Commit 81cf1ade authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'tcp-io_uring-zc-opts' 



Merge branch 'tcp-io_uring-zc-opts'

Pavel Begunkov says:

====================
minor tcp io_uring zc optimisations

Patch 1 is a simple cleanup, patch 2 gives removes 2 atomics from the
io_uring zc TCP submission path, which yielded extra 0.5% for my
throughput CPU bound tests based on liburing/examples/send-zerocopy.c
====================

Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 833e24ae a7533584

net/ipv4/tcp.c

+7 −5
Original line number Diff line number Diff line
@@ -1229,13 +1229,11 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) 
	flags = msg->msg_flags;



	if ((flags & MSG_ZEROCOPY) && size) {

		skb = tcp_write_queue_tail(sk);



		if (msg->msg_ubuf) {

			uarg = msg->msg_ubuf;

			net_zcopy_get(uarg);

			zc = sk->sk_route_caps & NETIF_F_SG;

		} else if (sock_flag(sk, SOCK_ZEROCOPY)) {

			skb = tcp_write_queue_tail(sk);

			uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb));

			if (!uarg) {

				err = -ENOBUFS;
@@ -1459,6 +1457,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) 
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);

	}

out_nopush:

	/* msg->msg_ubuf is pinned by the caller so we don't take extra refs */

	if (uarg && !msg->msg_ubuf)

		net_zcopy_put(uarg);

	return copied + copied_syn;
@@ -1468,6 +1468,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) 
	if (copied + copied_syn)

		goto out;

out_err:

	/* msg->msg_ubuf is pinned by the caller so we don't take extra refs */

	if (uarg && !msg->msg_ubuf)

		net_zcopy_put_abort(uarg, true);

	err = sk_stream_error(sk, flags, err);

	/* make sure we wake any epoll edge trigger waiter */