[v1,07/14] xprtrdma: Avoid calls to ro_unmap_safe()
diff mbox

Message ID 20161109190546.15007.28710.stgit@manet.1015granger.net
State New
Headers show

Commit Message

Chuck Lever Nov. 9, 2016, 7:05 p.m. UTC
Micro-optimization: Most of the time, calls to ro_unmap_safe are
expensive no-ops. Call only when there is work to do.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/xprtrdma/transport.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)


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Patch
diff mbox

diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index ed5e285..545d3fc 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -621,7 +621,8 @@ 
 
 	dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
 
-	ia->ri_ops->ro_unmap_safe(r_xprt, req, !RPC_IS_ASYNC(task));
+	if (unlikely(!list_empty(&req->rl_registered)))
+		ia->ri_ops->ro_unmap_safe(r_xprt, req, !RPC_IS_ASYNC(task));
 	rpcrdma_unmap_sges(ia, req);
 	rpcrdma_buffer_put(req);
 }
@@ -657,7 +658,8 @@ 
 	int rc = 0;
 
 	/* On retransmit, remove any previously registered chunks */
-	r_xprt->rx_ia.ri_ops->ro_unmap_safe(r_xprt, req, false);
+	if (unlikely(!list_empty(&req->rl_registered)))
+		r_xprt->rx_ia.ri_ops->ro_unmap_safe(r_xprt, req, false);
 
 	rc = rpcrdma_marshal_req(rqst);
 	if (rc < 0)