linux-nvme.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Keith Busch <kbusch@kernel.org>
To: linux-nvme@lists.infradead.org, hch@lst.de, sagi@grimberg.me
Cc: Keith Busch <kbusch@kernel.org>
Subject: [PATCH] nvme/pci: Remove last_sq_tail
Date: Fri,  6 Dec 2019 05:08:25 +0900	[thread overview]
Message-ID: <20191205200825.27651-1-kbusch@kernel.org> (raw)

We don't allocate enough tags to wrap the submission queue. Remove
tracking for this condition.

Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 drivers/nvme/host/pci.c | 20 ++++----------------
 1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 0590640ba62c..3acd1b4d7735 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -174,7 +174,6 @@ struct nvme_queue {
 	u16 q_depth;
 	u16 cq_vector;
 	u16 sq_tail;
-	u16 last_sq_tail;
 	u16 cq_head;
 	u16 qid;
 	u8 cq_phase;
@@ -462,21 +461,11 @@ static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
 /*
  * 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;
 }
 
 /**
@@ -493,7 +482,8 @@ 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);
 }
 
@@ -502,8 +492,7 @@ 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);
 }
 
@@ -1511,7 +1500,6 @@ 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];
-- 
2.21.0


_______________________________________________
linux-nvme mailing list
linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

             reply	other threads:[~2019-12-05 20:08 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-05 20:08 Keith Busch [this message]
2019-12-05 20:31 ` [PATCH] nvme/pci: Remove last_sq_tail Nadolski, Edmund
2019-12-05 20:48   ` Keith Busch
2019-12-12  9:20 ` Christoph Hellwig
2019-12-12 15:47   ` Keith Busch
2019-12-12 20:11     ` Sagi Grimberg

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191205200825.27651-1-kbusch@kernel.org \
    --to=kbusch@kernel.org \
    --cc=hch@lst.de \
    --cc=linux-nvme@lists.infradead.org \
    --cc=sagi@grimberg.me \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).