From 8ddab50839e29e965460b2cf794fd2b06a946893 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Fri, 22 Dec 2017 19:00:20 -0500 Subject: [PATCH] tcp: do not allocate linear memory for zerocopy skbs 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 Signed-off-by: David S. Miller --- 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 @@ restart: 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 @@ new_segment: 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; -- 2.30.2