Re: [ACPI] ACPI + Laptop Power Management

[Ducrot B. <du...@po...>]

On Fri, Nov 28, 2003 at 11:21:19AM +0800, Ow Mun Heng wrote:
> 
> 
> > -----Original Message-----
> > From: Micha Feigin [mailto:mi...@po...]
> > Sent: Friday, November 21, 2003 7:13 PM
> > To: acp...@li...
> > Subject: Re: [ACPI] ACPI + Laptop Power Management
> > 
> > 
> > On Fri, Nov 21, 2003 at 11:12:32AM +0100, Ducrot Bruno wrote:
                                              ^^^^^^^^^^^^

I *never* wrote the following (but there are good stuff
inside).

> > like said here, laptopmode is what you want since it holds back dirty
> > buffer flushes which is what you are experiencing. It will fire up the
> > disk on reads though. I attached a script that you can use to enter
> > laptopmode (was actually distributed with laptopmode as far as I could
> > tell when googling for the original patch). I call it in responce to
> > ac events from acpid to get it running when the power is disconnected.
> > Will have to make sure that you get those event though since I had to
> > twik my dsdt for that.
> > You can also look at cpufreq of acpi cpu throttling to 
> > throttle down you
> > cpu when on battery to conserve power (assuming you cpu 
> > supports that).
> 
> I took a look at laptop mode. However, as the author said "it adds a
> non-significant" amount of battery time.

Where have you read that?
Have you looked at linux/Documentation/laptop-mode.txt?


> The thing here is, even though it's flushing the buffers when there are
> others to flush, it makes not difference if the drive is still spinning and
> not in standby-mode! I can't figure out what is making the HD _not_ spin
> down.

man hdparm, hdparm -S something.

> BTW, Laptop_mode is merged into the 2.4.23-rc5 kernel (based on the
> changelogs)

As already said.

> With regard to ACPId events, can you tell me how yo get it to work? I'm
> having problems getting it running. It gets lodaded up during init, and it's
> running as root, but after logging in (GDM desktop), the events won't fire
> until I kill the acpid process and re-run it again. (once I logged in)
> I can't figure out how to get it to work. I read in one page where the
> auther said to put xhost +local somewhere at the end of /etc/X11/xinitrc.
> That didn't work either.

I don't know.  All my scripts for power managements via acpid certainly
do not use X.  I am wondering what is inside yours, but if they come
as default with a distribution, it is probably better to use another
distribution.

I doubt also the author of laptop-mode have done that.  Again, read
the documentation which come with laptop-mode.

> > I patched reiserfs to change the journal commit time 
> > according to the entry in
> > bdflush so that I can get the regular 30 sec journal flush 
> > time when on
> > ac and 10 minutes when of battery.
> > I could try making such a patch for ext3 if you want.
> 
> You mean that has to be patched at the Kernel Code Level?? Ah.. Dang!
> 

If you read the laptop-mode documentation, you will know that reiserfs
have to be modified, but not ext3.  BTW, I don't use reiserfs.

-- 
Ducrot Bruno

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.