powerd [was: make.conf options you cannot use for building CURRENT]

Fredrik Lindberg fli+freebsd-current at shapeshifter.se
Tue Dec 6 02:41:44 PST 2005

Dag-Erling Smørgrav wrote:
> Fredrik Lindberg <fli+freebsd-current at shapeshifter.se> writes:
>>Dag-Erling Smørgrav wrote:
>>>There is no reason to use threads in powerd.  Simply merge the
>>>devd_read() loop into your main loop, using select() with a timeout
>>>instead of usleep().
>>Wouldn't that turn in into a polling style again?
> No.
>>The reason to use
>>devd was to obtain a more interrupt driven model instead of the
>>sysctl-polling method originally used. Both metods are supported and
>>the devd method is only used if the devd.pipe is avaiable.
> If the devd loop is an *alternative* to the polling loop, there's even
> less reason to use threads.

Yes it's an alternative, reading a variable versus doing a sysctl call
each interation. It seemed like I good idea, when I first wrote this
(almost a year ago), to have a thread providing a cached value of the
AC state. But maybe I was trying to be too smart or something.

Anyone know what happened to the powerd SoC project? I never spent more
time on powerd because I assumed it would be more or less rewritten.
I wouldn't mind hacking on powerd but I don't want to step on somebodys
toes or duplicate work.

Fredrik Lindberg

More information about the freebsd-current mailing list