From 268f42de718128cd0301293177e79c08c38e39a6 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 14 Dec 2016 15:08:55 -0800 Subject: radix-tree: delete radix_tree_range_tag_if_tagged() This is an exceptionally complicated function with just one caller (tag_pages_for_writeback). We devote a large portion of the runtime of the test suite to testing this one function which has one caller. By introducing the new function radix_tree_iter_tag_set(), we can eliminate all of the complexity while keeping the performance. The caller can now use a fairly standard radix_tree_for_each() loop, and it doesn't need to worry about tricksy things like 'start' wrapping. The test suite continues to spend a large amount of time investigating this function, but now it's testing the underlying primitives such as radix_tree_iter_resume() and the radix_tree_for_each_tagged() iterator which are also used by other parts of the kernel. Link: http://lkml.kernel.org/r/1480369871-5271-57-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox Tested-by: Kirill A. Shutemov Cc: Konstantin Khlebnikov Cc: Ross Zwisler Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/radix-tree.h | 74 +++++++++++++++++++++++----------------------- 1 file changed, 37 insertions(+), 37 deletions(-) (limited to 'include/linux/radix-tree.h') diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index a13d3f7c6c65..7a8d2516c73a 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -120,6 +120,41 @@ static inline bool radix_tree_empty(struct radix_tree_root *root) return root->rnode == NULL; } +/** + * struct radix_tree_iter - radix tree iterator state + * + * @index: index of current slot + * @next_index: one beyond the last index for this chunk + * @tags: bit-mask for tag-iterating + * @node: node that contains current slot + * @shift: shift for the node that holds our slots + * + * This radix tree iterator works in terms of "chunks" of slots. A chunk is a + * subinterval of slots contained within one radix tree leaf node. It is + * described by a pointer to its first slot and a struct radix_tree_iter + * which holds the chunk's position in the tree and its size. For tagged + * iteration radix_tree_iter also holds the slots' bit-mask for one chosen + * radix tree tag. + */ +struct radix_tree_iter { + unsigned long index; + unsigned long next_index; + unsigned long tags; + struct radix_tree_node *node; +#ifdef CONFIG_RADIX_TREE_MULTIORDER + unsigned int shift; +#endif +}; + +static inline unsigned int iter_shift(const struct radix_tree_iter *iter) +{ +#ifdef CONFIG_RADIX_TREE_MULTIORDER + return iter->shift; +#else + return 0; +#endif +} + /** * Radix-tree synchronization * @@ -283,6 +318,8 @@ void *radix_tree_tag_clear(struct radix_tree_root *root, unsigned long index, unsigned int tag); int radix_tree_tag_get(struct radix_tree_root *root, unsigned long index, unsigned int tag); +void radix_tree_iter_tag_set(struct radix_tree_root *root, + const struct radix_tree_iter *iter, unsigned int tag); unsigned int radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, unsigned long first_index, unsigned int max_items, @@ -291,10 +328,6 @@ unsigned int radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results, unsigned long first_index, unsigned int max_items, unsigned int tag); -unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, - unsigned long *first_indexp, unsigned long last_index, - unsigned long nr_to_tag, - unsigned int fromtag, unsigned int totag); int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag); static inline void radix_tree_preload_end(void) @@ -302,39 +335,6 @@ static inline void radix_tree_preload_end(void) preempt_enable(); } -/** - * struct radix_tree_iter - radix tree iterator state - * - * @index: index of current slot - * @next_index: one beyond the last index for this chunk - * @tags: bit-mask for tag-iterating - * @shift: shift for the node that holds our slots - * - * This radix tree iterator works in terms of "chunks" of slots. A chunk is a - * subinterval of slots contained within one radix tree leaf node. It is - * described by a pointer to its first slot and a struct radix_tree_iter - * which holds the chunk's position in the tree and its size. For tagged - * iteration radix_tree_iter also holds the slots' bit-mask for one chosen - * radix tree tag. - */ -struct radix_tree_iter { - unsigned long index; - unsigned long next_index; - unsigned long tags; -#ifdef CONFIG_RADIX_TREE_MULTIORDER - unsigned int shift; -#endif -}; - -static inline unsigned int iter_shift(struct radix_tree_iter *iter) -{ -#ifdef CONFIG_RADIX_TREE_MULTIORDER - return iter->shift; -#else - return 0; -#endif -} - #define RADIX_TREE_ITER_TAG_MASK 0x00FF /* tag index in lower byte */ #define RADIX_TREE_ITER_TAGGED 0x0100 /* lookup tagged slots */ #define RADIX_TREE_ITER_CONTIG 0x0200 /* stop at first hole */ -- cgit v1.2.3-59-g8ed1b