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>
This commit is contained in:
Florian Westphal 2009-04-19 09:43:48 +00:00 committed by David S. Miller
parent 7eebb0b28f
commit a0f82f64e2
4 changed files with 18 additions and 8 deletions

View file

@ -265,6 +265,19 @@ static inline int tcp_too_many_orphans(struct sock *sk, int num)
atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]);
}
/* syncookies: remember time of last synqueue overflow */
static inline void tcp_synq_overflow(struct sock *sk)
{
tcp_sk(sk)->rx_opt.ts_recent_stamp = jiffies;
}
/* syncookies: no recent synqueue overflow on this listening socket? */
static inline int tcp_synq_no_recent_overflow(const struct sock *sk)
{
unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp;
return time_after(jiffies, last_overflow + TCP_TIMEOUT_INIT);
}
extern struct proto tcp_prot;
#define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field)