From patchwork Thu Mar 18 10:25:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ruifeng Wang X-Patchwork-Id: 89483 X-Patchwork-Delegate: david.marchand@redhat.com Return-Path: X-Original-To: patchwork@inbox.dpdk.org Delivered-To: patchwork@inbox.dpdk.org Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id A1B83A0561; Thu, 18 Mar 2021 11:26:36 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id E2F38140EB9; Thu, 18 Mar 2021 11:26:35 +0100 (CET) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mails.dpdk.org (Postfix) with ESMTP id 76C47140E9B for ; Thu, 18 Mar 2021 11:26:34 +0100 (CET) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E41D831B; Thu, 18 Mar 2021 03:26:33 -0700 (PDT) Received: from net-arm-n1amp-01.shanghai.arm.com (net-arm-n1amp-01.shanghai.arm.com [10.169.210.137]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 14F0B3F792; Thu, 18 Mar 2021 03:26:30 -0700 (PDT) From: Ruifeng Wang To: jerinj@marvell.com, hemant.agrawal@nxp.com, ferruh.yigit@intel.com, thomas@monjalon.net, david.marchand@redhat.com Cc: dev@dpdk.org, nd@arm.com, honnappa.nagarahalli@arm.com, Ruifeng Wang Date: Thu, 18 Mar 2021 10:25:49 +0000 Message-Id: <20210318102550.59265-4-ruifeng.wang@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210318102550.59265-1-ruifeng.wang@arm.com> References: <20210318102550.59265-1-ruifeng.wang@arm.com> MIME-Version: 1.0 Subject: [dpdk-dev] [PATCH 3/4] examples/l3fwd: eliminate unnecessary reloads in loop X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Number of rx queue and number of rx port in lcore config are constants during the period of l3 forward application running. But compiler has no this information. Copied values from lcore config to local variables and used the local variables for iteration. Compiler can see that the local variables are not changed, so qconf reloads at each iteration can be eliminated. The change showed 1.8% performance uplift in single core, single port, single queue test on N1SDP platform with MLX5 NIC. Signed-off-by: Ruifeng Wang --- examples/l3fwd/l3fwd_lpm.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/examples/l3fwd/l3fwd_lpm.c b/examples/l3fwd/l3fwd_lpm.c index 3dcf1fef1..d338590b9 100644 --- a/examples/l3fwd/l3fwd_lpm.c +++ b/examples/l3fwd/l3fwd_lpm.c @@ -190,14 +190,16 @@ lpm_main_loop(__rte_unused void *dummy) lcore_id = rte_lcore_id(); qconf = &lcore_conf[lcore_id]; - if (qconf->n_rx_queue == 0) { + uint16_t n_rx_q = qconf->n_rx_queue; + uint16_t n_tx_p = qconf->n_tx_port; + if (n_rx_q == 0) { RTE_LOG(INFO, L3FWD, "lcore %u has nothing to do\n", lcore_id); return 0; } RTE_LOG(INFO, L3FWD, "entering main loop on lcore %u\n", lcore_id); - for (i = 0; i < qconf->n_rx_queue; i++) { + for (i = 0; i < n_rx_q; i++) { portid = qconf->rx_queue_list[i].port_id; queueid = qconf->rx_queue_list[i].queue_id; @@ -216,7 +218,7 @@ lpm_main_loop(__rte_unused void *dummy) diff_tsc = cur_tsc - prev_tsc; if (unlikely(diff_tsc > drain_tsc)) { - for (i = 0; i < qconf->n_tx_port; ++i) { + for (i = 0; i < n_tx_p; ++i) { portid = qconf->tx_port_id[i]; if (qconf->tx_mbufs[portid].len == 0) continue; @@ -232,7 +234,7 @@ lpm_main_loop(__rte_unused void *dummy) /* * Read packet from RX queues */ - for (i = 0; i < qconf->n_rx_queue; ++i) { + for (i = 0; i < n_rx_q; ++i) { portid = qconf->rx_queue_list[i].port_id; queueid = qconf->rx_queue_list[i].queue_id; nb_rx = rte_eth_rx_burst(portid, queueid, pkts_burst,