Revert "net: init sk_cookie for inet socket"

This reverts commit <c6849a3ac17e> ("net: init sk_cookie for inet socket")

Per discussion with Eric, when update sock_net(sk)->cookie_gen, the
whole cache cache line will be invalidated, as this cache line is shared
with all cpus, that may cause great performace hit.

Bellow is the data form Eric.
"Performance is reduced from ~5 Mpps to ~3.8 Mpps with 16 RX queues on
my host" when running synflood test.

Have to revert it to prevent from cache line false sharing.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 7 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 17b78582ba63..5a17cfc75326 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -78,7 +78,6 @@
 #include <linux/errqueue.h>
 #include <trace/events/tcp.h>
 #include <linux/static_key.h>
-#include <linux/sock_diag.h>
 
 int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
 
@@ -6191,15 +6190,10 @@ struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
 #if IS_ENABLED(CONFIG_IPV6)
                 ireq->pktopts = NULL;
 #endif
+                atomic64_set(&ireq->ir_cookie, 0);
                 ireq->ireq_state = TCP_NEW_SYN_RECV;
                 write_pnet(&ireq->ireq_net, sock_net(sk_listener));
                 ireq->ireq_family = sk_listener->sk_family;
-
-                BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=
-                                        offsetof(struct sock, sk_cookie));
-                BUILD_BUG_ON(offsetof(struct inet_request_sock, ireq_net) !=
-                                        offsetof(struct sock, sk_net));
-                sock_init_cookie((struct sock *)ireq);
         }
 
         return req;