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tcp: suppress too verbose messages in tcp_send_ack()

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If tcp_send_ack() can not allocate skb, we properly handle this
and setup a timer to try later.

Use __GFP_NOWARN to avoid polluting syslog in the case host is
under memory pressure, so that pertinent messages are not lost under
a flood of useless information.

sk_gfp_atomic() can use its gfp_mask argument (all callers currently
were using GFP_ATOMIC before this patch)

We rename sk_gfp_atomic() to sk_gfp_mask() to clearly express this
function now takes into account its second argument (gfp_mask)

Note that when tcp_transmit_skb() is called with clone_it set to false,
we do not attempt memory allocations, so can pass a 0 gfp_mask, which
most compilers can emit faster than a non zero or constant value.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2015-11-30 08:57:28 -08:00 committed by David S. Miller
parent 0fe824d365
commit 7450aaf61f
3 changed files with 13 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/net/sock.h
View File

@ -775,9 +775,9 @@ static inline int sk_memalloc_socks(void)
#endif
static inline gfp_t sk_gfp_atomic(const struct sock *sk, gfp_t gfp_mask)
static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
{
return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC);
return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
}
static inline void sk_acceptq_removed(struct sock *sk)

14
net/ipv4/tcp_output.c
View File

@ -2296,7 +2296,7 @@ void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
return;
if (tcp_write_xmit(sk, cur_mss, nonagle, 0,
sk_gfp_atomic(sk, GFP_ATOMIC)))
sk_gfp_mask(sk, GFP_ATOMIC)))
tcp_check_probe_timer(sk);
}
@ -3352,8 +3352,9 @@ void tcp_send_ack(struct sock *sk)
* tcp_transmit_skb() will set the ownership to this
* sock.
*/
buff = alloc_skb(MAX_TCP_HEADER, sk_gfp_atomic(sk, GFP_ATOMIC));
if (!buff) {
buff = alloc_skb(MAX_TCP_HEADER,
sk_gfp_mask(sk, GFP_ATOMIC | __GFP_NOWARN));
if (unlikely(!buff)) {
inet_csk_schedule_ack(sk);
inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
@ -3375,7 +3376,7 @@ void tcp_send_ack(struct sock *sk)
/* Send it off, this clears delayed acks for us. */
skb_mstamp_get(&buff->skb_mstamp);
tcp_transmit_skb(sk, buff, 0, sk_gfp_atomic(sk, GFP_ATOMIC));
tcp_transmit_skb(sk, buff, 0, (__force gfp_t)0);
}
EXPORT_SYMBOL_GPL(tcp_send_ack);
@ -3396,7 +3397,8 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent, int mib)
struct sk_buff *skb;
/* We don't queue it, tcp_transmit_skb() sets ownership. */
skb = alloc_skb(MAX_TCP_HEADER, sk_gfp_atomic(sk, GFP_ATOMIC));
skb = alloc_skb(MAX_TCP_HEADER,
sk_gfp_mask(sk, GFP_ATOMIC | __GFP_NOWARN));
if (!skb)
return -1;
@ -3409,7 +3411,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent, int mib)
tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK);
skb_mstamp_get(&skb->skb_mstamp);
NET_INC_STATS(sock_net(sk), mib);
return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
return tcp_transmit_skb(sk, skb, 0, (__force gfp_t)0);
}
void tcp_send_window_probe(struct sock *sk)

6
net/ipv6/tcp_ipv6.c
View File

@ -1130,7 +1130,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
*/
tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
AF_INET6, key->key, key->keylen,
sk_gfp_atomic(sk, GFP_ATOMIC));
sk_gfp_mask(sk, GFP_ATOMIC));
}
#endif
@ -1146,7 +1146,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
/* Clone pktoptions received with SYN, if we own the req */
if (ireq->pktopts) {
newnp->pktoptions = skb_clone(ireq->pktopts,
sk_gfp_atomic(sk, GFP_ATOMIC));
sk_gfp_mask(sk, GFP_ATOMIC));
consume_skb(ireq->pktopts);
ireq->pktopts = NULL;
if (newnp->pktoptions)
@ -1212,7 +1212,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
--ANK (980728)
*/
if (np->rxopt.all)
opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
struct dst_entry *dst = sk->sk_rx_dst;