[PATCH 5.15 028/128] tcp: move inet->rx_dst_ifindex to sk->sk_rx_dst_ifindex

Greg Kroah-Hartman
2021-12-27T15:48:12Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 0c0a5ef809f9150e9229e7b13e43183b681b7a39 ]

Increase cache locality by moving rx_dst_ifindex next to sk->sk_rx_dst

This is part of an effort to reduce cache line misses in TCP fast path.

This removes one cache line miss in early demux.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/net/inet_sock.h | 3 +--
include/net/sock.h | 3 +++
net/ipv4/tcp_ipv4.c | 6 +++---
net/ipv6/tcp_ipv6.c | 6 +++---
4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 89163ef8cf4be..9e1111f5915bd 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -207,11 +207,10 @@ struct inet_sock {
__be32 inet_saddr;
__s16 uc_ttl;
__u16 cmsg_flags;
+ struct ip_options_rcu __rcu *inet_opt;
__be16 inet_sport;
__u16 inet_id;

- struct ip_options_rcu __rcu *inet_opt;
- int rx_dst_ifindex;
__u8 tos;
__u8 min_ttl;
__u8 mc_ttl;
diff --git a/include/net/sock.h b/include/net/sock.h
index 7ac5075f9c18a..752601265a955 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -259,6 +259,7 @@ struct bpf_local_storage;
* @sk_rcvbuf: size of receive buffer in bytes
* @sk_wq: sock wait queue and async head
* @sk_rx_dst: receive input route used by early demux
+ * @sk_rx_dst_ifindex: ifindex for @sk_rx_dst
* @sk_dst_cache: destination cache
* @sk_dst_pending_confirm: need to confirm neighbour
* @sk_policy: flow policy
@@ -431,6 +432,8 @@ struct sock {
struct xfrm_policy __rcu *sk_policy[2];
#endif
struct dst_entry *sk_rx_dst;
+ int sk_rx_dst_ifindex;
+
struct dst_entry __rcu *sk_dst_cache;
atomic_t sk_omem_alloc;
int sk_sndbuf;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 5b8ce65dfc067..f6838eec6ef73 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1703,7 +1703,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
sock_rps_save_rxhash(sk, skb);
sk_mark_napi_id(sk, skb);
if (dst) {
- if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
+ if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
!INDIRECT_CALL_1(dst->ops->check, ipv4_dst_check,
dst, 0)) {
dst_release(dst);
@@ -1788,7 +1788,7 @@ int tcp_v4_early_demux(struct sk_buff *skb)
if (dst)
dst = dst_check(dst, 0);
if (dst &&
- inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
+ sk->sk_rx_dst_ifindex == skb->skb_iif)
skb_dst_set_noref(skb, dst);
}
}
@@ -2201,7 +2201,7 @@ void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)

if (dst && dst_hold_safe(dst)) {
sk->sk_rx_dst = dst;
- inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
+ sk->sk_rx_dst_ifindex = skb->skb_iif;
}
}
EXPORT_SYMBOL(inet_sk_rx_dst_set);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index b03dd02c9f13c..c72586ee517ba 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -108,7 +108,7 @@ static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
const struct rt6_info *rt = (const struct rt6_info *)dst;

sk->sk_rx_dst = dst;
- inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
+ sk->sk_rx_dst_ifindex = skb->skb_iif;
tcp_inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
}
}
@@ -1509,7 +1509,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
sock_rps_save_rxhash(sk, skb);
sk_mark_napi_id(sk, skb);
if (dst) {
- if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
+ if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
dst, np->rx_dst_cookie) == NULL) {
dst_release(dst);
@@ -1880,7 +1880,7 @@ INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
if (dst)
dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie);
if (dst &&
- inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
+ sk->sk_rx_dst_ifindex == skb->skb_iif)
skb_dst_set_noref(skb, dst);
}
}
--
2.34.1