From patchwork Mon Dec 21 14:23:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joyce Kong X-Patchwork-Id: 85601 X-Patchwork-Delegate: maxime.coquelin@redhat.com Return-Path: X-Original-To: patchwork@inbox.dpdk.org Delivered-To: patchwork@inbox.dpdk.org Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id C0371A09EF; Mon, 21 Dec 2020 15:24:05 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 4C3A0CB7F; Mon, 21 Dec 2020 15:23:51 +0100 (CET) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id 16893CB76 for ; Mon, 21 Dec 2020 15:23:50 +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 815861042; Mon, 21 Dec 2020 06:23:48 -0800 (PST) Received: from net-arm-thunderx2-03.shanghai.arm.com (net-arm-thunderx2-03.shanghai.arm.com [10.169.208.206]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 53B4B3F6CF; Mon, 21 Dec 2020 06:23:46 -0800 (PST) From: Joyce Kong To: maxime.coquelin@redhat.com, chenbo.xia@intel.com, honnappa.nagarahalli@arm.com, ruifeng.wang@arm.com Cc: dev@dpdk.org, nd@arm.com Date: Mon, 21 Dec 2020 22:23:18 +0800 Message-Id: <20201221142321.51606-2-joyce.kong@arm.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201221142321.51606-1-joyce.kong@arm.com> References: <20201221142321.51606-1-joyce.kong@arm.com> MIME-Version: 1.0 Subject: [dpdk-dev] [PATCH v1 1/4] net/virtio: remove unnecessary rmb barrier 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" As desc_is_used has a load-acquire or rte_io_rmb inside and wait for used desc in virtqueue, it is ok to remove virtio_rmb behind it. Signed-off-by: Joyce Kong Reviewed-by: Ruifeng Wang Reviewed-by: Maxime Coquelin --- drivers/net/virtio/virtio_ethdev.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c index 6c233b75b..0d91f7a50 100644 --- a/drivers/net/virtio/virtio_ethdev.c +++ b/drivers/net/virtio/virtio_ethdev.c @@ -209,12 +209,12 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, virtio_wmb(vq->hw->weak_barriers); virtqueue_notify(vq); - /* wait for used descriptors in virtqueue */ + /* wait for used desc in virtqueue + * desc_is_used has a load-acquire or rte_io_rmb inside + */ while (!desc_is_used(&desc[head], vq)) usleep(100); - virtio_rmb(vq->hw->weak_barriers); - /* now get used descriptors */ vq->vq_free_cnt += nb_descs; vq->vq_used_cons_idx += nb_descs;