rdma_create_qp modifies the qp_init_attr structure passed in
by the user to return the actual QP capabilities that were
allocated. If the qp_init_attr does not specify CQs, the
librdmacm will allocate CQs for the user and return them.
rdma_get_request will allocate a QP off newly connected rdma_cm_id
if the corresponding listen request is associated with a
qp_init_attr structure. The librdmacm passes in the listen->
qp_init_attr structure into the rdma_create_qp call.
rdma_create_qp ends up modifying the qp_init_attr's associated
with the listen. The result is that future calls to
rdma_get_request will use the modified qp attributes, rather
than those specified by the user.
Fix this by having rdma_get_request pass in a copy of the
qp_init_attr, rather than modifying those associated with the
listen. Also update the man page for rdma_create_qp to indicate
that the qp_init_attr structure may be modified on output.
Signed-off-by: Sean Hefty <sean.he...@intel.com>
---
I added a while(1) loop to rdma_server to allow clients to connected
repeatedly, and this worked for me. Jonathan, can you see if this
works for your testing as well? If so, I'll commit.
man/rdma_create_qp.3 | 3 +++
src/cma.c | 5 ++++-
2 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/man/rdma_create_qp.3 b/man/rdma_create_qp.3
index 9d2de76..7445db3 100644
--- a/man/rdma_create_qp.3
+++ b/man/rdma_create_qp.3
@@ -39,6 +39,9 @@ a send or receive completion queue is not specified, then a
CQ will be
allocated by the rdma_cm for the QP, along with corresponding completion
channels. Completion channels and CQ data created by the rdma_cm are
exposed to the user through the rdma_cm_id structure.
+.P
+The actual capabilities and properties of the created QP will be
+returned to the user through the qp_init_attr parameter.
.SH "SEE ALSO"
rdma_bind_addr(3), rdma_resolve_addr(3), rdma_destroy_qp(3), ibv_create_qp(3),
ibv_modify_qp(3)
diff --git a/src/cma.c b/src/cma.c
index 253cf80..7ac5335 100755
--- a/src/cma.c
+++ b/src/cma.c
@@ -1368,7 +1368,10 @@ int rdma_get_request(struct rdma_cm_id *listen, struct
rdma_cm_id **id)
}
if (id_priv->qp_init_attr) {
- ret = rdma_create_qp(event->id, id_priv->pd,
id_priv->qp_init_attr);
+ struct ibv_qp_init_attr attr;
+
+ attr = *id_priv->qp_init_attr;
+ ret = rdma_create_qp(event->id, id_priv->pd, &attr);
if (ret)
goto err;
}
--
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