custom kernel rpm / repatching methods

[Vibol Hou <vibol khmer cc>]

I've been following the latest round of kernel updates by arjanv and 
i've been looking into creating a custom kernel with swsusp2 patched 
in.  i'm curious to know what methods the current redhat kernel 
maintainer(s) use to keep the rpm patched; is this process done 
manually?  for instance, i've noticed a number of redhat-applied patches 
that occur after the bk patchsets.  are the redhat-applied patches 
recreated manually to account for changes made by the bk patchset each time?

-Vibol