Btrfs: async threads should try harder to find work

Tracing shows the delay between when an async thread goes to sleep
and when more work is added is often very short.  This commit adds
a little bit of delay and extra checking to the code right before
we schedule out.

It allows more work to be added to the worker
without requiring notifications from other procs.

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

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 7feac5a475e9..9c3810047976 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1679,6 +1679,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
          * low idle thresh
          */
         fs_info->endio_workers.idle_thresh = 4;
+        fs_info->endio_meta_workers.idle_thresh = 4;
+
         fs_info->endio_write_workers.idle_thresh = 64;
         fs_info->endio_meta_write_workers.idle_thresh = 64;