From 70583295388a3ceabc22bddeb16e788f58225d70 Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Fri, 8 Mar 2019 15:41:21 -0800 Subject: [PATCH] nvmet-tcp: implement C2HData SUCCESS optimization TP 8000 says that the use of the SUCCESS flag depends on weather the controller support disabling sq_head pointer updates. Given that we support it by default, makes sense that we go the extra mile to actually use the SUCCESS flag. When we create the C2HData PDU header, we check if sqhd_disabled is set on our queue, if so, we set the SUCCESS flag in the PDU header and skip sending a completion response capsule. Signed-off-by: Sagi Grimberg Reviewed-by: Oliver Smith-Denny Tested-by: Oliver Smith-Denny Signed-off-by: Christoph Hellwig --- drivers/nvme/target/tcp.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index ad0df786fe93..0a941abf56ec 100644 --- a/drivers/nvme/target/tcp.c +++ b/drivers/nvme/target/tcp.c @@ -371,7 +371,8 @@ static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd) cmd->state = NVMET_TCP_SEND_DATA_PDU; pdu->hdr.type = nvme_tcp_c2h_data; - pdu->hdr.flags = NVME_TCP_F_DATA_LAST; + pdu->hdr.flags = NVME_TCP_F_DATA_LAST | (queue->nvme_sq.sqhd_disabled ? + NVME_TCP_F_DATA_SUCCESS : 0); pdu->hdr.hlen = sizeof(*pdu); pdu->hdr.pdo = pdu->hdr.hlen + hdgst; pdu->hdr.plen = @@ -542,8 +543,19 @@ static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd) cmd->state = NVMET_TCP_SEND_DDGST; cmd->offset = 0; } else { - nvmet_setup_response_pdu(cmd); + if (queue->nvme_sq.sqhd_disabled) { + cmd->queue->snd_cmd = NULL; + nvmet_tcp_put_cmd(cmd); + } else { + nvmet_setup_response_pdu(cmd); + } } + + if (queue->nvme_sq.sqhd_disabled) { + kfree(cmd->iov); + sgl_free(cmd->req.sg); + } + return 1; } @@ -619,7 +631,13 @@ static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd) return ret; cmd->offset += ret; - nvmet_setup_response_pdu(cmd); + + if (queue->nvme_sq.sqhd_disabled) { + cmd->queue->snd_cmd = NULL; + nvmet_tcp_put_cmd(cmd); + } else { + nvmet_setup_response_pdu(cmd); + } return 1; } -- 2.30.2