diff mbox series

[06/12] scsi: iscsi_tcp: Use sendpage for the PDU header

Message ID 20220308002747.122682-7-michael.christie@oracle.com
State New
Headers show
Series misc iscsi patches | expand

Commit Message

Mike Christie March 8, 2022, 12:27 a.m. UTC 
This has us use zero copy the PDU header.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/scsi/iscsi_tcp.c | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

Comments

Lee Duncan March 12, 2022, 7:42 p.m. UTC | #1 
On 3/7/22 16:27, Mike Christie wrote:
> This has us use zero copy the PDU header.
> 
> Signed-off-by: Mike Christie <michael.christie@oracle.com>
> ---
>   drivers/scsi/iscsi_tcp.c | 30 ++++++++++++++++++++++--------
>   1 file changed, 22 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
> index 261599938fc9..3bdefc4b6b17 100644
> --- a/drivers/scsi/iscsi_tcp.c
> +++ b/drivers/scsi/iscsi_tcp.c
> @@ -306,7 +306,7 @@ static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
>   		copy = segment->size - offset;
>   
>   		if (segment->total_copied + segment->size < segment->total_size)
> -			flags |= MSG_MORE;
> +			flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
>   
>   		/* Use sendpage if we can; else fall back to sendmsg */
>   		if (!segment->data) {
> @@ -315,13 +315,27 @@ static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
>   			r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
>   						  copy, flags);
>   		} else {
> -			struct msghdr msg = { .msg_flags = flags };
> -			struct kvec iov = {
> -				.iov_base = segment->data + offset,
> -				.iov_len = copy
> -			};
> -
> -			r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
> +			void *data = segment->data + offset;
> +
> +			/*
> +			 * Make sure it's ok to send the header using zero
> +			 * copy. The case where the sg page can't be zero
> +			 * copied will also go down the sendmsg path.
> +			 */
> +			if (sendpage_ok(data)) {
> +				r = tcp_sw_conn->sendpage(sk,
> +						virt_to_page(data),
> +						offset_in_page(data), copy,
> +						flags);
> +			} else {
> +				struct msghdr msg = { .msg_flags = flags };
> +				struct kvec iov = {
> +					.iov_base = data,
> +					.iov_len = copy,
> +				};
> +
> +				r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
> +			}
>   		}
>   
>   		if (r < 0) {

Reviewed-by: Lee Duncan <lduncan@suse.com>
diff mbox series

Patch

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 261599938fc9..3bdefc4b6b17 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -306,7 +306,7 @@  static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 		copy = segment->size - offset;
 
 		if (segment->total_copied + segment->size < segment->total_size)
-			flags |= MSG_MORE;
+			flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
 
 		/* Use sendpage if we can; else fall back to sendmsg */
 		if (!segment->data) {
@@ -315,13 +315,27 @@  static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 			r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
 						  copy, flags);
 		} else {
-			struct msghdr msg = { .msg_flags = flags };
-			struct kvec iov = {
-				.iov_base = segment->data + offset,
-				.iov_len = copy
-			};
-
-			r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
+			void *data = segment->data + offset;
+
+			/*
+			 * Make sure it's ok to send the header using zero
+			 * copy. The case where the sg page can't be zero
+			 * copied will also go down the sendmsg path.
+			 */
+			if (sendpage_ok(data)) {
+				r = tcp_sw_conn->sendpage(sk,
+						virt_to_page(data),
+						offset_in_page(data), copy,
+						flags);
+			} else {
+				struct msghdr msg = { .msg_flags = flags };
+				struct kvec iov = {
+					.iov_base = data,
+					.iov_len = copy,
+				};
+
+				r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
+			}
 		}
 
 		if (r < 0) {