diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-12-15 17:56:29 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-12-17 19:37:48 -0800 |
| commit | a853c609504e2d1d83e71285e3622fda1f1451d8 (patch) | |
| tree | b6d9cd4e2333cf6afc87beb0bc7675bc73777006 /net/ipv4/route.c | |
| parent | 50b362f21d6c10b0f7939c1482c6a1b43da82f1a (diff) | |
inetpeer: do not get a refcount in inet_getpeer()
All inet_getpeer() callers except ip4_frag_init() don't need
to acquire a permanent refcount on the inetpeer.
They can switch to full RCU protection.
Move the refcount_inc_not_zero() into ip4_frag_init(),
so that all the other callers no longer have to
perform a pair of expensive atomic operations on
a possibly contended cache line.
inet_putpeer() no longer needs to be exported.
After this patch, my DUT can receive 8,400,000 UDP packets
per second targeting closed ports, using 50% less cpu cycles
than before.
Also change two calls to l3mdev_master_ifindex() by
l3mdev_master_ifindex_rcu() (Ido ideas)
Fixes: 8c2bd38b95f7 ("icmp: change the order of rate limits")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241215175629.1248773-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/route.c')
| -rw-r--r-- | net/ipv4/route.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 297a9939c6e7..9f9d4e6ea1b9 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -870,11 +870,11 @@ void ip_rt_send_redirect(struct sk_buff *skb) } log_martians = IN_DEV_LOG_MARTIANS(in_dev); vif = l3mdev_master_ifindex_rcu(rt->dst.dev); - rcu_read_unlock(); net = dev_net(rt->dst.dev); peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif); if (!peer) { + rcu_read_unlock(); icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt_nexthop(rt, ip_hdr(skb)->daddr)); return; @@ -893,7 +893,7 @@ void ip_rt_send_redirect(struct sk_buff *skb) */ if (peer->n_redirects >= ip_rt_redirect_number) { peer->rate_last = jiffies; - goto out_put_peer; + goto out_unlock; } /* Check for load limit; set rate_last to the latest sent @@ -914,8 +914,8 @@ void ip_rt_send_redirect(struct sk_buff *skb) &ip_hdr(skb)->saddr, inet_iif(skb), &ip_hdr(skb)->daddr, &gw); } -out_put_peer: - inet_putpeer(peer); +out_unlock: + rcu_read_unlock(); } static int ip_error(struct sk_buff *skb) @@ -975,9 +975,9 @@ static int ip_error(struct sk_buff *skb) break; } + rcu_read_lock(); peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, - l3mdev_master_ifindex(skb->dev)); - + l3mdev_master_ifindex_rcu(skb->dev)); send = true; if (peer) { now = jiffies; @@ -989,8 +989,9 @@ static int ip_error(struct sk_buff *skb) peer->rate_tokens -= ip_rt_error_cost; else send = false; - inet_putpeer(peer); } + rcu_read_unlock(); + if (send) icmp_send(skb, ICMP_DEST_UNREACH, code, 0); |