bonding: optimize tlb_get_least_loaded_slave

In the worst case, when the first loop breaks an the end of the slave list,
the slave list is iterated through twice. This patch reduces this
function only to one loop. Also makes it simpler.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 40fdc41446cc130f1363e9d4a17a9d3203b3166b..25c14c6236f588fa84b8b93888a924d16a054993 100644 (file)
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -233,34 +233,27 @@ static void tlb_deinitialize(struct bonding *bond)
        _unlock_tx_hashtbl(bond);
 }
 
+static long long compute_gap(struct slave *slave)
+{
+       return (s64) (slave->speed << 20) - /* Convert to Megabit per sec */
+              (s64) (SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
+}
+
 /* Caller must hold bond lock for read */
 static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
 {
        struct slave *slave, *least_loaded;
-       s64 max_gap;
-       int i, found = 0;
-
-       /* Find the first enabled slave */
-       bond_for_each_slave(bond, slave, i) {
-               if (SLAVE_IS_OK(slave)) {
-                       found = 1;
-                       break;
-               }
-       }
-
-       if (!found) {
-               return NULL;
-       }
+       long long max_gap;
+       int i;
 
-       least_loaded = slave;
-       max_gap = (s64)(slave->speed << 20) - /* Convert to Megabit per sec */
-                       (s64)(SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
+       least_loaded = NULL;
+       max_gap = LLONG_MIN;
 
        /* Find the slave with the largest gap */
-       bond_for_each_slave_from(bond, slave, i, least_loaded) {
+       bond_for_each_slave(bond, slave, i) {
                if (SLAVE_IS_OK(slave)) {
-                       s64 gap = (s64)(slave->speed << 20) -
-                                       (s64)(SLAVE_TLB_INFO(slave).load << 3);
+                       long long gap = compute_gap(slave);
+
                        if (max_gap < gap) {
                                least_loaded = slave;
                                max_gap = gap;