From f6594633817374a64a5fb31007bd810cad1425ff Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Mon, 17 Jun 2024 19:00:33 -0400 Subject: [PATCH] lib/generic-radix-tree.c: genradix_ptr_inlined() Provide an inlined fast path Signed-off-by: Kent Overstreet --- include/linux/generic-radix-tree.h | 75 ++++++++++++++++++++++++++++++ lib/generic-radix-tree.c | 64 +------------------------ 2 files changed, 76 insertions(+), 63 deletions(-) diff --git a/include/linux/generic-radix-tree.h b/include/linux/generic-radix-tree.h index f3512fddf3d7..8a3e1e886d1c 100644 --- a/include/linux/generic-radix-tree.h +++ b/include/linux/generic-radix-tree.h @@ -48,6 +48,49 @@ struct genradix_root; #define GENRADIX_NODE_SHIFT 9 #define GENRADIX_NODE_SIZE (1U << GENRADIX_NODE_SHIFT) +#define GENRADIX_ARY (GENRADIX_NODE_SIZE / sizeof(struct genradix_node *)) +#define GENRADIX_ARY_SHIFT ilog2(GENRADIX_ARY) + +/* depth that's needed for a genradix that can address up to ULONG_MAX: */ +#define GENRADIX_MAX_DEPTH \ + DIV_ROUND_UP(BITS_PER_LONG - GENRADIX_NODE_SHIFT, GENRADIX_ARY_SHIFT) + +#define GENRADIX_DEPTH_MASK \ + ((unsigned long) (roundup_pow_of_two(GENRADIX_MAX_DEPTH + 1) - 1)) + +static inline int genradix_depth_shift(unsigned depth) +{ + return GENRADIX_NODE_SHIFT + GENRADIX_ARY_SHIFT * depth; +} + +/* + * Returns size (of data, in bytes) that a tree of a given depth holds: + */ +static inline size_t genradix_depth_size(unsigned depth) +{ + return 1UL << genradix_depth_shift(depth); +} + +static inline unsigned genradix_root_to_depth(struct genradix_root *r) +{ + return (unsigned long) r & GENRADIX_DEPTH_MASK; +} + +static inline struct genradix_node *genradix_root_to_node(struct genradix_root *r) +{ + return (void *) ((unsigned long) r & ~GENRADIX_DEPTH_MASK); +} + +struct genradix_node { + union { + /* Interior node: */ + struct genradix_node *children[GENRADIX_ARY]; + + /* Leaf: */ + u8 data[GENRADIX_NODE_SIZE]; + }; +}; + struct __genradix { struct genradix_root *root; }; @@ -128,6 +171,30 @@ static inline size_t __idx_to_offset(size_t idx, size_t obj_size) #define __genradix_idx_to_offset(_radix, _idx) \ __idx_to_offset(_idx, __genradix_obj_size(_radix)) +static inline void *__genradix_ptr_inlined(struct __genradix *radix, size_t offset) +{ + struct genradix_root *r = READ_ONCE(radix->root); + struct genradix_node *n = genradix_root_to_node(r); + unsigned level = genradix_root_to_depth(r); + unsigned shift = genradix_depth_shift(level); + + if (unlikely(ilog2(offset) >= genradix_depth_shift(level))) + return NULL; + + while (n && shift > GENRADIX_NODE_SHIFT) { + shift -= GENRADIX_ARY_SHIFT; + n = n->children[offset >> shift]; + offset &= (1UL << shift) - 1; + } + + return n ? &n->data[offset] : NULL; +} + +#define genradix_ptr_inlined(_radix, _idx) \ + (__genradix_cast(_radix) \ + __genradix_ptr_inlined(&(_radix)->tree, \ + __genradix_idx_to_offset(_radix, _idx))) + void *__genradix_ptr(struct __genradix *, size_t); /** @@ -144,6 +211,14 @@ void *__genradix_ptr(struct __genradix *, size_t); void *__genradix_ptr_alloc(struct __genradix *, size_t, gfp_t); +#define genradix_ptr_alloc_inlined(_radix, _idx, _gfp) \ + (__genradix_cast(_radix) \ + (__genradix_ptr_inlined(&(_radix)->tree, \ + __genradix_idx_to_offset(_radix, _idx)) ?: \ + __genradix_ptr_alloc(&(_radix)->tree, \ + __genradix_idx_to_offset(_radix, _idx), \ + _gfp))) + /** * genradix_ptr_alloc - get a pointer to a genradix entry, allocating it * if necessary diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c index fa692c86f069..4efae0663049 100644 --- a/lib/generic-radix-tree.c +++ b/lib/generic-radix-tree.c @@ -5,75 +5,13 @@ #include #include -#define GENRADIX_ARY (GENRADIX_NODE_SIZE / sizeof(struct genradix_node *)) -#define GENRADIX_ARY_SHIFT ilog2(GENRADIX_ARY) - -struct genradix_node { - union { - /* Interior node: */ - struct genradix_node *children[GENRADIX_ARY]; - - /* Leaf: */ - u8 data[GENRADIX_NODE_SIZE]; - }; -}; - -static inline int genradix_depth_shift(unsigned depth) -{ - return GENRADIX_NODE_SHIFT + GENRADIX_ARY_SHIFT * depth; -} - -/* - * Returns size (of data, in bytes) that a tree of a given depth holds: - */ -static inline size_t genradix_depth_size(unsigned depth) -{ - return 1UL << genradix_depth_shift(depth); -} - -/* depth that's needed for a genradix that can address up to ULONG_MAX: */ -#define GENRADIX_MAX_DEPTH \ - DIV_ROUND_UP(BITS_PER_LONG - GENRADIX_NODE_SHIFT, GENRADIX_ARY_SHIFT) - -#define GENRADIX_DEPTH_MASK \ - ((unsigned long) (roundup_pow_of_two(GENRADIX_MAX_DEPTH + 1) - 1)) - -static inline unsigned genradix_root_to_depth(struct genradix_root *r) -{ - return (unsigned long) r & GENRADIX_DEPTH_MASK; -} - -static inline struct genradix_node *genradix_root_to_node(struct genradix_root *r) -{ - return (void *) ((unsigned long) r & ~GENRADIX_DEPTH_MASK); -} - /* * Returns pointer to the specified byte @offset within @radix, or NULL if not * allocated */ void *__genradix_ptr(struct __genradix *radix, size_t offset) { - struct genradix_root *r = READ_ONCE(radix->root); - struct genradix_node *n = genradix_root_to_node(r); - unsigned level = genradix_root_to_depth(r); - - if (ilog2(offset) >= genradix_depth_shift(level)) - return NULL; - - while (1) { - if (!n) - return NULL; - if (!level) - break; - - level--; - - n = n->children[offset >> genradix_depth_shift(level)]; - offset &= genradix_depth_size(level) - 1; - } - - return &n->data[offset]; + return __genradix_ptr_inlined(radix, offset); } EXPORT_SYMBOL(__genradix_ptr);