[PATCH v3 17/33] radix-tree: Make radix_tree_find_next_bit more useful

Matthew Wilcox
2016-11-28T20:12:12Z

From: Matthew Wilcox <willy@linux.intel.com>

Since this function is specialised to the radix tree, pass in the node
and tag to calculate the address of the bitmap in radix_tree_find_next_bit()
instead of the caller. Likewise, there is no need to pass in the size of
the bitmap.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
lib/radix-tree.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index c72da89..01ed70b 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -190,13 +190,12 @@ static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag)
* Returns next bit offset, or size if nothing found.
*/
static __always_inline unsigned long
-radix_tree_find_next_bit(const unsigned long *addr,
- unsigned long size, unsigned long offset)
+radix_tree_find_next_bit(struct radix_tree_node *node, unsigned int tag,
+ unsigned long offset)
{
- if (!__builtin_constant_p(size))
- return find_next_bit(addr, size, offset);
+ const unsigned long *addr = node->tags[tag];

- if (offset < size) {
+ if (offset < RADIX_TREE_MAP_SIZE) {
unsigned long tmp;

addr += offset / BITS_PER_LONG;
@@ -204,14 +203,14 @@ radix_tree_find_next_bit(const unsigned long *addr,
if (tmp)
return __ffs(tmp) + offset;
offset = (offset + BITS_PER_LONG) & ~(BITS_PER_LONG - 1);
- while (offset < size) {
+ while (offset < RADIX_TREE_MAP_SIZE) {
tmp = *++addr;
if (tmp)
return __ffs(tmp) + offset;
offset += BITS_PER_LONG;
}
}
- return size;
+ return RADIX_TREE_MAP_SIZE;
}

#ifndef __KERNEL__
@@ -1159,9 +1158,7 @@ void **radix_tree_next_chunk(struct radix_tree_root *root,
return NULL;

if (flags & RADIX_TREE_ITER_TAGGED)
- offset = radix_tree_find_next_bit(
- node->tags[tag],
- RADIX_TREE_MAP_SIZE,
+ offset = radix_tree_find_next_bit(node, tag,
offset + 1);
else
while (++offset < RADIX_TREE_MAP_SIZE) {
--
2.10.2