Ensure that the chosen Receive Queue depth for a newly created
transport does not overrun the QP WR limit of the underlying device.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/svc_rdma_transport.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 2aa8473..cdb04f8 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -167,8 +167,8 @@ static bool svc_rdma_prealloc_ctxts(struct svcxprt_rdma *xprt)
{
unsigned int i;
- /* Each RPC/RDMA credit can consume a number of send
- * and receive WQEs. One ctxt is allocated for each.
+ /* Each RPC/RDMA credit can consume one Receive and
+ * one Send WQE at the same time.
*/
i = xprt->sc_sq_depth + xprt->sc_rq_depth;
@@ -742,13 +742,18 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
newxprt->sc_max_sge = min((size_t)dev->attrs.max_sge,
(size_t)RPCSVC_MAXPAGES);
newxprt->sc_max_req_size = svcrdma_max_req_size;
- newxprt->sc_max_requests = min_t(u32, dev->attrs.max_qp_wr,
- svcrdma_max_requests);
- newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests);
- newxprt->sc_max_bc_requests = min_t(u32, dev->attrs.max_qp_wr,
- svcrdma_max_bc_requests);
+ newxprt->sc_max_requests = svcrdma_max_requests;
+ newxprt->sc_max_bc_requests = svcrdma_max_bc_requests;
newxprt->sc_rq_depth = newxprt->sc_max_requests +
newxprt->sc_max_bc_requests;
+ if (newxprt->sc_rq_depth > dev->attrs.max_qp_wr) {
+ pr_warn("svcrdma: reducing receive depth to %d\n",
+ dev->attrs.max_qp_wr);
+ newxprt->sc_rq_depth = dev->attrs.max_qp_wr;
+ newxprt->sc_max_requests = newxprt->sc_rq_depth - 2;
+ newxprt->sc_max_bc_requests = 2;
+ }
+ newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests);
newxprt->sc_sq_depth = newxprt->sc_rq_depth;
atomic_set(&newxprt->sc_sq_avail, newxprt->sc_sq_depth);
--
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