Commit 702c290a authored by Gilad Naaman's avatar Gilad Naaman Committed by Paolo Abeni
Browse files

sctp: Avoid enqueuing addr events redundantly 



Avoid modifying or enqueuing new events if it's possible to tell that no
one will consume them.

Since enqueueing requires searching the current queue for opposite
events for the same address, adding addresses en-masse turns this
inetaddr_event into a bottle-neck, as it will get slower and slower
with each address added.

Signed-off-by: default avatarGilad Naaman <gnaaman@drivenets.com>
Acked-by: default avatarXin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20241104083545.114-1-gnaaman@drivenets.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 2a6f99ee

net/sctp/ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -103,10 +103,10 @@ static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev, 
			    ipv6_addr_equal(&addr->a.v6.sin6_addr,

					    &ifa->addr) &&

			    addr->a.v6.sin6_scope_id == ifa->idev->dev->ifindex) {

				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);

				found = 1;

				addr->valid = 0;

				list_del_rcu(&addr->list);

				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);

				break;

			}

		}

net/sctp/protocol.c

+15 −1
Original line number Diff line number Diff line
@@ -738,6 +738,20 @@ void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cm 
	 */



	spin_lock_bh(&net->sctp.addr_wq_lock);



	/* Avoid searching the queue or modifying it if there are no consumers,

	 * as it can lead to performance degradation if addresses are modified

	 * en-masse.

	 *

	 * If the queue already contains some events, update it anyway to avoid

	 * ugly races between new sessions and new address events.

	 */

	if (list_empty(&net->sctp.auto_asconf_splist) &&

	    list_empty(&net->sctp.addr_waitq)) {

		spin_unlock_bh(&net->sctp.addr_wq_lock);

		return;

	}



	/* Offsets existing events in addr_wq */

	addrw = sctp_addr_wq_lookup(net, addr);

	if (addrw) {
@@ -808,10 +822,10 @@ static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev, 
			if (addr->a.sa.sa_family == AF_INET &&

					addr->a.v4.sin_addr.s_addr ==

					ifa->ifa_local) {

				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);

				found = 1;

				addr->valid = 0;

				list_del_rcu(&addr->list);

				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);

				break;

			}

		}