svcrdma: Post Receives in the Receive completion handler

This change improves Receive efficiency by posting Receives only
on the same CPU that handles Receive completion. Improved latency
and throughput has been noted with this change.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 7 insertions, 18 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 46ec069150d5..9ad12a215b51 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -58,6 +58,7 @@
 
 #define RPCDBG_FACILITY	RPCDBG_SVCXPRT
 
+static int svc_rdma_post_recv(struct svcxprt_rdma *xprt);
 static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *, int);
 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
 					struct net *net,
@@ -320,6 +321,8 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
 	list_add_tail(&ctxt->list, &xprt->sc_rq_dto_q);
 	spin_unlock(&xprt->sc_rq_dto_lock);
 
+	svc_rdma_post_recv(xprt);
+
 	set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags);
 	if (test_bit(RDMAXPRT_CONN_PENDING, &xprt->sc_flags))
 		goto out;
@@ -404,7 +407,8 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
 	return cma_xprt;
 }
 
-int svc_rdma_post_recv(struct svcxprt_rdma *xprt, gfp_t flags)
+static int
+svc_rdma_post_recv(struct svcxprt_rdma *xprt)
 {
 	struct ib_recv_wr recv_wr, *bad_recv_wr;
 	struct svc_rdma_op_ctxt *ctxt;
@@ -423,7 +427,7 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt, gfp_t flags)
 			pr_err("svcrdma: Too many sges (%d)\n", sge_no);
 			goto err_put_ctxt;
 		}
-		page = alloc_page(flags);
+		page = alloc_page(GFP_KERNEL);
 		if (!page)
 			goto err_put_ctxt;
 		ctxt->pages[sge_no] = page;
@@ -459,21 +463,6 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt, gfp_t flags)
 	return -ENOMEM;
 }
 
-int svc_rdma_repost_recv(struct svcxprt_rdma *xprt, gfp_t flags)
-{
-	int ret = 0;
-
-	ret = svc_rdma_post_recv(xprt, flags);
-	if (ret) {
-		pr_err("svcrdma: could not post a receive buffer, err=%d.\n",
-		       ret);
-		pr_err("svcrdma: closing transport %p.\n", xprt);
-		set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
-		ret = -ENOTCONN;
-	}
-	return ret;
-}
-
 static void
 svc_rdma_parse_connect_private(struct svcxprt_rdma *newxprt,
 			       struct rdma_conn_param *param)
@@ -833,7 +822,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 
 	/* Post receive buffers */
 	for (i = 0; i < newxprt->sc_max_requests; i++) {
-		ret = svc_rdma_post_recv(newxprt, GFP_KERNEL);
+		ret = svc_rdma_post_recv(newxprt);
 		if (ret) {
 			dprintk("svcrdma: failure posting receive buffers\n");
 			goto errout;