radix tree test suite: allow testing other fan-out values

The defines in regression2.c are already in radix-tree.h and duplicating
them in the test case makes experimenting with other values for the
fan-out harder than necessary.  Allow the user of the radix tree to
decide what the fan-out should be rather than fixing it to 8 for
non-kernel uses.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/radix-tree.h

@@ -70,10 +70,8 @@ static inline int radix_tree_is_indirect_ptr(void *ptr)
 
 #define RADIX_TREE_MAX_TAGS 3
 
-#ifdef __KERNEL__
+#ifndef RADIX_TREE_MAP_SHIFT
 #define RADIX_TREE_MAP_SHIFT	(CONFIG_BASE_SMALL ? 4 : 6)
-#else
-#define RADIX_TREE_MAP_SHIFT	3	/* For more stressful testing */
 #endif
 
 #define RADIX_TREE_MAP_SIZE	(1UL << RADIX_TREE_MAP_SHIFT)

tools/testing/radix-tree/linux/kernel.h

@@ -12,6 +12,8 @@
 #define CONFIG_SHMEM
 #define CONFIG_SWAP
 
+#define RADIX_TREE_MAP_SHIFT	3
+
 #ifndef NULL
 #define NULL	0
 #endif

tools/testing/radix-tree/regression2.c

@@ -51,13 +51,6 @@
 
 #include "regression.h"
 
-#ifdef __KERNEL__
-#define RADIX_TREE_MAP_SHIFT    (CONFIG_BASE_SMALL ? 4 : 6)
-#else
-#define RADIX_TREE_MAP_SHIFT    3       /* For more stressful testing */
-#endif
-
-#define RADIX_TREE_MAP_SIZE     (1UL << RADIX_TREE_MAP_SHIFT)
 #define PAGECACHE_TAG_DIRTY     0
 #define PAGECACHE_TAG_WRITEBACK 1
 #define PAGECACHE_TAG_TOWRITE   2