From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: AW: AW: KVM performance Date: Tue, 07 Apr 2009 20:34:02 +0300 Message-ID: <49DB8E8A.1090908@redhat.com> References: <133D9897FB9C5E4E9DF2779DC91E947C518348@SLFSNX.rcs.alcatel-research.de> <49D9EB48.4030709@redhat.com> <133D9897FB9C5E4E9DF2779DC91E947C51834A@SLFSNX.rcs.alcatel-research.de> <49DA2F54.8090109@redhat.com> <133D9897FB9C5E4E9DF2779DC91E947C51834E@SLFSNX.rcs.alcatel-research.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: "BRAUN, Stefanie" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:37301 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755570AbZDGRd2 (ORCPT ); Tue, 7 Apr 2009 13:33:28 -0400 In-Reply-To: <133D9897FB9C5E4E9DF2779DC91E947C51834E@SLFSNX.rcs.alcatel-research.de> Sender: kvm-owner@vger.kernel.org List-ID: BRAUN, Stefanie wrote: > 1. Subtest: VLC reads video from local disk and streams it via udp to another pc > Host performance: 11% 11% > kvm process in host (top): 22% 22% > vlc process in vmu (top): 15% 7% > > While this isn't wonderful, it's not your major bottleneck now. What's the bandwidth generated by the workload? > > 4. Subtest: Reading video locally, adding a logo to the video stream and then saving the video locally > Host performance: 50% 50% > kvm process in host (top) : 99% 99% > vlc process in vmu (top) : 99% 99% > Now this is bad. Please provide the output of 'kvm_stat -1' while this is running. Also, describe the guest. Is it Linux? if so, i386 or x86_64? and is CONFIG_HIGHMEM enabled? UDP performance is a known issue now, and we are working on it. TCP is much better due to segmentation offload. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.