Filipe Manana
2014-Jul-28 18:37 UTC
[PATCH] Btrfs: avoid unnecessary switch of path locks to blocking mode
If we need to cow a node, increase the write lock level and retry the tree search, there's no point of changing the node locks in our path to blocking mode, as we only waste time and unnecessarily wake up other tasks waiting on the spinning locks (just to block them again shortly after) because we release our path before repeating the tree search. Signed-off-by: Filipe Manana <fdmanana@suse.com> --- fs/btrfs/ctree.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index bd0ae3e..783ea3b 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2792,8 +2792,6 @@ again: if (!should_cow_block(trans, root, b)) goto cow_done; - btrfs_set_path_blocking(p); - /* * must have write locks on this node and the * parent @@ -2807,6 +2805,7 @@ again: goto again; } + btrfs_set_path_blocking(p); err = btrfs_cow_block(trans, root, b, p->nodes[level + 1], p->slots[level + 1], &b); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html