diff --git a/headers/private/kernel/debug.h b/headers/private/kernel/debug.h
index 28cf902250..d7e88d030b 100644
--- a/headers/private/kernel/debug.h
+++ b/headers/private/kernel/debug.h
@@ -11,23 +11,34 @@
 
 #include <OS.h>
 
-struct kernel_args;
-
+//#define DEBUG 1
 
 #if DEBUG
-#	define ASSERT(x) \
-	if (x) {} else { panic("ASSERT FAILED (%s:%d): %s\n", __FILE__, __LINE__, #x); }
+/* 
+ * The kernel debug level. 
+ * Level 1 is usual asserts, > 1 should be used for very expensive runtime checks
+ */
+#define KDEBUG 1
+#endif
+
+#define ASSERT_ALWAYS(x) \
+	do { if (!(x)) { panic("ASSERT FAILED (%s:%d): %s\n", __FILE__, __LINE__, #x); } } while (0)
+
+#if KDEBUG
+#define ASSERT(x) ASSERT_ALWAYS(x)
 #else 
-#	define ASSERT(x) 
+#define ASSERT(x) \
+	do { } while(0)
 #endif
 
 extern int dbg_register_file[B_MAX_CPU_COUNT][14];
 
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+struct kernel_args;
+
 extern status_t debug_init(struct kernel_args *args);
 extern status_t	debug_init_post_vm(struct kernel_args *args);
 extern status_t	debug_init_post_modules(struct kernel_args *args);
diff --git a/headers/private/kernel/lock.h b/headers/private/kernel/lock.h
index 915fdfac51..0d19da5488 100644
--- a/headers/private/kernel/lock.h
+++ b/headers/private/kernel/lock.h
@@ -39,11 +39,14 @@ typedef struct rw_lock {
 
 #define RW_MAX_READERS 1000000
 
-#ifdef DEBUG
+#if 0 && KDEBUG // XXX disable this for now, it causes problems when including thread.h here
 #	include <thread.h>
-#endif
 #define ASSERT_LOCKED_RECURSIVE(r) { ASSERT(thread_get_current_thread_id() == (r)->holder); }
 #define ASSERT_LOCKED_MUTEX(m) { ASSERT(thread_get_current_thread_id() == (m)->holder); }
+#else
+#define ASSERT_LOCKED_RECURSIVE(r)
+#define ASSERT_LOCKED_MUTEX(m)
+#endif
 
 
 #ifdef __cplusplus
diff --git a/src/system/kernel/heap.c b/src/system/kernel/heap.c
index 4258753475..55f2902058 100644
--- a/src/system/kernel/heap.c
+++ b/src/system/kernel/heap.c
@@ -28,7 +28,7 @@
 #endif
 
 /* prevent freeing pointers that were not allocated by kmalloc or are already freeed */
-#ifdef DEBUG
+#if KDEBUG > 1
 #	define PARANOID_POINTER_CHECK 1
 #else
 #	define PARANOID_POINTER_CHECK 0
@@ -125,7 +125,7 @@ struct list sWalls;
 
 #if PARANOID_POINTER_CHECK
 
-#define PTRCHECKLIST_ENTRIES 8192
+#define PTRCHECKLIST_ENTRIES 32768
 static void *ptrchecklist[PTRCHECKLIST_ENTRIES]; /* automatically initialized to zero */
 
 static void