kernel updates from external trees

[Josh Boyer]

On Tue, 2004-04-27 at 13:16, David T Hollis wrote:
> Not a RH kernel developer but .... I would be quite certain that no
> extra effort is made to pull in external trees just prior to release.
> That would invalidate all of the prior testing to ensure that a stable
> kernel is included in the release.  Sure, you may lose some nifty new
> feature, or even miss out on a few bug fixes, but the end goal is a
> known commodity that can be unleashed on the world.  The bug fixes can
> be incorporated into an errata kernel after they have been more
> thoroughly tested.

Yep, and I agree with all of that too.  I guess I am still not being
very clear, so here goes another attempt at asking this question:

At _any_ point during the development of the kernel for a new product
release, do the kernel developers bring in changes from external trees? 
If so, which ones?

Obviously during development they pull from the kernel.org tree.  For
FC2, the kernel has gone from pre 2.6, to 2.6.5 already.  It's pretty
common knowledge that Red Hat/Fedora kernels contain changes by the
kernel developers for various reasons (i.e. bug fixes, backports, etc). 
So, do those changes contain fixes from other trees or all they all done
"in-house"?

If they do pull in changes from external trees, it might be easier to
open bugs and point them to the tree for a fix.  Or maybe I am just
blabbering.  I guess I am just curious.

Thanks for all the responses.  They are appreciated even though I sound
like a broken record :)

thx,
josh