From e3d039656384288bbe952413d8d404b3035fe7d7 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Thu, 23 Aug 2018 03:51:50 +0800 Subject: Btrfs: delayed-refs: use rb_first_cached for ref_tree 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 href->ref_tree need to get the first entry, this converts href->ref_tree 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/disk-io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index a21a96786813..517484ecad96 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -4221,11 +4221,11 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, continue; } spin_lock(&head->lock); - while ((n = rb_first(&head->ref_tree)) != NULL) { + while ((n = rb_first_cached(&head->ref_tree)) != NULL) { ref = rb_entry(n, struct btrfs_delayed_ref_node, ref_node); ref->in_tree = 0; - rb_erase(&ref->ref_node, &head->ref_tree); + rb_erase_cached(&ref->ref_node, &head->ref_tree); RB_CLEAR_NODE(&ref->ref_node); if (!list_empty(&ref->add_list)) list_del(&ref->add_list); -- cgit v1.2.3