[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>

2 files changed, 9 insertions, 1 deletions

diff --git a/mm/slab.c b/mm/slab.c
index c32af7e..b1d643b 100644
--- a/mm/slab.c
+++ b/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,
diff --git a/mm/sparse.c b/mm/sparse.c
index d7c32de..c5e89eb 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -32,7 +32,7 @@ static struct mem_section *sparse_index_alloc(int nid)
 	unsigned long array_size = SECTIONS_PER_ROOT *
 				   sizeof(struct mem_section);
 
-	if (system_state == SYSTEM_RUNNING)
+	if (slab_is_available())
 		section = kmalloc_node(array_size, GFP_KERNEL, nid);
 	else
 		section = alloc_bootmem_node(NODE_DATA(nid), array_size);