All of lore.kernel.org
 help / color / mirror / Atom feed
From: Bob Pearson <rpearsonhpe@gmail.com>
To: jgg@nvidia.com, zyjzyj2000@gmail.com,
	matsuda-daisuke@fujitsu.com, jhack@hpe.com,
	linux-rdma@vger.kernel.org
Cc: Bob Pearson <rpearsonhpe@gmail.com>
Subject: [PATCH for-next 8/9] RDMA/rxe: Remove qp reference counting in tasks
Date: Wed, 22 Feb 2023 17:32:37 -0600	[thread overview]
Message-ID: <20230222233237.48940-9-rpearsonhpe@gmail.com> (raw)
In-Reply-To: <20230222233237.48940-1-rpearsonhpe@gmail.com>

Currently each of the three tasklets requester, completer and
responder in the rxe driver take and release a reference to the
qp argument at the beginning and end of the subroutines. The
caller passing in the qp argument should be responsible for holding
a reference to qp so these are not required. Further doing so
breaks the qp cleanup code in rxe_qp_do_cleanup which calls these
routines after all the references have been dropped so they cannot
drain the packet and work request queues as intended.

In fact if these routines are deferred by calling tasklet_schedule
there is no guarantee that the calling code does have a qp reference.
That is a bug in rxe_task.c which will be fixed in the next patch.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_comp.c | 4 ----
 drivers/infiniband/sw/rxe/rxe_req.c  | 5 -----
 drivers/infiniband/sw/rxe/rxe_resp.c | 4 ----
 3 files changed, 13 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_comp.c b/drivers/infiniband/sw/rxe/rxe_comp.c
index cbfa16b3a490..6eea13381476 100644
--- a/drivers/infiniband/sw/rxe/rxe_comp.c
+++ b/drivers/infiniband/sw/rxe/rxe_comp.c
@@ -584,9 +584,6 @@ int rxe_completer(struct rxe_qp *qp)
 	enum comp_state state;
 	int ret;
 
-	if (!rxe_get(qp))
-		return -EAGAIN;
-
 	if (!qp->valid || qp->comp.state == QP_STATE_ERROR ||
 	    qp->comp.state == QP_STATE_RESET) {
 		rxe_drain_resp_pkts(qp, qp->valid &&
@@ -787,7 +784,6 @@ int rxe_completer(struct rxe_qp *qp)
 out:
 	if (pkt)
 		free_pkt(pkt);
-	rxe_put(qp);
 
 	return ret;
 }
diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c
index f2dc2d191e16..abc65c54bfd6 100644
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -653,9 +653,6 @@ int rxe_requester(struct rxe_qp *qp)
 	struct rxe_ah *ah;
 	struct rxe_av *av;
 
-	if (!rxe_get(qp))
-		return -EAGAIN;
-
 	if (unlikely(!qp->valid))
 		goto exit;
 
@@ -844,7 +841,5 @@ int rxe_requester(struct rxe_qp *qp)
 exit:
 	ret = -EAGAIN;
 out:
-	rxe_put(qp);
-
 	return ret;
 }
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index 7cb1b962d665..09271c861cc6 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -1450,9 +1450,6 @@ int rxe_responder(struct rxe_qp *qp)
 	struct rxe_pkt_info *pkt = NULL;
 	int ret;
 
-	if (!rxe_get(qp))
-		return -EAGAIN;
-
 	qp->resp.aeth_syndrome = AETH_ACK_UNLIMITED;
 
 	if (!qp->valid)
@@ -1651,6 +1648,5 @@ int rxe_responder(struct rxe_qp *qp)
 exit:
 	ret = -EAGAIN;
 out:
-	rxe_put(qp);
 	return ret;
 }
-- 
2.37.2


  parent reply	other threads:[~2023-02-22 23:35 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-22 23:32 [PATCH for-next 0/9] RDMA/rxe: Correct qp reference counting Bob Pearson
2023-02-22 23:32 ` [PATCH for-next 1/9] RDMA/rxe: Extend debug log messages Bob Pearson
2023-02-22 23:32 ` [PATCH for-next 2/9] RDMA/rxe: Add error messages Bob Pearson
2023-02-22 23:32 ` [PATCH for-next 3/9] RDMA/rxe: Convert tasklet args to queue pairs Bob Pearson
2023-02-22 23:32 ` [PATCH for-next 4/9] RDMA/rxe: Remove extra rxe_get(qp) in rxe_rcv_mcast_pkt Bob Pearson
2023-02-22 23:32 ` [PATCH for-next 5/9] RDMA/rxe: Add a warning if refcnt zero in rxe_put Bob Pearson
2023-02-22 23:32 ` [PATCH for-next 6/9] RDMA/rxe: Replace some __rxe_do_task by rxe_sched_task Bob Pearson
2023-02-22 23:32 ` [PATCH for-next 7/9] RDMA/rxe: Check for unsupported wr opcodes Bob Pearson
2023-02-22 23:32 ` Bob Pearson [this message]
2023-02-22 23:32 ` [PATCH for-next 9/9] RDMA/rxe: Rewrite rxe_task.c Bob Pearson

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=20230222233237.48940-9-rpearsonhpe@gmail.com \
    --to=rpearsonhpe@gmail.com \
    --cc=jgg@nvidia.com \
    --cc=jhack@hpe.com \
    --cc=linux-rdma@vger.kernel.org \
    --cc=matsuda-daisuke@fujitsu.com \
    --cc=zyjzyj2000@gmail.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.