X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=lib%2Fradix-tree.c;h=aa9bfd0bdbd1bd720ed1eb8c5416b180bad3b98a;hb=fc9e8b4e275b6882cb537154c8fc7cde3692eea0;hp=6a8bc6e06431eec49c1af2f34ec42d7d100e4e0b;hpb=905ec87e93bc9e01b15c60035cd6a50c636cbaef;p=powerpc.git diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 6a8bc6e064..aa9bfd0bdb 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -33,11 +33,10 @@ #ifdef __KERNEL__ -#define RADIX_TREE_MAP_SHIFT 6 +#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) #else #define RADIX_TREE_MAP_SHIFT 3 /* For more stressful testing */ #endif -#define RADIX_TREE_TAGS 2 #define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT) #define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1) @@ -48,7 +47,7 @@ struct radix_tree_node { unsigned int count; void *slots[RADIX_TREE_MAP_SIZE]; - unsigned long tags[RADIX_TREE_TAGS][RADIX_TREE_TAG_LONGS]; + unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS]; }; struct radix_tree_path { @@ -75,6 +74,11 @@ struct radix_tree_preload { }; DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, }; +static inline gfp_t root_gfp_mask(struct radix_tree_root *root) +{ + return root->gfp_mask & __GFP_BITS_MASK; +} + /* * This assumes that the caller has performed appropriate preallocation, and * that the caller has pinned this thread of control to the current CPU. @@ -83,9 +87,10 @@ static struct radix_tree_node * radix_tree_node_alloc(struct radix_tree_root *root) { struct radix_tree_node *ret; + gfp_t gfp_mask = root_gfp_mask(root); - ret = kmem_cache_alloc(radix_tree_node_cachep, root->gfp_mask); - if (ret == NULL && !(root->gfp_mask & __GFP_WAIT)) { + ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); + if (ret == NULL && !(gfp_mask & __GFP_WAIT)) { struct radix_tree_preload *rtp; rtp = &__get_cpu_var(radix_tree_preloads); @@ -110,7 +115,7 @@ radix_tree_node_free(struct radix_tree_node *node) * success, return zero, with preemption disabled. On error, return -ENOMEM * with preemption not disabled. */ -int radix_tree_preload(unsigned int __nocast gfp_mask) +int radix_tree_preload(gfp_t gfp_mask) { struct radix_tree_preload *rtp; struct radix_tree_node *node; @@ -135,20 +140,57 @@ out: return ret; } -static inline void tag_set(struct radix_tree_node *node, int tag, int offset) +static inline void tag_set(struct radix_tree_node *node, unsigned int tag, + int offset) +{ + __set_bit(offset, node->tags[tag]); +} + +static inline void tag_clear(struct radix_tree_node *node, unsigned int tag, + int offset) +{ + __clear_bit(offset, node->tags[tag]); +} + +static inline int tag_get(struct radix_tree_node *node, unsigned int tag, + int offset) +{ + return test_bit(offset, node->tags[tag]); +} + +static inline void root_tag_set(struct radix_tree_root *root, unsigned int tag) +{ + root->gfp_mask |= (__force gfp_t)(1 << (tag + __GFP_BITS_SHIFT)); +} + + +static inline void root_tag_clear(struct radix_tree_root *root, unsigned int tag) +{ + root->gfp_mask &= (__force gfp_t)~(1 << (tag + __GFP_BITS_SHIFT)); +} + +static inline void root_tag_clear_all(struct radix_tree_root *root) { - if (!test_bit(offset, &node->tags[tag][0])) - __set_bit(offset, &node->tags[tag][0]); + root->gfp_mask &= __GFP_BITS_MASK; } -static inline void tag_clear(struct radix_tree_node *node, int tag, int offset) +static inline int root_tag_get(struct radix_tree_root *root, unsigned int tag) { - __clear_bit(offset, &node->tags[tag][0]); + return (__force unsigned)root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT)); } -static inline int tag_get(struct radix_tree_node *node, int tag, int offset) +/* + * Returns 1 if any slot in the node has this tag set. + * Otherwise returns 0. + */ +static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag) { - return test_bit(offset, &node->tags[tag][0]); + int idx; + for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { + if (node->tags[tag][idx]) + return 1; + } + return 0; } /* @@ -167,7 +209,6 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) { struct radix_tree_node *node; unsigned int height; - char tags[RADIX_TREE_TAGS]; int tag; /* Figure out what the height should be. */ @@ -180,22 +221,6 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) goto out; } - /* - * Prepare the tag status of the top-level node for propagation - * into the newly-pushed top-level node(s) - */ - for (tag = 0; tag < RADIX_TREE_TAGS; tag++) { - int idx; - - tags[tag] = 0; - for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { - if (root->rnode->tags[tag][idx]) { - tags[tag] = 1; - break; - } - } - } - do { if (!(node = radix_tree_node_alloc(root))) return -ENOMEM; @@ -204,8 +229,8 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) node->slots[0] = root->rnode; /* Propagate the aggregated tag info into the new root */ - for (tag = 0; tag < RADIX_TREE_TAGS; tag++) { - if (tags[tag]) + for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { + if (root_tag_get(root, tag)) tag_set(node, tag, 0); } @@ -234,8 +259,7 @@ int radix_tree_insert(struct radix_tree_root *root, int error; /* Make sure the tree is high enough. */ - if ((!index && !root->rnode) || - index > radix_tree_maxindex(root->height)) { + if (index > radix_tree_maxindex(root->height)) { error = radix_tree_extend(root, index); if (error) return error; @@ -274,42 +298,74 @@ int radix_tree_insert(struct radix_tree_root *root, node->slots[offset] = item; BUG_ON(tag_get(node, 0, offset)); BUG_ON(tag_get(node, 1, offset)); - } else + } else { root->rnode = item; + BUG_ON(root_tag_get(root, 0)); + BUG_ON(root_tag_get(root, 1)); + } return 0; } EXPORT_SYMBOL(radix_tree_insert); -/** - * radix_tree_lookup - perform lookup operation on a radix tree - * @root: radix tree root - * @index: index key - * - * Lookup the item at the position @index in the radix tree @root. - */ -void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index) +static inline void **__lookup_slot(struct radix_tree_root *root, + unsigned long index) { unsigned int height, shift; - struct radix_tree_node *slot; + struct radix_tree_node **slot; height = root->height; + if (index > radix_tree_maxindex(height)) return NULL; + if (height == 0 && root->rnode) + return (void **)&root->rnode; + shift = (height-1) * RADIX_TREE_MAP_SHIFT; - slot = root->rnode; + slot = &root->rnode; while (height > 0) { - if (slot == NULL) + if (*slot == NULL) return NULL; - slot = slot->slots[(index >> shift) & RADIX_TREE_MAP_MASK]; + slot = (struct radix_tree_node **) + ((*slot)->slots + + ((index >> shift) & RADIX_TREE_MAP_MASK)); shift -= RADIX_TREE_MAP_SHIFT; height--; } - return slot; + return (void **)slot; +} + +/** + * radix_tree_lookup_slot - lookup a slot in a radix tree + * @root: radix tree root + * @index: index key + * + * Lookup the slot corresponding to the position @index in the radix tree + * @root. This is useful for update-if-exists operations. + */ +void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index) +{ + return __lookup_slot(root, index); +} +EXPORT_SYMBOL(radix_tree_lookup_slot); + +/** + * radix_tree_lookup - perform lookup operation on a radix tree + * @root: radix tree root + * @index: index key + * + * Lookup the item at the position @index in the radix tree @root. + */ +void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index) +{ + void **slot; + + slot = __lookup_slot(root, index); + return slot != NULL ? *slot : NULL; } EXPORT_SYMBOL(radix_tree_lookup); @@ -319,36 +375,41 @@ EXPORT_SYMBOL(radix_tree_lookup); * @index: index key * @tag: tag index * - * Set the search tag corresponging to @index in the radix tree. From + * Set the search tag (which must be < RADIX_TREE_MAX_TAGS) + * corresponding to @index in the radix tree. From * the root all the way down to the leaf node. * * Returns the address of the tagged item. Setting a tag on a not-present * item is a bug. */ void *radix_tree_tag_set(struct radix_tree_root *root, - unsigned long index, int tag) + unsigned long index, unsigned int tag) { unsigned int height, shift; struct radix_tree_node *slot; height = root->height; - if (index > radix_tree_maxindex(height)) - return NULL; + BUG_ON(index > radix_tree_maxindex(height)); - shift = (height - 1) * RADIX_TREE_MAP_SHIFT; slot = root->rnode; + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; while (height > 0) { int offset; offset = (index >> shift) & RADIX_TREE_MAP_MASK; - tag_set(slot, tag, offset); + if (!tag_get(slot, tag, offset)) + tag_set(slot, tag, offset); slot = slot->slots[offset]; BUG_ON(slot == NULL); shift -= RADIX_TREE_MAP_SHIFT; height--; } + /* set the root's tag bit */ + if (slot && !root_tag_get(root, tag)) + root_tag_set(root, tag); + return slot; } EXPORT_SYMBOL(radix_tree_tag_set); @@ -359,7 +420,8 @@ EXPORT_SYMBOL(radix_tree_tag_set); * @index: index key * @tag: tag index * - * Clear the search tag corresponging to @index in the radix tree. If + * Clear the search tag (which must be < RADIX_TREE_MAX_TAGS) + * corresponding to @index in the radix tree. If * this causes the leaf node to have no tags set then clear the tag in the * next-to-leaf node, etc. * @@ -367,12 +429,11 @@ EXPORT_SYMBOL(radix_tree_tag_set); * has the same return value and semantics as radix_tree_lookup(). */ void *radix_tree_tag_clear(struct radix_tree_root *root, - unsigned long index, int tag) + unsigned long index, unsigned int tag) { struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path; - struct radix_tree_node *slot; + struct radix_tree_node *slot = NULL; unsigned int height, shift; - void *ret = NULL; height = root->height; if (index > radix_tree_maxindex(height)) @@ -397,22 +458,24 @@ void *radix_tree_tag_clear(struct radix_tree_root *root, height--; } - ret = slot; - if (ret == NULL) + if (slot == NULL) goto out; - do { - int idx; - + while (pathp->node) { + if (!tag_get(pathp->node, tag, pathp->offset)) + goto out; tag_clear(pathp->node, tag, pathp->offset); - for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { - if (pathp->node->tags[tag][idx]) - goto out; - } + if (any_tag_set(pathp->node, tag)) + goto out; pathp--; - } while (pathp->node); + } + + /* clear the root's tag bit */ + if (root_tag_get(root, tag)) + root_tag_clear(root, tag); + out: - return ret; + return slot; } EXPORT_SYMBOL(radix_tree_tag_clear); @@ -421,16 +484,15 @@ EXPORT_SYMBOL(radix_tree_tag_clear); * radix_tree_tag_get - get a tag on a radix tree node * @root: radix tree root * @index: index key - * @tag: tag index + * @tag: tag index (< RADIX_TREE_MAX_TAGS) * * Return values: * - * 0: tag not present - * 1: tag present, set - * -1: tag present, unset + * 0: tag not present or not set + * 1: tag set */ int radix_tree_tag_get(struct radix_tree_root *root, - unsigned long index, int tag) + unsigned long index, unsigned int tag) { unsigned int height, shift; struct radix_tree_node *slot; @@ -440,6 +502,13 @@ int radix_tree_tag_get(struct radix_tree_root *root, if (index > radix_tree_maxindex(height)) return 0; + /* check the root's tag bit */ + if (!root_tag_get(root, tag)) + return 0; + + if (height == 0) + return 1; + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; slot = root->rnode; @@ -461,7 +530,7 @@ int radix_tree_tag_get(struct radix_tree_root *root, int ret = tag_get(slot, tag, offset); BUG_ON(ret && saw_unset_tag); - return ret ? 1 : -1; + return !!ret; } slot = slot->slots[offset]; shift -= RADIX_TREE_MAP_SHIFT; @@ -481,8 +550,11 @@ __lookup(struct radix_tree_root *root, void **results, unsigned long index, unsigned long i; height = root->height; - if (height == 0) + if (height == 0) { + if (root->rnode && index == 0) + results[nr_found++] = root->rnode; goto out; + } shift = (height-1) * RADIX_TREE_MAP_SHIFT; slot = root->rnode; @@ -563,17 +635,23 @@ EXPORT_SYMBOL(radix_tree_gang_lookup); */ static unsigned int __lookup_tag(struct radix_tree_root *root, void **results, unsigned long index, - unsigned int max_items, unsigned long *next_index, int tag) + unsigned int max_items, unsigned long *next_index, unsigned int tag) { unsigned int nr_found = 0; unsigned int shift; unsigned int height = root->height; struct radix_tree_node *slot; + if (height == 0) { + if (root->rnode && index == 0) + results[nr_found++] = root->rnode; + goto out; + } + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; slot = root->rnode; - while (height > 0) { + do { unsigned long i = (index >> shift) & RADIX_TREE_MAP_MASK; for ( ; i < RADIX_TREE_MAP_SIZE; i++) { @@ -604,7 +682,7 @@ __lookup_tag(struct radix_tree_root *root, void **results, unsigned long index, } shift -= RADIX_TREE_MAP_SHIFT; slot = slot->slots[i]; - } + } while (height > 0); out: *next_index = index; return nr_found; @@ -617,7 +695,7 @@ out: * @results: where the results of the lookup are placed * @first_index: start the lookup from this key * @max_items: place up to this many items at *results - * @tag: the tag index + * @tag: the tag index (< RADIX_TREE_MAX_TAGS) * * Performs an index-ascending scan of the tree for present items which * have the tag indexed by @tag set. Places the items at *@results and @@ -625,12 +703,17 @@ out: */ unsigned int radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, - unsigned long first_index, unsigned int max_items, int tag) + unsigned long first_index, unsigned int max_items, + unsigned int tag) { const unsigned long max_index = radix_tree_maxindex(root->height); unsigned long cur_index = first_index; unsigned int ret = 0; + /* check the root's tag bit */ + if (!root_tag_get(root, tag)) + return 0; + while (ret < max_items) { unsigned int nr_found; unsigned long next_index; /* Index of next search */ @@ -648,6 +731,29 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, } EXPORT_SYMBOL(radix_tree_gang_lookup_tag); +/** + * radix_tree_shrink - shrink height of a radix tree to minimal + * @root radix tree root + */ +static inline void radix_tree_shrink(struct radix_tree_root *root) +{ + /* try to shrink tree height */ + while (root->height > 0 && + root->rnode->count == 1 && + root->rnode->slots[0]) { + struct radix_tree_node *to_free = root->rnode; + + root->rnode = to_free->slots[0]; + root->height--; + /* must only free zeroed nodes into the slab */ + tag_clear(to_free, 0, 0); + tag_clear(to_free, 1, 0); + to_free->slots[0] = NULL; + to_free->count = 0; + radix_tree_node_free(to_free); + } +} + /** * radix_tree_delete - delete an item from a radix tree * @root: radix tree root @@ -660,81 +766,71 @@ EXPORT_SYMBOL(radix_tree_gang_lookup_tag); void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) { struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path; - struct radix_tree_path *orig_pathp; - struct radix_tree_node *slot; + struct radix_tree_node *slot = NULL; unsigned int height, shift; - void *ret = NULL; - char tags[RADIX_TREE_TAGS]; - int nr_cleared_tags; + int tag; + int offset; height = root->height; if (index > radix_tree_maxindex(height)) goto out; - shift = (height - 1) * RADIX_TREE_MAP_SHIFT; - pathp->node = NULL; slot = root->rnode; + if (height == 0 && root->rnode) { + root_tag_clear_all(root); + root->rnode = NULL; + goto out; + } - for ( ; height > 0; height--) { - int offset; + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; + pathp->node = NULL; + do { if (slot == NULL) goto out; + pathp++; offset = (index >> shift) & RADIX_TREE_MAP_MASK; - pathp[1].offset = offset; - pathp[1].node = slot; + pathp->offset = offset; + pathp->node = slot; slot = slot->slots[offset]; - pathp++; shift -= RADIX_TREE_MAP_SHIFT; - } + height--; + } while (height > 0); - ret = slot; - if (ret == NULL) + if (slot == NULL) goto out; - orig_pathp = pathp; - /* * Clear all tags associated with the just-deleted item */ - memset(tags, 0, sizeof(tags)); - do { - int tag; - - nr_cleared_tags = RADIX_TREE_TAGS; - for (tag = 0; tag < RADIX_TREE_TAGS; tag++) { - int idx; - - if (tags[tag]) - continue; - - tag_clear(pathp->node, tag, pathp->offset); - - for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { - if (pathp->node->tags[tag][idx]) { - tags[tag] = 1; - nr_cleared_tags--; - break; - } - } - } - pathp--; - } while (pathp->node && nr_cleared_tags); + for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { + if (tag_get(pathp->node, tag, pathp->offset)) + radix_tree_tag_clear(root, index, tag); + } /* Now free the nodes we do not need anymore */ - for (pathp = orig_pathp; pathp->node; pathp--) { + while (pathp->node) { pathp->node->slots[pathp->offset] = NULL; - if (--pathp->node->count) + pathp->node->count--; + + if (pathp->node->count) { + if (pathp->node == root->rnode) + radix_tree_shrink(root); goto out; + } /* Node with zero slots in use so free it */ radix_tree_node_free(pathp->node); + + pathp--; } - root->rnode = NULL; + root_tag_clear_all(root); root->height = 0; + root->rnode = NULL; + out: - return ret; + return slot; } EXPORT_SYMBOL(radix_tree_delete); @@ -743,17 +839,9 @@ EXPORT_SYMBOL(radix_tree_delete); * @root: radix tree root * @tag: tag to test */ -int radix_tree_tagged(struct radix_tree_root *root, int tag) +int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag) { - int idx; - - if (!root->rnode) - return 0; - for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { - if (root->rnode->tags[tag][idx]) - return 1; - } - return 0; + return root_tag_get(root, tag); } EXPORT_SYMBOL(radix_tree_tagged);