Merge branch 'sched/rt' into sched/core, to pick up -rt changes

Pick up the first couple of patches working towards PREEMPT_RT.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 98fccce4208c..393eceda57c8 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -346,9 +346,12 @@ void btrfs_tree_unlock(struct extent_buffer *eb)
         if (blockers) {
                 btrfs_assert_no_spinning_writers(eb);
                 eb->blocking_writers--;
-                /* Use the lighter barrier after atomic */
-                smp_mb__after_atomic();
-                cond_wake_up_nomb(&eb->write_lock_wq);
+                /*
+                 * We need to order modifying blocking_writers above with
+                 * actually waking up the sleepers to ensure they see the
+                 * updated value of blocking_writers
+                 */
+                cond_wake_up(&eb->write_lock_wq);
         } else {
                 btrfs_assert_spinning_writers_put(eb);
                 write_unlock(&eb->lock);