Applications selection discussion....

[Jeremy Katz]

On Thu, 2008-09-04 at 08:42 -0400, Jim Gettys wrote:
> On Thu, 2008-09-04 at 01:24 -0400, Greg Dekoenigsberg wrote:
> > On Wed, 3 Sep 2008, Jeremy Katz wrote:
> > >> Nor will any existing spin fit in 1GB of internal flash.
> > >
> > > We fit on 700 meg CDs, so it's definitely doable.  There's nothing that
> > > would fundamentally prevent the way we do things for the cds to also
> > > function off of jffs2.  Two different compressions is kind of silly,
> > > though.
> 
> It is also a performance killer; you're taking a slow processor and
> having it decompress twice.  We need to get to the bottom of why the
> current spins are so slow off USB/SD as quickly as possible, while
> Daniel's native install on SD is very usable.

As I mentioned earlier in the week, trying off of SD was looking quite a
bit better as far as usability was concerned.  So I think either I
picked the wrong USB stick or the one I picked is beginning its death
throes.

> Unfortunately, jffs2 does not have a way to say "don't compress a file",
> though dwmw2 has talked about this from time to time.

A bit of an aside and not really relevant for the Fedora on XO
discussion, especially in the short-term, but ubifs might be interesting
to look at as an alternative to jffs2 as it seems to be adding a lot of
the things which have stalled out in jffs2

> Not having wear leveling on bare NAND is a non-starter, if there is any
> substantial write use.  We may need to page to make a viable system, and
> will need to page to a file.

Where did anyone even suggest using the bare NAND?

> > > Also, I did state "off of a USB stick or SD card".  I actually think
> > > that in a lot of ways, that's better because it means that we can not
> > > worry about using any of the built-in flash leaving all of it for use
> > > with Sugar and then wanting to run a joyride build, etc.
> > 
> > In my latest discussions with Kim, it seems unlikely that we will be able 
> > to get something to the hardware manufacturers in time for an "onboard" 
> > solution anyway.  
> 
> But olpc-update allows a late-binding: you can install bits later with
> no hardware cost.  I'm pretty sure a small enough spin is not very hard
> to do.

Making spins is fundamentally trivial.  Adding more variations of things
to build, support and maintain is not trivial.

Jeremy