crypto: wait for a full jiffy in do_xor_speed
In the existing do_xor_speed(), there is no guarantee that we actually
run do_2() for a full jiffy. We get the current jiffy, then run do_2()
until the next jiffy.
Instead, let's get the current jiffy, then wait until the next jiffy
to start our test.
Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/crypto/xor.c b/crypto/xor.c
index b75182d..8788443 100644
--- a/crypto/xor.c
+++ b/crypto/xor.c
@@ -63,7 +63,7 @@
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;
@@ -76,9 +76,11 @@
*/
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();
