Btrfs: Throttle tuning

This avoids waiting for transactions with pages locked by breaking out
the code to wait for the current transaction to close into a function
called by btrfs_throttle.

It also lowers the limits for where we start throttling.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 4765248000fd..b003b4364ddb 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2526,6 +2526,9 @@ static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
                                 *level = 0;
                                 break;
                         }
+                        if (printk_ratelimit())
+                                printk("leaf ref miss for bytenr %llu\n",
+                                       (unsigned long long)bytenr);
                 }
                 next = btrfs_find_tree_block(root, bytenr, blocksize);
                 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {