The rdma_rw API adjusts max_send_wr upwards during the
rdma_create_qp() call. If the ULP actually wants to take advantage
of these extra resources, it must increase the size of its send
completion queue (created before rdma_create_qp is called) and
increase its send queue accounting limit.
Use the new rdma_rw_mr_factor API to figure out the correct value
to use for the Send Queue and Send Completion Queue depths.
And, ensure that the chosen Send Queue depth for a newly created
transport does not overrun the QP WR limit of the underlying device.
Lastly, there's no longer a need to carry the Send Queue depth in
struct svcxprt_rdma, since the value is used only in the
svc_rdma_accept() path.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/svc_rdma_transport.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index cdb04f8..5caf8e7 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -51,6 +51,7 @@
#include <linux/workqueue.h>
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
+#include <rdma/rw.h>
#include <linux/sunrpc/svc_rdma.h>
#include <linux/export.h>
#include "xprt_rdma.h"
@@ -713,7 +714,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
struct ib_qp_init_attr qp_attr;
struct ib_device *dev;
struct sockaddr *sap;
- unsigned int i;
+ unsigned int i, ctxts;
int ret = 0;
listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt);
@@ -754,7 +755,14 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
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;
+ ctxts = rdma_rw_mr_factor(dev, newxprt->sc_port_num, RPCSVC_MAXPAGES);
+ ctxts *= newxprt->sc_max_requests;
+ newxprt->sc_sq_depth = newxprt->sc_rq_depth + ctxts;
+ if (newxprt->sc_sq_depth > dev->attrs.max_qp_wr) {
+ pr_warn("svcrdma: reducing send depth to %d\n",
+ dev->attrs.max_qp_wr);
+ newxprt->sc_sq_depth = dev->attrs.max_qp_wr;
+ }
atomic_set(&newxprt->sc_sq_avail, newxprt->sc_sq_depth);
if (!svc_rdma_prealloc_ctxts(newxprt))
@@ -789,8 +797,8 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
qp_attr.event_handler = qp_event_handler;
qp_attr.qp_context = &newxprt->sc_xprt;
qp_attr.port_num = newxprt->sc_port_num;
- qp_attr.cap.max_rdma_ctxs = newxprt->sc_max_requests;
- qp_attr.cap.max_send_wr = newxprt->sc_sq_depth;
+ qp_attr.cap.max_rdma_ctxs = ctxts;
+ qp_attr.cap.max_send_wr = newxprt->sc_sq_depth - ctxts;
qp_attr.cap.max_recv_wr = newxprt->sc_rq_depth;
qp_attr.cap.max_send_sge = newxprt->sc_max_sge;
qp_attr.cap.max_recv_sge = newxprt->sc_max_sge;
@@ -858,6 +866,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
dprintk(" remote address : %pIS:%u\n", sap, rpc_get_port(sap));
dprintk(" max_sge : %d\n", newxprt->sc_max_sge);
dprintk(" sq_depth : %d\n", newxprt->sc_sq_depth);
+ dprintk(" rdma_rw_ctxs : %d\n", ctxts);
dprintk(" max_requests : %d\n", newxprt->sc_max_requests);
dprintk(" ord : %d\n", newxprt->sc_ord);
--
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