[PATCH net-next 4/4] tcp: do not allocate linear memory for zerocopy skbs
flat view
STALE3217d
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2017-12-23 00:00:27
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
From: Willem de Bruijn <willemb@google.com> Zerocopy payload is now always stored in frags, and space for headers is reversed, so this memory is unused. Signed-off-by: Willem de Bruijn <willemb@google.com> --- net/ipv4/tcp.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 947348872c3e..7ac583a2b9fe 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c@@ -1104,12 +1104,15 @@ static int linear_payload_sz(bool first_skb) return 0; } -static int select_size(const struct sock *sk, bool sg, bool first_skb) +static int select_size(const struct sock *sk, bool sg, bool first_skb, bool zc) { const struct tcp_sock *tp = tcp_sk(sk); int tmp = tp->mss_cache; if (sg) { + if (zc) + return 0; + if (sk_can_gso(sk)) { tmp = linear_payload_sz(first_skb); } else {
@@ -1282,6 +1285,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) { bool first_skb; + int linear; new_segment: /* Allocate new segment. If the interface is SG,
@@ -1295,9 +1299,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) goto restart; } first_skb = tcp_rtx_and_write_queues_empty(sk); - skb = sk_stream_alloc_skb(sk, - select_size(sk, sg, first_skb), - sk->sk_allocation, + linear = select_size(sk, sg, first_skb, zc); + skb = sk_stream_alloc_skb(sk, linear, sk->sk_allocation, first_skb); if (!skb) goto wait_for_memory;
--
2.15.1.620.gb9897f4670-goog