5 sec boot

[Jeremy Katz]

On Fri, 2008-10-03 at 11:49 -0700, david at lang.hm wrote:
> On Fri, 3 Oct 2008, Jeremy Katz wrote:
> > [1] With the one[2] obvious exception of "whatever is done in the initrd
> > takes time" -- but if those things are moved later, they still take the
> > same time.  And if they're not needed, don't do them.
> > [2] Also, there might be a tiny amount of time needed to uncompress the
> > initrd and un-cpio, but that really should be nominal.  If not, it means
> > other problems later in the boot sequence
> 
> the default distro initrd images do a _lot_ of stuff that takes a 
> significant amount of time, 

Yes, the distro initrds do a lot more than they used to.  And do you
know why -- because people *wanted* functionality and also because of
functionality being moved out of the kernel into userspace.  Trust me,
at least some of the people maintaining initrd stuff would far rather
have less code :-)

> but since the OLPC initrd is doing completely 
> different stuff it should not have the same problem, but that goes back to 
> 'make it do as little as possible'

'As little as possible' is still far from nothing and thus if initrds
inherently introduce significant slow-downs just by being there, then
that's very worth fixing rather than having kernel people bury their
head in the sand.  But I already had that argument with Arjan :-)

Jeremy