[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <4D6506FB.2090809@redhat.com>
Date: Wed, 23 Feb 2011 15:09:15 +0200
From: Avi Kivity <avi@...hat.com>
To: Alex Williamson <alex.williamson@...hat.com>
CC: linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
mtosatti@...hat.com, xiaoguangrong@...fujitsu.com,
Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [RFC PATCH 1/3] Weight-balanced tree
On 02/22/2011 08:55 PM, Alex Williamson wrote:
> Signed-off-by: Alex Williamson<alex.williamson@...hat.com>
> ---
>
> 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
>
Andrew, can we add something like this to the tree? Can it go through
the kvm tree?
> 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<alex.williamson@...hat.com>
> + *
> + * 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<linux/kernel.h>
> +#include<linux/stddef.h>
> +
> +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
>
obj-$(CONFIG_WEIGHT_BALANCED_TREE) += wbtree.o
then kvm can select it, and the impact on non-kvm kernels is removed.
> ifeq ($(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<alex.williamson@...hat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2. See
> + * the COPYING file in the top-level directory.
> + */
> +#include<linux/wbtree.h>
> +#include<linux/module.h>
> +
> +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);
>
--
error compiling committee.c: too many arguments to function
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists