AcoSail/kernel_optimize_test
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bonding: rebuild the lock use for bond_loadbalance_arp_mon()

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The bond_loadbalance_arp_mon() use the bond lock to protect the
bond slave list, it is no effect, so I could use RTNL or RCU to
replace it, considering the performance impact, the RCU is more
better here, so the bond lock replace with the RCU.

The bond_select_active_slave() need RTNL and curr_slave_lock
together, but there is no RTNL lock here, so add a rtnl_rtylock.

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>
This commit is contained in:
dingtianhong 2013-12-13 10:19:50 +08:00 committed by David S. Miller
parent 733ab63935
commit 2e52f4fe36
1 changed files with 12 additions and 6 deletions
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18
drivers/net/bonding/bond_main.c
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@ -2411,12 +2411,12 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
struct list_head *iter;
int do_failover = 0;
read_lock(&bond->lock);
if (!bond_has_slaves(bond))
goto re_arm;
oldcurrent = bond->curr_active_slave;
rcu_read_lock();
oldcurrent = ACCESS_ONCE(bond->curr_active_slave);
/* see if any of the previous devices are up now (i.e. they have
* xmt and rcv traffic). the curr_active_slave does not come into
* the picture unless it is null. also, slave->jiffies is not needed
@ -2425,7 +2425,7 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
* TODO: what about up/down delay in arp mode? it wasn't here before
* so it can wait
*/
bond_for_each_slave(bond, slave, iter) {
bond_for_each_slave_rcu(bond, slave, iter) {
unsigned long trans_start = dev_trans_start(slave->dev);
if (slave->link != BOND_LINK_UP) {
@ -2487,7 +2487,14 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
bond_arp_send_all(bond, slave);
}
rcu_read_unlock();
if (do_failover) {
/* the bond_select_active_slave must hold RTNL
* and curr_slave_lock for write.
*/
if (!rtnl_trylock())
goto re_arm;
block_netpoll_tx();
write_lock_bh(&bond->curr_slave_lock);
@ -2495,14 +2502,13 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
write_unlock_bh(&bond->curr_slave_lock);
unblock_netpoll_tx();
rtnl_unlock();
}
re_arm:
if (bond->params.arp_interval)
queue_delayed_work(bond->wq, &bond->arp_work,
msecs_to_jiffies(bond->params.arp_interval));
read_unlock(&bond->lock);
}
/*