4.4.21-rt31-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

It has been pointed out by tglx that on UP the non-RT task could spin
its entire time slice because the lock owner is preempted. This won't
happen on !RT. So we back to "chill" if we can't cond_resched() did not
work.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 fs/dcache.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 3730c7f757ff..e80471cbfc19 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -40,8 +40,6 @@
 #include <linux/ratelimit.h>
 #include <linux/list_lru.h>
 #include <linux/kasan.h>
-#include <linux/sched/rt.h>
-#include <linux/sched/deadline.h>
 
 #include "internal.h"
 #include "mount.h"
@@ -795,10 +793,11 @@ kill_it:
 		if (parent == dentry) {
 			/* the task with the highest priority won't schedule */
 			r = cond_resched();
-			if (!r && (rt_task(current) || dl_task(current)))
+			if (!r)
 				cpu_chill();
-		} else
+		} else {
 			dentry = parent;
+		}
 		goto repeat;
 	}
 }
-- 
2.8.1