nvme-pci: remove last_sq_tail

The nvme driver does not have enough tags to wrap the queue, and blk-mq
will no longer call commit_rqs() when there are no new submissions to
notify.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Keith Busch 2020-04-27 11:54:46 -07:00 committed by Jens Axboe
parent 74943d45ee
commit 54b2fcee1d

View File

@ -173,7 +173,6 @@ struct nvme_queue {
u16 q_depth;
u16 cq_vector;
u16 sq_tail;
u16 last_sq_tail;
u16 cq_head;
u16 qid;
u8 cq_phase;
@ -446,24 +445,11 @@ static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
return 0;
}
/*
* Write sq tail if we are asked to, or if the next command would wrap.
*/
static inline void nvme_write_sq_db(struct nvme_queue *nvmeq, bool write_sq)
static inline void nvme_write_sq_db(struct nvme_queue *nvmeq)
{
if (!write_sq) {
u16 next_tail = nvmeq->sq_tail + 1;
if (next_tail == nvmeq->q_depth)
next_tail = 0;
if (next_tail != nvmeq->last_sq_tail)
return;
}
if (nvme_dbbuf_update_and_check_event(nvmeq->sq_tail,
nvmeq->dbbuf_sq_db, nvmeq->dbbuf_sq_ei))
writel(nvmeq->sq_tail, nvmeq->q_db);
nvmeq->last_sq_tail = nvmeq->sq_tail;
}
/**
@ -480,7 +466,8 @@ static void nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd,
cmd, sizeof(*cmd));
if (++nvmeq->sq_tail == nvmeq->q_depth)
nvmeq->sq_tail = 0;
nvme_write_sq_db(nvmeq, write_sq);
if (write_sq)
nvme_write_sq_db(nvmeq);
spin_unlock(&nvmeq->sq_lock);
}
@ -489,8 +476,7 @@ static void nvme_commit_rqs(struct blk_mq_hw_ctx *hctx)
struct nvme_queue *nvmeq = hctx->driver_data;
spin_lock(&nvmeq->sq_lock);
if (nvmeq->sq_tail != nvmeq->last_sq_tail)
nvme_write_sq_db(nvmeq, true);
nvme_write_sq_db(nvmeq);
spin_unlock(&nvmeq->sq_lock);
}
@ -1494,7 +1480,6 @@ static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
struct nvme_dev *dev = nvmeq->dev;
nvmeq->sq_tail = 0;
nvmeq->last_sq_tail = 0;
nvmeq->cq_head = 0;
nvmeq->cq_phase = 1;
nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];