From 57ff8cb3a043da1e6c6e5fdc54e8dad71304865d Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 8 May 2020 09:17:23 +0000 Subject: [PATCH] mptcp: fill skb page frag cache outside of mptcp_sendmsg_frag The mptcp_sendmsg_frag helper contains a loop that will wait on the subflow sk. It seems preferrable to only wait in mptcp_sendmsg() when blocking io is requested. mptcp_sendmsg already has such a wait loop that is used when no subflow socket is available for transmission. This is another preparation patch that makes sure we call mptcp_sendmsg_frag only if the page frag cache has been refilled. Followup patch will remove the wait loop from mptcp_sendmsg_frag(). The retransmit worker doesn't need to do this refill as it won't transmit new mptcp-level data. Signed-off-by: Florian Westphal --- net/mptcp/protocol.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 5b63ae4ec61f4..4c10c938d94a9 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -739,6 +739,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { int mss_now = 0, size_goal = 0, ret = 0; struct mptcp_sock *msk = mptcp_sk(sk); + struct page_frag *pfrag; struct socket *ssock; size_t copied = 0; struct sock *ssk; @@ -767,12 +768,15 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) return ret >= 0 ? ret + copied : (copied ? copied : ret); } + pfrag = sk_page_frag(sk); restart: mptcp_clean_una(sk); __mptcp_flush_join_list(msk); ssk = mptcp_subflow_get_send(msk); - while (!sk_stream_memory_free(sk) || !ssk) { + while (!sk_stream_memory_free(sk) || + !ssk || + !mptcp_page_frag_refill(ssk, pfrag)) { ret = sk_stream_wait_memory(sk, &timeo); if (ret) goto out; @@ -822,6 +826,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (!tx_ok) break; if (!sk_stream_memory_free(ssk) || + !mptcp_page_frag_refill(ssk, pfrag) || !mptcp_ext_cache_refill(msk)) { tcp_push(ssk, msg->msg_flags, mss_now, tcp_sk(ssk)->nonagle, size_goal);