From 6e3ca03ee934572d5de4fb2224c01e12c4d422c8 Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Fri, 2 Nov 2018 10:28:15 -0700 Subject: nvme: support traffic based keep-alive If the controller supports traffic based keep alive, we restart the keep alive timer if any admin or io commands was completed during the kato period. This prevents a possible starvation of keep alive commands in the presence of heavy traffic as in such case, we already have a health indication from the host perspective. Only set a comp_seen indicator in case the controller supports keep alive to minimize the overhead for pci controllers. Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/nvme/host/core.c | 13 +++++++++++++ drivers/nvme/host/nvme.h | 1 + 2 files changed, 14 insertions(+) (limited to 'drivers/nvme/host') diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 9de6244a345c..48ffb1d685c2 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -251,6 +251,9 @@ void nvme_complete_rq(struct request *req) trace_nvme_complete_rq(req); + if (nvme_req(req)->ctrl->kas) + nvme_req(req)->ctrl->comp_seen = true; + if (unlikely(status != BLK_STS_OK && nvme_req_needs_retry(req))) { if ((req->cmd_flags & REQ_NVME_MPATH) && blk_path_error(status)) { @@ -839,6 +842,7 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status) return; } + ctrl->comp_seen = false; schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); } @@ -863,6 +867,15 @@ static void nvme_keep_alive_work(struct work_struct *work) { struct nvme_ctrl *ctrl = container_of(to_delayed_work(work), struct nvme_ctrl, ka_work); + bool comp_seen = ctrl->comp_seen; + + if ((ctrl->ctratt & NVME_CTRL_ATTR_TBKAS) && comp_seen) { + dev_dbg(ctrl->device, + "reschedule traffic based keep-alive timer\n"); + ctrl->comp_seen = false; + schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); + return; + } if (nvme_keep_alive(ctrl)) { /* allocation failure, reset the controller */ diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 4be7bbcfe66d..f2594d468f29 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -145,6 +145,7 @@ enum nvme_ctrl_state { }; struct nvme_ctrl { + bool comp_seen; enum nvme_ctrl_state state; bool identified; spinlock_t lock; -- cgit v1.2.3-59-g8ed1b