From 48016dce46ad504a378849490bfb99c98be5cfaa Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 29 Nov 2016 10:52:48 -0500 Subject: [PATCH] xprtrdma: Avoid calls to ro_unmap_safe() 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 Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/transport.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index ed5e285fd2ea..545d3fc8de5a 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -621,7 +621,8 @@ xprt_rdma_free(struct rpc_task *task) 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 @@ xprt_rdma_send_request(struct rpc_task *task) 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)