From: Manfred Spraul <manfred@colorfullife.com>

attached is the promised cleanup/bugfix patch for the slab bootstrap:

- kmem_cache_init & kmem_cache_sizes_init merged into one function,
  called after mem_init().  It's impossible to bring slab to an operational
  state without working gfp, thus the early partial initialization is not
  necessary.

- g_cpucache_up set to FULL at the end of kmem_cache_init instead of the
  module init call.  This is a bugfix: slab was completely initialized,
  just the update of the state was missing.

- some documentation for the bootstrap added.

The minimal fix for the bug is a two-liner: move g_cpucache_up=FULL from
cpucache_init to kmem_cache_sizes_init, but I want to get rid of
kmem_cache_sizes_init, too.