diff options
| author |   Sagi Grimberg <sagi@grimberg.me> | 2020-06-18 17:30:23 -0700 |
|---|---|---|
| committer |   Christoph Hellwig <hch@lst.de> | 2020-07-08 16:16:18 +0200 |
| commit | 86f0348ace1510d7ac25124b096fb88a6ab45270 (patch) | |
| tree | 852edd5979aea8494b0f68d065fde21d66471986 /drivers/nvme/host/tcp.c | |
| parent | nvme-tcp: have queue prod/cons send list become a llist (diff) | |
| download | linux-dev-86f0348ace1510d7ac25124b096fb88a6ab45270.tar.xz linux-dev-86f0348ace1510d7ac25124b096fb88a6ab45270.zip | |
nvme-tcp: leverage request plugging
blk-mq request plugging can improve the execution of our pipeline.
When we queue a request we actually trigger our I/O worker thread
yielding a context switch by definition. However if we know that
there are more requests in the pipe that are coming, we are better
off not trigger our I/O worker and only do that for the last request
in the batch (bd->last). By having it, we improve efficiency by
amortizing context switches over a batch of requests.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/nvme/host/tcp.c')
| -rw-r--r-- | drivers/nvme/host/tcp.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 478868572c81..2d3962c164a4 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -262,7 +262,7 @@ static inline void nvme_tcp_advance_req(struct nvme_tcp_request *req, } static inline void nvme_tcp_queue_request(struct nvme_tcp_request *req, - bool sync) + bool sync, bool last) { struct nvme_tcp_queue *queue = req->queue; bool empty; @@ -279,7 +279,7 @@ static inline void nvme_tcp_queue_request(struct nvme_tcp_request *req, sync && empty && mutex_trylock(&queue->send_mutex)) { nvme_tcp_try_send(queue); mutex_unlock(&queue->send_mutex); - } else { + } else if (last) { queue_work_on(queue->io_cpu, nvme_tcp_wq, &queue->io_work); } } @@ -610,7 +610,7 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue, req->state = NVME_TCP_SEND_H2C_PDU; req->offset = 0; - nvme_tcp_queue_request(req, false); + nvme_tcp_queue_request(req, false, true); return 0; } @@ -2120,7 +2120,7 @@ static void nvme_tcp_submit_async_event(struct nvme_ctrl *arg) ctrl->async_req.curr_bio = NULL; ctrl->async_req.data_len = 0; - nvme_tcp_queue_request(&ctrl->async_req, true); + nvme_tcp_queue_request(&ctrl->async_req, true, true); } static enum blk_eh_timer_return @@ -2232,6 +2232,14 @@ static blk_status_t nvme_tcp_setup_cmd_pdu(struct nvme_ns *ns, return 0; } +static void nvme_tcp_commit_rqs(struct blk_mq_hw_ctx *hctx) +{ + struct nvme_tcp_queue *queue = hctx->driver_data; + + if (!llist_empty(&queue->req_list)) + queue_work_on(queue->io_cpu, nvme_tcp_wq, &queue->io_work); +} + static blk_status_t nvme_tcp_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { @@ -2251,7 +2259,7 @@ static blk_status_t nvme_tcp_queue_rq(struct blk_mq_hw_ctx *hctx, blk_mq_start_request(rq); - nvme_tcp_queue_request(req, true); + nvme_tcp_queue_request(req, true, bd->last); return BLK_STS_OK; } @@ -2319,6 +2327,7 @@ static int nvme_tcp_poll(struct blk_mq_hw_ctx *hctx) static const struct blk_mq_ops nvme_tcp_mq_ops = { .queue_rq = nvme_tcp_queue_rq, + .commit_rqs = nvme_tcp_commit_rqs, .complete = nvme_complete_rq, .init_request = nvme_tcp_init_request, .exit_request = nvme_tcp_exit_request, |