[PATCH] add slab_is_available() routine for boot code

slab_is_available() indicates slab based allocators are available for use.
SPARSEMEM code needs to know this as it can be called at various times
during the boot process.

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

mm/slab.c

@@ -700,6 +700,14 @@ static enum {
 	FULL
 } g_cpucache_up;
 
+/*
+ * used by boot code to determine if it can use slab based allocator
+ */
+int slab_is_available(void)
+{
+	return g_cpucache_up == FULL;
+}
+
 static DEFINE_PER_CPU(struct work_struct, reap_work);
 
 static void free_block(struct kmem_cache *cachep, void **objpp, int len,