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authorSagi Grimberg <sagi@grimberg.me>2018-11-02 10:28:15 -0700
committerJens Axboe <axboe@kernel.dk>2018-12-07 22:26:55 -0700
commit6e3ca03ee934572d5de4fb2224c01e12c4d422c8 (patch)
treeb6e8dc7fa480aefbd87f68712e651e3cda747078
parent3e53ba38a9404434a8b57683825279f4305b5a76 (diff)
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 <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--drivers/nvme/host/core.c13
-rw-r--r--drivers/nvme/host/nvme.h1
-rw-r--r--include/linux/nvme.h1
3 files changed, 15 insertions, 0 deletions
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;
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 753c83a5c01f..429c4cf90899 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -200,6 +200,7 @@ enum {
enum nvme_ctrl_attr {
NVME_CTRL_ATTR_HID_128_BIT = (1 << 0),
+ NVME_CTRL_ATTR_TBKAS = (1 << 6),
};
struct nvme_id_ctrl {