Re: [dm-devel] [Lsf-pc] [LSF/MM TOPIC] a few storage topics

[Dave Chinner <david fromorbit com>]

On Thu, Jan 26, 2012 at 11:25:56AM -0500, Vivek Goyal wrote:
> On Wed, Jan 25, 2012 at 02:35:52PM +0800, Wu Fengguang wrote:
> > > It would also be
> > > possible to trigger on the size of the device so that the 32MB USB stick
> > > doesn't sit busy for a minute with readahead that is useless.
> > 
> > Yeah, I do have a patch for shrinking readahead size based on device size.
> 
> Should it be a udev rule to change read_ahead_kb on device based on device
> size, instead of a kernel patch?

That's effectively what vendors like SGI have been doing since udev
was first introduced, though more often the rules are based on device
type rather than size. e.g. a 64GB device might be a USB flash drive
now, but a 40GB device might be a really fast SSD....

Cheers,

Dave.
-- 
Dave Chinner
david fromorbit com