bonding: rebuild the lock use for bond_alb_monitor()

The bond_alb_monitor use bond lock to protect the bond slave list,
it is no effect here, we need to use RTNL or RCU to replace bond lock,
the bond_alb_monitor will called 10 times one second, RTNL may loss
performance here, so I replace bond lock with RCU to protect the
bond slave list, also the RTNL is preserved, the logic of the monitor
did not changed.

Suggested-by: Nikolay Aleksandrov <nikolay@redhat.com>
Suggested-by: Jay Vosburgh <fubar@us.ibm.com>
Suggested-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.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 7b806e3..759ddee 100644 (file)
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -815,7 +815,7 @@ static void rlb_rebalance(struct bonding *bond)
        for (; hash_index != RLB_NULL_INDEX;
             hash_index = client_info->used_next) {
                client_info = &(bond_info->rx_hashtbl[hash_index]);
-               assigned_slave = rlb_next_rx_slave(bond);
+               assigned_slave = __rlb_next_rx_slave(bond);
                if (assigned_slave && (client_info->slave != assigned_slave)) {
                        client_info->slave = assigned_slave;
                        client_info->ntt = 1;
@@ -1494,14 +1494,14 @@ void bond_alb_monitor(struct work_struct *work)
        struct list_head *iter;
        struct slave *slave;
 
-       read_lock(&bond->lock);
-
        if (!bond_has_slaves(bond)) {
                bond_info->tx_rebalance_counter = 0;
                bond_info->lp_counter = 0;
                goto re_arm;
        }
 
+       rcu_read_lock();
+
        bond_info->tx_rebalance_counter++;
        bond_info->lp_counter++;
 
@@ -1514,7 +1514,7 @@ void bond_alb_monitor(struct work_struct *work)
                 */
                read_lock(&bond->curr_slave_lock);
 
-               bond_for_each_slave(bond, slave, iter)
+               bond_for_each_slave_rcu(bond, slave, iter)
                        alb_send_learning_packets(slave, slave->dev->dev_addr);
 
                read_unlock(&bond->curr_slave_lock);
@@ -1527,7 +1527,7 @@ void bond_alb_monitor(struct work_struct *work)
 
                read_lock(&bond->curr_slave_lock);
 
-               bond_for_each_slave(bond, slave, iter) {
+               bond_for_each_slave_rcu(bond, slave, iter) {
                        tlb_clear_slave(bond, slave, 1);
                        if (slave == bond->curr_active_slave) {
                                SLAVE_TLB_INFO(slave).load =
@@ -1551,11 +1551,9 @@ void bond_alb_monitor(struct work_struct *work)
                         * dev_set_promiscuity requires rtnl and
                         * nothing else.  Avoid race with bond_close.
                         */
-                       read_unlock(&bond->lock);
-                       if (!rtnl_trylock()) {
-                               read_lock(&bond->lock);
+                       rcu_read_unlock();
+                       if (!rtnl_trylock())
                                goto re_arm;
-                       }
 
                        bond_info->rlb_promisc_timeout_counter = 0;
 
@@ -1567,7 +1565,7 @@ void bond_alb_monitor(struct work_struct *work)
                        bond_info->primary_is_promisc = 0;
 
                        rtnl_unlock();
-                       read_lock(&bond->lock);
+                       rcu_read_lock();
                }
 
                if (bond_info->rlb_rebalance) {
@@ -1589,11 +1587,9 @@ void bond_alb_monitor(struct work_struct *work)
                        }
                }
        }
-
+       rcu_read_unlock();
 re_arm:
        queue_delayed_work(bond->wq, &bond->alb_work, alb_delta_in_ticks);
-
-       read_unlock(&bond->lock);
 }
 
 /* assumption: called before the slave is attached to the bond