radix tree test harness

This code is mostly from Andrew Morton and Nick Piggin; tarball downloaded
from http://ozlabs.org/~akpm/rtth.tar.gz with sha1sum
0ce679db9ec047296b5d1ff7a1dfaa03a7bef1bd

Some small modifications were necessary to the test harness to fix the
build with the current Linux source code.

I also made minor modifications to automatically test the radix-tree.c
and radix-tree.h files that are in the current source tree, as opposed
to a copied and slightly modified version.  I am sure more could be done
to tidy up the harness, as well as adding more tests.

[koct9i@gmail.com: fix compilation]
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

@@ -0,0 +1,28 @@
+#ifndef SLAB_H
+#define SLAB_H
+
+#include <linux/types.h>
+
+#define GFP_KERNEL 1
+#define SLAB_HWCACHE_ALIGN 1
+#define SLAB_PANIC 2
+#define SLAB_RECLAIM_ACCOUNT    0x00020000UL            /* Objects are reclaimable */
+
+static inline int gfpflags_allow_blocking(gfp_t mask)
+{
+	return 1;
+}
+
+struct kmem_cache {
+	int size;
+	void (*ctor)(void *);
+};
+
+void *kmem_cache_alloc(struct kmem_cache *cachep, int flags);
+void kmem_cache_free(struct kmem_cache *cachep, void *objp);
+
+struct kmem_cache *
+kmem_cache_create(const char *name, size_t size, size_t offset,
+	unsigned long flags, void (*ctor)(void *));
+
+#endif		/* SLAB_H */