From 7450aaf61f0ae2ee6cc6491138d11df2c25e7609 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 30 Nov 2015 08:57:28 -0800 Subject: [PATCH] tcp: suppress too verbose messages in tcp_send_ack() 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 Signed-off-by: David S. Miller --- include/net/sock.h | 4 ++-- net/ipv4/tcp_output.c | 14 ++++++++------ net/ipv6/tcp_ipv6.c | 6 +++--- 3 files changed, 13 insertions(+), 11 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index 62d35afcb3ac..9065f8b7e646 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -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) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index cb7ca569052c..a800cee88035 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -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) diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index c5429a636f1a..41bcd59a2ac7 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -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; -- 2.20.1