1 files changed, 16 insertions, 4 deletions

diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index c45b3233d486..c51faaa5e291 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -834,8 +834,11 @@ xfsaild_wakeup(
         struct xfs_ail          *ailp,
         xfs_lsn_t               threshold_lsn)
 {
-        ailp->xa_target = threshold_lsn;
-        wake_up_process(ailp->xa_task);
+        /* only ever move the target forwards */
+        if (XFS_LSN_CMP(threshold_lsn, ailp->xa_target) > 0) {
+                ailp->xa_target = threshold_lsn;
+                wake_up_process(ailp->xa_task);
+        }
 }
 
 STATIC int
@@ -847,8 +850,17 @@ xfsaild(
         long            tout = 0; /* milliseconds */
 
         while (!kthread_should_stop()) {
-                schedule_timeout_interruptible(tout ?
-                                msecs_to_jiffies(tout) : MAX_SCHEDULE_TIMEOUT);
+                /*
+                 * for short sleeps indicating congestion, don't allow us to
+                 * get woken early. Otherwise all we do is bang on the AIL lock
+                 * without making progress.
+                 */
+                if (tout && tout <= 20)
+                        __set_current_state(TASK_KILLABLE);
+                else
+                        __set_current_state(TASK_INTERRUPTIBLE);
+                schedule_timeout(tout ?
+                                 msecs_to_jiffies(tout) : MAX_SCHEDULE_TIMEOUT);
 
                 /* swsusp */
                 try_to_freeze();