syncookies: remove last_synq_overflow from struct tcp_sock
last_synq_overflow eats 4 or 8 bytes in struct tcp_sock, even
though it is only used when a listening sockets syn queue
is full.
We can (ab)use rx_opt.ts_recent_stamp to store the same information;
it is not used otherwise as long as a socket is in listen state.
Move linger2 around to avoid splitting struct mtu_probe
across cacheline boundary on 32 bit arches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 9d5078b..8afac76 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -377,7 +377,7 @@
unsigned int keepalive_time; /* time before keep alive takes place */
unsigned int keepalive_intvl; /* time interval between keep alive probes */
- unsigned long last_synq_overflow;
+ int linger2;
/* Receiver side RTT estimation */
struct {
@@ -406,8 +406,6 @@
/* TCP MD5 Signagure Option information */
struct tcp_md5sig_info *md5sig_info;
#endif
-
- int linger2;
};
static inline struct tcp_sock *tcp_sk(const struct sock *sk)
