Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754521Ab1BVSzO (ORCPT ); Tue, 22 Feb 2011 13:55:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:10463 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750744Ab1BVSzJ (ORCPT ); Tue, 22 Feb 2011 13:55:09 -0500 From: Alex Williamson Subject: [RFC PATCH 1/3] Weight-balanced tree To: avi@redhat.com Cc: alex.williamson@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, mtosatti@redhat.com, xiaoguangrong@cn.fujitsu.com Date: Tue, 22 Feb 2011 11:55:05 -0700 Message-ID: <20110222185456.22026.28200.stgit@s20.home> In-Reply-To: <20110222183822.22026.62832.stgit@s20.home> References: <20110222183822.22026.62832.stgit@s20.home> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6602 Lines: 267 Signed-off-by: Alex Williamson --- include/linux/wbtree.h | 55 ++++++++++++++++ lib/Makefile | 3 + lib/wbtree.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 227 insertions(+), 1 deletions(-) create mode 100644 include/linux/wbtree.h create mode 100644 lib/wbtree.c diff --git a/include/linux/wbtree.h b/include/linux/wbtree.h new file mode 100644 index 0000000..ef70f6f --- /dev/null +++ b/include/linux/wbtree.h @@ -0,0 +1,55 @@ +/* + * Weight-balanced binary tree + * + * The balance of this tree is based on search probability. The + * heaviest weighted nodes (the ones we're most likely to hit), are + * at the top of each subtree. + * + * Copywrite (C) 2011 Red Hat, Inc. + * + * Authors: + * Alex Williamson + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ +#ifndef _LINUX_WBTREE_H +#define _LINUX_WBTREE_H + +#include +#include + +struct wb_node { + struct wb_node *wb_parent; + struct wb_node *wb_left; + struct wb_node *wb_right; + unsigned long wb_weight; +}; + +struct wb_root { + struct wb_node *wb_node; +}; + +#define WB_ROOT (struct wb_root) { NULL, } +#define wb_entry(ptr, type, member) container_of(ptr, type, member) + +extern void wb_rebalance(struct wb_node *node, struct wb_root *root); +extern void wb_erase(struct wb_node *node, struct wb_root *root); +extern struct wb_node *wb_first(struct wb_root *root); +extern struct wb_node *wb_last(struct wb_root *root); +extern struct wb_node *wb_next(struct wb_node *node); +extern struct wb_node *wb_prev(struct wb_node *node); + +static inline void wb_set_weight(struct wb_node *node, unsigned long weight) +{ + node->wb_weight = weight; +} + +static inline void wb_link_node(struct wb_node *node, struct wb_node *parent, + struct wb_node **wb_link) +{ + node->wb_left = node->wb_right = NULL; + node->wb_parent = parent; + *wb_link = node; +} +#endif /* _LINUX_WBTREE_H */ diff --git a/lib/Makefile b/lib/Makefile index cbb774f..5c42e63 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -21,7 +21,8 @@ lib-y += kobject.o kref.o klist.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ - string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o + string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o \ + wbtree.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/wbtree.c b/lib/wbtree.c new file mode 100644 index 0000000..54c3817 --- /dev/null +++ b/lib/wbtree.c @@ -0,0 +1,170 @@ +/* + * Weight-balanced binary tree + * + * The balance of this tree is based on search probability. The + * heaviest weighted nodes (the ones we're most likely to hit), are + * at the top of each subtree. + * + * Copywrite (C) 2011 Red Hat, Inc. + * + * Authors: + * Alex Williamson + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ +#include +#include + +static void __wb_rotate_left(struct wb_node *node, struct wb_root *root) +{ + struct wb_node *right = node->wb_right; + struct wb_node *parent = node->wb_parent; + + if ((node->wb_right = right->wb_left)) + right->wb_left->wb_parent = node; + right->wb_left = node; + + right->wb_parent = parent; + + if (parent) { + if (node == parent->wb_left) + parent->wb_left = right; + else + parent->wb_right = right; + } else + root->wb_node = right; + + node->wb_parent = right; +} + +static void __wb_rotate_right(struct wb_node *node, struct wb_root *root) +{ + struct wb_node *left = node->wb_left; + struct wb_node *parent = node->wb_parent; + + if ((node->wb_left = left->wb_right)) + left->wb_right->wb_parent = node; + left->wb_right = node; + + left->wb_parent = parent; + + if (parent) { + if (node == parent->wb_right) + parent->wb_right = left; + else + parent->wb_left = left; + } else + root->wb_node = left; + + node->wb_parent = left; +} + +void wb_rebalance(struct wb_node *node, struct wb_root *root) +{ + while (node->wb_parent && node->wb_parent->wb_weight < node->wb_weight) { + if (node == node->wb_parent->wb_left) + __wb_rotate_right(node->wb_parent, root); + else + __wb_rotate_left(node->wb_parent, root); + } +} +EXPORT_SYMBOL(wb_rebalance); + +void wb_erase(struct wb_node *node, struct wb_root *root) +{ + while (node->wb_left || node->wb_right) { + if (!node->wb_left) + __wb_rotate_left(node, root); + else if (!node->wb_right) + __wb_rotate_right(node, root); + else { + if (node->wb_left->wb_weight > + node->wb_right->wb_weight) + __wb_rotate_right(node, root); + else + __wb_rotate_left(node, root); + } + } + + if (node->wb_parent) { + if (node->wb_parent->wb_left == node) + node->wb_parent->wb_left = NULL; + else + node->wb_parent->wb_right = NULL; + } else + root->wb_node = NULL; +} +EXPORT_SYMBOL(wb_erase); + +struct wb_node *wb_first(struct wb_root *root) +{ + struct wb_node *node; + + node = root->wb_node; + if (!node) + return NULL; + + while (node->wb_left) + node = node->wb_left; + + return node; +} +EXPORT_SYMBOL(wb_first); + +struct wb_node *wb_last(struct wb_root *root) +{ + struct wb_node *node; + + node = root->wb_node; + if (!node) + return NULL; + + while (node->wb_right) + node = node->wb_right; + + return node; +} +EXPORT_SYMBOL(wb_last); + +struct wb_node *wb_next(struct wb_node *node) +{ + struct wb_node *parent; + + if (node->wb_parent == node) + return NULL; + + if (node->wb_right) { + node = node->wb_right; + while (node->wb_left) + node = node->wb_left; + return node; + } + + while ((parent = node->wb_parent) && node == parent->wb_right) + node = parent; + + return parent; +} +EXPORT_SYMBOL(wb_next); + +struct wb_node *wb_prev(struct wb_node *node) +{ + struct wb_node *parent; + + if (node->wb_parent == node) + return NULL; + + if (node->wb_left) { + node = node->wb_left; + while (node->wb_right) + node = node->wb_right; + return node; + } + + while ((parent = node->wb_parent) && node == parent->wb_left) + node = parent; + + return parent; +} +EXPORT_SYMBOL(wb_prev); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/