Commit 0f37666d authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'net-avoid-slow-rcu' 



Eric Dumazet says:

====================
net: avoid slow rcu synchronizations in cleanup_net()

RTNL is a contended mutex, we prefer to expedite rcu synchronizations
in contexts we hold RTNL.

Similarly, cleanup_net() is a single threaded critical component and
should also use synchronize_rcu_expedited() even when not holding RTNL.

First patch removes a barrier with no clear purpose in ipv6_mc_down()
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 03f568a1 1ebb85f9

net/bridge/br_vlan.c

+2 −2
Original line number Diff line number Diff line
@@ -841,7 +841,7 @@ void br_vlan_flush(struct net_bridge *br) 
	vg = br_vlan_group(br);

	__vlan_flush(br, NULL, vg);

	RCU_INIT_POINTER(br->vlgrp, NULL);

	synchronize_rcu();

	synchronize_net();

	__vlan_group_free(vg);

}
@@ -1372,7 +1372,7 @@ void nbp_vlan_flush(struct net_bridge_port *port) 
	vg = nbp_vlan_group(port);

	__vlan_flush(port->br, port, vg);

	RCU_INIT_POINTER(port->vlgrp, NULL);

	synchronize_rcu();

	synchronize_net();

	__vlan_group_free(vg);

}

net/core/dev.c

+1 −1
Original line number Diff line number Diff line
@@ -1239,7 +1239,7 @@ int dev_change_name(struct net_device *dev, const char *newname) 
	netdev_name_node_del(dev->name_node);

	write_unlock(&dev_base_lock);



	synchronize_rcu();

	synchronize_net();



	write_lock(&dev_base_lock);

	netdev_name_node_add(net, dev->name_node);

net/core/net_namespace.c

+1 −1
Original line number Diff line number Diff line
@@ -622,7 +622,7 @@ static void cleanup_net(struct work_struct *work) 
	 * the rcu_barrier() below isn't sufficient alone.

	 * Also the pre_exit() and exit() methods need this barrier.

	 */

	synchronize_rcu();

	synchronize_rcu_expedited();



	rtnl_lock();

	list_for_each_entry_reverse(ops, &pernet_list, list) {

net/ipv4/fib_trie.c

+1 −1
Original line number Diff line number Diff line
@@ -501,7 +501,7 @@ static void tnode_free(struct key_vector *tn) 


	if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) {

		tnode_free_size = 0;

		synchronize_rcu();

		synchronize_net();

	}

}

net/ipv6/mcast.c

+0 −1
Original line number Diff line number Diff line
@@ -2719,7 +2719,6 @@ void ipv6_mc_down(struct inet6_dev *idev) 
	/* Should stop work after group drop. or we will

	 * start work again in mld_ifc_event()

	 */

	synchronize_net();

	mld_query_stop_work(idev);

	mld_report_stop_work(idev);