Re: Beagle indexing when running on batteries

Hi,

On 11/19/07, Andrey Melentyev <[email protected]> wrote:
> But actually I'm mostly worried by the number of wakeups-from-idle per
> second that beagled generates when AC is unplugged. PowerTOP (
> http://www.lesswatts.org/projects/powertop/ ) utility says that
> beagled produces:
>    1,6% ( 10,0)           beagled : futex_wait (hrtimer_wakeup)
>
> 10 wakeups-from-idle per second. It is not much, but it reduces the
> time that my laptop can work from battery a little bit.

This is a Mono bug, it has little to do with Beagle itself.  It was
supposed to be fixed for the 1.2.5 release, but it's been put off.
Unfortunately it seems to be something we can't do anything about.

I don't have a bugzilla number offhand, but I know that the Mono
developers are aware of the problem.  I've CCed Miguel to poke him
about it again.

> So I have two questions:
> 1) How can I check if Beagle got the fact that system works on battery

There should be something in the logs in ~/.beagle/Log/current-Beagle
to that effect.

> 2) If the Beagle already entered the "powersaving" mode successfully,
> is there any way to reduce the number of wakeups-per-second? As I
> understand, if Beagle is using /proc filesystem to get AC status, it
> needs some kind of polling. Is that the reason of wakeups?

As I mentioned, this is a Mono bug.  You're correct, it does poll
/proc, but not 10 times a second.

Thanks,
Joe