diff options
| -rw-r--r-- | include/linux/radix-tree.h | 5 | ||||
| -rw-r--r-- | lib/radix-tree.c | 192 |
2 files changed, 114 insertions, 83 deletions
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index dd83cca28001..9158a68140c9 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -23,6 +23,9 @@ #include <linux/preempt.h> #include <linux/types.h> +#define RADIX_TREE_MAX_TAGS 2 + +/* root tags are stored in gfp_mask, shifted by __GFP_BITS_SHIFT */ struct radix_tree_root { unsigned int height; gfp_t gfp_mask; @@ -45,8 +48,6 @@ do { \ (root)->rnode = NULL; \ } while (0) -#define RADIX_TREE_MAX_TAGS 2 - int radix_tree_insert(struct radix_tree_root *, unsigned long, void *); void *radix_tree_lookup(struct radix_tree_root *, unsigned long); void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long); diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 7097bb239e40..35a2d93b3528 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -74,6 +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. @@ -82,9 +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); @@ -152,6 +158,27 @@ static inline int tag_get(struct radix_tree_node *node, unsigned int tag, return test_bit(offset, node->tags[tag]); } +static inline void root_tag_set(struct radix_tree_root *root, unsigned int tag) +{ + root->gfp_mask |= (1 << (tag + __GFP_BITS_SHIFT)); +} + + +static inline void root_tag_clear(struct radix_tree_root *root, unsigned int tag) +{ + root->gfp_mask &= ~(1 << (tag + __GFP_BITS_SHIFT)); +} + +static inline void root_tag_clear_all(struct radix_tree_root *root) +{ + root->gfp_mask &= __GFP_BITS_MASK; +} + +static inline int root_tag_get(struct radix_tree_root *root, unsigned int tag) +{ + return root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT)); +} + /* * Returns 1 if any slot in the node has this tag set. * Otherwise returns 0. @@ -182,7 +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_MAX_TAGS]; int tag; /* Figure out what the height should be. */ @@ -195,16 +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_MAX_TAGS; tag++) { - tags[tag] = 0; - if (any_tag_set(root->rnode, tag)) - tags[tag] = 1; - } - do { if (!(node = radix_tree_node_alloc(root))) return -ENOMEM; @@ -214,7 +230,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) /* Propagate the aggregated tag info into the new root */ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { - if (tags[tag]) + if (root_tag_get(root, tag)) tag_set(node, tag, 0); } @@ -243,8 +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; @@ -255,7 +270,7 @@ int radix_tree_insert(struct radix_tree_root *root, shift = (height-1) * RADIX_TREE_MAP_SHIFT; offset = 0; /* uninitialised var warning */ - do { + while (height > 0) { if (slot == NULL) { /* Have to add a child node. */ if (!(slot = radix_tree_node_alloc(root))) @@ -273,16 +288,21 @@ int radix_tree_insert(struct radix_tree_root *root, slot = node->slots[offset]; shift -= RADIX_TREE_MAP_SHIFT; height--; - } while (height > 0); + } if (slot != NULL) return -EEXIST; - BUG_ON(!node); - node->count++; - node->slots[offset] = item; - BUG_ON(tag_get(node, 0, offset)); - BUG_ON(tag_get(node, 1, offset)); + if (node) { + node->count++; + node->slots[offset] = item; + BUG_ON(tag_get(node, 0, offset)); + BUG_ON(tag_get(node, 1, offset)); + } else { + root->rnode = item; + BUG_ON(root_tag_get(root, 0)); + BUG_ON(root_tag_get(root, 1)); + } return 0; } @@ -295,9 +315,13 @@ static inline void **__lookup_slot(struct radix_tree_root *root, 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; @@ -368,8 +392,8 @@ void *radix_tree_tag_set(struct radix_tree_root *root, if (index > radix_tree_maxindex(height)) return NULL; - shift = (height - 1) * RADIX_TREE_MAP_SHIFT; slot = root->rnode; + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; while (height > 0) { int offset; @@ -383,6 +407,10 @@ void *radix_tree_tag_set(struct radix_tree_root *root, 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); @@ -405,9 +433,8 @@ void *radix_tree_tag_clear(struct radix_tree_root *root, 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)) @@ -432,20 +459,24 @@ void *radix_tree_tag_clear(struct radix_tree_root *root, height--; } - ret = slot; - if (ret == NULL) + if (slot == NULL) goto out; - do { + while (pathp->node) { if (!tag_get(pathp->node, tag, pathp->offset)) goto out; tag_clear(pathp->node, tag, pathp->offset); 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); @@ -458,9 +489,8 @@ EXPORT_SYMBOL(radix_tree_tag_clear); * * 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, unsigned int tag) @@ -473,6 +503,13 @@ 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; @@ -494,7 +531,7 @@ 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; @@ -514,8 +551,11 @@ __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; @@ -603,10 +643,16 @@ __lookup_tag(struct radix_tree_root *root, void **results, unsigned long index, 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++) { @@ -637,7 +683,7 @@ __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; @@ -665,6 +711,10 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, 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 */ @@ -689,7 +739,7 @@ EXPORT_SYMBOL(radix_tree_gang_lookup_tag); static inline void radix_tree_shrink(struct radix_tree_root *root) { /* try to shrink tree height */ - while (root->height > 1 && + while (root->height > 0 && root->rnode->count == 1 && root->rnode->slots[0]) { struct radix_tree_node *to_free = root->rnode; @@ -717,12 +767,8 @@ static inline void radix_tree_shrink(struct radix_tree_root *root) 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_MAX_TAGS]; - int nr_cleared_tags; int tag; int offset; @@ -730,11 +776,17 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) if (index > radix_tree_maxindex(height)) goto out; + slot = root->rnode; + if (height == 0 && root->rnode) { + root_tag_clear_all(root); + root->rnode = NULL; + goto out; + } + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; pathp->node = NULL; - slot = root->rnode; - for ( ; height > 0; height--) { + do { if (slot == NULL) goto out; @@ -744,44 +796,22 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) pathp->node = slot; slot = slot->slots[offset]; 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 */ - nr_cleared_tags = 0; for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { - tags[tag] = 1; - if (tag_get(pathp->node, tag, pathp->offset)) { - tag_clear(pathp->node, tag, pathp->offset); - if (!any_tag_set(pathp->node, tag)) { - tags[tag] = 0; - nr_cleared_tags++; - } - } - } - - for (pathp--; nr_cleared_tags && pathp->node; pathp--) { - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { - if (tags[tag]) - continue; - - tag_clear(pathp->node, tag, pathp->offset); - if (any_tag_set(pathp->node, tag)) { - tags[tag] = 1; - nr_cleared_tags--; - } - } + 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; pathp->node->count--; @@ -793,11 +823,15 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) /* 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); @@ -808,11 +842,7 @@ EXPORT_SYMBOL(radix_tree_delete); */ int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag) { - struct radix_tree_node *rnode; - rnode = root->rnode; - if (!rnode) - return 0; - return any_tag_set(rnode, tag); + return root_tag_get(root, tag); } EXPORT_SYMBOL(radix_tree_tagged); |