With FRWR, the client transport can perform memory registration and
post a Send with just a single ib_post_send.
This reduces contention between the send_request path and the Send
Completion handlers, and reduces the overhead of registering a chunk
that has multiple segments.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/fmr_ops.c | 11 ++++++++
net/sunrpc/xprtrdma/frwr_ops.c | 51 +++++++++++++++++++++++++++------------
net/sunrpc/xprtrdma/verbs.c | 3 +-
net/sunrpc/xprtrdma/xprt_rdma.h | 2 ++
4 files changed, 49 insertions(+), 18 deletions(-)
diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
index 629e539..5cc68a8 100644
--- a/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/net/sunrpc/xprtrdma/fmr_ops.c
@@ -251,6 +251,16 @@ enum {
return ERR_PTR(-EIO);
}
+/* Post Send WR containing the RPC Call message.
+ */
+static int
+fmr_op_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
+{
+ struct ib_send_wr *bad_wr;
+
+ return ib_post_send(ia->ri_id->qp, &req->rl_sendctx->sc_wr, &bad_wr);
+}
+
/* Invalidate all memory regions that were registered for "req".
*
* Sleeps until it is safe for the host CPU to access the
@@ -305,6 +315,7 @@ enum {
const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops = {
.ro_map = fmr_op_map,
+ .ro_send = fmr_op_send,
.ro_unmap_sync = fmr_op_unmap_sync,
.ro_recover_mr = fmr_op_recover_mr,
.ro_open = fmr_op_open,
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index e21781c..c5743a0 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -357,8 +357,7 @@
struct rpcrdma_mr *mr;
struct ib_mr *ibmr;
struct ib_reg_wr *reg_wr;
- struct ib_send_wr *bad_wr;
- int rc, i, n;
+ int i, n;
u8 key;
mr = NULL;
@@ -407,22 +406,12 @@
ib_update_fast_reg_key(ibmr, ++key);
reg_wr = &frwr->fr_regwr;
- reg_wr->wr.next = NULL;
- reg_wr->wr.opcode = IB_WR_REG_MR;
- frwr->fr_cqe.done = frwr_wc_fastreg;
- reg_wr->wr.wr_cqe = &frwr->fr_cqe;
- reg_wr->wr.num_sge = 0;
- reg_wr->wr.send_flags = 0;
reg_wr->mr = ibmr;
reg_wr->key = ibmr->rkey;
reg_wr->access = writing ?
IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
IB_ACCESS_REMOTE_READ;
- rc = ib_post_send(ia->ri_id->qp, ®_wr->wr, &bad_wr);
- if (rc)
- goto out_senderr;
-
mr->mr_handle = ibmr->rkey;
mr->mr_length = ibmr->length;
mr->mr_offset = ibmr->iova;
@@ -442,11 +431,40 @@
frwr->fr_mr, n, mr->mr_nents);
rpcrdma_mr_defer_recovery(mr);
return ERR_PTR(-EIO);
+}
-out_senderr:
- pr_err("rpcrdma: FRWR registration ib_post_send returned %i\n", rc);
- rpcrdma_mr_defer_recovery(mr);
- return ERR_PTR(-ENOTCONN);
+/* Post Send WR containing the RPC Call message.
+ *
+ * For FRMR, chain any FastReg WRs to the Send WR. Only a
+ * single ib_post_send call is needed to register memory
+ * and then post the Send WR.
+ */
+static int
+frwr_op_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
+{
+ struct ib_send_wr *post_wr, *bad_wr;
+ struct rpcrdma_mr *mr;
+
+ post_wr = &req->rl_sendctx->sc_wr;
+ list_for_each_entry(mr, &req->rl_registered, mr_list) {
+ struct rpcrdma_frwr *frwr;
+
+ frwr = &mr->frwr;
+
+ frwr->fr_cqe.done = frwr_wc_fastreg;
+ frwr->fr_regwr.wr.next = post_wr;
+ frwr->fr_regwr.wr.wr_cqe = &frwr->fr_cqe;
+ frwr->fr_regwr.wr.num_sge = 0;
+ frwr->fr_regwr.wr.opcode = IB_WR_REG_MR;
+ frwr->fr_regwr.wr.send_flags = 0;
+
+ post_wr = &frwr->fr_regwr.wr;
+ }
+
+ /* If ib_post_send fails, the next ->send_request for
+ * @req will queue these MWs for recovery.
+ */
+ return ib_post_send(ia->ri_id->qp, post_wr, &bad_wr);
}
/* Handle a remotely invalidated mr on the @mrs list
@@ -561,6 +579,7 @@
const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
.ro_map = frwr_op_map,
+ .ro_send = frwr_op_send,
.ro_reminv = frwr_op_reminv,
.ro_unmap_sync = frwr_op_unmap_sync,
.ro_recover_mr = frwr_op_recover_mr,
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index ab86724..626fd30 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1535,7 +1535,6 @@ struct rpcrdma_regbuf *
struct rpcrdma_req *req)
{
struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
- struct ib_send_wr *send_wr_fail;
int rc;
if (req->rl_reply) {
@@ -1554,7 +1553,7 @@ struct rpcrdma_regbuf *
--ep->rep_send_count;
}
- rc = ib_post_send(ia->ri_id->qp, send_wr, &send_wr_fail);
+ rc = ia->ri_ops->ro_send(ia, req);
trace_xprtrdma_post_send(req, rc);
if (rc)
return -ENOTCONN;
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 29ea0b4..3d3b423 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -472,6 +472,8 @@ struct rpcrdma_memreg_ops {
(*ro_map)(struct rpcrdma_xprt *,
struct rpcrdma_mr_seg *, int, bool,
struct rpcrdma_mr **);
+ int (*ro_send)(struct rpcrdma_ia *ia,
+ struct rpcrdma_req *req);
void (*ro_reminv)(struct rpcrdma_rep *rep,
struct list_head *mrs);
void (*ro_unmap_sync)(struct rpcrdma_xprt *,
--
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