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authorJohannes Weiner <hannes@cmpxchg.org>2014-04-04 01:47:54 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-04 03:21:01 +0400
commit139e561660fe11e0fc35e142a800df3dd7d03e9d (patch)
treeb46c699ad4840fb76e71fe17b340f890587e2f6a /include
parenta528910e12ec7ee203095eb1711468a66b9b60b0 (diff)
downloadlinux-139e561660fe11e0fc35e142a800df3dd7d03e9d.tar.xz
lib: radix_tree: tree node interface
Make struct radix_tree_node part of the public interface and provide API functions to create, look up, and delete whole nodes. Refactor the existing insert, look up, delete functions on top of these new node primitives. This will allow the VM to track and garbage collect page cache radix tree nodes. [sasha.levin@oracle.com: return correct error code on insertion failure] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Metin Doslu <metin@citusdata.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ozgun Erdogan <ozgun@citusdata.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/radix-tree.h34
1 files changed, 34 insertions, 0 deletions
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index e8be53ecfc45..13636c40bc42 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -60,6 +60,33 @@ static inline int radix_tree_is_indirect_ptr(void *ptr)
#define RADIX_TREE_MAX_TAGS 3
+#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 RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1)
+
+#define RADIX_TREE_TAG_LONGS \
+ ((RADIX_TREE_MAP_SIZE + BITS_PER_LONG - 1) / BITS_PER_LONG)
+
+struct radix_tree_node {
+ unsigned int height; /* Height from the bottom */
+ unsigned int count;
+ union {
+ struct radix_tree_node *parent; /* Used when ascending tree */
+ struct rcu_head rcu_head; /* Used when freeing node */
+ };
+ void __rcu *slots[RADIX_TREE_MAP_SIZE];
+ unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
+};
+
+#define RADIX_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long))
+#define RADIX_TREE_MAX_PATH (DIV_ROUND_UP(RADIX_TREE_INDEX_BITS, \
+ RADIX_TREE_MAP_SHIFT))
+
/* root tags are stored in gfp_mask, shifted by __GFP_BITS_SHIFT */
struct radix_tree_root {
unsigned int height;
@@ -101,6 +128,7 @@ do { \
* concurrently with other readers.
*
* The notable exceptions to this rule are the following functions:
+ * __radix_tree_lookup
* radix_tree_lookup
* radix_tree_lookup_slot
* radix_tree_tag_get
@@ -216,9 +244,15 @@ static inline void radix_tree_replace_slot(void **pslot, void *item)
rcu_assign_pointer(*pslot, item);
}
+int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
+ struct radix_tree_node **nodep, void ***slotp);
int radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
+void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index,
+ struct radix_tree_node **nodep, void ***slotp);
void *radix_tree_lookup(struct radix_tree_root *, unsigned long);
void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long);
+bool __radix_tree_delete_node(struct radix_tree_root *root, unsigned long index,
+ struct radix_tree_node *node);
void *radix_tree_delete_item(struct radix_tree_root *, unsigned long, void *);
void *radix_tree_delete(struct radix_tree_root *, unsigned long);
unsigned int