Merge commit '8700c95adb03' into timers/nohz

The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.

Merge a common upstream merge point that has these
updates.

Conflicts:
	include/linux/perf_event.h
	kernel/rcutree.h
	kernel/rcutree_plugin.h

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 19 insertions, 13 deletions

diff --git a/lib/int_sqrt.c b/lib/int_sqrt.c
index fc2eeb7cb2e..1ef4cc34497 100644
--- a/lib/int_sqrt.c
+++ b/lib/int_sqrt.c
@@ -1,3 +1,9 @@
+/*
+ * Copyright (C) 2013 Davidlohr Bueso <davidlohr.bueso@hp.com>
+ *
+ *  Based on the shift-and-subtract algorithm for computing integer
+ *  square root from Guy L. Steele.
+ */
 
 #include <linux/kernel.h>
 #include <linux/export.h>
@@ -10,23 +16,23 @@
  */
 unsigned long int_sqrt(unsigned long x)
 {
-	unsigned long op, res, one;
+	unsigned long b, m, y = 0;
 
-	op = x;
-	res = 0;
+	if (x <= 1)
+		return x;
 
-	one = 1UL << (BITS_PER_LONG - 2);
-	while (one > op)
-		one >>= 2;
+	m = 1UL << (BITS_PER_LONG - 2);
+	while (m != 0) {
+		b = y + m;
+		y >>= 1;
 
-	while (one != 0) {
-		if (op >= res + one) {
-			op = op - (res + one);
-			res = res +  2 * one;
+		if (x >= b) {
+			x -= b;
+			y += m;
 		}
-		res /= 2;
-		one /= 4;
+		m >>= 2;
 	}
-	return res;
+
+	return y;
 }
 EXPORT_SYMBOL(int_sqrt);