From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f181.google.com (mail-pf0-f181.google.com [209.85.192.181]) by dpdk.org (Postfix) with ESMTP id 780AE68F2 for ; Fri, 23 Sep 2016 22:27:55 +0200 (CEST) Received: by mail-pf0-f181.google.com with SMTP id 21so45235552pfy.0 for ; Fri, 23 Sep 2016 13:27:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bIcUiBtEyMXO+gpabg9KdQVqrUGE2knBoy50tQHDDbs=; b=xbe4762+WMvudELKQ+t3pTKfWjgKJaZ5JGCid3A6y4xD0YjGxAP1QXnKtZ7XEmf5xg Ch65xgDE0RjHDtx6tv6qqR4VjLy3WyrS5iD6gFd7vAclB+9RCWCOPS156d0zAgWj3sY6 y15e/dfRfCQws1EyWL5qxX2loNRoc2FrdOInNcjSNUEonmIodzRCW0C8g0jzeB7f6xBo r9Fw6XkzsTKO0/ACx/bxIS+/wUiBEearOLzbAr0YVj9AC7mEBOsoKBJLNoDy1jtEv0tS tN4UUQqH8IpI6+x2AHGHwn6P5dqilyEs8JtyJD10Do6RVLMfgI/d3SemzaP1zaHLiJBw 5x0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bIcUiBtEyMXO+gpabg9KdQVqrUGE2knBoy50tQHDDbs=; b=TXskG7clQmClLQyszGZUPYX4NyrYmVSIWhZdU6y9tCqUAeHTFPUZzHtQ9owe6Us2C+ tPlWE4qT7zYJd7q/gJZ0FokoYU3JKLacDZKTTer9rOdtzNtOH5lwE7yp7uTbgHE+KHfb UXS/8w5if2MOd4bwGXv7Ym5H3SPVEbqJip87gnlYn+UfAeG4x79T4EN1cyb94JoFd8ff BApuuyNK3T4oj1Pct4PyhK3OfnbPnPFtofsBObVOyxCBQKMIW8RuEUmxzsGFF6LtxGX0 d8zwqNBGwAPSQtbm4hHMwbsx58dHdwPeeDH1lr9VgGrwYc2KuOi774JD8Nr03LUGiAOj 9GzA== X-Gm-Message-State: AE9vXwNOIJSmLiW2jtxXGUqwvqruuBg3M18NlHoYdCZ9VA2mNyVY2GnLyxz9ESSnkFBkgA== X-Received: by 10.98.204.207 with SMTP id j76mr15554766pfk.6.1474662474790; Fri, 23 Sep 2016 13:27:54 -0700 (PDT) Received: from xeon-e3 (static-50-53-69-251.bvtn.or.frontiernet.net. [50.53.69.251]) by smtp.gmail.com with ESMTPSA id si1sm944622pab.0.2016.09.23.13.27.54 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 23 Sep 2016 13:27:54 -0700 (PDT) Date: Fri, 23 Sep 2016 13:28:05 -0700 From: Stephen Hemminger To: "Michael S. Tsirkin" Cc: Maxime Coquelin , yuanhan.liu@linux.intel.com, huawei.xie@intel.com, dev@dpdk.org, vkaplans@redhat.com Message-ID: <20160923132805.3207f1fa@xeon-e3> In-Reply-To: <20160923213055-mutt-send-email-mst@kernel.org> References: <1474615009-26626-1-git-send-email-maxime.coquelin@redhat.com> <20160923112416.4f798b4b@xeon-e3> <20160923213055-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v2] vhost: Add indirect descriptors support to the TX path X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Sep 2016 20:27:56 -0000 On Fri, 23 Sep 2016 21:31:27 +0300 "Michael S. Tsirkin" wrote: > On Fri, Sep 23, 2016 at 11:24:16AM -0700, Stephen Hemminger wrote: > > On Fri, 23 Sep 2016 09:16:49 +0200 > > Maxime Coquelin wrote: > > > > > Indirect descriptors are usually supported by virtio-net devices, > > > allowing to dispatch a larger number of requests. > > > > > > When the virtio device sends a packet using indirect descriptors, > > > only one slot is used in the ring, even for large packets. > > > > > > The main effect is to improve the 0% packet loss benchmark. > > > A PVP benchmark using Moongen (64 bytes) on the TE, and testpmd > > > (fwd io for host, macswap for VM) on DUT shows a +50% gain for > > > zero loss. > > > > > > On the downside, micro-benchmark using testpmd txonly in VM and > > > rxonly on host shows a loss between 1 and 4%.i But depending on > > > the needs, feature can be disabled at VM boot time by passing > > > indirect_desc=off argument to vhost-user device in Qemu. > > > > > > Signed-off-by: Maxime Coquelin > > > > What about supporting VIRTIO_F_ANY_LAYOUT? > > I thought it's already supported. > That's required by virtio 1 and dpdk claims support for that. > I don't see the flag set in the DPDK vhost driver feature bits (at least in the source). /* Features supported by this lib. */ #define VHOST_SUPPORTED_FEATURES ((1ULL << VIRTIO_NET_F_MRG_RXBUF) | \ (1ULL << VIRTIO_NET_F_CTRL_VQ) | \ (1ULL << VIRTIO_NET_F_CTRL_RX) | \ (1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE) | \ (VHOST_SUPPORTS_MQ) | \ (1ULL << VIRTIO_F_VERSION_1) | \ (1ULL << VHOST_F_LOG_ALL) | \ (1ULL << VHOST_USER_F_PROTOCOL_FEATURES) | \ (1ULL << VIRTIO_NET_F_HOST_TSO4) | \ (1ULL << VIRTIO_NET_F_HOST_TSO6) | \ (1ULL << VIRTIO_NET_F_CSUM) | \ (1ULL << VIRTIO_NET_F_GUEST_CSUM) | \ (1ULL << VIRTIO_NET_F_GUEST_TSO4) | \ (1ULL << VIRTIO_NET_F_GUEST_TSO6))