diff options
Diffstat (limited to 'include/linux/interval_tree_generic.h')
| -rw-r--r-- | include/linux/interval_tree_generic.h | 94 |
1 files changed, 43 insertions, 51 deletions
diff --git a/include/linux/interval_tree_generic.h b/include/linux/interval_tree_generic.h index 58370e1862ad..c5a2fed49eb0 100644 --- a/include/linux/interval_tree_generic.h +++ b/include/linux/interval_tree_generic.h @@ -1,20 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* Interval Trees (C) 2012 Michel Lespinasse <walken@google.com> - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA include/linux/interval_tree_generic.h */ @@ -33,7 +21,7 @@ * ITSTATIC: 'static' or empty * ITPREFIX: prefix to use for the inline tree definitions * - * Note - before using this, please consider if non-generic version + * Note - before using this, please consider if generic version * (interval_tree.h) would work for you... */ @@ -42,34 +30,18 @@ \ /* Callbacks for augmented rbtree insert and remove */ \ \ -static inline ITTYPE ITPREFIX ## _compute_subtree_last(ITSTRUCT *node) \ -{ \ - ITTYPE max = ITLAST(node), subtree_last; \ - if (node->ITRB.rb_left) { \ - subtree_last = rb_entry(node->ITRB.rb_left, \ - ITSTRUCT, ITRB)->ITSUBTREE; \ - if (max < subtree_last) \ - max = subtree_last; \ - } \ - if (node->ITRB.rb_right) { \ - subtree_last = rb_entry(node->ITRB.rb_right, \ - ITSTRUCT, ITRB)->ITSUBTREE; \ - if (max < subtree_last) \ - max = subtree_last; \ - } \ - return max; \ -} \ - \ -RB_DECLARE_CALLBACKS(static, ITPREFIX ## _augment, ITSTRUCT, ITRB, \ - ITTYPE, ITSUBTREE, ITPREFIX ## _compute_subtree_last) \ +RB_DECLARE_CALLBACKS_MAX(static, ITPREFIX ## _augment, \ + ITSTRUCT, ITRB, ITTYPE, ITSUBTREE, ITLAST) \ \ /* Insert / remove interval nodes from the tree */ \ \ -ITSTATIC void ITPREFIX ## _insert(ITSTRUCT *node, struct rb_root *root) \ +ITSTATIC void ITPREFIX ## _insert(ITSTRUCT *node, \ + struct rb_root_cached *root) \ { \ - struct rb_node **link = &root->rb_node, *rb_parent = NULL; \ + struct rb_node **link = &root->rb_root.rb_node, *rb_parent = NULL; \ ITTYPE start = ITSTART(node), last = ITLAST(node); \ ITSTRUCT *parent; \ + bool leftmost = true; \ \ while (*link) { \ rb_parent = *link; \ @@ -78,18 +50,22 @@ ITSTATIC void ITPREFIX ## _insert(ITSTRUCT *node, struct rb_root *root) \ parent->ITSUBTREE = last; \ if (start < ITSTART(parent)) \ link = &parent->ITRB.rb_left; \ - else \ + else { \ link = &parent->ITRB.rb_right; \ + leftmost = false; \ + } \ } \ \ node->ITSUBTREE = last; \ rb_link_node(&node->ITRB, rb_parent, link); \ - rb_insert_augmented(&node->ITRB, root, &ITPREFIX ## _augment); \ + rb_insert_augmented_cached(&node->ITRB, root, \ + leftmost, &ITPREFIX ## _augment); \ } \ \ -ITSTATIC void ITPREFIX ## _remove(ITSTRUCT *node, struct rb_root *root) \ +ITSTATIC void ITPREFIX ## _remove(ITSTRUCT *node, \ + struct rb_root_cached *root) \ { \ - rb_erase_augmented(&node->ITRB, root, &ITPREFIX ## _augment); \ + rb_erase_augmented_cached(&node->ITRB, root, &ITPREFIX ## _augment); \ } \ \ /* \ @@ -101,7 +77,7 @@ ITSTATIC void ITPREFIX ## _remove(ITSTRUCT *node, struct rb_root *root) \ * Cond2: start <= ITLAST(node) \ */ \ \ -static ITSTRUCT * \ +ITSTATIC ITSTRUCT * \ ITPREFIX ## _subtree_search(ITSTRUCT *node, ITTYPE start, ITTYPE last) \ { \ while (true) { \ @@ -128,27 +104,43 @@ ITPREFIX ## _subtree_search(ITSTRUCT *node, ITTYPE start, ITTYPE last) \ if (ITSTART(node) <= last) { /* Cond1 */ \ if (start <= ITLAST(node)) /* Cond2 */ \ return node; /* node is leftmost match */ \ - if (node->ITRB.rb_right) { \ - node = rb_entry(node->ITRB.rb_right, \ - ITSTRUCT, ITRB); \ - if (start <= node->ITSUBTREE) \ - continue; \ - } \ + node = rb_entry(node->ITRB.rb_right, ITSTRUCT, ITRB); \ + continue; \ } \ return NULL; /* No match */ \ } \ } \ \ ITSTATIC ITSTRUCT * \ -ITPREFIX ## _iter_first(struct rb_root *root, ITTYPE start, ITTYPE last) \ +ITPREFIX ## _iter_first(struct rb_root_cached *root, \ + ITTYPE start, ITTYPE last) \ { \ - ITSTRUCT *node; \ + ITSTRUCT *node, *leftmost; \ \ - if (!root->rb_node) \ + if (!root->rb_root.rb_node) \ return NULL; \ - node = rb_entry(root->rb_node, ITSTRUCT, ITRB); \ + \ + /* \ + * Fastpath range intersection/overlap between A: [a0, a1] and \ + * B: [b0, b1] is given by: \ + * \ + * a0 <= b1 && b0 <= a1 \ + * \ + * ... where A holds the lock range and B holds the smallest \ + * 'start' and largest 'last' in the tree. For the later, we \ + * rely on the root node, which by augmented interval tree \ + * property, holds the largest value in its last-in-subtree. \ + * This allows mitigating some of the tree walk overhead for \ + * for non-intersecting ranges, maintained and consulted in O(1). \ + */ \ + node = rb_entry(root->rb_root.rb_node, ITSTRUCT, ITRB); \ if (node->ITSUBTREE < start) \ return NULL; \ + \ + leftmost = rb_entry(root->rb_leftmost, ITSTRUCT, ITRB); \ + if (ITSTART(leftmost) > last) \ + return NULL; \ + \ return ITPREFIX ## _subtree_search(node, start, last); \ } \ \ |