diff options
| author | Andrew Boyer <andrew.boyer@dell.com> | 2016-11-23 18:39:18 +0100 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2016-12-12 22:31:45 +0100 |
| commit | dd753d87436ce7ef2a958d684b38d5acc99c9f5c (patch) | |
| tree | bde5eb088fba64caa154cc0e8c3691f9cd38b63f /drivers/infiniband | |
| parent | IB/rxe: Remove buffer used for printing IP address (diff) | |
| download | linux-dd753d87436ce7ef2a958d684b38d5acc99c9f5c.tar.xz linux-dd753d87436ce7ef2a958d684b38d5acc99c9f5c.zip | |
IB/rxe: Advance the consumer pointer before posting the CQE
A simple userspace application might poll the CQ, find a completion,
and then attempt to post a new WQE to the SQ. A spurious error can
occur if the userspace application detects a full SQ in the instant
before the kernel is able to advance the SQ consumer pointer.
This is noticeable when using single-entry SQs with ibv_rc_pingpong
if lots of kernel and userspace library debugging is enabled.
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Reviewed-by: Yonatan Cohen <yonatanc@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/sw/rxe/rxe_comp.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_comp.c b/drivers/infiniband/sw/rxe/rxe_comp.c index 6c5e29db88e3..d46c49b33b13 100644 --- a/drivers/infiniband/sw/rxe/rxe_comp.c +++ b/drivers/infiniband/sw/rxe/rxe_comp.c @@ -420,11 +420,12 @@ static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe) (wqe->wr.send_flags & IB_SEND_SIGNALED) || (qp->req.state == QP_STATE_ERROR)) { make_send_cqe(qp, wqe, &cqe); + advance_consumer(qp->sq.queue); rxe_cq_post(qp->scq, &cqe, 0); + } else { + advance_consumer(qp->sq.queue); } - advance_consumer(qp->sq.queue); - /* * we completed something so let req run again * if it is trying to fence |