From: Pavel Begunkov <[email protected]>
To: [email protected], [email protected],
[email protected], [email protected], [email protected],
[email protected], [email protected]
Cc: Pavel Begunkov <[email protected]>
Subject: [PATCH net-next 2/2] net/tcp: optimise io_uring zc ubuf refcounting
Date: Mon, 15 May 2023 17:06:37 +0100 [thread overview]
Message-ID: <bdbbff06f20c100c00e59932ffecbd18ad699f57.1684166247.git.asml.silence@gmail.com> (raw)
In-Reply-To: <[email protected]>
io_uring keeps a reference to ubuf_info during submission, so if
tcp_sendmsg_locked() sees msghdr::msg_ubuf in can be sure the buffer
will be kept alive and doesn't need to additionally pin it.
Signed-off-by: Pavel Begunkov <[email protected]>
---
net/ipv4/tcp.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 40f591f7fce1..3d18e295bb2f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1231,7 +1231,6 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
if ((flags & MSG_ZEROCOPY) && size) {
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);
@@ -1458,7 +1457,9 @@ 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:
- net_zcopy_put(uarg);
+ /* 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;
do_error:
@@ -1467,7 +1468,9 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
if (copied + copied_syn)
goto out;
out_err:
- net_zcopy_put_abort(uarg, true);
+ /* 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 */
if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) {
--
2.40.0
next prev parent reply other threads:[~2023-05-15 16:08 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-15 16:06 [PATCH net-next 0/2] minor tcp io_uring zc optimisations Pavel Begunkov
2023-05-15 16:06 ` [PATCH net-next 1/2] net/tcp: don't peek at tail for io_uring zc Pavel Begunkov
2023-05-15 17:27 ` David Ahern
2023-05-15 18:11 ` Eric Dumazet
2023-05-15 16:06 ` Pavel Begunkov [this message]
2023-05-15 17:29 ` [PATCH net-next 2/2] net/tcp: optimise io_uring zc ubuf refcounting David Ahern
2023-05-15 18:14 ` Eric Dumazet
2023-05-15 18:40 ` David Ahern
2023-05-16 12:59 ` Pavel Begunkov
2023-05-16 14:37 ` David Ahern
2023-05-16 17:46 ` Pavel Begunkov
2023-05-17 7:40 ` [PATCH net-next 0/2] minor tcp io_uring zc optimisations patchwork-bot+netdevbpf
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