[PATCH net-next v10 09/16] siw: Inline do_tcp_sendpages()

From: David Howells
Date: Mon May 22 2023 - 08:13:40 EST


do_tcp_sendpages() is now just a small wrapper around tcp_sendmsg_locked(),
so inline it, allowing do_tcp_sendpages() to be removed. This is part of
replacing ->sendpage() with a call to sendmsg() with MSG_SPLICE_PAGES set.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Reviewed-by: Bernard Metzler <bmt@xxxxxxxxxxxxxx>
Reviewed-by: Tom Talpey <tom@xxxxxxxxxx>
cc: Jason Gunthorpe <jgg@xxxxxxxx>
cc: Leon Romanovsky <leon@xxxxxxxxxx>
cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
cc: Eric Dumazet <edumazet@xxxxxxxxxx>
cc: Jakub Kicinski <kuba@xxxxxxxxxx>
cc: Paolo Abeni <pabeni@xxxxxxxxxx>
cc: Jens Axboe <axboe@xxxxxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
cc: linux-rdma@xxxxxxxxxxxxxxx
cc: netdev@xxxxxxxxxxxxxxx
---

Notes:
ver #6)
- Don't clear MSG_SPLICE_PAGES on the last page.

drivers/infiniband/sw/siw/siw_qp_tx.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c b/drivers/infiniband/sw/siw/siw_qp_tx.c
index 4b292e0504f1..ffb16beb6c30 100644
--- a/drivers/infiniband/sw/siw/siw_qp_tx.c
+++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
@@ -312,7 +312,7 @@ static int siw_tx_ctrl(struct siw_iwarp_tx *c_tx, struct socket *s,
}

/*
- * 0copy TCP transmit interface: Use do_tcp_sendpages.
+ * 0copy TCP transmit interface: Use MSG_SPLICE_PAGES.
*
* Using sendpage to push page by page appears to be less efficient
* than using sendmsg, even if data are copied.
@@ -323,20 +323,27 @@ static int siw_tx_ctrl(struct siw_iwarp_tx *c_tx, struct socket *s,
static int siw_tcp_sendpages(struct socket *s, struct page **page, int offset,
size_t size)
{
+ struct bio_vec bvec;
+ struct msghdr msg = {
+ .msg_flags = (MSG_MORE | MSG_DONTWAIT | MSG_SENDPAGE_NOTLAST |
+ MSG_SPLICE_PAGES),
+ };
struct sock *sk = s->sk;
- int i = 0, rv = 0, sent = 0,
- flags = MSG_MORE | MSG_DONTWAIT | MSG_SENDPAGE_NOTLAST;
+ int i = 0, rv = 0, sent = 0;

while (size) {
size_t bytes = min_t(size_t, PAGE_SIZE - offset, size);

if (size + offset <= PAGE_SIZE)
- flags = MSG_MORE | MSG_DONTWAIT;
+ msg.msg_flags &= ~MSG_SENDPAGE_NOTLAST;

tcp_rate_check_app_limited(sk);
+ bvec_set_page(&bvec, page[i], bytes, offset);
+ iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size);
+
try_page_again:
lock_sock(sk);
- rv = do_tcp_sendpages(sk, page[i], offset, bytes, flags);
+ rv = tcp_sendmsg_locked(sk, &msg, size);
release_sock(sk);

if (rv > 0) {