diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2009-08-28 23:52:01 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-08-28 23:52:01 -0700 |
| commit | 30038fc61adfdab162b1966e34261f06eda67f02 (patch) | |
| tree | c9266e5d3c54c7a9a4b17bd68b28b24d629249b2 /net/ipv4/route.c | |
| parent | df19a6267705456f463871ae2aabc44299909d2a (diff) | |
| download | blackbird-op-linux-30038fc61adfdab162b1966e34261f06eda67f02.tar.gz blackbird-op-linux-30038fc61adfdab162b1966e34261f06eda67f02.zip | |
net: ip_rt_send_redirect() optimization
While doing some forwarding benchmarks, I noticed
ip_rt_send_redirect() is rather expensive, even if send_redirects is
false for the device.
Fix is to avoid two atomic ops, we dont really need to take a
reference on in_dev
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/route.c')
| -rw-r--r-- | net/ipv4/route.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index fafbe163e2b5..91867d3e6328 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1514,13 +1514,17 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) void ip_rt_send_redirect(struct sk_buff *skb) { struct rtable *rt = skb_rtable(skb); - struct in_device *in_dev = in_dev_get(rt->u.dst.dev); + struct in_device *in_dev; + int log_martians; - if (!in_dev) + rcu_read_lock(); + in_dev = __in_dev_get_rcu(rt->u.dst.dev); + if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { + rcu_read_unlock(); return; - - if (!IN_DEV_TX_REDIRECTS(in_dev)) - goto out; + } + log_martians = IN_DEV_LOG_MARTIANS(in_dev); + rcu_read_unlock(); /* No redirected packets during ip_rt_redirect_silence; * reset the algorithm. @@ -1533,7 +1537,7 @@ void ip_rt_send_redirect(struct sk_buff *skb) */ if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) { rt->u.dst.rate_last = jiffies; - goto out; + return; } /* Check for load limit; set rate_last to the latest sent @@ -1547,7 +1551,7 @@ void ip_rt_send_redirect(struct sk_buff *skb) rt->u.dst.rate_last = jiffies; ++rt->u.dst.rate_tokens; #ifdef CONFIG_IP_ROUTE_VERBOSE - if (IN_DEV_LOG_MARTIANS(in_dev) && + if (log_martians && rt->u.dst.rate_tokens == ip_rt_redirect_number && net_ratelimit()) printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n", @@ -1555,8 +1559,6 @@ void ip_rt_send_redirect(struct sk_buff *skb) &rt->rt_dst, &rt->rt_gateway); #endif } -out: - in_dev_put(in_dev); } static int ip_error(struct sk_buff *skb) |
