From patchwork Fri Jun 14 13:55:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luigi Leonardi X-Patchwork-Id: 13698730 X-Patchwork-Delegate: kuba@kernel.org Received: from EUR03-AM7-obe.outbound.protection.outlook.com (mail-am7eur03olkn2057.outbound.protection.outlook.com [40.92.59.57]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D15FABE65; Fri, 14 Jun 2024 13:55:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.92.59.57 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718373360; cv=fail; b=gpkcIzoTo3Lrt2GheGa3mb3POlN1Dm5htcgHJRU0xa1IDszohdBg/bhtl7Zqa8cyv69kdoV9uODupUa7toiRuhzr+z7NGT5TRsNUoPE9+7r875pjSZ5dz2UaadCHNIG1cmYktzV6T9ORReCVHeoKid7LNbkYRYRheelZ2QSapjg= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718373360; c=relaxed/simple; bh=PbcR8chyGrvRobCuehcXslLl+Q50d6BejioPRAdAJOM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=hJAIiv35YQLCeSdKUDHSYg7MVXggAS6GfYauyMxF616sgXMRa8V6Av7ZkZMahcJZIHpk5iVjSjCC2pkV2vMVe7g/EKJGAyYXFiqYr5a7HZ+e9BpM2vV+No+yRfcXBZCr5EhHQqhxVwS9ms6A6ZXrZCribfXqPOfMf/8VqE31DGg= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=outlook.com; spf=pass smtp.mailfrom=outlook.com; dkim=pass (2048-bit key) header.d=outlook.com header.i=@outlook.com header.b=dLfUj49/; arc=fail smtp.client-ip=40.92.59.57 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=outlook.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=outlook.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=outlook.com header.i=@outlook.com header.b="dLfUj49/" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=E2DaS/H4saj1To0E2acGxi9jQxMWbt2h3MTmV8TzgP7IRyVGzFAEKdk7ar4yOec9XFsXvf3C7eAVDBJf+27cDiWizU7MZwIigGldJElLXEOc9hoIBgWrwGEcIuFHSwNyb/SIIOHFjyWytu34Ls7fjyNYsFq/5WbpXKyJDjG841ghaCncL5I8d9ymFL13b8yiVPflN+v8ogoHEjqzXNE18t8HfuLjwFftfDym8f52JQzRn/sSWOAHtoCsSi64ZO8YRzLvFAE4Qb6oEFWRRh5pC4xtRJrkFlbD5kHKSv7BJ4zS7dKSau/SzymB9vVqjJNyIf+aNIEIPTgXuBT60CkgZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=Vbq4SBZ24qmRTbz8LqgCwYGwTDk8D5Sa4oWquQYwEhM=; b=SLlDDuglFE/1LZjte4Y48COo1ICmM1G8iWWGiIzpzhI6rC5zqfU4DQJG/NtVpngm5B8Y14ht9HB1TdrgkIcKBVkmFXcKDitK2B4cCanVzcHgv4BL3gxyc7auAhnMGawQPUos7dI7JtRvG7lWKZxHutM0eIowWYkHduUkyEyerW4T4ulbsHM6Fkiq+H6IXasVDXKwBxdBcAMQqc5EmupHT7/K1K6Elxwyzpl7NRWUls11GcEpZHYmr/JYfn39VoxyJ1zk/cz9GbmmRgbCDtwiaDWJtQOgciKaA/5yMrLffx4EN15769WAlr5qJ3qebdGp+K4UZ6TRkqxckSuvmhLzOg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=outlook.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=Vbq4SBZ24qmRTbz8LqgCwYGwTDk8D5Sa4oWquQYwEhM=; b=dLfUj49/C5ACfMGcm2Rkvk1bXciMnwKmjzKs+MveUT+BPo1Sat3EHFQbdnNTFYpIYQ/m0MmMwtMBZm8DeAGjVJe2sdi4+oW463rfzL+EJzL/lJ7co5n1QzKn2pwiZw5jJRMyI+Cn7tlmLLnEFKquTEtZ7HU2ZZfBC1wt0BSAKfTncRDRM0SLrGSiWLjFsPdPimJlFaNfY0hGUeW6FY9+bKBjdOW24z6QFuCt1DrFwTCFA1aDa6Pd9osC5Jvomv3uGYLrG/WOhFsuEbEmKkWKLFP3ervGf28H3W8KqTBGv0kgxd4jMGqMQNH62zcP0Apvd/5B1xJWI0K3NPQh7bldyg== Received: from AS2P194MB2170.EURP194.PROD.OUTLOOK.COM (2603:10a6:20b:642::8) by PAXP194MB1469.EURP194.PROD.OUTLOOK.COM (2603:10a6:102:1a8::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7677.24; Fri, 14 Jun 2024 13:55:51 +0000 Received: from AS2P194MB2170.EURP194.PROD.OUTLOOK.COM ([fe80::3d63:e123:2c2f:c930]) by AS2P194MB2170.EURP194.PROD.OUTLOOK.COM ([fe80::3d63:e123:2c2f:c930%3]) with mapi id 15.20.7677.024; Fri, 14 Jun 2024 13:55:51 +0000 From: Luigi Leonardi To: sgarzare@redhat.com, edumazet@google.com, virtualization@lists.linux.dev, netdev@vger.kernel.org, kuba@kernel.org, kvm@vger.kernel.org, stefanha@redhat.com, pabeni@redhat.com, davem@davemloft.net Cc: Marco Pinna , Luigi Leonardi Subject: [PATCH net-next 2/2] vsock/virtio: avoid enqueue packets when work queue is empty Date: Fri, 14 Jun 2024 15:55:43 +0200 Message-ID: X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240614135543.31515-1-luigi.leonardi@outlook.com> References: <20240614135543.31515-1-luigi.leonardi@outlook.com> X-TMN: [zmAx0oZ3aW9aLNZjpKtjFc1D5puwy8oS] X-ClientProxiedBy: MI0P293CA0015.ITAP293.PROD.OUTLOOK.COM (2603:10a6:290:44::8) To AS2P194MB2170.EURP194.PROD.OUTLOOK.COM (2603:10a6:20b:642::8) X-Microsoft-Original-Message-ID: <20240614135543.31515-3-luigi.leonardi@outlook.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: AS2P194MB2170:EE_|PAXP194MB1469:EE_ X-MS-Office365-Filtering-Correlation-Id: 76ae548f-9d8b-46db-c92a-08dc8c79b3b9 X-Microsoft-Antispam: BCL:0;ARA:14566002|461199025|3412199022|440099025|1710799023; X-Microsoft-Antispam-Message-Info: WW/B1PvIk5+eqfQhx3R2kSqmMKWbQevi5x8gs1W3/3v/3NrEFRxD2ig37z7hTazVM2HqZizQKLNnLfQS8+ZOhVx/ZODmeNnqpwyIjddVTLqB3uVUR99KMHSHODY4syjMDpIouP5hAM9IGX9Tz50G7YX8+KYWMN9otMLm6N5f9I9yUQ0yfoqgG2qDs+vQ9MT8REdNFQrn8T7QSNLNnTdt1ylMF9zT+bPqNPrrG0tDA+Em0d1d0/iI5Xn1KbRVbzoFO9npNsfeM1a4ge9F0R6I/c7lBsqy4X8GIsLURSxi+sFHn+/vnV0/HaiNZ4ZWY+fotIWHOw+U7CG10XsZb1yfKLTt2YGjOTnjwwNo16PfirBzKTKyxnnd5nxOmkoyAzjbxHT2EEf4T/SlUfRbAoprtWo+ZFLVy5cJTvpvb0Aw3Lnv+GpNI/2XKxZsWWH5fsmFxrY0617zFBRWJF0oMD4aA7O7YbPecsse59AFQst2vHAzojwDbWGJ6qDLmi0mg1hng60Uo7c5gKXE6gwZaszUSBXR4eqiFsZjmkumusHsGbRizDy/s6k8GU1H5WXFyT9S/cBlcgGBP5Fz7pS2J7xzxVXO4ztG3E9Ggz9u7WY6fq5M5qNJTVxlvThMyLxNC/kU X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 76ae548f-9d8b-46db-c92a-08dc8c79b3b9 X-MS-Exchange-CrossTenant-AuthSource: AS2P194MB2170.EURP194.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Jun 2024 13:55:51.5906 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-Transport-CrossTenantHeadersStamped: PAXP194MB1469 X-Patchwork-Delegate: kuba@kernel.org From: Marco Pinna This introduces an optimization in virtio_transport_send_pkt: when the work queue (send_pkt_queue) is empty the packet is put directly in the virtqueue reducing latency. In the following benchmark (pingpong mode) the host sends a payload to the guest and waits for the same payload back. Tool: Fio version 3.37-56 Env: Phys host + L1 Guest Payload: 4k Runtime-per-test: 50s Mode: pingpong (h-g-h) Test runs: 50 Type: SOCK_STREAM Before (Linux 6.8.11) ------ mean(1st percentile): 722.45 ns mean(overall): 1686.23 ns mean(99th percentile): 35379.27 ns After ------ mean(1st percentile): 602.62 ns mean(overall): 1248.83 ns mean(99th percentile): 17557.33 ns Co-developed-by: Luigi Leonardi Signed-off-by: Luigi Leonardi Signed-off-by: Marco Pinna --- net/vmw_vsock/virtio_transport.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index c930235ecaec..e89bf87282b2 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -214,7 +214,9 @@ virtio_transport_send_pkt(struct sk_buff *skb) { struct virtio_vsock_hdr *hdr; struct virtio_vsock *vsock; + bool use_worker = true; int len = skb->len; + int ret = -1; hdr = virtio_vsock_hdr(skb); @@ -235,8 +237,34 @@ virtio_transport_send_pkt(struct sk_buff *skb) if (virtio_vsock_skb_reply(skb)) atomic_inc(&vsock->queued_replies); - virtio_vsock_skb_queue_tail(&vsock->send_pkt_queue, skb); - queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); + /* If the send_pkt_queue is empty there is no need to enqueue the packet. + * Just put it on the ringbuff using virtio_transport_send_skb. + */ + + if (skb_queue_empty_lockless(&vsock->send_pkt_queue)) { + bool restart_rx = false; + struct virtqueue *vq; + + mutex_lock(&vsock->tx_lock); + + vq = vsock->vqs[VSOCK_VQ_TX]; + + ret = virtio_transport_send_skb(skb, vq, vsock, &restart_rx); + if (ret == 0) { + use_worker = false; + virtqueue_kick(vq); + } + + mutex_unlock(&vsock->tx_lock); + + if (restart_rx) + queue_work(virtio_vsock_workqueue, &vsock->rx_work); + } + + if (use_worker) { + virtio_vsock_skb_queue_tail(&vsock->send_pkt_queue, skb); + queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); + } out_rcu: rcu_read_unlock();