ar mode to use while on battery power. .It Fl i Ar percent -Specifies the CPU idle percent level when -adaptive +Specifies the CPU load percent level when adaptive mode should begin to degrade performance to save power. -The default is 90% or higher. +The default is 50% or lower. .It Fl n Ar mode Selects the .Ar mode @@ -83,16 +85,15 @@ to use normally when the AC line state is unknown. .It Fl p Ar ival Specifies a different polling interval (in milliseconds) for AC line state and system idle levels. -The default is 500 ms. +The default is 250 ms. .It Fl P Ar pidfile Specifies an alternative file in which the process ID should be stored. The default is .Pa /var/run/powerd.pid . .It Fl r Ar percent -Specifies the CPU idle percent level where -adaptive +Specifies the CPU load percent level where adaptive mode should consider the CPU running and increase performance. -The default is 65% or lower. +The default is 75% or higther. .It Fl v Verbose mode. Messages about power changes will be printed to stdout and |