From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 825E2A0471 for ; Tue, 13 Aug 2019 12:44:07 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 7EACD1BE0C; Tue, 13 Aug 2019 12:44:03 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id 5FD161BE0C; Tue, 13 Aug 2019 12:44:01 +0200 (CEST) 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 AF6DB1570; Tue, 13 Aug 2019 03:44:00 -0700 (PDT) Received: from net-arm-thunderx2.test.ast.arm.com (net-arm-thunderx2.shanghai.arm.com [10.169.40.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9AEF13F694; Tue, 13 Aug 2019 03:43:58 -0700 (PDT) From: Gavin Hu To: dev@dpdk.org Cc: nd@arm.com, thomas@monjalon.net, jerinj@marvell.com, pbhagavatula@marvell.com, Honnappa.Nagarahalli@arm.com, qi.z.zhang@intel.com, bruce.richardson@intel.com, stable@dpdk.org Date: Tue, 13 Aug 2019 18:43:30 +0800 Message-Id: <1565693011-33998-2-git-send-email-gavin.hu@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1565693011-33998-1-git-send-email-gavin.hu@arm.com> References: <1565693011-33998-1-git-send-email-gavin.hu@arm.com> Subject: [dpdk-dev] [PATCH 1/2] net/i40e: desc loading is unnecessarily ordered for aarch64 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 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" For x86, the descriptors needs to be loaded in order, so in between two descriptors loading, there is a compiler barrier in place.[1] For aarch64, a patch [2] is in place to survive with discontinuous DD bits, the barriers can be removed to take full advantage of out-of-order execution. 50% performance gain in the RFC2544 NDR test was measured on ThunderX2. 12.50% performan gain in the RFC2544 NDR test was measured on Ampere eMAG80 platform. [1] http://inbox.dpdk.org/users/039ED4275CED7440929022BC67E7061153D71548@ SHSMSX105.ccr.corp.intel.com/ [2] https://mails.dpdk.org/archives/stable/2017-October/003324.html Fixes: ae0eb310f253 ("net/i40e: implement vector PMD for ARM") Cc: stable@dpdk.org Signed-off-by: Gavin Hu Reviewed-by: Ruifeng Wang Reviewed-by: Steve Capper --- drivers/net/i40e/i40e_rxtx_vec_neon.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/net/i40e/i40e_rxtx_vec_neon.c b/drivers/net/i40e/i40e_rxtx_vec_neon.c index 83572ef..5555e9b 100644 --- a/drivers/net/i40e/i40e_rxtx_vec_neon.c +++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c @@ -285,7 +285,6 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts, /* Read desc statuses backwards to avoid race condition */ /* A.1 load 4 pkts desc */ descs[3] = vld1q_u64((uint64_t *)(rxdp + 3)); - rte_rmb(); /* B.2 copy 2 mbuf point into rx_pkts */ vst1q_u64((uint64_t *)&rx_pkts[pos], mbp1); -- 2.7.4