On Wed, Jan 19, 2011 at 2:34 PM, Andrew Morton
[off-list ref] wrote:

It would be much more valuable if those 3.5 seconds were available to
devices which really really care about bootup times, but very few of
those devices use rotating disks nowadays, I expect?

And don't rotating disk modules read and buffer whole tracks, doing
their own readahead, anymore, anyway? Isn't that part of what "on-disk
cache" does?