Commit f016229e authored May 27, 2013 by Timo Teräs Committed by David S. Miller Jun 03, 2013

ipv4: rate limit updating of next hop exceptions with same pmtu



The tunnel devices call update_pmtu for each packet sent, this causes
contention on the fnhe_lock. Ignore the pmtu update if pmtu is not
actually changed, and there is still plenty of time before the entry
expires.

Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 387aa65a

net/ipv4/route.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -947,6 +947,10 @@ static void __ip_rt_update_pmtu(struct rtable rt, struct flowi4 fl4, u32 mtu)
		if (mtu < ip_rt_min_pmtu)
		mtu = ip_rt_min_pmtu;

		if (rt->rt_pmtu == mtu &&
		time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
		return;

		rcu_read_lock();
		if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
		struct fib_nh *nh = &FIB_RES_NH(res);