SLUB: Fix numa bootstrap

NUMA bootstrap calls new_slab() if more than one node is found on bootup.
new_slab() assumes a standard slab context where interrupts must be
disabled. It enables interrupts for the call into the page allocator
and then disables them again.

I dropped the interrupt preservation code just before SLUB v6 because
it looked useless there. SLUB worked on the following NUMA tests
that just had a single node. Sigh.

Enable interrupts after calling new_slab.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.21-rc5-mm4/mm/slub.c
===================================================================
--- linux-2.6.21-rc5-mm4.orig/mm/slub.c	2007-04-03 18:07:41.000000000 -0700
+++ linux-2.6.21-rc5-mm4/mm/slub.c	2007-04-03 18:08:17.000000000 -0700
@@ -1436,6 +1436,8 @@ static int init_kmem_cache_nodes(struct 
 
 			BUG_ON(s->size < sizeof(struct kmem_cache_node));
 			page = new_slab(kmalloc_caches, gfpflags, node);
+			/* new_slab() disables interupts */
+			local_irq_enable();
 
 			BUG_ON(!page);
 			n = page->freelist;