Preloading [WAS: Re: SuSE Project SUPER]

[Douglas McClendon]

Linus Walleij wrote:
> On Sun, 13 Jan 2008, Linus Walleij wrote:
> 
>> * They use a LOT of preloading,
> 
> I have now looked a bit closer at this, and it is *indeed* looking like 
> a major user-perceiveable thing, they preload pretty much everything and 
> also add other hints to the kernel of what may be expected to be used 
> soonish during boot, early-{x|g|k}dm and so forth.
> 
> It is rather crude: the actual mechanisms used are:

...

FYI, I recently outlined a (livecd) preloading implementation completely 
unrelated to all of this, which I'd bet money will speed up livecd boot 
by at least 10% (perhaps much more).

My method involves a devicemapper trick, the primary benefit of which is 
removing seeks.  Theoretically this could help disk (non-cdrom) based 
boots, but would require ext3 features for sorting that I don't think 
currently exist, and the benefit would probably be <<5% anyway.

Still, something to look forward to.  Now that my no-root-privs livecd 
generator tool is looking pretty swank along with liveusb persistence, I 
think I'm nearly ready to write the relatively few lines of bash code 
required to implement "super device-mapper caching" (just plain d.m.c. 
was already taken for something different that might help the disk boot 
case as well)

http://www.redhat.com/archives/fedora-livecd-list/2008-January/msg00036.html

-dmc