1 files changed, 10 insertions, 3 deletions

diff --git a/crypto/xor.c b/crypto/xor.c
index 664b6dfa9e2c..65c7b416b4a3 100644
--- a/crypto/xor.c
+++ b/crypto/xor.c
@@ -21,6 +21,7 @@
 #include <linux/gfp.h>
 #include <linux/raid/xor.h>
 #include <linux/jiffies.h>
+#include <linux/preempt.h>
 #include <asm/xor.h>
 
 /* The xor routines to use.  */
@@ -63,12 +64,14 @@ static void
 do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
 {
         int speed;
-        unsigned long now;
+        unsigned long now, j;
         int i, count, max;
 
         tmpl->next = template_list;
         template_list = tmpl;
 
+        preempt_disable();
+
         /*
          * Count the number of XORs done during a whole jiffy, and use
          * this to calculate the speed of checksumming.  We use a 2-page
@@ -76,9 +79,11 @@ do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
          */
         max = 0;
         for (i = 0; i < 5; i++) {
-                now = jiffies;
+                j = jiffies;
                 count = 0;
-                while (jiffies == now) {
+                while ((now = jiffies) == j)
+                        cpu_relax();
+                while (time_before(jiffies, now + 1)) {
                         mb(); /* prevent loop optimzation */
                         tmpl->do_2(BENCH_SIZE, b1, b2);
                         mb();
@@ -89,6 +94,8 @@ do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
                         max = count;
         }
 
+        preempt_enable();
+
         speed = max * (HZ * BENCH_SIZE / 1024);
         tmpl->speed = speed;