RFC: Changing default filesystem parameters for power management reasons

[Matthew Garrett]

On Fri, Nov 28, 2008 at 01:16:36PM +0100, Phil Knirsch wrote:

> Sounds like a great idea and something i've been working on myself 
> lately, too. I even went a bit further and thought about the idea if a 
> combination of a monitoring backend and a tuning engine could provide an 
> automatic adoption of the system to the current use. E.g. during daytime 
> when a user works with his machine we would typically see quite a few 
> reads and write all the time. Drive spindowns or other power saving 
> features could during that time be reduced so that the user will have 
> the best performance. During the night (in case he didn't turn of the 
> machine) only very few read and even fewer write operations should 
> happen, at which time the disk could then be powered down most of the 
> time. And of course this can be extended to not only disk drivces but 
> other tunable hardware components.

Indeed. There's been a fair amount of research into this - see 
http://www.soe.ucsc.edu/~tbisson/papers/bisson-fast04.pdf for instance. 
Some laptop drives will behave this way if APM settings are set 
appropriately, but a decent implementation of this in userspace would be 
very nice.

-- 
Matthew Garrett | mjg59 at srcf.ucam.org