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| author | Matthew Wilcox <willy@linux.intel.com> | 2016-05-20 17:03:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-20 17:58:30 -0700 |
| commit | 30ff46ccb303fb6f6c28b9aa9f2cdc4ba900ed3f (patch) | |
| tree | a401a527d4f4cafeab2a15befdd15ed29c2eade3 /include/linux/radix-tree.h | |
| parent | d0891265bbc988dc91ed8580b38eb3dac128581b (diff) | |
| download | linux-30ff46ccb303fb6f6c28b9aa9f2cdc4ba900ed3f.tar.gz | |
radix-tree: rename INDIRECT_PTR to INTERNAL_NODE
The name RADIX_TREE_INDIRECT_PTR doesn't really match the meaning.
RADIX_TREE_INTERNAL_NODE is a better name.
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>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/radix-tree.h')
| -rw-r--r-- | include/linux/radix-tree.h | 30 |
1 files changed, 13 insertions, 17 deletions
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index c0d223cfac008..c8cc879046c72 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -29,20 +29,16 @@ #include <linux/rcupdate.h> /* - * An indirect pointer (root->rnode pointing to a radix_tree_node, rather - * than a data item) is signalled by the low bit set in the root->rnode - * pointer. - * - * In this case root->height is > 0, but the indirect pointer tests are - * needed for RCU lookups (because root->height is unreliable). The only - * time callers need worry about this is when doing a lookup_slot under - * RCU. - * - * Indirect pointer in fact is also used to tag the last pointer of a node - * when it is shrunk, before we rcu free the node. See shrink code for - * details. + * Entries in the radix tree have the low bit set if they refer to a + * radix_tree_node. If the low bit is clear then the entry is user data. + * + * We also use the low bit to indicate that the slot will be freed in the + * next RCU idle period, and users need to re-walk the tree to find the + * new slot for the index that they were looking for. See the comment in + * radix_tree_shrink() for details. */ -#define RADIX_TREE_INDIRECT_PTR 1 +#define RADIX_TREE_INTERNAL_NODE 1 + /* * A common use of the radix tree is to store pointers to struct pages; * but shmem/tmpfs needs also to store swap entries in the same tree: @@ -63,7 +59,7 @@ static inline int radix_tree_is_indirect_ptr(void *ptr) { - return (int)((unsigned long)ptr & RADIX_TREE_INDIRECT_PTR); + return (int)((unsigned long)ptr & RADIX_TREE_INTERNAL_NODE); } /*** radix-tree API starts here ***/ @@ -228,7 +224,7 @@ static inline void *radix_tree_deref_slot_protected(void **pslot, */ static inline int radix_tree_deref_retry(void *arg) { - return unlikely((unsigned long)arg & RADIX_TREE_INDIRECT_PTR); + return unlikely(radix_tree_is_indirect_ptr(arg)); } /** @@ -250,7 +246,7 @@ static inline int radix_tree_exceptional_entry(void *arg) static inline int radix_tree_exception(void *arg) { return unlikely((unsigned long)arg & - (RADIX_TREE_INDIRECT_PTR | RADIX_TREE_EXCEPTIONAL_ENTRY)); + (RADIX_TREE_INTERNAL_NODE | RADIX_TREE_EXCEPTIONAL_ENTRY)); } /** @@ -448,7 +444,7 @@ radix_tree_chunk_size(struct radix_tree_iter *iter) static inline void *indirect_to_ptr(void *ptr) { - return (void *)((unsigned long)ptr & ~RADIX_TREE_INDIRECT_PTR); + return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE); } /** |