[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>

3 files changed, 10 insertions, 1 deletions

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 3af03b19c983..2d985d59c7b8 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -150,6 +150,7 @@ static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
 
 extern void kfree(const void *);
 extern unsigned int ksize(const void *);
+extern int slab_is_available(void);
 
 #ifdef CONFIG_NUMA
 extern void *kmem_cache_alloc_node(kmem_cache_t *, gfp_t flags, int node);
diff --git a/mm/slab.c b/mm/slab.c
index c32af7e7581e..b1d643b5238d 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 d7c32de99ee8..c5e89eb9ac8f 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);