tcp: introduce tcp_under_memory_pressure()

Introduce an optimized version of sk_under_memory_pressure()
for TCP. Our intent is to use it in fast paths.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2015-05-15 12:39:27 -07:00 committed by David S. Miller
parent a6c5ea4ccf
commit b8da51ebb1
4 changed files with 15 additions and 7 deletions

View file

@ -359,7 +359,7 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb)
/* Check #1 */
if (tp->rcv_ssthresh < tp->window_clamp &&
(int)tp->rcv_ssthresh < tcp_space(sk) &&
!sk_under_memory_pressure(sk)) {
!tcp_under_memory_pressure(sk)) {
int incr;
/* Check #2. Increase window, if skb with such overhead
@ -446,7 +446,7 @@ static void tcp_clamp_window(struct sock *sk)
if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
!(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
!sk_under_memory_pressure(sk) &&
!tcp_under_memory_pressure(sk) &&
sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)) {
sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
sysctl_tcp_rmem[2]);
@ -4781,7 +4781,7 @@ static int tcp_prune_queue(struct sock *sk)
if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
tcp_clamp_window(sk);
else if (sk_under_memory_pressure(sk))
else if (tcp_under_memory_pressure(sk))
tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
tcp_collapse_ofo_queue(sk);
@ -4825,7 +4825,7 @@ static bool tcp_should_expand_sndbuf(const struct sock *sk)
return false;
/* If we are under global TCP memory pressure, do not expand. */
if (sk_under_memory_pressure(sk))
if (tcp_under_memory_pressure(sk))
return false;
/* If we are under soft global TCP memory pressure, do not expand. */