net: optimize INET input path further

Followup of commit b178bb3dfc30 (net: reorder struct sock fields)

Optimize INET input path a bit further, by :

1) moving sk_refcnt close to sk_lock.

This reduces number of dirtied cache lines by one on 64bit arches (and
64 bytes cache line size).

2) moving inet_daddr & inet_rcv_saddr at the beginning of sk

(same cache line than hash / family / bound_dev_if / nulls_node)

This reduces number of accessed cache lines in lookups by one, and dont
increase size of inet and timewait socks.
inet and tw sockets now share same place-holder for these fields.

Before patch :

offsetof(struct sock, sk_refcnt) = 0x10
offsetof(struct sock, sk_lock) = 0x40
offsetof(struct sock, sk_receive_queue) = 0x60
offsetof(struct inet_sock, inet_daddr) = 0x270
offsetof(struct inet_sock, inet_rcv_saddr) = 0x274

After patch :

offsetof(struct sock, sk_refcnt) = 0x44
offsetof(struct sock, sk_lock) = 0x48
offsetof(struct sock, sk_receive_queue) = 0x68
offsetof(struct inet_sock, inet_daddr) = 0x0
offsetof(struct inet_sock, inet_rcv_saddr) = 0x4

compute_score() (udp or tcp) now use a single cache line per ignored
item, instead of two.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index b541a4e009fb..7aad12770867 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -54,8 +54,8 @@ int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
 {
         const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
         const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
-        __be32 sk1_rcv_saddr = inet_sk(sk)->inet_rcv_saddr;
-        __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
+        __be32 sk1_rcv_saddr = sk_rcv_saddr(sk);
+        __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
         int sk_ipv6only = ipv6_only_sock(sk);
         int sk2_ipv6only = inet_v6_ipv6only(sk2);
         int addr_type = ipv6_addr_type(sk_rcv_saddr6);