diff --git a/[refs] b/[refs]
index 07173cfd9877..47d44a15f147 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 00f0ad73ac90e3fba8b4cbe4cf21b2fb9a56cb72
+refs/heads/master: 7730d8655880f41f2ea519aca2ca6a1413dfd2c9
diff --git a/trunk/kernel/perf_counter.c b/trunk/kernel/perf_counter.c
index f3e1b27bc1b8..95e02575546b 100644
--- a/trunk/kernel/perf_counter.c
+++ b/trunk/kernel/perf_counter.c
@@ -1369,7 +1369,11 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
 	vma_size = vma->vm_end - vma->vm_start;
 	nr_pages = (vma_size / PAGE_SIZE) - 1;
 
-	if (nr_pages == 0 || !is_power_of_2(nr_pages))
+	/*
+	 * If we have data pages ensure they're a power-of-two number, so we
+	 * can do bitmasks instead of modulo.
+	 */
+	if (nr_pages != 0 && !is_power_of_2(nr_pages))
 		return -EINVAL;
 
 	if (vma_size != PAGE_SIZE * (1 + nr_pages))