From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:53698) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TVcxo-0006Nq-4B for qemu-devel@nongnu.org; Tue, 06 Nov 2012 01:48:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TVcxn-0001gt-1F for qemu-devel@nongnu.org; Tue, 06 Nov 2012 01:48:44 -0500 Received: from www.maurer-it.com ([213.129.239.114]:37113 helo=proxmox.maurer-it.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TVcxm-0001gd-NI for qemu-devel@nongnu.org; Tue, 06 Nov 2012 01:48:42 -0500 From: Dietmar Maurer Date: Tue, 6 Nov 2012 06:48:07 +0000 Message-ID: <24E144B8C0207547AD09C467A8259F75577E90DD@lisa.maurer-it.com> References: <24E144B8C0207547AD09C467A8259F75577D5BE5@lisa.maurer-it.com> In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [Qemu-devel] slow virtio network with vhost=on and multiple cores List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: "qemu-devel@nongnu.org" , "Michael S. Tsirkin" > Is the network path you are downloading across reasonably idle so that yo= u > get reproducible results between runs? Also tested with netperf (to local host) now. Results in short (performance in Mbit/sec): vhost=3Doff,cores=3D1: 3982 vhost=3Doff,cores=3D2: 3930 vhost=3Doff,cores=3D4: 3912 vhost=3Don,cores=3D1: 22065 vhost=3Don,cores=3D2: 1392 vhost=3Don,cores=3D4: 532 As you can see, vhost performance drops from 22065 to 532 - this is by fac= tor 40! And ideas? -- complete logs--- With vhost=3Doff / cores=3D1 # netperf -H maui TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to maui.maurer-it.com= (192.168.2.2) port 0 AF_INET : demo Recv Send Send =20 Socket Socket Message Elapsed =20 Size Size Size Time Throughput =20 bytes bytes bytes secs. 10^6bits/sec =20 87380 16384 16384 10.00 3982.74 =20 With vhost=3Doff / cores=3D2 # netperf -H maui TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to maui.maurer-it.com= (192.168.2.2) port 0 AF_INET : demo Recv Send Send =20 Socket Socket Message Elapsed =20 Size Size Size Time Throughput =20 bytes bytes bytes secs. 10^6bits/sec =20 87380 16384 16384 10.00 3930.62 =20 With vhost=3Doff / cores=3D4 # netperf -H maui TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to maui.maurer-it.com= (192.168.2.2) port 0 AF_INET : demo Recv Send Send =20 Socket Socket Message Elapsed =20 Size Size Size Time Throughput =20 bytes bytes bytes secs. 10^6bits/sec =20 87380 16384 16384 10.00 3912.36 =20 With vhost=3Don /cores=3D1 # netperf -H maui TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to maui.maurer-it.com= (192.168.2.2) port 0 AF_INET : demo Recv Send Send =20 Socket Socket Message Elapsed =20 Size Size Size Time Throughput =20 bytes bytes bytes secs. 10^6bits/sec =20 87380 16384 16384 10.00 22065.48=20 With vhost=3Don /cores=3D2 # netperf -H maui TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to maui.maurer-it.com= (192.168.2.2) port 0 AF_INET : demo Recv Send Send =20 Socket Socket Message Elapsed =20 Size Size Size Time Throughput =20 bytes bytes bytes secs. 10^6bits/sec =20 87380 16384 16384 10.01 1392.61 With vhost=3Don /cores=3D4 # netperf -H maui TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to maui.maurer-it.com= (192.168.2.2) port 0 AF_INET : demo Recv Send Send =20 Socket Socket Message Elapsed =20 Size Size Size Time Throughput =20 bytes bytes bytes secs. 10^6bits/sec =20 87380 16384 16384 10.05 532.31