From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chuck Lever Subject: [PATCH v3 06/12] xprtrdma: Avoid calls to ro_unmap_safe() Date: Tue, 29 Nov 2016 10:52:48 -0500 Message-ID: <20161129155248.23061.92870.stgit@manet.1015granger.net> References: <20161129154845.23061.29385.stgit@manet.1015granger.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20161129154845.23061.29385.stgit-FYjufvaPoItvLzlybtyyYzGyq/o6K9yX@public.gmane.org> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: anna.schumaker-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org 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 --- 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 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) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html