Btrfs: Lower contention on the csum mutex

This takes the csum mutex deeper in the call chain and releases it
more often.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 958cd8b5f0d7..2ee301740195 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -48,6 +48,7 @@ struct btrfs_worker_thread {
 
         /* number of things on the pending list */
         atomic_t num_pending;
+
         unsigned long sequence;
 
         /* protects the pending list. */
@@ -242,7 +243,7 @@ static struct btrfs_worker_thread *next_worker(struct btrfs_workers *workers)
         worker = list_entry(next, struct btrfs_worker_thread, worker_list);
         atomic_inc(&worker->num_pending);
         worker->sequence++;
-        if (worker->sequence % 4 == 0)
+        if (worker->sequence % workers->idle_thresh == 0)
                 list_move_tail(next, &workers->worker_list);
         return worker;
 }