acpi_osi=Linux on a MSI Wind

Hello!

I got a MSI Wind and since the battery only lasts for 1-1,5 hours I had a look 
at several powersaving realted things.

One thing I tried was acpi_osi=Linux. I noticed that some some figures changed 
after that. For example the "maximum allowed latency" in 
/proc/acpi/processor/CPU0/power increased. I searched on the web but could not 
find any detailed info about it. Can somebody tell me what it means if the 
number increases?

As far as I can see all keys and resuming etc work with acpi_osi=Linux, as 
they do without it. Should I leave it active or not? Are there any other test 
that I could do in order see what that setting changes?

Another question I have is, I had to put "hdparm -B 254 /dev/sda" into 
boot.local in order to prevent the harddisk from clicking every 5 seconds. Yet 
after resuming (suspend to disk), that setting is gone. Is there a way to 
apply it automatically when resuming?

When running powertop it tells me that I could stop HAL polling the CD-ROM 
drive. The Wind does not have one, yet it seems to poll the card reader or 
something like that. Is there are way to tell HAL to poll less often instead 
of killing it completely?

Thanks

Sven