From 03a1d4c891634dd5b98da865fb783e8b22d4d027 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Thu, 23 Aug 2018 03:51:51 +0800 Subject: [PATCH] Btrfs: delayed-inode: use rb_first_cached for ins_root and del_root MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit rb_first_cached() trades an extra pointer "leftmost" for doing the same job as rb_first() but in O(1). Functions manipulating delayed_item need to get the first entry, this converts it to use rb_first_cached(). For more details about the optimization see patch "Btrfs: delayed-refs: use rb_first_cached for href_root". Tested-by: Holger Hoffstätte Signed-off-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/delayed-inode.c | 29 ++++++++++++++++------------- fs/btrfs/delayed-inode.h | 4 ++-- 2 files changed, 18 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c index 47ce74cf134a..15dcbd6ef531 100644 --- a/fs/btrfs/delayed-inode.c +++ b/fs/btrfs/delayed-inode.c @@ -42,8 +42,8 @@ static inline void btrfs_init_delayed_node( delayed_node->root = root; delayed_node->inode_id = inode_id; refcount_set(&delayed_node->refs, 0); - delayed_node->ins_root = RB_ROOT; - delayed_node->del_root = RB_ROOT; + delayed_node->ins_root = RB_ROOT_CACHED; + delayed_node->del_root = RB_ROOT_CACHED; mutex_init(&delayed_node->mutex); INIT_LIST_HEAD(&delayed_node->n_list); INIT_LIST_HEAD(&delayed_node->p_list); @@ -390,7 +390,7 @@ static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item( struct btrfs_delayed_node *delayed_node, struct btrfs_key *key) { - return __btrfs_lookup_delayed_item(&delayed_node->ins_root, key, + return __btrfs_lookup_delayed_item(&delayed_node->ins_root.rb_root, key, NULL, NULL); } @@ -400,9 +400,10 @@ static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node, { struct rb_node **p, *node; struct rb_node *parent_node = NULL; - struct rb_root *root; + struct rb_root_cached *root; struct btrfs_delayed_item *item; int cmp; + bool leftmost = true; if (action == BTRFS_DELAYED_INSERTION_ITEM) root = &delayed_node->ins_root; @@ -410,7 +411,7 @@ static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node, root = &delayed_node->del_root; else BUG(); - p = &root->rb_node; + p = &root->rb_root.rb_node; node = &ins->rb_node; while (*p) { @@ -419,16 +420,18 @@ static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node, rb_node); cmp = btrfs_comp_cpu_keys(&item->key, &ins->key); - if (cmp < 0) + if (cmp < 0) { p = &(*p)->rb_right; - else if (cmp > 0) + leftmost = false; + } else if (cmp > 0) { p = &(*p)->rb_left; - else + } else { return -EEXIST; + } } rb_link_node(node, parent_node, p); - rb_insert_color(node, root); + rb_insert_color_cached(node, root, leftmost); ins->delayed_node = delayed_node; ins->ins_or_del = action; @@ -468,7 +471,7 @@ static void finish_one_item(struct btrfs_delayed_root *delayed_root) static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item) { - struct rb_root *root; + struct rb_root_cached *root; struct btrfs_delayed_root *delayed_root; delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root; @@ -482,7 +485,7 @@ static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item) else root = &delayed_item->delayed_node->del_root; - rb_erase(&delayed_item->rb_node, root); + rb_erase_cached(&delayed_item->rb_node, root); delayed_item->delayed_node->count--; finish_one_item(delayed_root); @@ -503,7 +506,7 @@ static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item( struct rb_node *p; struct btrfs_delayed_item *item = NULL; - p = rb_first(&delayed_node->ins_root); + p = rb_first_cached(&delayed_node->ins_root); if (p) item = rb_entry(p, struct btrfs_delayed_item, rb_node); @@ -516,7 +519,7 @@ static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item( struct rb_node *p; struct btrfs_delayed_item *item = NULL; - p = rb_first(&delayed_node->del_root); + p = rb_first_cached(&delayed_node->del_root); if (p) item = rb_entry(p, struct btrfs_delayed_item, rb_node); diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h index 33536cd681d4..74ae226ffaf0 100644 --- a/fs/btrfs/delayed-inode.h +++ b/fs/btrfs/delayed-inode.h @@ -50,8 +50,8 @@ struct btrfs_delayed_node { * is waiting to be dealt with by the async worker. */ struct list_head p_list; - struct rb_root ins_root; - struct rb_root del_root; + struct rb_root_cached ins_root; + struct rb_root_cached del_root; struct mutex mutex; struct btrfs_inode_item inode_item; refcount_t refs;