From 63ffc1f7c492df977353a0d2adf01d41069aad68 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Fri, 22 Sep 2023 11:39:07 +0100 Subject: btrfs: make tree iteration in extent_io_tree_release() more efficient Currently extent_io_tree_release() is a loop that keeps getting the first node in the io tree, using rb_first() which is a loop that gets to the leftmost node of the rbtree, and then for each node it calls rb_erase(), which often requires rebalancing the rbtree. We can make this more efficient by using rbtree_postorder_for_each_entry_safe() to free each node without having to delete it from the rbtree and without looping to get the first node. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent-io-tree.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c index 9fb4f38347fe..f9f7cf028ffb 100644 --- a/fs/btrfs/extent-io-tree.c +++ b/fs/btrfs/extent-io-tree.c @@ -114,14 +114,15 @@ void extent_io_tree_init(struct btrfs_fs_info *fs_info, */ void extent_io_tree_release(struct extent_io_tree *tree) { - spin_lock(&tree->lock); - while (!RB_EMPTY_ROOT(&tree->state)) { - struct rb_node *node; - struct extent_state *state; + struct rb_root root; + struct extent_state *state; + struct extent_state *tmp; - node = rb_first(&tree->state); - state = rb_entry(node, struct extent_state, rb_node); - rb_erase(&state->rb_node, &tree->state); + spin_lock(&tree->lock); + root = tree->state; + tree->state = RB_ROOT; + rbtree_postorder_for_each_entry_safe(state, tmp, &root, rb_node) { + /* Clear node to keep free_extent_state() happy. */ RB_CLEAR_NODE(&state->rb_node); ASSERT(!(state->state & EXTENT_LOCKED)); /* @@ -131,9 +132,13 @@ void extent_io_tree_release(struct extent_io_tree *tree) */ ASSERT(!waitqueue_active(&state->wq)); free_extent_state(state); - cond_resched_lock(&tree->lock); } + /* + * Should still be empty even after a reschedule, no other task should + * be accessing the tree anymore. + */ + ASSERT(RB_EMPTY_ROOT(&tree->state)); spin_unlock(&tree->lock); } -- cgit v1.2.3