Re: does cpu_idle() halt CPU?

[Jan Rychter <jan-JAsPCFd0eodBDgjK7y7TUQ@public.gmane.org>]

>>>>> "DB" == Ducrot Bruno <ducrot-kk6yZipjEM5g9hUCZPvPmw@public.gmane.org>:
[...]
 DB> You forgot at least disk activities especially if ext3, which
 DB> prevent almost all IDE drivers to go to idle state.  But that will
 DB> not explain why you can not go to C3 though.

By the way, let me ask here: does anybody know what would be the best
filesystem to use on a laptop, power saving being the #1 priority? Are
all journaling filesystems this bad?

There was a project to teach the Linux kernel about drive spindown and
manage drive accesses accordingly -- but last time I saw their docs they
said that all journaling filesystems pose serious problems...

USB preventing the machine from going into C3 is a serious problem. I
still don't understand if that's a hardware thing or can we have a more
reasonable HCI implementation that doesn't use DMA that much. How does
Windows deal with it?

--J.


-------------------------------------------------------
This SF.net email is sponsored by: ValueWeb: 
Dedicated Hosting for just $79/mo with 500 GB of bandwidth! 
No other company gives more support or power for your dedicated server
http://click.atdmt.com/AFF/go/sdnxxaff00300020aff/direct/01/