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Subject: [PATCH v1 2/8] svcrdma: Optimize svc_rdma_cc_init()
From: Chuck Lever <cel@kernel.org>
To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org
Cc: tom@talpey.com
Date: Mon, 11 Dec 2023 10:24:15 -0500
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From: Chuck Lever <chuck.lever@oracle.com>

The atomic_inc_return() in svc_rdma_send_cid_init() is expensive.

Some svc_rdma_chunk_ctxt's now reside in long-lived container
structures. They don't need a fresh completion ID for every I/O
operation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/xprtrdma/svc_rdma_recvfrom.c |    2 +-
 net/sunrpc/xprtrdma/svc_rdma_rw.c       |    9 +++++----
 net/sunrpc/xprtrdma/svc_rdma_sendto.c   |    2 +-
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index ac6351e292c5..38f01652dc6d 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -123,7 +123,7 @@ svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma)
 	dma_addr_t addr;
 	void *buffer;
 
-	ctxt = kmalloc_node(sizeof(*ctxt), GFP_KERNEL, node);
+	ctxt = kzalloc_node(sizeof(*ctxt), GFP_KERNEL, node);
 	if (!ctxt)
 		goto fail0;
 	buffer = kmalloc_node(rdma->sc_max_req_size, GFP_KERNEL, node);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c
index eab71f3867fa..ff54bb268b7d 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_rw.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c
@@ -154,7 +154,10 @@ static int svc_rdma_rw_ctx_init(struct svcxprt_rdma *rdma,
 void svc_rdma_cc_init(struct svcxprt_rdma *rdma,
 		      struct svc_rdma_chunk_ctxt *cc)
 {
-	svc_rdma_send_cid_init(rdma, &cc->cc_cid);
+	struct rpc_rdma_cid *cid = &cc->cc_cid;
+
+	if (unlikely(!cid->ci_completion_id))
+		svc_rdma_send_cid_init(rdma, cid);
 
 	INIT_LIST_HEAD(&cc->cc_rwctxts);
 	cc->cc_sqecount = 0;
@@ -221,15 +224,13 @@ svc_rdma_write_info_alloc(struct svcxprt_rdma *rdma,
 {
 	struct svc_rdma_write_info *info;
 
-	info = kmalloc_node(sizeof(*info), GFP_KERNEL,
+	info = kzalloc_node(sizeof(*info), GFP_KERNEL,
 			    ibdev_to_node(rdma->sc_cm_id->device));
 	if (!info)
 		return info;
 
 	info->wi_rdma = rdma;
 	info->wi_chunk = chunk;
-	info->wi_seg_off = 0;
-	info->wi_seg_no = 0;
 	svc_rdma_cc_init(rdma, &info->wi_cc);
 	info->wi_cc.cc_cqe.done = svc_rdma_write_done;
 	return info;
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index c9585e469ca8..1a49b7f02041 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -122,7 +122,7 @@ svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma)
 	void *buffer;
 	int i;
 
-	ctxt = kmalloc_node(struct_size(ctxt, sc_sges, rdma->sc_max_send_sges),
+	ctxt = kzalloc_node(struct_size(ctxt, sc_sges, rdma->sc_max_send_sges),
 			    GFP_KERNEL, node);
 	if (!ctxt)
 		goto fail0;