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nvmet-tcp: Use sendmsg(MSG_SPLICE_PAGES) rather then sendpage

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When transmitting data, call down into TCP using a single sendmsg with
MSG_SPLICE_PAGES to indicate that content should be spliced rather than
copied instead of calling sendpage.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Willem de Bruijn <willemb@google.com>
cc: Keith Busch <kbusch@kernel.org>
cc: Jens Axboe <axboe@fb.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Chaitanya Kulkarni <kch@nvidia.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-nvme@lists.infradead.org
Link: https://lore.kernel.org/r/20230623225513.2732256-9-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
David Howells 2023-06-23 23:55:05 +01:00 committed by Jakub Kicinski
parent 7769887817
commit c336a79983
1 changed files with 29 additions and 17 deletions
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46
drivers/nvme/target/tcp.c
View File

@ -576,13 +576,17 @@ static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd)
static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
{
struct msghdr msg = {
.msg_flags = MSG_DONTWAIT | MSG_MORE | MSG_SPLICE_PAGES,
};
struct bio_vec bvec;
u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
int ret;
ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
offset_in_page(cmd->data_pdu) + cmd->offset,
left, MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
bvec_set_virt(&bvec, (void *)cmd->data_pdu + cmd->offset, left);
iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, left);
ret = sock_sendmsg(cmd->queue->sock, &msg);
if (ret <= 0)
return ret;
@ -603,17 +607,21 @@ static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
int ret;
while (cmd->cur_sg) {
struct msghdr msg = {
.msg_flags = MSG_DONTWAIT | MSG_SPLICE_PAGES,
};
struct page *page = sg_page(cmd->cur_sg);
struct bio_vec bvec;
u32 left = cmd->cur_sg->length - cmd->offset;
int flags = MSG_DONTWAIT;
if ((!last_in_batch && cmd->queue->send_list_len) ||
cmd->wbytes_done + left < cmd->req.transfer_len ||
queue->data_digest || !queue->nvme_sq.sqhd_disabled)
flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
msg.msg_flags |= MSG_MORE;
ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
left, flags);
bvec_set_page(&bvec, page, left, cmd->offset);
iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, left);
ret = sock_sendmsg(cmd->queue->sock, &msg);
if (ret <= 0)
return ret;
@ -649,18 +657,20 @@ static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
bool last_in_batch)
{
struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_SPLICE_PAGES, };
struct bio_vec bvec;
u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
int flags = MSG_DONTWAIT;
int ret;
if (!last_in_batch && cmd->queue->send_list_len)
flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
msg.msg_flags |= MSG_MORE;
else
flags |= MSG_EOR;
msg.msg_flags |= MSG_EOR;
ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
bvec_set_virt(&bvec, (void *)cmd->rsp_pdu + cmd->offset, left);
iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, left);
ret = sock_sendmsg(cmd->queue->sock, &msg);
if (ret <= 0)
return ret;
cmd->offset += ret;
@ -677,18 +687,20 @@ static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
{
struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_SPLICE_PAGES, };
struct bio_vec bvec;
u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
int flags = MSG_DONTWAIT;
int ret;
if (!last_in_batch && cmd->queue->send_list_len)
flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
msg.msg_flags |= MSG_MORE;
else
flags |= MSG_EOR;
msg.msg_flags |= MSG_EOR;
ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
bvec_set_virt(&bvec, (void *)cmd->r2t_pdu + cmd->offset, left);
iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, left);
ret = sock_sendmsg(cmd->queue->sock, &msg);
if (ret <= 0)
return ret;
cmd->offset += ret;