From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f177.google.com (mail-pf0-f177.google.com [209.85.192.177]) by dpdk.org (Postfix) with ESMTP id 57364231C for ; Fri, 23 Sep 2016 20:24:07 +0200 (CEST) Received: by mail-pf0-f177.google.com with SMTP id s13so10088799pfd.2 for ; Fri, 23 Sep 2016 11:24:07 -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=DLBD+vG0lO4XQ1nD9swJEU316aIpI/f44PWi9TT653s=; b=gGNDTYT83ddC/2UHGVuL9mCMP5xTk9uVnISOw6Z0e0gnHfJy4/URpa01vyJ6+sdGj+ xoSrgu4528oqD/Ef1cWvNpMjpdFRa+AzKA71myWhjE2xH0ZSFdLG0BA3tEcx2fe82ao+ 15Yyx3B+m9LMkVHIv+A3oXDz0Y5AXNHCg5xcZPCxEf27H53CouEJTfo8pCPvg32lwIRl XoxBTD2wMnHTOp3JZpwDYMl9P5qDbEnAUj1QCQHaQdWbt7YFxoNAibMuv5p4SWOJ8sJ9 wg0f1FAj3e7cxTGwC0ELa1nt9qac7a9Bk78fNAQjxvUZEmPNJHfZjtcjpGlT+ROnU1qK NqoA== 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=DLBD+vG0lO4XQ1nD9swJEU316aIpI/f44PWi9TT653s=; b=h0fgAZ4Chbdwfu6rdKthQ2/lPZO/WbDfmmUWaApvd8FhqZWW+X1YVk32R+VkjjFl1D z63oHYHKIi4MZv9UqcjHt+ZlYTsHT6JEHAi3DWx217v2i9Zmhmjuzw8dCBbq+157Wael 2gIWfQPQaxkkSL5mnbdYhhDnGG7fj5WNqCo0k0pLRzNrT01mzsHW8VU+gEUDkrdqZFHk LNyyLPiOQrZSwFnQfCVp/aq8E85+eNoAn+QRNXczd0XMSxRoyvo46EqaYpHodNzgtHaj ylxZv3VDejarEu9TGnLFeV1flyHpUEAATnRaQEsrNoWicEBEuCos/K5kozI9qGq3g/EB 8uOg== X-Gm-Message-State: AE9vXwNYQK89WgNVw3TgF4QRVA/JwKsbvtTfSSp0u/BIpifYNjg8swlqU/NjB8iWX5lnHQ== X-Received: by 10.98.74.142 with SMTP id c14mr14634472pfj.29.1474655046701; Fri, 23 Sep 2016 11:24:06 -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 v6sm13191472pfv.8.2016.09.23.11.24.06 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 23 Sep 2016 11:24:06 -0700 (PDT) Date: Fri, 23 Sep 2016 11:24:16 -0700 From: Stephen Hemminger To: Maxime Coquelin Cc: yuanhan.liu@linux.intel.com, huawei.xie@intel.com, dev@dpdk.org, vkaplans@redhat.com, mst@redhat.com Message-ID: <20160923112416.4f798b4b@xeon-e3> In-Reply-To: <1474615009-26626-1-git-send-email-maxime.coquelin@redhat.com> References: <1474615009-26626-1-git-send-email-maxime.coquelin@redhat.com> 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 18:24:07 -0000 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?