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| author | Matthew Wilcox <willy@linux.intel.com> | 2016-12-14 15:08:37 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-14 16:04:10 -0800 |
| commit | 9498d2bb34b0866829c313569df35e77a83f12eb (patch) | |
| tree | db19aaa39dc04f8ad77335a06623a2443717a872 /lib | |
| parent | 91d9c05ac6c788531136888d31ef18c6a0ec160f (diff) | |
| download | lwn-9498d2bb34b0866829c313569df35e77a83f12eb.tar.gz lwn-9498d2bb34b0866829c313569df35e77a83f12eb.zip | |
radix-tree: create node_tag_set()
Similar to node_tag_clear(), factor node_tag_set() out of
radix_tree_range_tag_if_tagged().
Link: http://lkml.kernel.org/r/1480369871-5271-51-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/radix-tree.c | 41 |
1 files changed, 19 insertions, 22 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 8c5911eae5e2..a90a4371deb8 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -991,6 +991,22 @@ static void node_tag_clear(struct radix_tree_root *root, root_tag_clear(root, tag); } +static void node_tag_set(struct radix_tree_root *root, + struct radix_tree_node *node, + unsigned int tag, unsigned int offset) +{ + while (node) { + if (tag_get(node, tag, offset)) + return; + tag_set(node, tag, offset); + offset = node->offset; + node = node->parent; + } + + if (!root_tag_get(root, tag)) + root_tag_set(root, tag); +} + /** * radix_tree_tag_clear - clear a tag on a radix tree node * @root: radix tree root @@ -1229,7 +1245,7 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, unsigned long nr_to_tag, unsigned int iftag, unsigned int settag) { - struct radix_tree_node *parent, *node, *child; + struct radix_tree_node *node, *child; unsigned long maxindex; unsigned long tagged = 0; unsigned long index = *first_indexp; @@ -1264,22 +1280,8 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, continue; } - /* tag the leaf */ tagged++; - tag_set(node, settag, offset); - - /* walk back up the path tagging interior nodes */ - parent = node; - for (;;) { - offset = parent->offset; - parent = parent->parent; - if (!parent) - break; - /* stop if we find a node with the tag already set */ - if (tag_get(parent, settag, offset)) - break; - tag_set(parent, settag, offset); - } + node_tag_set(root, node, settag, offset); next: /* Go to next entry in node */ index = ((index >> node->shift) + 1) << node->shift; @@ -1301,12 +1303,7 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, if (tagged >= nr_to_tag) break; } - /* - * We need not to tag the root tag if there is no tag which is set with - * settag within the range from *first_indexp to last_index. - */ - if (tagged > 0) - root_tag_set(root, settag); + *first_indexp = index; return tagged; |