* to delete the gc timer at destroying/flushing a set */
#define IPTREE_DESTROY_SLEEP 100
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
static struct kmem_cache *branch_cachep;
static struct kmem_cache *leaf_cachep;
#else
#define IPTREEMAP_DEFAULT_GC_TIME (5 * 60)
#define IPTREEMAP_DESTROY_SLEEP (100)
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
static struct kmem_cache *cachep_b;
static struct kmem_cache *cachep_c;
static struct kmem_cache *cachep_d;
static size_t max_malloc_size = 0, max_page_size = 0;
-static inline bool init_max_page_size(void)
+static inline unsigned int init_max_page_size(void)
{
size_t page_size = 0;